app.py

from flask import Flask, render_template_string, request, redirect, url_for, flash, jsonify
import json
import os
import logging
import threading
import time
from datetime import datetime
from huggingface_hub import HfApi, hf_hub_download
from huggingface_hub.utils import RepositoryNotFoundError, HfHubHTTPError
from werkzeug.utils import secure_filename
from dotenv import load_dotenv
import requests
import uuid
from collections import Counter

load_dotenv()

app = Flask(__name__)
app.secret_key = 'your_unique_secret_key_soola_cosmetics_67890_no_login' # Replace with a strong, unique key
DATA_FILE = 'data.json'

SYNC_FILES = [DATA_FILE]

REPO_ID = "Kgshop/testsystem" # Replace with your actual repo ID
HF_TOKEN_WRITE = os.getenv("HF_TOKEN")
HF_TOKEN_READ = os.getenv("HF_TOKEN_READ")

STORE_ADDRESS = "Рынок Кербент, 6 ряд , контейнер 59 / 5 ряд , контейнер 68" # Your store address

CURRENCY_CODE = 'KGS'
CURRENCY_NAME = 'Кыргызский сом'

DOWNLOAD_RETRIES = 3
DOWNLOAD_DELAY = 5

# In-memory storage for active sale sessions (temporary, not persistent)
open_sale_sessions = {}

logging.basicConfig(level=logging.INFO, format='%(asctime)s - %(levelname)s - %(message)s')

def download_db_from_hf(specific_file=None, retries=DOWNLOAD_RETRIES, delay=DOWNLOAD_DELAY):
    """Downloads specified files or all sync files from Hugging Face."""
    token_to_use = HF_TOKEN_READ if HF_TOKEN_READ else HF_TOKEN_WRITE
    files_to_download = [specific_file] if specific_file else SYNC_FILES
    all_successful = True

    if not token_to_use:
        logging.warning("No Hugging Face token found (HF_TOKEN or HF_TOKEN_READ). Skipping download.")
        return False

    for file_name in files_to_download:
        success = False
        for attempt in range(retries + 1):
            try:
                hf_hub_download(
                    repo_id=REPO_ID,
                    filename=file_name,
                    repo_type="dataset",
                    token=token_to_use,
                    local_dir=".",
                    local_dir_use_symlinks=False,
                    force_download=True,
                    resume_download=False
                )
                success = True
                logging.info(f"Successfully downloaded {file_name} from Hugging Face.")
                break
            except RepositoryNotFoundError:
                logging.error(f"Repository {REPO_ID} not found. Download cancelled for all files.")
                return False
            except HfHubHTTPError as e:
                if e.response.status_code == 404:
                    logging.warning(f"File {file_name} not found in repo {REPO_ID} (404). Skipping this file.")
                    # If the file doesn't exist remotely and doesn't exist locally, create an empty one
                    if attempt == 0 and not os.path.exists(file_name):
                        logging.info(f"Local file {file_name} not found and not in repo. Creating empty local file.")
                        try:
                            if file_name == DATA_FILE:
                                with open(file_name, 'w', encoding='utf-8') as f:
                                    json.dump({'products': [], 'categories': [], 'orders': {}}, f)
                        except Exception as create_e:
                            logging.error(f"Failed to create empty local file {file_name}: {create_e}")
                    success = False # Treat 404 as success for this file, but continue loop for others
                    break
                else:
                    logging.error(f"HTTP error downloading {file_name} (Attempt {attempt + 1}): {e}. Retrying in {delay}s...")
            except requests.exceptions.RequestException as e:
                logging.error(f"Network error downloading {file_name} (Attempt {attempt + 1}): {e}. Retrying in {delay}s...")
            except Exception as e:
                logging.error(f"Unexpected error downloading {file_name} (Attempt {attempt + 1}): {e}. Retrying in {delay}s...", exc_info=True)

            if attempt < retries:
                time.sleep(delay)

        if not success and file_name in SYNC_FILES: # If a core sync file failed entirely
            logging.error(f"Failed to download {file_name} after {retries + 1} attempts.")
            all_successful = False
            # Continue attempting other files, but the overall process failed

    return all_successful

def upload_db_to_hf(specific_file=None):
    """Uploads specified files or all sync files to Hugging Face."""
    if not HF_TOKEN_WRITE:
        logging.warning("HF_TOKEN (for writing) not set. Skipping upload to Hugging Face.")
        return

    try:
        api = HfApi()
        files_to_upload = [specific_file] if specific_file else SYNC_FILES

        for file_name in files_to_upload:
            if os.path.exists(file_name):
                try:
                    api.upload_file(
                        path_or_fileobj=file_name,
                        path_in_repo=file_name,
                        repo_type="dataset",
                        token=HF_TOKEN_WRITE,
                        commit_message=f"Sync {file_name} {datetime.now().strftime('%Y-%m-%d %H:%M:%S')}"
                    )
                    logging.info(f"Successfully uploaded {file_name} to Hugging Face.")
                except Exception as e:
                    logging.error(f"Error uploading file {file_name} to Hugging Face: {e}")
            else:
                logging.warning(f"File {file_name} not found locally, skipping upload.")
    except Exception as e:
        logging.error(f"General error during Hugging Face upload initialization or process: {e}", exc_info=True)

def periodic_backup():
    """Performs periodic backup to Hugging Face."""
    backup_interval = 1800 # 30 minutes
    while True:
        time.sleep(backup_interval)
        logging.info("Starting periodic backup...")
        upload_db_to_hf()
        logging.info("Periodic backup finished.")

def load_data():
    """Loads data from the local JSON file, attempts download if missing or invalid."""
    default_data = {'products': [], 'categories': [], 'orders': {}}
    data = default_data
    data_loaded_from_local = False

    if os.path.exists(DATA_FILE):
        try:
            with open(DATA_FILE, 'r', encoding='utf-8') as file:
                data = json.load(file)
            if isinstance(data, dict):
                data_loaded_from_local = True
                logging.info(f"Data loaded successfully from local file: {DATA_FILE}")
            else:
                 logging.warning(f"Local {DATA_FILE} exists but is not a valid JSON object (dict). Attempting download.")
                 data = default_data # Reset data to default if local file is invalid
        except json.JSONDecodeError:
            logging.warning(f"Local {DATA_FILE} exists but is not valid JSON. Attempting download.")
            data = default_data # Reset data to default if local file is invalid
        except Exception as e:
            logging.error(f"Error reading local {DATA_FILE}: {e}. Attempting download.")
            data = default_data # Reset data to default on other read errors

    if not data_loaded_from_local:
        logging.info(f"Local data not loaded, attempting download of {DATA_FILE} from Hugging Face.")
        if download_db_from_hf(specific_file=DATA_FILE):
            try:
                with open(DATA_FILE, 'r', encoding='utf-8') as file:
                    downloaded_data = json.load(file)
                if isinstance(downloaded_data, dict):
                    data = downloaded_data
                    logging.info(f"Data loaded successfully after downloading {DATA_FILE}.")
                else:
                    logging.error(f"Downloaded {DATA_FILE} is not a valid JSON object (dict). Using default data.")
                    data = default_data
            except (FileNotFoundError, json.JSONDecodeError) as e:
                logging.error(f"Failed to read downloaded {DATA_FILE}: {e}. Using default data.")
                data = default_data
            except Exception as e:
                logging.error(f"Unexpected error reading downloaded {DATA_FILE}: {e}. Using default data.", exc_info=True)
        else:
            logging.warning(f"Failed to download {DATA_FILE}. Using default data.")
            data = default_data
            # If download failed and local file didn't exist or was invalid, try creating a default one
            if not os.path.exists(DATA_FILE):
                 logging.info(f"Attempting to create an empty local {DATA_FILE}.")
                 try:
                     with open(DATA_FILE, 'w', encoding='utf-8') as f:
                         json.dump(default_data, f)
                 except Exception as create_e:
                     logging.error(f"Failed to create empty local file {DATA_FILE}: {create_e}")


    # Ensure essential keys exist and add default values if needed
    if 'products' not in data: data['products'] = []
    if 'categories' not in data: data['categories'] = []
    if 'orders' not in data: data['orders'] = {}

    # Data structure migration/cleanup for products
    for product in data['products']:
        if 'id' not in product:
            product['id'] = uuid.uuid4().hex # Assign ID if missing
            logging.warning(f"Product missing ID, assigned {product['id']}")
        if 'stock' not in product:
            product['stock'] = 0 # Default stock to 0 if missing
            logging.warning(f"Product '{product.get('name', 'Unknown')}' missing stock, defaulted to 0")
        if 'barcode' not in product:
            product['barcode'] = '' # Add barcode field if missing
        if 'is_top' not in product:
             product['is_top'] = False # Add is_top field if missing
        if 'colors' not in product:
            product['colors'] = [] # Add colors field if missing

        # Ensure in_stock is correctly derived
        product['in_stock'] = product.get('stock', 0) > 0

    return data

def save_data(data):
    """Saves data to the local JSON file and uploads to Hugging Face."""
    try:
        # Basic validation before saving
        if not isinstance(data, dict):
            logging.error("Attempted to save invalid data structure (not a dict). Aborting save.")
            return
        if 'products' not in data or 'categories' not in data or 'orders' not in data:
             logging.error("Attempted to save data structure missing essential keys. Aborting save.")
             return

        # Ensure in_stock is correctly derived before saving
        for product in data.get('products', []):
             product['in_stock'] = product.get('stock', 0) > 0

        with open(DATA_FILE, 'w', encoding='utf-8') as file:
            json.dump(data, file, ensure_ascii=False, indent=4)
        logging.info(f"Data successfully saved to local file: {DATA_FILE}.")
        upload_db_to_hf(specific_file=DATA_FILE)
    except Exception as e:
        logging.error(f"Error saving data to {DATA_FILE}: {e}", exc_info=True)

CATALOG_TEMPLATE = '''
    <!DOCTYPE html>
    <html lang="ru">
    <head>
        <meta charset="UTF-8">
        <meta name="viewport" content="width=device-width, initial-scale=1.0">
        <title>Aikas_optom - Каталог</title>
        <link rel="stylesheet" href="https://cdnjs.cloudflare.com/ajax/libs/font-awesome/6.5.1/css/all.min.css">
        <link href="https://fonts.googleapis.com/css2?family=Poppins:wght@300;400;600&display=swap" rel="stylesheet">
        <link rel="stylesheet" href="https://cdnjs.cloudflare.com/ajax/libs/Swiper/10.2.0/swiper-bundle.min.css">
        <style>
            * { margin: 0; padding: 0; box-sizing: border-box; }
            body { font-family: 'Poppins', sans-serif; background: #F5F5F5; color: #263238; line-height: 1.6; transition: background 0.3s, color 0.3s; }
            body.dark-mode { background: #1A237E; color: #BBDEFB; }
            .container { max-width: 1300px; margin: 0 auto; padding: 20px; }
            .header { display: flex; justify-content: space-between; align-items: center; padding: 15px 0; border-bottom: 1px solid #CFD8DC; }
            body.dark-mode .header { border-bottom-color: #42A5F5; }
            .header h1 { font-size: 1.8rem; font-weight: 600; color: #3F51B5; }
            .theme-toggle { background: none; border: none; font-size: 1.5rem; cursor: pointer; color: #607D8B; transition: color 0.3s ease; }
            .theme-toggle:hover { color: #303F9F; }
            body.dark-mode .theme-toggle { color: #BBDEFB; }
            body.dark-mode .theme-toggle:hover { color: #90CAF9; }
            .store-address { padding: 15px; text-align: center; background-color: #FFFFFF; margin: 20px 0; border-radius: 8px; box-shadow: 0 2px 4px rgba(0,0,0,0.05); font-size: 1rem; color: #607D8B; }
            body.dark-mode .store-address { background-color: #283593; color: #BBDEFB; }
            .filters-container { margin: 20px 0; display: flex; flex-wrap: wrap; gap: 10px; justify-content: center; }
            .search-container { margin: 20px 0; text-align: center; }
            #search-input { width: 90%; max-width: 600px; padding: 12px 18px; font-size: 1rem; border: 1px solid #CFD8DC; border-radius: 25px; outline: none; box-shadow: 0 2px 5px rgba(0,0,0,0.05); transition: all 0.3s ease; }
            body.dark-mode #search-input { background-color: #283593; border-color: #42A5F5; color: #BBDEFB; }
            #search-input:focus { border-color: #3F51B5; box-shadow: 0 0 0 3px rgba(63, 81, 181, 0.2); }
            body.dark-mode #search-input:focus { border-color: #5C6BC0; box-shadow: 0 0 0 3px rgba(92, 107, 192, 0.3); }
            .category-filter { padding: 8px 16px; border: 1px solid #CFD8DC; border-radius: 20px; background-color: #fff; cursor: pointer; transition: all 0.3s cubic-bezier(0.4, 0, 0.2, 1); font-size: 0.9rem; font-weight: 400; color: #303F9F; }
            body.dark-mode .category-filter { background-color: #283593; border-color: #42A5F5; color: #90CAF9; }
            .category-filter.active, .category-filter:hover { background-color: #3F51B5; color: white; border-color: #3F51B5; box-shadow: 0 2px 10px rgba(63, 81, 181, 0.3); }
            body.dark-mode .category-filter.active, body.dark-mode .category-filter:hover { background-color: #5C6BC0; border-color: #5C6BC0; color: #1A237E; box-shadow: 0 2px 10px rgba(92, 107, 192, 0.4); }
            .products-grid { display: grid; grid-template-columns: repeat(auto-fill, minmax(150px, 1fr)); gap: 20px; padding: 10px; }
            @media (min-width: 600px) { .products-grid { grid-template-columns: repeat(auto-fill, minmax(200px, 1fr)); } }
            @media (min-width: 900px) { .products-grid { grid-template-columns: repeat(auto-fill, minmax(250px, 1fr)); } }

            .product { background: #fff; border-radius: 15px; padding: 0; box-shadow: 0 4px 15px rgba(0, 0, 0, 0.08); transition: transform 0.3s cubic-bezier(0.4, 0, 0.2, 1), box-shadow 0.3s ease; overflow: hidden; display: flex; flex-direction: column; justify-content: space-between; height: 100%; border: 1px solid #E0E0E0;}
            body.dark-mode .product { background: #283593; box-shadow: 0 4px 15px rgba(0, 0, 0, 0.2); border-color: #42A5F5; }
            .product:hover { transform: translateY(-5px) scale(1.02); box-shadow: 0 6px 20px rgba(0, 0, 0, 0.12); }
            body.dark-mode .product:hover { box-shadow: 0 6px 20px rgba(0, 0, 0, 0.3); }
            .product-image { width: 100%; aspect-ratio: 1 / 1; background-color: #fff; border-radius: 10px 10px 0 0; overflow: hidden; display: flex; justify-content: center; align-items: center; margin-bottom: 0; }
            .product-image img { max-width: 100%; max-height: 100%; object-fit: contain; transition: transform 0.3s ease; }
            .product-info { padding: 15px; flex-grow: 1; display: flex; flex-direction: column; justify-content: center; }
            .product h2 { font-size: 1.1rem; font-weight: 600; margin: 0 0 8px 0; text-align: center; white-space: nowrap; overflow: hidden; text-overflow: ellipsis; color: #263238; }
            body.dark-mode .product h2 { color: #BBDEFB; }
            .product-price { font-size: 1.2rem; color: #303F9F; font-weight: 700; text-align: center; margin: 5px 0; }
            body.dark-mode .product-price { color: #90CAF9; }
            .product-description { font-size: 0.85rem; color: #607D8B; text-align: center; margin-bottom: 15px; overflow: hidden; text-overflow: ellipsis; white-space: nowrap; }
            body.dark-mode .product-description { color: #BBDEFB; }
            .product-actions { padding: 0 15px 15px 15px; display: flex; flex-direction: column; gap: 8px; }
            .product-button { display: block; width: 100%; padding: 10px; border: none; border-radius: 8px; background-color: #3F51B5; color: white; font-size: 0.9rem; font-weight: 500; cursor: pointer; transition: all 0.3s cubic-bezier(0.4, 0, 0.2, 1); text-align: center; text-decoration: none; }
            .product-button:hover { background-color: #303F9F; box-shadow: 0 4px 15px rgba(48, 63, 159, 0.4); transform: translateY(-2px); }
            .product-button i { margin-right: 5px; }
            .add-to-cart { background-color: #3F51B5; }
            .add-to-cart:hover { background-color: #303F9F; box-shadow: 0 4px 15px rgba(48, 63, 159, 0.4); }
            #cart-button { position: fixed; bottom: 25px; right: 25px; background-color: #3F51B5; color: white; border: none; border-radius: 50%; width: 55px; height: 55px; font-size: 1.5rem; cursor: pointer; display: none; align-items: center; justify-content: center; box-shadow: 0 4px 15px rgba(63, 81, 181, 0.4); transition: all 0.3s cubic-bezier(0.4, 0, 0.2, 1); z-index: 1000; }
            #cart-button .fa-shopping-cart { margin-right: 0; }
            #cart-button span { position: absolute; top: -5px; right: -5px; background-color: #303F9F; color: white; border-radius: 50%; padding: 2px 6px; font-size: 0.7rem; font-weight: bold; }
            .modal { display: none; position: fixed; z-index: 1001; left: 0; top: 0; width: 100%; height: 100%; background-color: rgba(0,0,0,0.6); backdrop-filter: blur(5px); overflow-y: auto; }
            .modal-content { background: #ffffff; margin: 5% auto; padding: 25px; border-radius: 15px; width: 90%; max-width: 700px; box-shadow: 0 10px 30px rgba(0,0,0,0.2); animation: slideIn 0.3s ease-out; position: relative; }
            body.dark-mode .modal-content { background: #283593; color: #BBDEFB; }
            @keyframes slideIn { from { transform: translateY(-30px); opacity: 0; } to { transform: translateY(0); opacity: 1; } }
            .close { position: absolute; top: 15px; right: 15px; font-size: 1.8rem; color: #aaa; cursor: pointer; transition: color 0.3s; line-height: 1; }
            .close:hover { color: #333; }
            body.dark-mode .close { color: #BBDEFB; }
            body.dark-mode .close:hover { color: #ffffff; }
            .modal-content h2 { margin-top: 0; margin-bottom: 20px; color: #3F51B5; display: flex; align-items: center; gap: 10px;}
            body.dark-mode .modal-content h2 { color: #90CAF9; }
            .cart-item { display: grid; grid-template-columns: auto 1fr auto auto; gap: 15px; align-items: center; padding: 15px 0; border-bottom: 1px solid #CFD8DC; }
            body.dark-mode .cart-item { border-bottom-color: #42A5F5; }
            .cart-item:last-child { border-bottom: none; }
            .cart-item img { width: 60px; height: 60px; object-fit: contain; border-radius: 8px; background-color: #fff; padding: 5px; grid-column: 1; }
            .cart-item-details { grid-column: 2; }
            .cart-item-details strong { display: block; margin-bottom: 5px; font-size: 1rem; }
            .cart-item-price { font-size: 0.9rem; color: #607D8B; }
            body.dark-mode .cart-item-price { color: #BBDEFB; }
            .cart-item-total { font-weight: bold; text-align: right; grid-column: 3; font-size: 1rem;}
            .cart-item-remove { grid-column: 4; background:none; border:none; color:#f56565; cursor:pointer; font-size: 1.3em; padding: 5px; line-height: 1; }
            .cart-item-remove:hover { color: #c53030; }
            .quantity-input, .color-select { width: 100%; max-width: 180px; padding: 10px; border: 1px solid #CFD8DC; border-radius: 8px; font-size: 1rem; margin: 10px 0; box-sizing: border-box; }
            body.dark-mode .quantity-input, body.dark-mode .color-select { background-color: #1A237E; border-color: #42A5F5; color: #BBDEFB; }
            .cart-summary { margin-top: 20px; text-align: right; border-top: 1px solid #CFD8DC; padding-top: 15px; }
            body.dark-mode .cart-summary { border-top-color: #42A5F5; }
            .cart-summary strong { font-size: 1.2rem; }
            .cart-actions { margin-top: 25px; display: flex; justify-content: space-between; gap: 10px; flex-wrap: wrap; }
            .cart-actions .product-button { width: auto; flex-grow: 1; }
            .clear-cart { background-color: #9E9E9E; }
            .clear-cart:hover { background-color: #757575; box-shadow: 0 4px 15px rgba(117, 117, 117, 0.4); }
            .formulate-order-button { background-color: #3F51B5; }
            .formulate-order-button:hover { background-color: #303F9F; box-shadow: 0 4px 15px rgba(48, 63, 159, 0.4); }
            .notification { position: fixed; bottom: 80px; left: 50%; transform: translateX(-50%); background-color: #3F51B5; color: white; padding: 10px 20px; border-radius: 20px; box-shadow: 0 4px 10px rgba(0,0,0,0.2); z-index: 1002; opacity: 0; transition: opacity 0.5s ease; font-size: 0.9rem;}
            .notification.show { opacity: 1;}
            .no-results-message { grid-column: 1 / -1; text-align: center; padding: 40px; font-size: 1.1rem; color: #607D8B; }
            body.dark-mode .no-results-message { color: #BBDEFB; }
            .top-product-indicator { position: absolute; top: 8px; right: 8px; background-color: rgba(255, 215, 0, 0.8); color: #333; padding: 2px 6px; font-size: 0.7rem; border-radius: 4px; font-weight: bold; z-index: 10; backdrop-filter: blur(2px); }
            .product { position: relative; }
        </style>
    </head>
    <body>
        <div class="container">
             <div class="header">
                 <div class="logo-title-container" style="display: flex; align-items: center; gap: 15px;">
                    <img src="https://cdn-avatars.huggingface.co/v1/production/uploads/67c280ccb9d3dfdee58ecfdd/p2TVtSc6UQr0De1jDYBLk.jpeg" alt="Aikas_optom Logo" style="height: 40px; width: auto; border-radius: 4px;">
                    <h1>Aikas_optom</h1>
                </div>
                <button class="theme-toggle" onclick="toggleTheme()" aria-label="Переключить тему">
                    <i class="fas fa-moon"></i>
                </button>
            </div>

            <div class="store-address">Наш адрес: {{ store_address }}</div>

            <div class="filters-container">
                <button class="category-filter active" data-category="all">Все категории</button>
                {% for category in categories %}
                <button class="category-filter" data-category="{{ category }}">{{ category }}</button>
                {% endfor %}
            </div>

            <div class="search-container">
                <input type="text" id="search-input" placeholder="Поиск по названию или описанию...">
            </div>

            <div class="products-grid" id="products-grid">
                {% for product in products %}
                <div class="product"
                     data-name="{{ product['name']|lower }}"
                     data-description="{{ product.get('description', '')|lower }}"
                     data-category="{{ product.get('category', 'Без категории') }}"
                     data-product-id="{{ product['id'] }}">
                     {% if product.get('is_top', False) %}
                        <span class="top-product-indicator"><i class="fas fa-star"></i> Топ</span>
                     {% endif %}
                    <div class="product-image">
                        {% if product.get('photos') and product['photos']|length > 0 %}
                            <img src="https://huggingface.co/datasets/{{ repo_id }}/resolve/main/photos/{{ product['photos'][0] }}"
                                 alt="{{ product['name'] }}"
                                 loading="lazy">
                        {% else %}
                            <img src="https://via.placeholder.com/250x250.png?text=No+Image" alt="No Image" loading="lazy">
                        {% endif %}
                    </div>
                    <div class="product-info">
                        <h2>{{ product['name'] }}</h2>
                        <div class="product-price">{{ "%.2f"|format(product['price']) }} {{ currency_code }}</div>
                        <p class="product-description">{{ product.get('description', '')[:50] }}{% if product.get('description', '')|length > 50 %}...{% endif %}</p>
                    </div>
                    <div class="product-actions">
                        <button class="product-button" onclick="openModal('{{ product['id'] }}')">Подробнее</button>
                        <button class="product-button add-to-cart" onclick="openQuantityModal('{{ product['id'] }}')">
                           <i class="fas fa-cart-plus"></i> В корзину
                        </button>
                    </div>
                </div>
                {% endfor %}
                 {% if not products %}
                 <p class="no-results-message">Товары пока не добавлены.</p>
                 {% endif %}
            </div>
        </div>

        <div id="productModal" class="modal">
            <div class="modal-content">
                <span class="close" onclick="closeModal('productModal')" aria-label="Закрыть">×</span>
                <div id="modalContent"></div>
            </div>
        </div>

        <div id="quantityModal" class="modal">
            <div class="modal-content">
                <span class="close" onclick="closeModal('quantityModal')" aria-label="Закрыть">×</span>
                <h2>Укажите количество и цвет</h2>
                <label for="quantityInput">Количество:</label>
                <input type="number" id="quantityInput" class="quantity-input" min="1" value="1">
                <label for="colorSelect">Цвет/Вариант:</label>
                <select id="colorSelect" class="color-select"></select>
                <button class="product-button add-to-cart" onclick="confirmAddToCart()"><i class="fas fa-check"></i> Добавить в корзину</button>
            </div>
        </div>

        <div id="cartModal" class="modal">
            <div class="modal-content">
                <span class="close" onclick="closeModal('cartModal')" aria-label="Закрыть">×</span>
                <h2><i class="fas fa-shopping-cart"></i> Ваша корзина</h2>
                <div id="cartContent"><p style="text-align: center; padding: 20px;">Ваша корзина пуста.</p></div>
                <div class="cart-summary">
                    <strong>Итого: <span id="cartTotal">0.00</span> {{ currency_code }}</strong>
                </div>
                <div class="cart-actions">
                    <button class="product-button clear-cart" onclick="clearCart()">
                       <i class="fas fa-trash"></i> Очистить корзину
                    </button>
                    <button class="product-button formulate-order-button" onclick="formulateOrder()">
                       <i class="fas fa-file-alt"></i> Сформировать заказ
                    </button>
                </div>
            </div>
        </div>

        <button id="cart-button" onclick="openCartModal()" aria-label="Открыть корзину">
           <i class="fas fa-shopping-cart"></i>
           <span id="cart-count">0</span>
        </button>

        <div id="notification-placeholder"></div>

        <script src="https://cdnjs.cloudflare.com/ajax/libs/Swiper/10.2.0/swiper-bundle.min.js"></script>
        <script>
            const products = {{ products|tojson }};
            const repoId = '{{ repo_id }}';
            const currencyCode = '{{ currency_code }}';
            let selectedProductId = null;
            let cart = JSON.parse(localStorage.getItem('soolaCart') || '[]');

            function toggleTheme() {
                document.body.classList.toggle('dark-mode');
                const icon = document.querySelector('.theme-toggle i');
                const isDarkMode = document.body.classList.contains('dark-mode');
                icon.classList.toggle('fa-moon', !isDarkMode);
                icon.classList.toggle('fa-sun', isDarkMode);
                localStorage.setItem('soolaTheme', isDarkMode ? 'dark' : 'light');
            }

            function applyInitialTheme() {
                const savedTheme = localStorage.getItem('soolaTheme');
                if (savedTheme === 'dark') {
                    document.body.classList.add('dark-mode');
                    const icon = document.querySelector('.theme-toggle i');
                    if (icon) icon.classList.replace('fa-moon', 'fa-sun');
                } else if (!savedTheme) {
                    // Check system preference
                    if (window.matchMedia && window.matchMedia('(prefers-color-scheme: dark)').matches) {
                         document.body.classList.add('dark-mode');
                         const icon = document.querySelector('.theme-toggle i');
                         if (icon) icon.classList.replace('fa-moon', 'fa-sun');
                    }
                }
            }

            function openModal(productId) {
                const modalContent = document.getElementById('modalContent');
                modalContent.innerHTML = '<p style="text-align:center; padding: 40px;">Загрузка...</p>';
                fetch('/product/' + productId)
                    .then(response => {
                        if (!response.ok) throw new Error(`Ошибка ${response.status}: ${response.statusText}`);
                        return response.text();
                    })
                    .then(data => {
                        modalContent.innerHTML = data;
                        initializeSwiper();
                    })
                    .catch(error => {
                        console.error('Ошибка загрузки деталей продукта:', error);
                        modalContent.innerHTML = `<p style="color: red; text-align:center; padding: 40px;">Не удалось загрузить информацию о товаре. ${error.message}</p>`;
                    });
                const modal = document.getElementById('productModal');
                if (modal) {
                    modal.style.display = "block";
                    document.body.style.overflow = 'hidden';
                }
            }

            function closeModal(modalId) {
                const modal = document.getElementById(modalId);
                 if (modal) {
                     modal.style.display = "none";
                 }
                 const anyModalOpen = document.querySelector('.modal[style*="display: block"]');
                 if (!anyModalOpen) {
                    document.body.style.overflow = 'auto';
                 }
            }

            function initializeSwiper() {
                const swiperContainer = document.querySelector('#productModal .swiper-container');
                if (swiperContainer) {
                    new Swiper(swiperContainer, {
                        slidesPerView: 1,
                        spaceBetween: 20,
                        loop: true,
                        grabCursor: true,
                        pagination: { el: '.swiper-pagination', clickable: true },
                        navigation: { nextEl: '.swiper-button-next', prevEl: '.swiper-button-prev' },
                        zoom: { maxRatio: 3, containerClass: 'swiper-zoom-container' },
                        autoplay: { delay: 5000, disableOnInteraction: true, },
                    });
                }
            }

            function openQuantityModal(productId) {
                selectedProductId = productId;
                const product = products.find(p => p.id === productId);
                if (!product) {
                    alert("Ошибка: товар не найден.");
                    return;
                }

                const quantityInput = document.getElementById('quantityInput');
                quantityInput.value = 1;
                // Use the product's actual stock for max quantity
                quantityInput.max = product.stock;
                quantityInput.oninput = () => {
                    let val = parseInt(quantityInput.value);
                    if (isNaN(val) || val < 1) val = 1;
                     // Check against currently available stock considering other items already in cart
                    let currentQtyInCart = cart.reduce((sum, item) => {
                        // Sum quantity for this product and selected color
                         if (item.product_id === product.id && item.color === saleColorSelect.value) {
                            return sum + item.quantity;
                         }
                         return sum;
                    }, 0);

                    if (product.stock < currentQtyInCart + val) {
                         val = product.stock - currentQtyInCart;
                         if (val < 0) val = 0; // Should not happen if cart check is correct, but safety
                         quantityInput.value = val;
                         alert(`Недостаточно товара "${product.name}" (цвет: ${saleColorSelect.value}). Доступно: ${product.stock} шт. (Уже в корзине: ${currentQtyInCart}). Вы можете добавить не более ${val} шт.`);
                    } else {
                         quantityInput.value = val;
                    }
                };


                const colorSelect = document.getElementById('colorSelect');
                const colorLabel = document.querySelector('label[for="colorSelect"]');
                colorSelect.innerHTML = '';

                const validColors = product.colors ? product.colors.filter(c => c && c.trim() !== "") : [];

                if (validColors.length > 0) {
                    validColors.forEach(color => {
                         const option = document.createElement('option');
                         option.value = color.trim();
                         option.text = color.trim();
                         colorSelect.appendChild(option);
                    });
                    colorSelect.style.display = 'block';
                    if(colorLabel) colorLabel.style.display = 'block';
                } else {
                    const option = document.createElement('option');
                    option.value = 'N/A';
                    option.text = 'N/A';
                    colorSelect.appendChild(option);
                    colorSelect.style.display = 'none';
                    if(colorLabel) colorLabel.style.display = 'none';
                }

                const modal = document.getElementById('quantityModal');
                 if(modal) {
                    modal.style.display = 'block';
                    document.body.style.overflow = 'hidden';
                 }
            }

            function confirmAddToCart() {
                if (selectedProductId === null) return;

                const quantityInput = document.getElementById('quantityInput');
                const quantity = parseInt(quantityInput.value);
                const colorSelect = document.getElementById('colorSelect');
                const color = colorSelect.style.display !== 'none' && colorSelect.value ? colorSelect.value : 'N/A';

                if (isNaN(quantity) || quantity <= 0) {
                    alert("Пожалуйста, укажите корректное количество (больше 0).");
                    quantityInput.focus();
                    return;
                }

                const product = products.find(p => p.id === selectedProductId);
                 if (!product) {
                    alert("Ошибка добавления: товар не найден.");
                    return;
                 }

                let currentTotalInCartForThisItem = cart.reduce((sum, item) => {
                     if (item.product_id === product.id && item.color === color) {
                        return sum + item.quantity;
                     }
                     return sum;
                }, 0);

                const requestedTotal = currentTotalInCartForThisItem + quantity;

                if (requestedTotal > product.stock) {
                    alert(`Недостаточно товара "${product.name}" (цвет: ${color}). Доступно: ${product.stock} шт. (Уже в корзине: ${currentTotalInCartForThisItem}).`);
                    quantityInput.value = product.stock - currentTotalInCartForThisItem;
                    if (parseInt(quantityInput.value) < 0) quantityInput.value = 0;
                    quantityInput.focus();
                    return;
                }

                const cartItemId = `${product.id}-${color}`;
                const existingItemIndexInCart = cart.findIndex(item => item.id === cartItemId); // Find by compound ID
                if (existingItemIndexInCart > -1) {
                    cart[existingItemIndexInCart].quantity = requestedTotal; // Update quantity
                } else {
                    cart.push({
                        id: cartItemId, // Use compound ID for uniqueness
                        product_id: product.id,
                        name: product.name,
                        price: product.price,
                        photo: product.photos && product.photos.length > 0 ? product.photos[0] : null,
                        quantity: quantity,
                        color: color
                    });
                }

                localStorage.setItem('soolaCart', JSON.stringify(cart));
                closeModal('quantityModal');
                updateCartButton();
                showNotification(`${product.name} добавлен в корзину!`);
            }

            function updateCartButton() {
                 const cartCountElement = document.getElementById('cart-count');
                 const cartButton = document.getElementById('cart-button');
                 if (!cartCountElement || !cartButton) return;

                 let totalItems = cart.reduce((sum, item) => sum + item.quantity, 0); // Sum up quantities

                 if (totalItems > 0) {
                     cartCountElement.textContent = totalItems;
                     cartButton.style.display = 'flex';
                 } else {
                     cartCountElement.textContent = '0';
                     cartButton.style.display = 'none';
                 }
            }

            function openCartModal() {
                const cartContent = document.getElementById('cartContent');
                const cartTotalElement = document.getElementById('cartTotal');
                if (!cartContent || !cartTotalElement) return;

                let total = 0;

                if (cart.length === 0) {
                    cartContent.innerHTML = '<p style="text-align: center; padding: 20px;">Ваша корзина пуста.</p>';
                    cartTotalElement.textContent = '0.00';
                } else {
                    cartContent.innerHTML = cart.map(item => {
                        const itemTotal = item.price * item.quantity;
                        total += itemTotal;
                        const photoUrl = item.photo
                            ? `https://huggingface.co/datasets/${repoId}/resolve/main/photos/${item.photo}`
                            : 'https://via.placeholder.com/60x60.png?text=N/A';
                        const colorText = item.color && item.color !== 'N/A' ? ` (Цвет: ${item.color})` : '';

                        return `
                            <div class="cart-item">
                                <img src="${photoUrl}" alt="${item.name}">
                                <div class="cart-item-details">
                                    <strong>${item.name}${colorText}</strong>
                                    <p class="cart-item-price">${item.price.toFixed(2)} ${currencyCode} × ${item.quantity}</p>
                                </div>
                                <span class="cart-item-total">${itemTotal.toFixed(2)} ${currencyCode}</span>
                                <button class="cart-item-remove" onclick="removeFromCart('${item.id}')" title="Удалить товар">×</button>
                            </div>
                        `;
                    }).join('');
                    cartTotalElement.textContent = total.toFixed(2);
                }
                 const modal = document.getElementById('cartModal');
                 if (modal) {
                    modal.style.display = 'block';
                    document.body.style.overflow = 'hidden';
                 }
            }

             function removeFromCart(itemId) {
                cart = cart.filter(item => item.id !== itemId); // Filter by compound ID
                localStorage.setItem('soolaCart', JSON.stringify(cart));
                openCartModal(); // Re-render cart modal
                updateCartButton();
             }

            function clearCart() {
                if (confirm("Вы уверены, что хотите очистить корзину?")) {
                    cart = [];
                    localStorage.removeItem('soolaCart');
                    openCartModal();
                    updateCartButton();
                }
            }

            function formulateOrder() {
                if (cart.length === 0) {
                    alert("Корзина пуста! Добавьте товары перед формированием заказа.");
                    return;
                }

                const orderData = {
                    cart: cart
                };

                const formulateButton = document.querySelector('.formulate-order-button');
                if (formulateButton) formulateButton.disabled = true;

                showNotification("Формируем заказ...", 5000);

                fetch('/create_order', {
                    method: 'POST',
                    headers: { 'Content-Type': 'application/json' },
                    body: JSON.stringify(orderData)
                })
                .then(response => {
                    // Re-enable button regardless of success/failure
                     if (formulateButton) formulateButton.disabled = false;

                    if (!response.ok) {
                        return response.json().then(err => {
                            // If server returned a specific error related to stock
                            if (err.error && err.error.includes('Недостаточно товара')) {
                                 // Potentially update local cart based on server response, or just alert
                                 // For now, just alert and leave cart as is for user to fix
                                 throw new Error(err.error);
                            }
                            throw new Error(err.error || `Не удалось создать заказ. Статус: ${response.status}`);
                         });
                    }
                    return response.json();
                })
                .then(data => {
                    if (data.order_id) {
                        localStorage.removeItem('soolaCart');
                        cart = [];
                        updateCartButton();
                        closeModal('cartModal');
                        window.location.href = `/order/${data.order_id}`;
                    } else {
                        // This case should ideally be caught by the !response.ok check, but as a fallback
                        throw new Error('Не получен ID заказа от сервера.');
                    }
                })
                .catch(error => {
                    console.error('Ошибка при формировании заказа:', error);
                    alert(`Ошибка: ${error.message}`);
                });
            }

            function filterProducts() {
                const searchTerm = document.getElementById('search-input').value.toLowerCase().trim();
                const activeCategoryButton = document.querySelector('.category-filter.active');
                const activeCategory = activeCategoryButton ? activeCategoryButton.dataset.category : 'all';
                const grid = document.getElementById('products-grid');
                let visibleProducts = 0;

                const existingNoResults = grid.querySelector('.no-results-message');
                if (existingNoResults) existingNoResults.remove();

                document.querySelectorAll('.products-grid .product').forEach(productElement => {
                    const name = productElement.getAttribute('data-name');
                    const description = productElement.getAttribute('data-description');
                    const category = productElement.getAttribute('data-category');

                    const matchesSearch = !searchTerm || name.includes(searchTerm) || description.includes(searchTerm);
                    const matchesCategory = activeCategory === 'all' || category === activeCategory;

                    if (matchesSearch && matchesCategory) {
                        productElement.style.display = 'flex';
                        visibleProducts++;
                    } else {
                        productElement.style.display = 'none';
                    }
                });

                 if (visibleProducts === 0 && products.length > 0) {
                    const p = document.createElement('p');
                    p.className = 'no-results-message';
                    p.textContent = 'По вашему запросу товары не найдены.';
                    grid.appendChild(p);
                 } else if (products.length === 0 && !grid.querySelector('.no-results-message')) {
                     const p = document.createElement('p');
                     p.className = 'no-results-message';
                     p.textContent = 'Товары пока не добавлены.';
                     grid.appendChild(p);
                 }
            }

             function setupFilters() {
                 const searchInput = document.getElementById('search-input');
                 const categoryFilters = document.querySelectorAll('.category-filter');

                 if(searchInput) searchInput.addEventListener('input', filterProducts);

                 categoryFilters.forEach(filter => {
                     filter.addEventListener('click', function() {
                         categoryFilters.forEach(f => f.classList.remove('active'));
                         this.classList.add('active');
                         filterProducts();
                     });
                 });
                 filterProducts();
             }

             function showNotification(message, duration = 3000) {
                let placeholder = document.getElementById('notification-placeholder');
                if (!placeholder) {
                    const newPlaceholder = document.createElement('div');
                    newPlaceholder.id = 'notification-placeholder';
                    newPlaceholder.style.position = 'fixed';
                    newPlaceholder.style.bottom = '80px';
                    newPlaceholder.style.left = '50%';
                    newPlaceholder.style.transform = 'translateX(-50%)';
                    newPlaceholder.style.zIndex = '1002';
                    document.body.appendChild(newPlaceholder);
                    placeholder = newPlaceholder;
                 }

                // Remove any existing notifications before adding a new one
                placeholder.innerHTML = '';

                const notification = document.createElement('div');
                notification.className = 'notification';
                notification.textContent = message;
                placeholder.appendChild(notification);

                // Trigger reflow to ensure transition runs
                void notification.offsetWidth;

                notification.classList.add('show');

                setTimeout(() => {
                    notification.classList.remove('show');
                    notification.addEventListener('transitionend', () => notification.remove());
                }, duration);
             }

            document.addEventListener('DOMContentLoaded', () => {
                applyInitialTheme();
                updateCartButton();
                setupFilters();

                window.addEventListener('click', function(event) {
                    // Check if click is outside modal content but inside modal background
                    if (event.target.classList && event.target.classList.contains('modal')) {
                        closeModal(event.target.id);
                    }
                });

                window.addEventListener('keydown', function(event) {
                    if (event.key === 'Escape') {
                         document.querySelectorAll('.modal[style*="display: block"]').forEach(modal => {
                             closeModal(modal.id);
                         });
                    }
                });
            });

        </script>
    </body>
    </html>
'''

PRODUCT_DETAIL_TEMPLATE = '''
    <div style="padding: 10px;">
        <h2 style="font-size: 1.6rem; font-weight: 600; margin-bottom: 15px; text-align: center; color: #3F51B5;">{{ product['name'] }}</h2>
        <div class="swiper-container" style="max-width: 450px; margin: 0 auto 20px; border-radius: 10px; overflow: hidden; background-color: #fff;">
            <div class="swiper-wrapper">
                {% if product.get('photos') and product['photos']|length > 0 %}
                    {% for photo in product['photos'] %}
                    <div class="swiper-slide" style="display: flex; justify-content: center; align-items: center; padding: 10px;">
                         <div class="swiper-zoom-container">
                             <img src="https://huggingface.co/datasets/{{ repo_id }}/resolve/main/photos/{{ photo }}"
                                  alt="{{ product['name'] }} - фото {{ loop.index }}"
                                  style="max-width: 100%; max-height: 400px; object-fit: contain; display: block; margin: auto; cursor: grab;">
                         </div>
                    </div>
                    {% endfor %}
                {% else %}
                    <div class="swiper-slide" style="display: flex; justify-content: center; align-items: center;">
                         <img src="https://via.placeholder.com/400x400.png?text=No+Image" alt="Изображение отсутствует" style="max-width: 100%; max-height: 400px; object-fit: contain;">
                    </div>
                {% endif %}
            </div>
            {% if product.get('photos') and product['photos']|length > 1 %}
            <div class="swiper-pagination" style="position: relative; bottom: 5px;"></div>
            <div class="swiper-button-next" style="color: #3F51B5;"></div>
            <div class="swiper-button-prev" style="color: #3F51B5;"></div>
            {% endif %}
        </div>

        <div style="margin-top: 20px; font-size: 1rem; line-height: 1.7;">
            <p><strong>Категория:</strong> {{ product.get('category', 'Без категории') }}</p>
            <p style="font-size: 1.2rem; font-weight: bold; color: #303F9F;"><strong>Цена:</strong> {{ "%.2f"|format(product['price']) }} {{ currency_code }}</p>
            <p><strong>Остаток:</strong> {{ product.get('stock', 0) }} шт.</p>
            <p><strong>Описание:</strong><br> {{ product.get('description', 'Описание отсутствует.')|replace('\\n', '<br>')|safe }}</p>
            {% set colors = product.get('colors', []) %}
            {% if colors and colors|select('ne', '')|list|length > 0 %}
                <p><strong>Доступные цвета/варианты:</strong> {{ colors|select('ne', '')|join(', ') }}</p>
            {% endif %}
             {% if product.get('barcode') %}
                 <p><strong>Штрихкод:</strong> {{ product['barcode'] }}</p>
             {% endif %}
        </div>
    </div>
'''

ORDER_TEMPLATE = '''
<!DOCTYPE html>
<html lang="ru">
<head>
    <meta charset="UTF-8">
    <meta name="viewport" content="width=device-width, initial-scale=1.0">
    <title>Заказ №{{ order.id }} - Aikas_optom</title>
    <link href="https://fonts.googleapis.com/css2?family=Poppins:wght@300;400;600&display=swap" rel="stylesheet">
    <link rel="stylesheet" href="https://cdnjs.cloudflare.com/ajax/libs/font-awesome/6.5.1/css/all.min.css">
    <style>
        body { font-family: 'Poppins', sans-serif; background: #F5F5F5; color: #263238; line-height: 1.6; padding: 20px; }
        .container { max-width: 800px; margin: 20px auto; padding: 30px; background: #fff; border-radius: 15px; box-shadow: 0 4px 15px rgba(0, 0, 0, 0.1); border: 1px solid #CFD8DC; }
        h1 { text-align: center; color: #3F51B5; margin-bottom: 25px; font-size: 1.8rem; font-weight: 600; }
        h2 { color: #303F9F; margin-top: 30px; margin-bottom: 15px; font-size: 1.4rem; border-bottom: 1px solid #CFD8DC; padding-bottom: 8px;}
        .order-meta { font-size: 0.9rem; color: #607D8B; margin-bottom: 20px; text-align: center; }
        .order-item { display: grid; grid-template-columns: 60px 1fr auto; gap: 15px; align-items: center; padding: 15px 0; border-bottom: 1px solid #E0E0E0; }
        .order-item:last-child { border-bottom: none; }
        .order-item img { width: 60px; height: 60px; object-fit: contain; border-radius: 8px; background-color: #fff; padding: 5px; border: 1px solid #E0E0E0;}
        .item-details strong { display: block; margin-bottom: 5px; font-size: 1.05rem; color: #263238;}
        .item-details span { font-size: 0.9rem; color: #607D8B; display: block;}
        .item-total { font-weight: bold; text-align: right; font-size: 1rem; color: #303F9F;}
        .order-summary { margin-top: 30px; padding-top: 20px; border-top: 2px solid #3F51B5; text-align: right; }
        .order-summary p { margin-bottom: 10px; font-size: 1.1rem; }
        .order-summary strong { font-size: 1.3rem; color: #3F51B5; }
        .customer-info { margin-top: 30px; background-color: #e8eaf6; padding: 20px; border-radius: 8px; border: 1px solid #CFD8DC;}
        .customer-info p { margin-bottom: 8px; font-size: 0.95rem; }
        .customer-info strong { color: #303F9F; }
        .actions { margin-top: 30px; text-align: center; }
        .button { padding: 12px 25px; border: none; border-radius: 8px; background-color: #3F51B5; color: white; font-weight: 600; cursor: pointer; transition: background-color 0.3s ease, transform 0.1s ease; font-size: 1rem; display: inline-flex; align-items: center; gap: 8px; text-decoration: none; }
        .button:hover { background-color: #303F9F; }
        .button:active { transform: scale(0.98); }
        .button i { font-size: 1.2rem; }
        .catalog-link { display: block; text-align: center; margin-top: 25px; color: #303F9F; text-decoration: none; font-size: 0.9rem; }
        .catalog-link:hover { text-decoration: underline; }
        .not-found { text-align: center; color: #c53030; font-size: 1.2rem; padding: 40px 0;}
    </style>
</head>
<body>
    <div class="container">
        {% if order %}
            <h1><i class="fas fa-receipt"></i> Ваш Заказ №{{ order.id }}</h1>
            <p class="order-meta">Дата создания: {{ order.created_at }}</p>

            <h2><i class="fas fa-shopping-bag"></i> Товары в заказе</h2>
            <div id="orderItems">
                {% for item in order.cart %}
                    <div class="order-item">
                        <img src="{{ item.photo_url }}" alt="{{ item.name }}">
                        <div class="item-details">
                            <strong>{{ item.name }} {% if item.color != 'N/A' %}({{ item.color }}){% endif %}</strong>
                            <span>{{ "%.2f"|format(item.price) }} {{ currency_code }} × {{ item.quantity }}</span>
                        </div>
                        <div class="item-total">
                            {{ "%.2f"|format(item.price * item.quantity) }} {{ currency_code }}
                        </div>
                    </div>
                {% endfor %}
            </div>

            <div class="order-summary">
                <p>Общая сумма товаров: <strong>{{ "%.2f"|format(order.total_price) }} {{ currency_code }}</strong></p>
                <p><strong>ИТОГО К ОПЛАТЕ: {{ "%.2f"|format(order.total_price) }} {{ currency_code }}</strong></p>
            </div>

            <div class="customer-info">
                 <h2><i class="fas fa-info-circle"></i> Информация о заказе</h2>
                 <p>Заказ оформлен через сайт.</p>
                 <p>Пожалуйста, свяжитесь с нами по WhatsApp для подтверждения и уточнения деталей.</p>
            </div>

            <div class="actions">
                 <button class="button" onclick="sendOrderViaWhatsApp()"><i class="fab fa-whatsapp"></i> Отправить заказ в WhatsApp</button>
            </div>

            <a href="{{ url_for('catalog') }}" class="catalog-link">← Вернуться в каталог</a>

            <script>
                function sendOrderViaWhatsApp() {
                    const orderId = '{{ order.id }}';
                    const orderUrl = `{{ request.url }}`;
                    // Replace with your WhatsApp number
                    const whatsappNumber = "996507003777";

                    let message = `Здравствуйте! Хочу подтвердить свой заказ на Aikas_optom:%0A%0A`;
                    message += `*Номер заказа:* ${orderId}%0A`;
                    message += `*Ссылка на заказ:* ${encodeURIComponent(orderUrl)}%0A%0A`;
                    message += `Пожалуйста, свяжитесь со мной для уточнения деталей оплаты и доставки.`;

                    const whatsappUrl = `https://wa.me/${whatsappNumber}?text=${message}`; // Using wa.me for better compatibility
                    window.open(whatsappUrl, '_blank');
                }
            </script>

        {% else %}
            <h1 style="color: #c53030;"><i class="fas fa-exclamation-triangle"></i> Ошибка</h1>
            <p class="not-found">Заказ с таким ID не найден.</p>
            <a href="{{ url_for('catalog') }}" class="catalog-link">← Вернуться в каталог</a>
        {% endif %}
    </div>
</body>
</html>
'''

ADMIN_TEMPLATE = '''
    <!DOCTYPE html>
    <html lang="ru">
    <head>
        <meta charset="UTF-8">
        <meta name="viewport" content="width=device-width, initial-scale=1.0">
        <title>Админ-панель - Aikas_optom</title>
        <link href="https://fonts.googleapis.com/css2?family=Poppins:wght@300;400;600&display=swap" rel="stylesheet">
        <link rel="stylesheet" href="https://cdnjs.cloudflare.com/ajax/libs/font-awesome/6.5.1/css/all.min.css">
        <script src="https://cdn.jsdelivr.net/npm/@zxing/library@0.20.0"></script>
        <style>
            body { font-family: 'Poppins', sans-serif; background-color: #F5F5F5; color: #263238; padding: 20px; line-height: 1.6; }
            .container { max-width: 1200px; margin: 0 auto; background-color: #fff; padding: 25px; border-radius: 10px; box-shadow: 0 3px 10px rgba(0,0,0,0.05); }
            .header { padding-bottom: 15px; margin-bottom: 25px; border-bottom: 1px solid #CFD8DC; display: flex; justify-content: space-between; align-items: center; flex-wrap: wrap; gap: 10px;}
            h1, h2, h3 { font-weight: 600; color: #3F51B5; margin-bottom: 15px; }
            h1 { font-size: 1.8rem; }
            h2 { font-size: 1.5rem; margin-top: 30px; display: flex; align-items: center; gap: 8px; }
            h3 { font-size: 1.2rem; color: #303F9F; margin-top: 20px; }
            .section { margin-bottom: 30px; padding: 20px; background-color: #e8eaf6; border: 1px solid #CFD8DC; border-radius: 8px; }
            form { margin-bottom: 20px; }
            label { font-weight: 500; margin-top: 10px; display: block; color: #607D8B; font-size: 0.9rem;}
            input[type="text"], input[type="number"], input[type="password"], input[type="tel"], textarea, select, .admin-search-input { width: 100%; padding: 10px 12px; margin-top: 5px; border: 1px solid #CFD8DC; border-radius: 6px; font-size: 0.95rem; box-sizing: border-box; transition: border-color 0.3s ease; background-color: #fff; }
            input:focus, textarea:focus, select:focus { border-color: #3F51B5; outline: none; box-shadow: 0 0 0 2px rgba(63, 81, 181, 0.1); }
            textarea { min-height: 80px; resize: vertical; }
            input[type="file"] { padding: 8px; background-color: #e8eaf6; cursor: pointer; border: 1px solid #CFD8DC;}
            input[type="file"]::file-selector-button { padding: 5px 10px; border-radius: 4px; background-color: #BBDEFB; border: 1px solid #90CAF9; cursor: pointer; margin-right: 10px;}
            input[type="checkbox"] { margin-right: 5px; vertical-align: middle; }
            label.inline-label { display: inline-block; margin-top: 10px; font-weight: normal; }
            button, .button { padding: 10px 18px; border: none; border-radius: 6px; background-color: #3F51B5; color: white; font-weight: 500; cursor: pointer; transition: background-color 0.3s ease, transform 0.1s ease; margin-top: 15px; font-size: 0.95rem; display: inline-flex; align-items: center; gap: 5px; text-decoration: none; line-height: 1.2;}
            button:hover, .button:hover { background-color: #303F9F; }
            button:active, .button:active { transform: scale(0.98); }
            button[type="submit"] { min-width: 120px; justify-content: center; }
            .delete-button { background-color: #f56565; }
            .delete-button:hover { background-color: #e53e3e; }
            .add-button { background-color: #3F51B5; }
            .add-button:hover { background-color: #303F9F; }
            .item-list { display: grid; gap: 20px; }
            .item { background: #fff; padding: 15px 20px; border-radius: 8px; box-shadow: 0 2px 5px rgba(0,0,0,0.07); border: 1px solid #E0E0E0; }
            .item p { margin: 5px 0; font-size: 0.9rem; color: #607D8B; }
            .item strong { color: #263238; }
            .item .description { font-size: 0.85rem; color: #607D8B; max-height: 60px; overflow: hidden; text-overflow: ellipsis; }
            .item-actions { margin-top: 15px; display: flex; gap: 10px; flex-wrap: wrap; align-items: center; }
            .item-actions button:not(.delete-button) { background-color: #3F51B5; }
            .item-actions button:not(.delete-button):hover { background-color: #303F9F; }
            .edit-form-container { margin-top: 15px; padding: 20px; background: #e8eaf6; border: 1px dashed #CFD8DC; border-radius: 6px; display: none; }
            details { background-color: #e8eaf6; border: 1px solid #CFD8DC; border-radius: 8px; margin-bottom: 20px; }
            details > summary { cursor: pointer; font-weight: 600; color: #303F9F; display: block; padding: 15px; border-bottom: 1px solid #CFD8DC; list-style: none; position: relative; }
            details > summary::after { content: '\\f078'; font-family: 'Font Awesome 6 Free'; font-weight: 900; position: absolute; right: 20px; top: 50%; transform: translateY(-50%); transition: transform 0.2s ease; color: #3F51B5; }
            details[open] > summary::after { transform: translateY(-50%) rotate(180deg); }
            details[open] > summary { border-bottom: 1px solid #CFD8DC; }
            details .form-content { padding: 20px; }
            .color-input-group { display: flex; align-items: center; gap: 10px; margin-bottom: 8px; }
            .color-input-group input { flex-grow: 1; margin: 0; }
            .remove-color-btn { background-color: #f56565; padding: 6px 10px; font-size: 0.8rem; margin-top: 0; line-height: 1; }
            .remove-color-btn:hover { background-color: #e53e3e; }
            .add-color-btn { background-color: #BBDEFB; color: #303F9F; }
            .add-color-btn:hover { background-color: #90CAF9; }
            .photo-preview img { max-width: 70px; max-height: 70px; border-radius: 5px; margin: 5px 5px 0 0; border: 1px solid #CFD8DC; object-fit: cover;}
            .sync-buttons { display: flex; gap: 10px; margin-bottom: 20px; flex-wrap: wrap; }
            .download-hf-button { background-color: #9E9E9E; }
            .download-hf-button:hover { background-color: #757575; }
            .flex-container { display: flex; flex-wrap: wrap; gap: 20px; }
            .flex-item { flex: 1; min-width: 350px; }
            .message { padding: 10px 15px; border-radius: 6px; margin-bottom: 15px; font-size: 0.9rem;}
            .message.success { background-color: #e8f5e9; color: #2e7d32; border: 1px solid #a5d6a7;}
            .message.error { background-color: #ffebee; color: #c62828; border: 1px solid #ef9a9a;}
            .message.warning { background-color: #fffde7; color: #ef6c00; border: 1px solid #ffcc80; }
            .status-indicator { display: inline-block; padding: 3px 8px; border-radius: 12px; font-size: 0.8rem; font-weight: 500; margin-left: 10px; vertical-align: middle; }
            .status-indicator.in-stock { background-color: #c8e6c9; color: #388e3c; }
            .status-indicator.out-of-stock { background-color: #ffcdd2; color: #d32f2f; }
            .status-indicator.top-product { background-color: #ffe0b2; color: #e65100; margin-left: 5px;}

            #sale-items-list div {
                display: flex;
                justify-content: space-between;
                align-items: center;
                padding: 8px 0;
                border-bottom: 1px dashed #CFD8DC;
            }
            #sale-items-list div:last-child { border-bottom: none; }
            #sale-items-list p { text-align: center; color: #607D8B; padding: 10px; }

            .order-item h3 {
                margin-top: 0;
                margin-bottom: 10px;
                color: #3F51B5;
            }
            .order-item p {
                margin: 5px 0;
                font-size: 0.95rem;
            }
            .order-item details {
                margin-top: 10px;
                background-color: #fff;
                border: 1px solid #CFD8DC;
            }
            .order-item details summary {
                color: #303F9F;
                padding: 10px 15px;
                border-bottom: none;
            }
            .order-item details[open] summary {
                border-bottom: 1px solid #CFD8DC;
            }
            .order-item details ul {
                padding: 10px 20px;
                font-size: 0.9rem;
            }
            .admin-search-input {
                width: 100%;
                padding: 10px 12px;
                margin-bottom: 15px;
                border: 1px solid #CFD8DC;
                border-radius: 6px;
                font-size: 0.95rem;
                box-sizing: border-box;
            }
            .header a.button { background-color: #3F51B5 !important; }
            .header a.button:hover { background-color: #303F9F !important; }

            /* Barcode Scanner Modal */
            #scannerModal {
                display: none;
                position: fixed;
                z-index: 1003; /* Higher than other modals */
                left: 0;
                top: 0;
                width: 100%;
                height: 100%;
                background-color: rgba(0,0,0,0.8);
                backdrop-filter: blur(8px);
                overflow: auto;
                justify-content: center;
                align-items: center;
                flex-direction: column;
                color: white;
            }
            #scannerModal .modal-content {
                 background: none; /* No background for scanner */
                 box-shadow: none;
                 margin: auto; /* Center content */
                 max-width: 90%;
                 width: 500px; /* Max width for video feed */
                 padding: 0;
                 position: relative;
                 display: flex;
                 flex-direction: column;
                 align-items: center;
            }
            #scannerModal .close {
                 position: absolute;
                 top: 15px;
                 right: 15px;
                 z-index: 1004;
                 color: rgba(255,255,255,0.8);
                 font-size: 2rem;
            }
             #scannerModal .close:hover { color: white; }

            #interactive.viewport {
                 position: relative;
                 width: 100%;
                 height: 300px; /* Adjust height as needed */
                 text-align: center;
                 overflow: hidden;
                 border-radius: 10px;
                 background-color: #333;
                 display: flex;
                 justify-content: center;
                 align-items: center;
            }
             #interactive video {
                 max-width: 100%;
                 max-height: 100%;
                 object-fit: cover; /* Cover the container */
                 display: block;
             }
             #interactive .scan-line {
                 position: absolute;
                 top: 50%;
                 left: 0;
                 width: 100%;
                 height: 2px;
                 background: red;
                 animation: scan-line 2s linear infinite;
             }
             @keyframes scan-line {
                 0% { top: 0%; }
                 50% { top: 100%; }
                 100% { top: 0%; }
             }
            #scannerModal p { margin-top: 15px; font-size: 1rem; text-align: center; }
            .barcode-input-group { display: flex; gap: 10px; align-items: flex-end; }
            .barcode-input-group input { flex-grow: 1; margin-top: 5px; }
            .barcode-input-group button { margin-top: 0; padding: 10px 12px; line-height: 1; font-size: 0.95rem;}


        </style>
    </head>
    <body>
        <div class="container">
            <div class="header">
                <div class="logo-title-container" style="display: flex; align-items: center; gap: 15px;">
                    <img src="https://cdn-avatars.huggingface.co/v1/production/uploads/67c280ccb9d3dfdee58ecfdd/p2TVtSc6UQr0De1jDYBLk.jpeg" alt="Aikas_optom Logo" style="height: 40px; width: auto; border-radius: 4px;">
                    <h1><i class="fas fa-tools"></i> Админ-панель Aikas_optom</h1>
                </div>
                <a href="{{ url_for('catalog') }}" class="button" style="background-color: #3F51B5;"><i class="fas fa-store"></i> Перейти в каталог</a>
                <a href="{{ url_for('sale_register') }}" class="button" style="background-color: #3F51B5;"><i class="fas fa-cash-register"></i> Касса</a>
            </div>


            {% with messages = get_flashed_messages(with_categories=true) %}
                {% if messages %}
                    {% for category, message in messages %}
                        <div class="message {{ category }}">{{ message }}</div>
                    {% endfor %}
                {% endif %}
            {% endwith %}

            <div class="section">
                <details>
                    <summary><h2><i class="fas fa-sync-alt"></i> Синхронизация с Датацентром</h2></summary>
                    <div class="form-content">
                        <div class="sync-buttons">
                            <form method="POST" action="{{ url_for('force_upload') }}" style="display: inline;" onsubmit="return confirm('Вы уверены, что хотите принудительно загрузить локальные данные на сервер? Это перезапишет данные на сервере.');">
                                <button type="submit" class="button" title="Загрузить локальные файлы на Hugging Face"><i class="fas fa-upload"></i> Загрузить БД</button>
                            </form>
                            <form method="POST" action="{{ url_for('force_download') }}" style="display: inline;" onsubmit="return confirm('Вы уверены, что хотите принудительно скачать данные с сервера? Это перезапишет ваши локальные файлы.');">
                                <button type="submit" class="button download-hf-button" title="Скачать файлы  (перезапишет локальные)"><i class="fas fa-download"></i> Скачать БД</button>
                            </form>
                        </div>
                         <p style="font-size: 0.85rem; color: #607D8B;">Резервное копирование происходит автоматически каждые 30 минут, а также после каждого сохранения данных. Используйте эти кнопки для немедленной синхронизации.</p>
                    </div>
                </details>
            </div>

            <div class="flex-container">
                 <div class="flex-item">
                     <div class="section">
                         <details>
                             <summary><h2><i class="fas fa-tags"></i> Управление категориями</h2></summary>
                             <div class="form-content">
                                 <details>
                                     <summary><i class="fas fa-plus-circle"></i> Добавить новую категорию</summary>
                                     <div class="form-content">
                                         <form method="POST">
                                             <input type="hidden" name="action" value="add_category">
                                             <label for="add_category_name">Название новой категории:</label>
                                             <input type="text" id="add_category_name" name="category_name" required>
                                             <button type="submit" class="add-button"><i class="fas fa-plus"></i> Добавить</button>
                                         </form>
                                     </div>
                                 </details>

                                 <h3>Существующие категории:</h3>
                                 <input type="text" id="category-search-input" class="admin-search-input" placeholder="Поиск по категориям...">
                                 <div class="item-list" id="admin-categories-list">
                                     {% if categories %}
                                     {% for category in categories %}
                                     <div class="item category-item" style="display: flex; justify-content: space-between; align-items: center;" data-name="{{ category|lower }}">
                                         <span>{{ category }}</span>
                                         <form method="POST" style="margin: 0;" onsubmit="return confirm('Вы уверены, что хотите удалить категорию \'{{ category }}\'? Товары этой категории будут помечены как \'Без категории\'.');">
                                             <input type="hidden" name="action" value="delete_category">
                                             <input type="hidden" name="category_name" value="{{ category }}">
                                             <button type="submit" class="delete-button" style="padding: 5px 10px; font-size: 0.8rem; margin: 0;"><i class="fas fa-trash-alt"></i></button>
                                         </form>
                                     </div>
                                     {% endfor %}
                                     {% else %}
                                     <p>Категорий пока нет.</p>
                                     {% endif %}
                                 </div>
                             </div>
                         </details>
                     </div>
                 </div>

                 <div class="flex-item">
                      <div class="section">
                        <details>
                            <summary><h2><i class="fas fa-chart-line"></i> Отчеты и статистика</h2></summary>
                            <div class="form-content">
                                <h3>Общая статистика:</h3>
                                <p><strong>Всего заказов/продаж:</strong> {{ stats.total_orders }}</p>
                                <p><strong>Общая сумма продаж:</strong> {{ "%.2f"|format(stats.total_revenue) }} {{ currency_code }}</p>
                                <p><strong>Количество товаров:</strong> {{ stats.total_products }}</p>
                                <p><strong>В наличии:</strong> {{ stats.products_in_stock }} ({{ "%.1f"|format(stats.products_in_stock_percent) }}%)</p>
                                <p><strong>Нет в наличии:</strong> {{ stats.products_out_of_stock }}</p>

                                <h3>Топ-5 продаваемых товаров (по количеству):</h3>
                                {% if stats.top_selling_products %}
                                <ol style="padding-left: 20px;">
                                    {% for product_name, quantity in stats.top_selling_products %}
                                        <li>{{ product_name }}: {{ quantity }} шт.</li>
                                    {% endfor %}
                                </ol>
                                {% else %}
                                <p>Нет данных о продажах.</p>
                                {% endif %}

                                <h3>Товары с низким остатком (менее 10 шт.):</h3>
                                {% if stats.low_stock_products %}
                                <ul style="padding-left: 20px;">
                                    {% for product in stats.low_stock_products %}
                                        <li>{{ product.name }}: {{ product.stock }} шт.</li>
                                    {% endfor %}
                                </ul>
                                {% else %}
                                <p>Все товары в достаточном количестве.</p>
                                {% endif %}
                            </div>
                        </details>
                    </div>
                 </div>
            </div>

            <div class="section">
                <details>
                    <summary><h2><i class="fas fa-box-open"></i> Управление товарами</h2></summary>
                    <div class="form-content">
                         <details>
                             <summary><i class="fas fa-plus-circle"></i> Добавить новый товар</summary>
                             <div class="form-content">
                                 <form method="POST" enctype="multipart/form-data">
                                     <input type="hidden" name="action" value="add_product">
                                     <label for="add_name">Название товара *:</label>
                                     <input type="text" id="add_name" name="name" required>
                                     <label for="add_price">Цена ({{ currency_code }}) *:</label>
                                     <input type="number" id="add_price" name="price" step="0.01" min="0" required>
                                     <label for="add_stock">Начальный остаток на складе *:</label>
                                     <input type="number" id="add_stock" name="stock" min="0" value="0" required>
                                     <label for="add_description">Описание:</label>
                                     <textarea id="add_description" name="description" rows="4"></textarea>
                                     <label for="add_category">Категория:</label>
                                     <select id="add_category" name="category">
                                         <option value="Без категории">Без категории</option>
                                         {% for category in categories %}
                                         <option value="{{ category }}">{{ category }}</option>
                                         {% endfor %}
                                     </select>
                                     <label for="add_photos">Фотографии (до 10 шт.):</label>
                                     <input type="file" id="add_photos" name="photos" accept="image/*" multiple>

                                     <label for="add_barcode">Штрихкод:</label>
                                     <div class="barcode-input-group">
                                         <input type="text" id="add_barcode" name="barcode" placeholder="Отсканируйте или введите">
                                         <button type="button" class="button" onclick="scanBarcode('add_barcode')"><i class="fas fa-barcode"></i> Сканировать</button>
                                     </div>


                                     <label>Цвета/Варианты (оставьте пустым, если нет):</label>
                                     <div id="add-color-inputs">
                                         <div class="color-input-group">
                                             <input type="text" name="colors" placeholder="Например: Розовый">
                                             <button type="button" class="remove-color-btn" onclick="removeColorInput(this)"><i class="fas fa-times"></i></button>
                                         </div>
                                     </div>
                                     <button type="button" class="button add-color-btn" style="margin-top: 5px;" onclick="addColorInput('add-color-inputs')"><i class="fas fa-palette"></i> Добавить поле для цвета/варианта</button>
                                     <br>
                                     <div style="margin-top: 5px;">
                                         <input type="checkbox" id="add_is_top" name="is_top">
                                         <label for="add_is_top" class="inline-label">Топ товар (показывать наверху)</label>
                                     </div>
                                     <br>
                                     <button type="submit" class="add-button" style="margin-top: 20px;"><i class="fas fa-save"></i> Добавить товар</button>
                                 </form>
                             </div>
                        </details>

                        <h3>Список товаров:</h3>
                        <input type="text" id="product-search-input" class="admin-search-input" placeholder="Поиск товаров по названию, описанию или штрихкоду...">
                        <div class="item-list" id="admin-products-list">
                            {% if products %}
                            {% for product in products %}
                            <div class="item product-item"
                                 data-name="{{ product['name']|lower }}"
                                 data-description="{{ product.get('description', '')|lower }}"
                                 data-barcode="{{ product.get('barcode', '')|lower }}"
                                 >
                                <div style="display: flex; gap: 15px; align-items: flex-start;">
                                     <div class="photo-preview" style="flex-shrink: 0;">
                                        {% if product.get('photos') and product['photos']|length > 0 %}
                                        <a href="https://huggingface.co/datasets/{{ repo_id }}/resolve/main/photos/{{ product['photos'][0] }}" target="_blank" title="Посмотреть первое фото">
                                           <img src="https://huggingface.co/datasets/{{ repo_id }}/resolve/main/photos/{{ product['photos'][0] }}" alt="Фото">
                                        </a>
                                        {% else %}
                                        <img src="https://via.placeholder.com/70x70.png?text=N/A" alt="Нет фото">
                                        {% endif %}
                                    </div>
                                    <div style="flex-grow: 1;">
                                        <h3 style="margin-top: 0; margin-bottom: 5px; color: #263238;">
                                            {{ product['name'] }}
                                             {% if product.get('in_stock', True) %}
                                                <span class="status-indicator in-stock">В наличии</span>
                                             {% else %}
                                                <span class="status-indicator out-of-stock">Нет в наличии</span>
                                             {% endif %}
                                             {% if product.get('is_top', False) %}
                                                <span class="status-indicator top-product"><i class="fas fa-star"></i> Топ</span>
                                             {% endif %}
                                        </h3>
                                        <p><strong>Категория:</strong> {{ product.get('category', 'Без категории') }}</p>
                                        <p><strong>Цена:</strong> {{ "%.2f"|format(product['price']) }} {{ currency_code }}</p>
                                        <p><strong>Остаток:</b> {{ product.get('stock', 0) }} шт.</p>
                                        <p class="description" title="{{ product.get('description', '') }}"><strong>Описание:</strong> {{ product.get('description', 'N/A')[:150] }}{% if product.get('description', '')|length > 150 %}...{% endif %}</p>
                                         {% if product.get('barcode') %}
                                             <p><strong>Штрихкод:</strong> {{ product['barcode'] }}</p>
                                         {% endif %}
                                        {% if product.get('colors') and product['colors']|select('ne', '')|list|length > 0 %}
                                            <p><strong>Цвета/Вар-ты:</strong> {{ product['colors']|select('ne', '')|join(', ') }}</p>
                                        {% endif %}
                                        {% if product.get('photos') and product['photos']|length > 1 %}
                                            <p style="font-size: 0.8rem; color: #607D8B;">(Всего фото: {{ product['photos']|length }})</p>
                                        {% endif %}
                                    </div>
                                </div>

                                <div class="item-actions">
                                     <button type="button" class="button" onclick="toggleEditForm('edit-form-{{ product['id'] }}')"><i class="fas fa-edit"></i> Редактировать</button>
                                    <form method="POST" style="margin:0;" onsubmit="return confirm('Вы уверены, что хотите удалить товар \'{{ product['name'] }}\'?');">
                                        <input type="hidden" name="action" value="delete_product">
                                        <input type="hidden" name="product_id" value="{{ product['id'] }}">
                                        <button type="submit" class="delete-button"><i class="fas fa-trash-alt"></i> Удалить</button>
                                    </form>
                                </div>

                                <div id="edit-form-{{ product['id'] }}" class="edit-form-container">
                                    <h4><i class="fas fa-edit"></i> Редактирование: {{ product['name'] }}</h4>
                                    <form method="POST" enctype="multipart/form-data">
                                        <input type="hidden" name="action" value="edit_product">
                                        <input type="hidden" name="product_id" value="{{ product['id'] }}">
                                        <label>Название *:</label>
                                        <input type="text" name="name" value="{{ product['name'] }}" required>
                                        <label>Цена ({{ currency_code }}) *:</label>
                                        <input type="number" name="price" step="0.01" min="0" value="{{ product['price'] }}" required>
                                        <label>Остаток на складе *:</label>
                                        <input type="number" name="stock" min="0" value="{{ product.get('stock', 0) }}" required>
                                        <label>Описание:</label>
                                        <textarea name="description" rows="4">{{ product.get('description', '') }}</textarea>
                                        <label>Категория:</label>
                                        <select name="category">
                                            <option value="Без категории" {% if product.get('category', 'Без категории') == 'Без категории' %}selected{% endif %}>Без категории</option>
                                            {% for category in categories %}
                                            <option value="{{ category }}" {% if product.get('category') == category %}selected{% endif %}>{{ category }}</option>
                                            {% endfor %}
                                        </select>
                                        <label>Заменить фотографии (выберите новые файлы, до 10 шт.):</label>
                                        <input type="file" name="photos" accept="image/*" multiple>
                                         {% if product.get('photos') %}
                                            <p style="font-size: 0.85rem; margin-top: 5px;">Текущие фото:</p>
                                            <div class="photo-preview">
                                                {% for photo in product['photos'] %}
                                                <img src="https://huggingface.co/datasets/{{ repo_id }}/resolve/main/photos/{{ photo }}" alt="Фото {{ loop.index }}">
                                                {% endfor %}
                                            </div>
                                        {% endif %}

                                        <label for="edit_barcode_{{ product['id'] }}">Штрихкод:</label>
                                        <div class="barcode-input-group">
                                            <input type="text" id="edit_barcode_{{ product['id'] }}" name="barcode" value="{{ product.get('barcode', '') }}" placeholder="Отсканируйте или введите">
                                            <button type="button" class="button" onclick="scanBarcode('edit_barcode_{{ product['id'] }}')"><i class="fas fa-barcode"></i> Сканировать</button>
                                        </div>

                                        <label>Цвета/Варианты:</label>
                                        <div id="edit-color-inputs-{{ product['id'] }}">
                                            {% set current_colors = product.get('colors', []) %}
                                            {% if current_colors and current_colors|select('ne', '')|list|length > 0 %}
                                                {% for color in current_colors %}
                                                    {% if color.strip() %}
                                                    <div class="color-input-group">
                                                        <input type="text" name="colors" value="{{ color }}">
                                                        <button type="button" class="remove-color-btn" onclick="removeColorInput(this)"><i class="fas fa-times"></i></button>
                                                    </div>
                                                    {% endif %}
                                                {% endfor %}
                                             {% else %}
                                                 <div class="color-input-group">
                                                    <input type="text" name="colors" placeholder="Например: Цвет">
                                                    <button type="button" class="remove-color-btn" onclick="removeColorInput(this)"><i class="fas fa-times"></i></button>
                                                 </div>
                                             {% endif %}
                                        </div>
                                        <button type="button" class="button add-color-btn" style="margin-top: 5px;" onclick="addColorInput('edit-color-inputs-{{ product['id'] }}')"><i class="fas fa-palette"></i> Добавить поле для цвета</button>
                                        <br>
                                        <div style="margin-top: 5px;">
                                             <input type="checkbox" id="edit_is_top_{{ product['id'] }}" name="is_top" {% if product.get('is_top', False) %}checked{% endif %}>
                                             <label for="edit_is_top_{{ product['id'] }}" class="inline-label">Топ товар</label>
                                        </div>
                                        <br>
                                        <button type="submit" class="add-button" style="margin-top: 20px;"><i class="fas fa-save"></i> Сохранить изменения</button>
                                    </form>
                                </div>
                            </div>
                            {% endfor %}
                            {% else %}
                            <p>Товаров пока нет.</p>
                            {% endif %}
                        </div>
                    </div>
                </details>
            </div>

            <div class="section">
                <details>
                    <summary><h2><i class="fas fa-boxes"></i> Управление остатками</h2></summary>
                    <div class="form-content">
                        <form method="POST">
                            <input type="hidden" name="action" value="adjust_stock">
                            <label for="adjust_product_select">Выберите товар:</label>
                            <select id="adjust_product_select" name="product_id" required>
                                <option value="">-- Выберите товар --</option>
                                {% for product in products %}
                                <option value="{{ product.id }}">{{ product.name }} (Текущий остаток: {{ product.get('stock', 0) }} шт.)</option>
                                {% endfor %}
                            </select>
                            <label for="adjust_quantity">Количество для корректировки:</label>
                            <input type="number" id="adjust_quantity" name="quantity" min="1" value="1" required>
                            <label>Тип корректировки:</label>
                            <input type="radio" id="adjust_add" name="adjustment_type" value="add" checked>
                            <label for="adjust_add" class="inline-label">Добавить</label>
                            <input type="radio" id="adjust_subtract" name="adjustment_type" value="subtract">
                            <label for="adjust_subtract" class="inline-label">Вычесть</label>
                            <br>
                            <button type="submit" class="button"><i class="fas fa-exchange-alt"></i> Применить корректировку</button>
                        </form>
                    </div>
                </details>
            </div>

            <div class="section">
                <details>
                    <summary><h2><i class="fas fa-clipboard-list"></i> Управление заказами</h2></summary>
                    <div class="form-content">
                        <input type="text" id="order-search-input" class="admin-search-input" placeholder="Поиск по ID, клиенту или товару...">
                        <div id="admin-orders-list" class="item-list">
                        </div>
                    </div>
                </details>
            </div>
        </div>

        <!-- Barcode Scanner Modal -->
        <div id="scannerModal" class="modal">
            <div class="modal-content">
                <span class="close" onclick="closeScannerModal()" aria-label="Закрыть сканер">×</span>
                <h2>Сканирование штрихкода</h2>
                <div id="interactive" class="viewport">
                    <video></video>
                     <div class="scan-line"></div>
                </div>
                <p id="scanner-message">Наведите камеру на штрихкод...</p>
            </div>
        </div>


        <script>
            let codeReader = null;
            let currentBarcodeInputId = null;

            function toggleEditForm(formId) {
                const formContainer = document.getElementById(formId);
                if (formContainer) {
                    formContainer.style.display = formContainer.style.display === 'none' || formContainer.style.display === '' ? 'block' : 'none';
                }
            }

            function addColorInput(containerId) {
                const container = document.getElementById(containerId);
                if (container) {
                    const newInputGroup = document.createElement('div');
                    newInputGroup.className = 'color-input-group';
                    newInputGroup.innerHTML = `
                        <input type="text" name="colors" placeholder="Новый цвет/вариант">
                        <button type="button" class="remove-color-btn" onclick="removeColorInput(this)"><i class="fas fa-times"></i></button>
                    `;
                    container.appendChild(newInputGroup);
                    const newInput = newInputGroup.querySelector('input[name="colors"]');
                    if (newInput) {
                        newInput.focus();
                    }
                }
            }

            function removeColorInput(button) {
                const group = button.closest('.color-input-group');
                if (group) {
                    const container = group.parentNode;
                    group.remove();
                    // Optional: add a placeholder if all color inputs are removed
                    if (container && container.children.length === 0) {
                         const placeholderGroup = document.createElement('div');
                         placeholderGroup.className = 'color-input-group';
                         placeholderGroup.innerHTML = `
                             <input type="text" name="colors" placeholder="Например: Цвет">
                             <button type="button" class="remove-color-btn" onclick="removeColorInput(this)"><i class="fas fa-times"></i></button>
                         `;
                         container.appendChild(placeholderGroup);
                    }
                } else {
                     console.warn("Could not find parent .color-input-group for remove button");
                }
            }

            // Barcode Scanner Functions
            async function scanBarcode(inputId) {
                currentBarcodeInputId = inputId;
                const scannerModal = document.getElementById('scannerModal');
                const videoElement = scannerModal.querySelector('video');
                const scannerMessage = document.getElementById('scanner-message');

                if (!scannerModal || !videoElement || !scannerMessage) {
                    console.error("Scanner modal elements not found.");
                    return;
                }

                scannerMessage.textContent = 'Запуск камеры...';
                scannerModal.style.display = 'flex';
                document.body.style.overflow = 'hidden'; // Prevent scrolling

                try {
                    codeReader = new ZXing.BrowserMultiFormatReader();
                     // Prefer rear camera
                    const devices = await codeReader.listVideoInputDevices();
                    const rearCamera = devices.find(device => device.label.toLowerCase().includes('rear')) || devices[0];


                    codeReader.decodeFromVideoDevice(rearCamera.deviceId, videoElement, (result, err) => {
                        if (result) {
                            console.log('Scanned barcode:', result.text);
                            document.getElementById(currentBarcodeInputId).value = result.text;
                            scannerMessage.textContent = 'Штрихкод отсканирован: ' + result.text;
                            closeScannerModal();
                        }
                        if (err && !(err instanceof ZXing.NotFoundException)) {
                            // Log error but keep trying if it's not just "not found"
                            console.error(err);
                            scannerMessage.textContent = 'Ошибка сканирования: ' + err.message;
                        }
                    });
                     scannerMessage.textContent = 'Наведите камеру на штрихкод...';

                } catch (error) {
                    console.error('Error accessing camera:', error);
                    scannerMessage.textContent = 'Не удалось запустить камеру: ' + error.message;
                    // Optionally auto-close modal if camera fails
                    // setTimeout(closeScannerModal, 3000);
                }
            }

            function closeScannerModal() {
                const scannerModal = document.getElementById('scannerModal');
                if (codeReader) {
                    codeReader.reset();
                    codeReader = null;
                }
                if (scannerModal) {
                    scannerModal.style.display = 'none';
                    const anyModalOpen = document.querySelector('.modal[style*="display: block"]');
                    if (!anyModalOpen) {
                       document.body.style.overflow = 'auto';
                    }
                }
                currentBarcodeInputId = null;
            }


            const allProducts = {{ products|tojson }};
            const allOrders = {{ display_orders|tojson }};

            function filterAdminProducts() {
                const searchTerm = document.getElementById('product-search-input').value.toLowerCase().trim();
                document.querySelectorAll('#admin-products-list .product-item').forEach(productElement => {
                    const name = productElement.dataset.name;
                    const description = productElement.dataset.description;
                    const barcode = productElement.dataset.barcode;

                    const matches = name.includes(searchTerm) || description.includes(searchTerm) || barcode.includes(searchTerm);

                    if (matches) {
                        productElement.style.display = 'block';
                    } else {
                        productElement.style.display = 'none';
                    }
                });
            }

            function filterAdminCategories() {
                const searchTerm = document.getElementById('category-search-input').value.toLowerCase().trim();
                document.querySelectorAll('#admin-categories-list .category-item').forEach(categoryElement => {
                    const categoryName = categoryElement.dataset.name;
                    if (categoryName.includes(searchTerm)) {
                        categoryElement.style.display = 'flex';
                    } else {
                        categoryElement.style.display = 'none';
                    }
                });
            }

            function renderAdminOrders() {
                const orderListContainer = document.getElementById('admin-orders-list');
                orderListContainer.innerHTML = '';
                if (allOrders.length === 0) {
                    orderListContainer.innerHTML = '<p>Заказов пока нет.</p>';
                    return;
                }

                allOrders.forEach(order => {
                    const orderDiv = document.createElement('div');
                    orderDiv.className = 'item order-item';
                    orderDiv.dataset.orderId = order.id.toLowerCase();
                    orderDiv.dataset.customerName = (order.customer_name || '').toLowerCase();
                    orderDiv.dataset.products = order.cart.map(item => item.name.toLowerCase()).join(' ');

                    let itemsHtml = order.cart.map(item => {
                        const colorText = item.color && item.color !== 'N/A' ? ` (${item.color})` : '';
                        return `<li>${item.name}${colorText} &times; ${item.quantity} (${item.price.toFixed(2)} {{ currency_code }} each)</li>`;
                    }).join('');

                    orderDiv.innerHTML = `
                        <h3><i class="fas fa-receipt"></i> Заказ №${order.id}</h3>
                        <p><strong>Дата:</strong> ${order.created_at}</p>
                        <p><strong>Клиент:</strong> ${order.customer_name || 'Анонимный'}</p>
                        <p><strong>Контакт:</strong> ${order.customer_contact || 'Не указан'}</p>
                        <p><strong>Статус:</strong> ${order.status}</p>
                        <p><strong>Сумма:</strong> ${order.total_price.toFixed(2)} {{ currency_code }}</p>
                        <details>
                            <summary>Состав заказа</summary>
                            <ul style="padding-left: 20px; list-style: disc;">${itemsHtml}</ul>
                        </details>
                    `;
                    orderListContainer.appendChild(orderDiv);
                });
                filterAdminOrders();
            }

            function filterAdminOrders() {
                const searchTerm = document.getElementById('order-search-input').value.toLowerCase().trim();
                document.querySelectorAll('#admin-orders-list .order-item').forEach(orderElement => {
                    const orderId = orderElement.dataset.orderId;
                    const customerName = orderElement.dataset.customerName;
                    const productsInOrder = orderElement.dataset.products;

                    // Combine all searchable data into one string for easier check
                    const searchableData = `${orderId} ${customerName} ${productsInOrder}`;

                    if (searchableData.includes(searchTerm)) {
                        orderElement.style.display = 'block';
                    } else {
                        orderElement.style.display = 'none';
                    }
                });
            }


            document.addEventListener('DOMContentLoaded', () => {
                document.getElementById('product-search-input').addEventListener('input', filterAdminProducts);
                document.getElementById('category-search-input').addEventListener('input', filterAdminCategories);
                document.getElementById('order-search-input').addEventListener('input', filterAdminOrders);

                filterAdminProducts();
                filterAdminCategories();
                renderAdminOrders();

                // Ensure scanner modal can be closed by clicking outside
                const scannerModal = document.getElementById('scannerModal');
                if (scannerModal) {
                    scannerModal.addEventListener('click', function(event) {
                        // Check if the click target is the modal itself, not its content
                        if (event.target === scannerModal) {
                            closeScannerModal();
                        }
                    });
                }

                 // Add keydown listener for Escape specifically for the scanner modal
                 window.addEventListener('keydown', function(event) {
                    if (event.key === 'Escape' && scannerModal && scannerModal.style.display === 'flex') {
                        closeScannerModal();
                    }
                 });
            });
        </script>
    </body>
    </html>
'''

SALE_TEMPLATE = '''
<!DOCTYPE html>
<html lang="ru">
<head>
    <meta charset="UTF-8">
    <meta name="viewport" content="width=device-width, initial-scale=1.0">
    <title>Касса - Aikas_optom</title>
    <link href="https://fonts.googleapis.com/css2?family=Poppins:wght@300;400;600&display=swap" rel="stylesheet">
    <link rel="stylesheet" href="https://cdnjs.cloudflare.com/ajax/libs/font-awesome/6.5.1/css/all.min.css">
    <script src="https://cdn.jsdelivr.net/npm/@zxing/library@0.20.0"></script>
    <style>
        body { font-family: 'Poppins', sans-serif; background-color: #F5F5F5; color: #263238; padding: 20px; line-height: 1.6; }
        .container { max-width: 1400px; margin: 0 auto; background-color: #fff; padding: 25px; border-radius: 10px; box-shadow: 0 3px 10px rgba(0,0,0,0.05); }
        .header { padding-bottom: 15px; margin-bottom: 25px; border-bottom: 1px solid #CFD8DC; display: flex; justify-content: space-between; align-items: center; flex-wrap: wrap; gap: 10px;}
        h1, h2, h3 { font-weight: 600; color: #3F51B5; margin-bottom: 15px; }
        h1 { font-size: 1.8rem; }
        h2 { font-size: 1.5rem; margin-top: 30px; display: flex; align-items: center; gap: 8px; }
        h3 { font-size: 1.2rem; color: #303F9F; margin-top: 20px; }
        .button { padding: 10px 18px; border: none; border-radius: 6px; background-color: #3F51B5; color: white; font-weight: 500; cursor: pointer; transition: background-color 0.3s ease, transform 0.1s ease; margin-top: 15px; font-size: 0.95rem; display: inline-flex; align-items: center; gap: 5px; text-decoration: none; line-height: 1.2;}
        .button:hover { background-color: #303F9F; }
        .button:active { transform: scale(0.98); }
        .button i { font-size: 1.2rem; }
        .add-button { background-color: #3F51B5; }
        .add-button:hover { background-color: #303F9F; }
        .delete-button { background-color: #f56565; }
        .delete-button:hover { background-color: #e53e3e; }
        .message { padding: 10px 15px; border-radius: 6px; margin-bottom: 15px; font-size: 0.9rem;}
        .message.success { background-color: #e8f5e9; color: #2e7d32; border: 1px solid #a5d6a7;}
        .message.error { background-color: #ffebee; color: #c62828; border: 1px solid #ef9a9a;}
        .message.warning { background-color: #fffde7; color: #ef6c00; border: 1px solid #ffcc80; }
        input[type="text"], input[type="number"], input[type="tel"], textarea, select { width: 100%; padding: 10px 12px; margin-top: 5px; border: 1px solid #CFD8DC; border-radius: 6px; font-size: 0.95rem; box-sizing: border-box; transition: border-color 0.3s ease; background-color: #fff; }
        input:focus, textarea:focus, select:focus { border-color: #3F51B5; outline: none; box-shadow: 0 0 0 2px rgba(63, 81, 181, 0.1); }
        label { font-weight: 500; margin-top: 10px; display: block; color: #607D8B; font-size: 0.9rem;}

        .sale-management-container {
            display: flex;
            flex-direction: column; /* Default to column for mobile */
            gap: 20px;
            margin-top: 20px;
        }

        .active-sales-panel {
            flex-shrink: 0;
            width: 100%; /* Full width on mobile */
            background-color: #e8eaf6;
            border: 1px solid #CFD8DC;
            border-radius: 8px;
            padding: 20px;
            box-shadow: 0 2px 5px rgba(0,0,0,0.07);
        }
        .active-sales-panel h3 { margin-top: 0; color: #303F9F; }
        .sale-session-item {
            display: flex;
            justify-content: space-between;
            align-items: center;
            padding: 10px 15px;
            background-color: #fff;
            border: 1px solid #E0E0E0;
            border-radius: 6px;
            margin-bottom: 8px;
            cursor: pointer;
            transition: all 0.2s ease;
        }
        .sale-session-item.active {
            background-color: #3F51B5;
            color: white;
            border-color: #3F51B5;
            box-shadow: 0 2px 8px rgba(63, 81, 181, 0.2);
        }
        .sale-session-item:not(.active):hover {
            background-color: #e8eaf6;
            border-color: #3F51B5;
        }
        .sale-session-item button { margin-top: 0; padding: 5px 8px; font-size: 0.75rem; }

        .current-sale-area {
            flex-grow: 1;
            display: flex;
            flex-direction: column;
            gap: 20px;
            width: 100%; /* Full width on mobile */
        }
        .current-sale-area h3 { margin-top: 0; }
        .product-selection-panel, .product-details-for-sale, .sale-items-panel {
            background-color: #e8eaf6;
            border: 1px solid #CFD8DC;
            border-radius: 8px;
            padding: 20px;
            box-shadow: 0 2px 5px rgba(0,0,0,0.07);
        }

        .sale-search-barcode-group { display: flex; gap: 10px; align-items: flex-end; margin-bottom: 15px; }
        .sale-search-barcode-group input { flex-grow: 1; margin-bottom: 0;}
         .sale-search-barcode-group button { margin-top: 0; padding: 10px 12px; line-height: 1; font-size: 0.95rem; }


        #sale-product-search-results {
            border: 1px solid #CFD8DC;
            border-radius: 6px;
            margin-top: 10px;
            max-height: 200px;
            overflow-y: auto;
            background-color: #fff;
            display: none; /* Hidden by default */
        }
        #sale-product-search-results > div {
            padding: 8px 10px;
            border-bottom: 1px solid #eee;
            cursor: pointer;
            display: flex;
            align-items: center;
            gap: 10px;
            transition: background-color 0.2s ease;
        }
        #sale-product-search-results > div:hover { background-color: #e8eaf6; }
        #sale-product-search-results img { width: 50px; height: 50px; object-fit: contain; border-radius: 4px; border: 1px solid #CFD8DC;}

        .all-products-grid {
            display: grid;
            grid-template-columns: repeat(auto-fill, minmax(80px, 1fr)); /* Smaller cards on small screens */
            gap: 15px;
            margin-top: 20px;
            max-height: 600px;
            overflow-y: auto;
            padding-right: 10px;
        }
        .all-products-grid .product-card {
            background: #fff;
            border-radius: 10px;
            padding: 10px;
            box-shadow: 0 2px 5px rgba(0,0,0,0.05);
            transition: transform 0.2s ease, box-shadow 0.2s ease;
            cursor: pointer;
            border: 1px solid #E0E0E0;
            display: flex;
            flex-direction: column;
            align-items: center;
            text-align: center;
        }
        .all-products-grid .product-card:hover {
            transform: translateY(-3px);
            box-shadow: 0 4px 10px rgba(0,0,0,0.1);
        }
        .product-card img {
            width: 80px;
            height: 80px;
            object-fit: contain;
            border-radius: 5px;
            margin-bottom: 8px;
            border: 1px solid #CFD8DC;
        }
        .product-card strong {
            font-size: 0.9em;
            color: #263238;
            margin-bottom: 4px;
            white-space: nowrap;
            overflow: hidden;
            text-overflow: ellipsis;
            width: 100%;
        }
        .product-card .price {
            font-size: 0.8em;
            color: #303F9F;
            font-weight: bold;
        }
        .product-card .stock {
            font-size: 0.75em;
            color: #607D8B;
        }
        .product-card.out-of-stock {
            opacity: 0.6;
            cursor: not-allowed;
        }
        .product-card.out-of-stock .price {
            color: #c53030;
        }


        #selected-sale-product-info {
            display: flex;
            align-items: center;
            gap: 15px;
            padding: 10px;
            background-color: #fff;
            border-radius: 8px;
            border: 1px dashed #CFD8DC;
            margin-bottom: 15px;
        }
        #selected-sale-product-image { width: 70px; height: 70px; object-fit: contain; border-radius: 5px; border: 1px solid #CFD8DC; }
        #selected-sale-product-name { margin: 0; font-weight: bold; font-size: 1.1em; color: #263238; }
        #selected-sale-product-price { margin: 5px 0 0; color: #303F9F; font-weight: bold; }
        #selected-sale-product-stock { margin: 0; font-size: 0.9em; color: #607D8B; }

        #sale-items-list {
            min-height: 100px;
            border: 1px solid #CFD8DC;
            border-radius: 6px;
            padding: 10px;
            background-color: #fff;
        }
        #sale-items-list > p#no-sale-items-message { text-align: center; color: #607D8B; padding: 10px; }

        .sale-item-row {
            display: flex;
            justify-content: space-between;
            align-items: center;
            padding: 8px 0;
            border-bottom: 1px dashed #CFD8DC;
            flex-wrap: wrap; /* Allow wrapping on small screens */
            gap: 5px; /* Adjust gap for wrapped items */
        }
        .sale-item-row:last-child { border-bottom: none; }

        .sale-item-detail-group {
            display: flex;
            align-items: center;
            gap: 10px;
            flex-grow: 1;
            min-width: 200px; /* Ensure enough space for text and input */
        }
        .sale-item-thumbnail {
            width: 50px;
            height: 50px;
            object-fit: contain;
            border-radius: 4px;
            border: 1px solid #CFD8DC;
            flex-shrink: 0;
        }
        .sale-item-text-info {
            display: flex;
            flex-direction: column;
            justify-content: center;
            flex-grow: 1;
        }
        .sale-item-text-info strong {
            font-size: 0.95rem;
            color: #263238;
            white-space: nowrap;
            overflow: hidden;
            text-overflow: ellipsis;
        }
        .sale-item-qty-input {
            width: 80px;
            padding: 4px 8px;
            border: 1px solid #CFD8DC;
            border-radius: 4px;
            font-size: 0.85rem;
            box-sizing: border-box;
            margin-top: 5px;
        }
        .sale-item-total {
            font-weight: bold;
            text-align: right;
            font-size: 0.95rem;
            color: #303F9F;
            flex-shrink: 0;
            width: 100px;
        }
        .remove-sale-item-btn {
            background-color: #f56565;
            padding: 6px 10px;
            font-size: 0.8rem;
            margin: 0;
            line-height: 1;
            flex-shrink: 0;
        }

        /* Barcode Scanner Modal (Same as Admin) */
        #scannerModal {
            display: none;
            position: fixed;
            z-index: 1003; /* Higher than other modals */
            left: 0;
            top: 0;
            width: 100%;
            height: 100%;
            background-color: rgba(0,0,0,0.8);
            backdrop-filter: blur(8px);
            overflow: auto;
            justify-content: center;
            align-items: center;
            flex-direction: column;
            color: white;
        }
        #scannerModal .modal-content {
             background: none; /* No background for scanner */
             box-shadow: none;
             margin: auto; /* Center content */
             max-width: 90%;
             width: 500px; /* Max width for video feed */
             padding: 0;
             position: relative;
             display: flex;
             flex-direction: column;
             align-items: center;
        }
        #scannerModal .close {
             position: absolute;
             top: 15px;
             right: 15px;
             z-index: 1004;
             color: rgba(255,255,255,0.8);
             font-size: 2rem;
        }
         #scannerModal .close:hover { color: white; }

        #interactive.viewport {
             position: relative;
             width: 100%;
             height: 300px; /* Adjust height as needed */
             text-align: center;
             overflow: hidden;
             border-radius: 10px;
             background-color: #333;
             display: flex;
             justify-content: center;
             align-items: center;
        }
         #interactive video {
             max-width: 100%;
             max-height: 100%;
             object-fit: cover; /* Cover the container */
             display: block;
         }
         #interactive .scan-line {
             position: absolute;
             top: 50%;
             left: 0;
             width: 100%;
             height: 2px;
             background: red;
             animation: scan-line 2s linear infinite;
         }


        @media (min-width: 768px) {
            .sale-management-container {
                flex-direction: row; /* Side-by-side on larger screens */
            }
            .active-sales-panel {
                width: 250px; /* Fixed width for sidebar */
            }
            .current-sale-area {
                flex-grow: 1; /* Takes remaining space */
            }
            .all-products-grid {
                grid-template-columns: repeat(auto-fill, minmax(120px, 1fr)); /* Original size on larger screens */
            }
            .sale-item-row {
                flex-wrap: nowrap; /* Prevent wrapping on larger screens */
                gap: 15px; /* Restore original gap */
            }
        }
        @media (min-width: 480px) and (max-width: 767px) {
            .all-products-grid {
                grid-template-columns: repeat(auto-fill, minmax(100px, 1fr)); /* Adjust for medium screens */
            }
        }
    </style>
</head>
<body>
    <div class="container">
        <div class="header">
            <div class="logo-title-container" style="display: flex; align-items: center; gap: 15px;">
                <img src="https://cdn-avatars.huggingface.co/v1/production/uploads/67c280ccb9d3dfdee58ecfdd/p2TVtSc6UQr0De1jDYBLk.jpeg" alt="Aikas_optom Logo" style="height: 40px; width: auto; border-radius: 4px;">
                <h1><i class="fas fa-cash-register"></i> Касса Aikas_optom</h1>
            </div>
            <a href="{{ url_for('catalog') }}" class="button" style="background-color: #3F51B5;"><i class="fas fa-store"></i> Каталог</a>
        </div>

        {% with messages = get_flashed_messages(with_categories=true) %}
            {% if messages %}
                {% for category, message in messages %}
                    <div class="message {{ category }}">{{ message }}</div>
                {% endfor %}
            {% endif %}
        {% endwith %}

        <div class="sale-management-container">
            <div class="active-sales-panel">
                <h3>Активные кассы</h3>
                <div id="sale-sessions-list">
                </div>
                <button class="button add-new-cash-button" onclick="createNewSaleSession()">+ Новая касса</button>
            </div>

            <div class="current-sale-area">
                <h3>Текущая продажа (<span id="current-sale-session-name">Нет активной кассы</span>)</h3>

                <div class="product-selection-panel">
                    <h3>Поиск и выбор товара</h3>
                    <div class="sale-search-barcode-group">
                        <input type="text" id="sale_product_search_input" placeholder="Название, описание или штрихкод...">
                         <button type="button" class="button" onclick="scanBarcodeForSale()"><i class="fas fa-barcode"></i></button>
                    </div>

                    <div id="sale-product-search-results" style="display: none;"></div>

                    <div class="all-products-grid" id="all-products-for-sale">
                        {% for product in all_products %}
                        <div class="product-card {% if product.get('stock', 0) <= 0 %}out-of-stock{% endif %}"
                             data-product-id="{{ product['id'] }}"
                             data-product-name="{{ product['name']|lower }}"
                             data-product-description="{{ product.get('description', '')|lower }}"
                             data-product-barcode="{{ product.get('barcode', '')|lower }}"
                             onclick="selectProductForSale('{{ product['id'] }}')"
                             >
                            <img src="https://huggingface.co/datasets/{{ repo_id }}/resolve/main/photos/{{ product['photos'][0] }}" alt="{{ product['name'] }}" loading="lazy">
                            <strong>{{ product['name'] }}</strong>
                            <span class="price">{{ "%.2f"|format(product['price']) }} {{ currency_code }}</span>
                            <span class="stock">Остаток: {{ product.get('stock', 0) }} шт.</span>
                        </div>
                        {% endfor %}
                    </div>
                </div>

                <div class="product-details-for-sale">
                    <h3>Добавить в чек</h3>
                    <div id="selected-sale-product-info" style="display: none;">
                        <img id="selected-sale-product-image" src="" alt="Изображение товара">
                        <div>
                            <p id="selected-sale-product-name"></p>
                            <p id="selected-sale-product-price"></p>
                            <p id="selected-sale-product-stock"></p>
                        </div>
                    </div>

                    <label for="sale_quantity_input">Количество:</label>
                    <input type="number" id="sale_quantity_input" min="1" value="1" disabled>

                    <label for="sale_color_select">Цвет/Вариант:</label>
                    <select id="sale_color_select" disabled></select>

                    <button type="button" class="button add-button" onclick="addSaleItemToCurrentSession()" id="add-to-sale-button" disabled><i class="fas fa-cart-plus"></i> Добавить в чек</button>
                </div>

                <div class="sale-items-panel">
                    <h3>Товары в текущей продаже:</h3>
                    <div id="sale-items-list">
                        <p id="no-sale-items-message">Список пуст.</p>
                    </div>

                    <p style="text-align: right; font-size: 1.2rem; font-weight: bold; margin-top: 15px;">
                        Итоговая сумма: <span id="current-sale-total">0.00</span> {{ currency_code }}
                    </p>

                    <label for="customer_name">Имя покупателя (необязательно):</label>
                    <input type="text" id="customer_name" placeholder="Например: Иван">
                    <label for="customer_contact">Контакт покупателя (телефон/WhatsApp, необязательно):</label>
                    <input type="tel" id="customer_contact" placeholder="Например: +996777123456">

                    <button type="button" class="button add-button" style="margin-top: 20px;" id="confirm-sale-button" disabled onclick="finalizeCurrentSale()">
                        <i class="fas fa-check-circle"></i> Зарегистрировать продажу
                    </button>
                    <button type="button" class="button delete-button" style="margin-top: 10px;" id="clear-current-sale-button" disabled onclick="clearCurrentSaleSession()">
                        <i class="fas fa-trash"></i> Очистить текущий чек
                    </button>
                </div>
            </div>
        </div>

        <!-- Barcode Scanner Modal -->
        <div id="scannerModal" class="modal">
            <div class="modal-content">
                <span class="close" onclick="closeScannerModal()" aria-label="Закрыть сканер">×</span>
                <h2>Сканирование штрихкода</h2>
                <div id="interactive" class="viewport">
                    <video></video>
                     <div class="scan-line"></div>
                </div>
                <p id="scanner-message">Наведите камеру на штрихкод...</p>
            </div>
        </div>


    <script>
        const allProducts = {{ all_products|tojson }};
        const repoId = '{{ repo_id }}';
        const currencyCode = '{{ currency_code }}';
        let currentSaleSessionId = null;
        let selectedProductForSale = null; // Holds the full product object from allProducts

        const saleProductSearchInput = document.getElementById('sale_product_search_input');
        const saleProductSearchResults = document.getElementById('sale-product-search-results');
        const allProductsForSaleGrid = document.getElementById('all-products-for-sale');
        const selectedSaleProductInfoDiv = document.getElementById('selected-sale-product-info');
        const selectedSaleProductName = document.getElementById('selected-sale-product-name');
        const selectedSaleProductPrice = document.getElementById('selected-sale-product-price');
        const selectedSaleProductStock = document.getElementById('selected-sale-product-stock');
        const selectedSaleProductImage = document.getElementById('selected-sale-product-image');
        const saleQuantityInput = document.getElementById('sale_quantity_input');
        const saleColorSelect = document.getElementById('sale_color_select');
        const addToSaleButton = document.getElementById('add-to-sale-button');
        const customerNameInput = document.getElementById('customer_name');
        const customerContactInput = document.getElementById('customer_contact');
        const confirmSaleButton = document.getElementById('confirm-sale-button');
        const clearCurrentSaleButton = document.getElementById('clear-current-sale-button');

        let codeReader = null;


        function renderAllProductsForSale(productsToRender) {
            allProductsForSaleGrid.innerHTML = '';
            if (productsToRender.length === 0) {
                allProductsForSaleGrid.innerHTML = '<p style="grid-column: 1 / -1; text-align: center; color: #607D8B;">Товары не найдены.</p>';
                return;
            }
            productsToRender.forEach(product => {
                const photoUrl = product.photos && product.photos.length > 0 && product.photos[0] !== 'placeholder.png'
                    ? `https://huggingface.co/datasets/${repoId}/resolve/main/photos/${product.photos[0]}`
                    : `https://via.placeholder.com/80x80.png?text=No+Image`;

                const productCard = document.createElement('div');
                productCard.className = `product-card ${product.stock <= 0 ? 'out-of-stock' : ''}`;
                productCard.dataset.productId = product.id;
                productCard.dataset.productName = product.name.toLowerCase();
                productCard.dataset.productDescription = product.description ? product.description.toLowerCase() : '';
                productCard.dataset.productBarcode = product.barcode ? product.barcode.toLowerCase() : '';

                // Prevent click on out-of-stock items
                if (product.stock > 0) {
                     productCard.onclick = () => selectProductForSale(product.id);
                } else {
                     productCard.style.cursor = 'not-allowed';
                }


                productCard.innerHTML = `
                    <img src="${photoUrl}" alt="${product.name}" loading="lazy">
                    <strong>${product.name}</strong>
                    <span class="price">${product.price.toFixed(2)} ${currencyCode}</span>
                    <span class="stock">Остаток: ${product.stock} шт.</span>
                `;
                allProductsForSaleGrid.appendChild(productCard);
            });
        }

        function filterProductsForSaleGrid() {
            const searchTerm = saleProductSearchInput.value.toLowerCase().trim();
            const filteredProducts = allProducts.filter(p => {
                 const name = p.name.toLowerCase();
                 const description = p.description ? p.description.toLowerCase() : '';
                 const barcode = p.barcode ? p.barcode.toLowerCase() : '';
                 return name.includes(searchTerm) || description.includes(searchTerm) || barcode.includes(searchTerm);
            });
            renderAllProductsForSale(filteredProducts);
        }


        // Barcode Scanner Functions
        async function scanBarcodeForSale() {
            const scannerModal = document.getElementById('scannerModal');
            const videoElement = scannerModal.querySelector('video');
            const scannerMessage = document.getElementById('scanner-message');

            if (!scannerModal || !videoElement || !scannerMessage) {
                console.error("Scanner modal elements not found.");
                alert("Ошибка: Не удалось инициализировать сканер.");
                return;
            }

            scannerMessage.textContent = 'Запуск камеры...';
            scannerModal.style.display = 'flex';
            document.body.style.overflow = 'hidden'; // Prevent scrolling

            try {
                codeReader = new ZXing.BrowserMultiFormatReader();
                 // Prefer rear camera
                const devices = await codeReader.listVideoInputDevices();
                const rearCamera = devices.find(device => device.label.toLowerCase().includes('rear')) || devices[0];

                if (!rearCamera) {
                    scannerMessage.textContent = 'Камера не найдена.';
                    alert("Ошибка: Камера не найдена.");
                    return;
                }


                codeReader.decodeFromVideoDevice(rearCamera.deviceId, videoElement, (result, err) => {
                    if (result) {
                        console.log('Scanned barcode:', result.text);
                        const scannedBarcode = result.text;
                        scannerMessage.textContent = 'Штрихкод отсканирован: ' + scannedBarcode;
                        closeScannerModal();
                        // Now, find the product by this barcode
                        findProductByBarcode(scannedBarcode);

                    }
                    if (err && !(err instanceof ZXing.NotFoundException)) {
                        // Log error but keep trying if it's not just "not found"
                        console.error(err);
                        scannerMessage.textContent = 'Ошибка сканирования: ' + err.message;
                    }
                });
                 scannerMessage.textContent = 'Наведите камеру на штрихкод...';

            } catch (error) {
                console.error('Error accessing camera:', error);
                scannerMessage.textContent = 'Не удалось запустить камеру: ' + error.message;
                alert("Ошибка доступа к камере.");
                // Optionally auto-close modal if camera fails
                // setTimeout(closeScannerModal, 3000);
            }
        }

        function closeScannerModal() {
            const scannerModal = document.getElementById('scannerModal');
            if (codeReader) {
                codeReader.reset();
                codeReader = null;
            }
            if (scannerModal) {
                scannerModal.style.display = 'none';
                 const anyModalOpen = document.querySelector('.modal[style*="display: block"]');
                 if (!anyModalOpen) {
                    document.body.style.overflow = 'auto';
                 }
            }
        }

        async function findProductByBarcode(barcode) {
             if (!barcode) return;

             // Simulate API call to find product by barcode (or do it client-side for this example)
             // In a real app, you'd fetch('/api/find_product_by_barcode/' + barcode)
             const product = allProducts.find(p => p.barcode === barcode);

             if (product) {
                  if (product.stock <= 0) {
                       alert(`Товар "${product.name}" со штрихкодом ${barcode} отсутствует на складе.`);
                       // Clear selected product UI
                       selectedProductForSale = null;
                       selectedSaleProductInfoDiv.style.display = 'none';
                       saleQuantityInput.disabled = true;
                       saleColorSelect.disabled = true;
                       addToSaleButton.disabled = true;
                       return;
                  }
                  selectProductForSale(product.id); // Select the found product
             } else {
                  alert(`Товар со штрихкодом "${barcode}" не найден.`);
                  // Clear selected product UI
                  selectedProductForSale = null;
                  selectedSaleProductInfoDiv.style.display = 'none';
                  saleQuantityInput.disabled = true;
                  saleColorSelect.disabled = true;
                  addToSaleButton.disabled = true;
             }
        }


        function selectProductForSale(productId) {
            const product = allProducts.find(p => p.id === productId);
            if (!product) {
                alert("Ошибка: товар не найден.");
                return;
            }
             if (product.stock <= 0) {
                alert(`Товар "${product.name}" отсутствует на складе.`);
                // Clear any previously selected product info display
                selectedProductForSale = null;
                selectedSaleProductInfoDiv.style.display = 'none';
                saleQuantityInput.disabled = true;
                saleColorSelect.disabled = true;
                addToSaleButton.disabled = true;
                return;
            }


            selectedProductForSale = product;
            selectedSaleProductName.textContent = product.name;
            selectedSaleProductPrice.textContent = `${product.price.toFixed(2)} ${currencyCode}`;
            selectedSaleProductStock.textContent = `Остаток: ${product.stock} шт.`;
            selectedSaleProductImage.src = product.photos && product.photos.length > 0 && product.photos[0] !== 'placeholder.png'
                ? `https://huggingface.co/datasets/${repoId}/resolve/main/photos/${product.photos[0]}`
                : `https://via.placeholder.com/70x70.png?text=N/A`;
            selectedSaleProductInfoDiv.style.display = 'flex';

            saleQuantityInput.value = 1;
            saleQuantityInput.max = product.stock; // Set max to product stock
            saleQuantityInput.disabled = false;
            saleQuantityInput.oninput = () => {
                let val = parseInt(saleQuantityInput.value);
                if (isNaN(val) || val < 1) val = 1;

                 // Check quantity against available stock *in the current session*
                let currentQtyInSession = openSaleSessionsData && openSaleSessionsData[currentSaleSessionId]
                     ? openSaleSessionsData[currentSaleSessionId].cart_items.reduce((sum, item) => {
                        // Sum quantity for this product and selected color
                         if (item.product_id === selectedProductForSale.id && item.color === saleColorSelect.value) {
                            return sum + item.quantity;
                         }
                         return sum;
                    }, 0) : 0;

                // Calculate remaining stock considering other sessions
                 let totalReservedInOtherSessions = 0;
                 if(openSaleSessionsData){
                     for(const sessionId in openSaleSessionsData){
                         if(sessionId !== currentSaleSessionId){
                              totalReservedInOtherSessions += openSaleSessionsData[sessionId].cart_items.reduce((sum, item) => {
                                  if (item.product_id === selectedProductForSale.id && item.color === saleColorSelect.value) {
                                      return sum + item.quantity;
                                  }
                                  return sum;
                              }, 0);
                         }
                     }
                 }

                 const effectiveStock = selectedProductForSale.stock - totalReservedInOtherSessions;

                if (effectiveStock < currentQtyInSession + val) {
                     val = effectiveStock - currentQtyInSession;
                     if (val < 0) val = 0; // Should not happen if checks are correct, but safety
                     saleQuantityInput.value = val;
                     alert(`Недостаточно товара "${selectedProductForSale.name}" (цвет: ${saleColorSelect.value}). Доступно на складе: ${selectedProductForSale.stock} шт. (Из них ${totalReservedInOtherSessions} шт. зарезервированы в других кассах. Уже в этой кассе: ${currentQtyInSession}). Вы можете добавить не более ${val} шт.`);
                } else {
                     saleQuantityInput.value = val;
                }
            };

            const colors = product.colors ? product.colors.filter(c => c && c.trim() !== "") : [];
            saleColorSelect.innerHTML = '';
            if (colors.length > 0) {
                colors.forEach(color => {
                    const option = document.createElement('option');
                    option.value = color.trim();
                    option.text = color.trim();
                    saleColorSelect.appendChild(option);
                });
                saleColorSelect.style.display = 'block';
                document.querySelector('label[for="sale_color_select"]').style.display = 'block';
            } else {
                const option = document.createElement('option');
                option.value = 'N/A';
                option.text = 'N/A';
                saleColorSelect.appendChild(option);
                saleColorSelect.style.display = 'none';
                document.querySelector('label[for="sale_color_select"]').style.display = 'none';
            }
            saleColorSelect.disabled = false;
            addToSaleButton.disabled = false;
            // Clear search input and grid after selection? Or just filter grid?
            // saleProductSearchInput.value = product.name; // Optional: put name back in search
            // filterProductsForSaleGrid(); // Optional: re-filter grid
        }

        async function addSaleItemToCurrentSession() {
            if (!currentSaleSessionId) {
                alert("Пожалуйста, выберите активную кассу или создайте новую.");
                return;
            }
            if (!selectedProductForSale) {
                alert("Пожалуйста, выберите товар для добавления в чек.");
                return;
            }

            const productId = selectedProductForSale.id;
            const quantity = parseInt(saleQuantityInput.value);
            const color = saleColorSelect.value;

            if (isNaN(quantity) || quantity <= 0) {
                alert("Пожалуйста, укажите корректное количество (больше 0).");
                saleQuantityInput.focus();
                return;
            }

            try {
                const response = await fetch('/sale/add_item', {
                    method: 'POST',
                    headers: { 'Content-Type': 'application/json' },
                    body: JSON.stringify({
                        session_id: currentSaleSessionId,
                        product_id: productId,
                        quantity: quantity,
                        color: color
                    })
                });
                const result = await response.json();
                if (response.ok) {
                    openSaleSessionsData = result.active_sessions_data; // Update local session data
                    renderCurrentSaleItems(result.current_sale_cart);
                    updateSaleButtons();
                    selectedProductForSale = null; // Deselect after adding
                    selectedSaleProductInfoDiv.style.display = 'none';
                    saleQuantityInput.disabled = true;
                    saleColorSelect.disabled = true;
                    addToSaleButton.disabled = true;
                    saleProductSearchInput.value = ''; // Clear search input
                    filterProductsForSaleGrid(); // Refresh product grid based on current stock/availability
                    showNotification(`Товар добавлен в кассу ${currentSaleSessionId.substring(0, 8)}.`);
                } else {
                    alert(result.error || "Ошибка при добавлении товара.");
                    // If stock error, update max quantity based on error response?
                    if (result.max_quantity !== undefined) {
                         saleQuantityInput.max = result.max_quantity;
                         saleQuantityInput.value = result.max_quantity; // Set to max available
                         saleQuantityInput.focus();
                    }
                }
            } catch (error) {
                console.error('Ошибка:', error);
                alert("Произошла ошибка при добавлении товара.");
            }
        }

        async function removeSaleItemFromCurrentSession(tempId) {
            if (!currentSaleSessionId) return;

            try {
                const response = await fetch('/sale/remove_item', {
                    method: 'POST',
                    headers: { 'Content-Type': 'application/json' },
                    body: JSON.stringify({
                        session_id: currentSaleSessionId,
                        temp_id: tempId
                    })
                });
                const result = await response.json();
                if (response.ok) {
                    openSaleSessionsData = result.active_sessions_data; // Update local session data
                    renderCurrentSaleItems(result.current_sale_cart);
                    updateSaleButtons();
                    filterProductsForSaleGrid(); // Refresh product grid
                    showNotification("Товар удален из чека.");
                } else {
                    alert(result.error || "Ошибка при удалении товара.");
                }
            } catch (error) {
                console.error('Ошибка:', error);
                alert("Произошла ошибка при удалении товара.");
            }
        }

        async function updateSaleItemQuantity(inputElement) {
            const tempId = inputElement.dataset.tempId;
            const newQuantity = parseInt(inputElement.value);
            const originalQuantity = inputElement.defaultValue ? parseInt(inputElement.defaultValue) : parseInt(inputElement.getAttribute('value')); // Get initial value

            if (isNaN(newQuantity) || newQuantity < 1) {
                alert("Количество должно быть не менее 1.");
                inputElement.value = originalQuantity;
                return;
            }

             // Optimistically update the input value attribute so subsequent changes work correctly
             inputElement.setAttribute('value', newQuantity);


            try {
                const response = await fetch('/sale/update_item_quantity', {
                    method: 'POST',
                    headers: { 'Content-Type': 'application/json' },
                    body: JSON.stringify({
                        session_id: currentSaleSessionId,
                        temp_id: tempId,
                        new_quantity: newQuantity
                    })
                });
                const result = await response.json();
                if (response.ok) {
                     // Update the actual rendered list if needed, but the input itself is already updated visually
                    // renderCurrentSaleItems(result.current_sale_cart); // Only necessary if server calculates total prices differently
                    updateSaleButtons();
                    filterProductsForSaleGrid(); // Refresh product grid
                    showNotification("Количество обновлено.");

                     // Update the displayed total for the item if needed (can be done client-side)
                     const itemRow = inputElement.closest('.sale-item-row');
                     if(itemRow){
                         const item = result.current_sale_cart.find(item => item.temp_id === tempId);
                         if(item){
                              itemRow.querySelector('.sale-item-total').textContent = `${(item.price * item.quantity).toFixed(2)} ${currencyCode}`;
                         }
                     }
                     // Update the overall total (must fetch or calculate)
                     updateCurrentSaleTotalDisplay(result.current_sale_cart);

                } else {
                    alert(result.error || "Ошибка при обновлении количества.");
                    inputElement.value = originalQuantity; // Revert input value on error
                     inputElement.setAttribute('value', originalQuantity); // Revert attribute too
                    if (result.max_quantity !== undefined) {
                         // Optionally update max based on server response if stock was the issue
                         inputElement.max = result.max_quantity;
                         alert(`Недостаточно товара. Макс. доступно: ${result.max_quantity}.`);
                    }
                }
            } catch (error) {
                console.error('Ошибка:', error);
                alert("Произошла ошибка при обновлении количества.");
                inputElement.value = originalQuantity; // Revert input value on error
                 inputElement.setAttribute('value', originalQuantity); // Revert attribute too
            }
        }

         function updateCurrentSaleTotalDisplay(cartItems) {
             const currentSaleTotalElement = document.getElementById('current-sale-total');
             let total = cartItems.reduce((sum, item) => sum + (item.price * item.quantity), 0);
             currentSaleTotalElement.textContent = total.toFixed(2);
         }


        function enforceMinMax(inputElement, maxStock) {
            let value = parseInt(inputElement.value);
            const min = parseInt(inputElement.min);

            if (isNaN(value) || value < min) {
                inputElement.value = min;
            } else if (value > maxStock) {
                inputElement.value = maxStock;
                alert(`Максимальное количество для этого товара: ${maxStock} шт.`);
            }
        }


        async function createNewSaleSession() {
            try {
                const response = await fetch('/sale/new_session', { method: 'POST' });
                const result = await response.json();
                if (response.ok) {
                    await loadSaleSession(result.session_id); // Load the new session
                    showNotification(`Новая касса (ID: ${result.session_id.substring(0, 8)}) создана.`);
                } else {
                    alert(result.error || "Не удалось создать новую кассу.");
                }
            } catch (error) {
                console.error('Ошибка:', error);
                alert("Произошла ошибка при создании новой кассы.");
            }
        }

        let openSaleSessionsData = {}; // Cache session data locally

        async function loadSaleSession(sessionId) {
            try {
                const response = await fetch(`/sale/load_session/${sessionId}`);
                const result = await response.json();
                if (response.ok) {
                    currentSaleSessionId = sessionId;
                    document.getElementById('current-sale-session-name').textContent = `Касса ${sessionId.substring(0, 8)}`;
                    customerNameInput.value = result.customer_name || '';
                    customerContactInput.value = result.customer_contact || '';
                    renderCurrentSaleItems(result.current_sale_cart);
                    openSaleSessionsData = result.active_sessions_data; // Cache loaded sessions data
                    renderSaleSessionsList(Object.values(openSaleSessionsData)); // Render list from cached data
                    updateSaleButtons();
                    // Reset product selection area
                    selectedProductForSale = null;
                    selectedSaleProductInfoDiv.style.display = 'none';
                    saleQuantityInput.disabled = true;
                    saleColorSelect.disabled = true;
                    addToSaleButton.disabled = true;
                    saleProductSearchInput.value = '';
                    filterProductsForSaleGrid(); // Refresh product grid
                } else {
                    alert(result.error || "Не удалось загрузить кассу.");
                     // If loading failed for the current ID, clear it
                    if (currentSaleSessionId === sessionId) {
                        currentSaleSessionId = null;
                        document.getElementById('current-sale-session-name').textContent = 'Нет активной кассы';
                        renderCurrentSaleItems([]);
                        customerNameInput.value = '';
                        customerContactInput.value = '';
                        updateSaleButtons();
                        filterProductsForSaleGrid();
                    }
                }
            } catch (error) {
                console.error('Ошибка:', error);
                alert("Произошла ошибка при загрузке кассы.");
                 if (currentSaleSessionId === sessionId) {
                    currentSaleSessionId = null;
                    document.getElementById('current-sale-session-name').textContent = 'Нет активной кассы';
                    renderCurrentSaleItems([]);
                    customerNameInput.value = '';
                    customerContactInput.value = '';
                    updateSaleButtons();
                    filterProductsForSaleGrid();
                }
            }
        }


        function renderSaleSessionsList(sessions) {
            const listContainer = document.getElementById('sale-sessions-list');
            listContainer.innerHTML = '';
            if (sessions.length === 0) {
                listContainer.innerHTML = '<p style="text-align: center; color: #607D8B;">Активных касс нет.</p>';
                // If no sessions, ensure no session is selected
                if (currentSaleSessionId && !sessions.find(s => s.id === currentSaleSessionId)) {
                     currentSaleSessionId = null;
                     document.getElementById('current-sale-session-name').textContent = 'Нет активной кассы';
                     renderCurrentSaleItems([]);
                     customerNameInput.value = '';
                     customerContactInput.value = '';
                     updateSaleButtons();
                     filterProductsForSaleGrid();
                }
                return;
            }
            sessions.sort((a, b) => new Date(b.created_at) - new Date(a.created_at)); // Sort by latest first
            sessions.forEach(session => {
                const sessionDiv = document.createElement('div');
                sessionDiv.className = `sale-session-item ${session.id === currentSaleSessionId ? 'active' : ''}`;
                const totalItems = session.cart_items.reduce((sum, item) => sum + item.quantity, 0);
                sessionDiv.innerHTML = `
                    <span>Касса ${session.id.substring(0, 8)} (${totalItems} т.)</span>
                    <button class="delete-button" onclick="deleteSaleSession('${session.id}', event)">
                        <i class="fas fa-times"></i>
                    </button>
                `;
                sessionDiv.onclick = () => loadSaleSession(session.id);
                listContainer.appendChild(sessionDiv);
            });
        }

        async function deleteSaleSession(sessionId, event) {
            event.stopPropagation(); // Prevent loading the session when clicking delete
            if (!confirm(`Вы уверены, что хотите удалить кассу ${sessionId.substring(0, 8)}? Все товары в ней будут потеряны.`)) {
                return;
            }
            try {
                const response = await fetch('/sale/delete_session', {
                    method: 'POST',
                    headers: { 'Content-Type': 'application/json' },
                    body: JSON.stringify({ session_id: sessionId })
                });
                const result = await response.json();
                if (response.ok) {
                     openSaleSessionsData = result.active_sessions_data; // Update local session data
                    if (sessionId === currentSaleSessionId) {
                        currentSaleSessionId = null;
                        document.getElementById('current-sale-session-name').textContent = 'Нет активной кассы';
                        renderCurrentSaleItems([]); // Clear current items display
                        customerNameInput.value = '';
                        customerContactInput.value = '';
                        showNotification(`Касса ${sessionId.substring(0, 8)} удалена.`);
                    }
                    renderSaleSessionsList(Object.values(openSaleSessionsData)); // Render updated list
                    updateSaleButtons();
                    filterProductsForSaleGrid(); // Refresh product grid
                } else {
                    alert(result.error || "Не удалось удалить кассу.");
                }
            } catch (error) {
                console.error('Ошибка:', error);
                alert("Произошла ошибка при удалении кассы.");
            }
        }

        async function clearCurrentSaleSession() {
            if (!currentSaleSessionId) return;
            if (!confirm(`Вы уверены, что хотите очистить текущий чек Кассы ${currentSaleSessionId.substring(0, 8)}?`)) {
                return;
            }
            try {
                const response = await fetch('/sale/clear_session', {
                    method: 'POST',
                    headers: { 'Content-Type': 'application/json' },
                    body: JSON.stringify({ session_id: currentSaleSessionId })
                });
                const result = await response.json();
                if (response.ok) {
                     openSaleSessionsData = result.active_sessions_data; // Update local session data
                    renderCurrentSaleItems(result.current_sale_cart);
                    renderSaleSessionsList(Object.values(openSaleSessionsData)); // Re-render sessions list (total might change)
                    customerNameInput.value = '';
                    customerContactInput.value = '';
                    updateSaleButtons();
                    filterProductsForSaleGrid(); // Refresh product grid (stock availability might change)
                    showNotification(`Текущий чек Кассы ${currentSaleSessionId.substring(0, 8)} очищен.`);
                } else {
                    alert(result.error || "Не удалось очистить кассу.");
                }
            } catch (error) {
                console.error('Ошибка:', error);
                alert("Произошла ошибка при очистке кассы.");
            }
        }

        async function finalizeCurrentSale() {
            if (!currentSaleSessionId) {
                alert("Нет активной кассы для регистрации продажи.");
                return;
            }
             const currentSaleData = openSaleSessionsData[currentSaleSessionId];
             if (!currentSaleData || currentSaleData.cart_items.length === 0) {
                  alert("Чек пуст. Невозможно зарегистрировать продажу.");
                  return;
             }

            const customerName = customerNameInput.value.trim();
            const customerContact = customerContactInput.value.trim();

            const confirmButton = document.getElementById('confirm-sale-button');
            if (confirmButton) confirmButton.disabled = true;

            showNotification("Регистрация продажи...", 5000);

            try {
                const response = await fetch('/sale/finalize_sale', {
                    method: 'POST',
                    headers: { 'Content-Type': 'application/json' },
                    body: JSON.stringify({
                        session_id: currentSaleSessionId,
                        customer_name: customerName,
                        customer_contact: customerContact
                    })
                });
                const result = await response.json();
                if (response.ok) {
                    alert(`Продажа №${result.order_id} успешно зарегистрирована!`);

                    // Clean up the session locally
                    delete openSaleSessionsData[currentSaleSessionId];
                    currentSaleSessionId = null;
                    document.getElementById('current-sale-session-name').textContent = 'Нет активной кассы';
                    customerNameInput.value = '';
                    customerContactInput.value = '';
                    renderCurrentSaleItems([]); // Clear current items display
                    renderSaleSessionsList(Object.values(openSaleSessionsData)); // Re-render sessions list

                    updateSaleButtons();
                    filterProductsForSaleGrid(); // Refresh product grid (stock updated)

                } else {
                    alert(result.error || "Не удалось зарегистрировать продажу.");
                }
            } catch (error) {
                console.error('Ошибка:', error);
                alert("Произошла ошибка при регистрации продажи.");
            } finally {
                if (confirmButton) confirmButton.disabled = false;
            }
        }

        function updateSaleButtons() {
             // Check if there is an active session and if it has items
            const currentSaleData = currentSaleSessionId && openSaleSessionsData[currentSaleSessionId]
                ? openSaleSessionsData[currentSaleSessionId]
                : null;

            const hasItems = currentSaleData && currentSaleData.cart_items.length > 0;

            confirmSaleButton.disabled = !hasItems;
            clearCurrentSaleButton.disabled = !hasItems;

            // Add/Color/Quantity buttons depend on selectedProductForSale AND active session
             const isProductSelected = selectedProductForSale !== null;
             addToSaleButton.disabled = !isProductSelected || !currentSaleSessionId;
             saleQuantityInput.disabled = !isProductSelected || !currentSaleSessionId;
             saleColorSelect.disabled = !isProductSelected || !currentSaleSessionId;

        }

        function showNotification(message, duration = 3000) {
            let placeholder = document.getElementById('notification-placeholder');
            // Use the Admin template's notification logic or duplicate if needed
            // For now, duplicating for simplicity in SALE_TEMPLATE
            if (!placeholder) {
                const newPlaceholder = document.createElement('div');
                newPlaceholder.id = 'notification-placeholder';
                newPlaceholder.style.position = 'fixed';
                newPlaceholder.style.bottom = '25px'; /* Adjust position if needed for Sale page */
                newPlaceholder.style.left = '50%';
                newPlaceholder.style.transform = 'translateX(-50%)';
                newPlaceholder.style.zIndex = '1002';
                document.body.appendChild(newPlaceholder);
                placeholder = newPlaceholder;
             }

            // Remove any existing notifications before adding a new one
            placeholder.innerHTML = '';

            const notification = document.createElement('div');
            notification.className = 'notification'; // Use existing .notification style
            notification.textContent = message;
            placeholder.appendChild(notification);

            // Trigger reflow to ensure transition runs
            void notification.offsetWidth;

            notification.classList.add('show');

            setTimeout(() => {
                notification.classList.remove('show');
                notification.addEventListener('transitionend', () => notification.remove());
            }, duration);
         }


        document.addEventListener('DOMContentLoaded', () => {
            saleProductSearchInput.addEventListener('input', filterProductsForSaleGrid);
            renderAllProductsForSale(allProducts);

            // Initialize scanner modal close listener
            const scannerModal = document.getElementById('scannerModal');
            if (scannerModal) {
                scannerModal.addEventListener('click', function(event) {
                    if (event.target === scannerModal) {
                        closeScannerModal();
                    }
                });
                 // Add keydown listener for Escape specifically for the scanner modal
                 window.addEventListener('keydown', function(event) {
                    if (event.key === 'Escape' && scannerModal && scannerModal.style.display === 'flex') {
                        closeScannerModal();
                    }
                 });
            }


            // Load active sessions on page load
            fetch('/sale/active_sessions')
                .then(response => response.json())
                .then(data => {
                    openSaleSessionsData = data.active_sessions_data; // Cache received data structure
                    renderSaleSessionsList(Object.values(openSaleSessionsData));
                    // Attempt to load the first session if any exist
                    const sessionIds = Object.keys(openSaleSessionsData);
                    if (sessionIds.length > 0) {
                        // Find the latest session by created_at timestamp to load
                        const latestSessionId = sessionIds.sort((a, b) =>
                            new Date(openSaleSessionsData[b].created_at) - new Date(openSaleSessionsData[a].created_at)
                        )[0];
                        loadSaleSession(latestSessionId);
                    } else {
                        updateSaleButtons(); // Ensure buttons are disabled if no sessions
                    }
                })
                .catch(error => {
                    console.error('Ошибка загрузки активных сессий:', error);
                    alert("Не удалось загрузить список активных касс.");
                     updateSaleButtons(); // Ensure buttons are disabled on error
                });
        });
    </script>
</body>
</html>
'''


@app.route('/')
def catalog():
    data = load_data()
    all_products = data.get('products', [])
    categories = sorted(data.get('categories', []))

    # Filter and sort products for display in catalog
    products_in_stock = [p for p in all_products if p.get('stock', 0) > 0]
    # Sort by 'is_top' (True comes first) then by name
    products_sorted = sorted(products_in_stock, key=lambda p: (not p.get('is_top', False), p.get('name', '').lower()))

    return render_template_string(
        CATALOG_TEMPLATE,
        products=products_sorted,
        categories=categories,
        repo_id=REPO_ID,
        store_address=STORE_ADDRESS,
        currency_code=CURRENCY_CODE
    )

@app.route('/product/<product_id>')
def product_detail(product_id):
    data = load_data()
    all_products = data.get('products', [])

    # Only show details for products that exist and are in stock
    product = next((p for p in all_products if p.get('id') == product_id and p.get('stock', 0) > 0), None)

    if not product:
        # Render a simple error page or message
        return render_template_string(
            '''
            <!DOCTYPE html>
            <html lang="ru">
            <head>
                <meta charset="UTF-8">
                <meta name="viewport" content="width=device-width, initial-scale=1.0">
                <title>Товар не найден</title>
                <link href="https://fonts.googleapis.com/css2?family=Poppins:wght@300;400;600&display=swap" rel="stylesheet">
                 <style>
                    body { font-family: 'Poppins', sans-serif; background: #F5F5F5; color: #263238; line-height: 1.6; padding: 40px; text-align: center;}
                    .container { max-width: 600px; margin: 20px auto; padding: 30px; background: #fff; border-radius: 15px; box-shadow: 0 4px 15px rgba(0, 0, 0, 0.1); border: 1px solid #CFD8DC; }
                    h1 { color: #c53030; margin-bottom: 20px; }
                    p { font-size: 1.1rem; color: #607D8B; }
                     a { display: inline-block; margin-top: 20px; color: #303F9F; text-decoration: none; font-weight: 500;}
                     a:hover { text-decoration: underline;}
                 </style>
            </head>
            <body>
                <div class="container">
                    <h1>Товар не найден</h1>
                    <p>Возможно, товар был удален, распродан или временно недоступен.</p>
                    <a href="{{ url_for('catalog') }}">Вернуться в каталог</a>
                </div>
            </body>
            </html>
            '''
            , url_for=url_for), 404

    # Ensure photos list exists and has at least one placeholder if empty
    if not product.get('photos') or len(product['photos']) == 0:
        product['photos'] = ['placeholder.png'] # Use a dummy filename for template

    return render_template_string(
        PRODUCT_DETAIL_TEMPLATE,
        product=product,
        repo_id=REPO_ID,
        currency_code=CURRENCY_CODE
    )

@app.route('/create_order', methods=['POST'])
def create_order():
    """Creates an order from the shopping cart."""
    order_data = request.get_json()

    if not order_data or 'cart' not in order_data or not order_data['cart']:
        return jsonify({"error": "Корзина пуста или не передана."}), 400

    cart_items_raw = order_data['cart']
    data = load_data()
    all_products_map = {p['id']: p for p in data.get('products', [])}

    total_price = 0
    processed_cart = []
    products_to_update_stock = {} # Dict to track stock changes

    for item_raw in cart_items_raw:
        required_keys = ['product_id', 'name', 'price', 'quantity', 'color'] # Include color
        if not all(k in item_raw for k in required_keys):
            logging.error(f"Invalid item format in cart: {item_raw}")
            return jsonify({"error": "Неверный формат товара в корзине. Пожалуйста, обновите страницу."}), 400

        product_id = item_raw['product_id']
        quantity = int(item_raw['quantity'])
        price = float(item_raw['price'])
        color = item_raw.get('color', 'N/A') # Get color, default to N/A

        if quantity <= 0:
            return jsonify({"error": f"Неверное количество ({quantity}) для товара '{item_raw['name']}'."}), 400

        product_in_db = all_products_map.get(product_id)
        if not product_in_db:
            logging.error(f"Product ID {product_id} from cart not found in DB.")
            return jsonify({"error": f"Товар '{item_raw['name']}' не найден в базе данных. Возможно, он был удален. Пожалуйста, обновите страницу."}), 400

        current_stock = product_in_db.get('stock', 0)
        if current_stock < quantity:
            logging.warning(f"Stock insufficient for product {product_id} ('{item_raw['name']}'). Requested {quantity}, Available {current_stock}.")
            # Restore stock in products_to_update_stock if it was decremented by a previous item in the same order (unlikely with unique IDs, but safe)
            products_to_update_stock.pop(product_id, None)
            return jsonify({"error": f"Недостаточно товара '{item_raw['name']}' на складе. Доступно: {current_stock} шт."}), 400

        # Decrement stock for this product *in the pending updates*
        # This handles multiple items of the same product in the same order correctly
        products_to_update_stock[product_id] = products_to_update_stock.get(product_id, current_stock) - quantity


        total_price += price * quantity

        photo_filename = product_in_db.get('photos')
        selected_photo = photo_filename[0] if photo_filename and len(photo_filename) > 0 else 'placeholder.png'

        processed_cart.append({
            "product_id": product_id,
            "name": item_raw['name'],
            "price": price,
            "quantity": quantity,
            "color": color, # Store color
            "photo": selected_photo,
            "photo_url": f"https://huggingface.co/datasets/{REPO_ID}/resolve/main/photos/{selected_photo}" if selected_photo != 'placeholder.png' else "https://via.placeholder.com/60x60.png?text=N/A"
        })

    order_id = f"{datetime.now().strftime('%Y%m%d%H%M%S')}-{uuid.uuid4().hex[:6]}"
    order_timestamp = datetime.now().strftime('%Y-%m-%d %H:%M:%S')

    new_order = {
        "id": order_id,
        "created_at": order_timestamp,
        "cart": processed_cart,
        "total_price": round(total_price, 2),
        "user_info": "Website Anonymous Order", # Indicate origin
        "status": "new", # Default status for website orders
        "customer_name": None, # Customer info not collected on catalog page
        "customer_contact": None # Customer info not collected on catalog page
    }

    try:
        # Apply the stock updates to the actual data object
        for prod_in_list in data['products']:
            if prod_in_list['id'] in products_to_update_stock:
                prod_in_list['stock'] = products_to_update_stock[prod_in_list['id']]
                prod_in_list['in_stock'] = prod_in_list['stock'] > 0 # Update in_stock status

        if 'orders' not in data or not isinstance(data.get('orders'), dict):
            data['orders'] = {}
        data['orders'][order_id] = new_order

        save_data(data)
        logging.info(f"Order {order_id} created and saved successfully.")
        return jsonify({"order_id": order_id}), 201

    except Exception as e:
        logging.error(f"Failed to save order {order_id} or update stock: {e}", exc_info=True)
        # Attempt to revert stock changes in memory if save fails
        # Note: This doesn't revert changes if the process crashes *after* updating 'data' but *before* save_data finishes
        # A more robust system would use transactions or a proper database.
        try:
            current_data_after_failure = load_data() # Reload to potentially revert if save failed half-way
            # Find the original product stocks before the failed order processing
            original_products_map = {p['id']: p for p in load_data().get('products', [])} # This loads the state *before* the failed attempt
            for prod_in_list in data['products']: # Iterate through the data object *before* the failed save
                 original_product = original_products_map.get(prod_in_list['id'])
                 if original_product:
                      prod_in_list['stock'] = original_product.get('stock', 0)
                      prod_in_list['in_stock'] = prod_in_list['stock'] > 0
            # Remove the failed order from the data object before returning error
            data['orders'].pop(order_id, None)
            # Optionally, try saving the reverted state, but be careful not to loop on save errors
            # save_data(data) # <-- Might cause infinite loop if save_data is the problem

        except Exception as revert_e:
             logging.error(f"Failed to attempt stock and order revert after primary save failure: {revert_e}", exc_info=True)

        return jsonify({"error": "Ошибка сервера при сохранении заказа. Пожалуйста, попробуйте позже."}), 500

@app.route('/order/<order_id>')
def view_order(order_id):
    """Displays a specific order details page."""
    data = load_data()
    order = data.get('orders', {}).get(order_id)

    # Ensure photo_url is present for template (backward compatibility or if missing)
    if order and 'cart' in order:
        for item in order['cart']:
             if 'photo_url' not in item:
                 photo_filename = item.get('photo', 'placeholder.png')
                 item['photo_url'] = f"https://huggingface.co/datasets/{REPO_ID}/resolve/main/photos/{photo_filename}" if photo_filename != 'placeholder.png' else "https://via.placeholder.com/60x60.png?text=N/A"


    return render_template_string(ORDER_TEMPLATE,
                                  order=order,
                                  repo_id=REPO_ID,
                                  currency_code=CURRENCY_CODE)

@app.route('/admin', methods=['GET', 'POST'])
def admin():
    """Admin panel for managing products, categories, and orders."""
    data = load_data()
    products = data.get('products', [])
    categories = data.get('categories', [])
    orders = data.get('orders', {})

    if request.method == 'POST':
        action = request.form.get('action')
        redirect_url = url_for('admin') # Default redirect

        try:
            if action == 'add_category':
                category_name = request.form.get('category_name', '').strip()
                if category_name and category_name not in categories:
                    categories.append(category_name)
                    data['categories'] = categories
                    save_data(data)
                    flash(f"Категория '{category_name}' успешно добавлена.", 'success')
                elif not category_name:
                    flash("Название категории не может быть пустым.", 'error')
                else:
                    flash(f"Категория '{category_name}' уже существует.", 'error')

            elif action == 'delete_category':
                category_to_delete = request.form.get('category_name')
                if category_to_delete and category_to_delete in categories:
                    categories.remove(category_to_delete)
                    updated_count = 0
                    for product in products:
                        if product.get('category') == category_to_delete:
                            product['category'] = 'Без категории'
                            updated_count += 1
                    data['categories'] = categories
                    data['products'] = products # Update products reference in data
                    save_data(data)
                    flash(f"Категория '{category_to_delete}' удалена. {updated_count} товаров обновлено.", 'success')
                else:
                    flash(f"Не удалось удалить категорию '{category_to_delete}'.", 'error')

            elif action == 'add_product':
                name = request.form.get('name', '').strip()
                price_str = request.form.get('price', '').replace(',', '.')
                initial_stock_str = request.form.get('stock', '0')
                description = request.form.get('description', '').strip()
                category = request.form.get('category')
                barcode = request.form.get('barcode', '').strip()
                photos_files = request.files.getlist('photos')
                colors = [c.strip() for c in request.form.getlist('colors') if c.strip()]
                is_top = 'is_top' in request.form

                if not name or not price_str:
                    flash("Название и цена товара обязательны.", 'error')
                    return redirect(redirect_url)

                try:
                    price = round(float(price_str), 2)
                    if price < 0: price = 0
                except ValueError:
                    flash("Неверный формат цены.", 'error')
                    return redirect(redirect_url)

                try:
                    initial_stock = int(initial_stock_str)
                    if initial_stock < 0: initial_stock = 0
                except ValueError:
                    flash("Неверный формат начального остатка.", 'error')
                    return redirect(redirect_url)

                # Check for duplicate barcode if provided
                if barcode:
                    if any(p.get('barcode') == barcode for p in products):
                        flash(f"Штрихкод '{barcode}' уже присвоен другому товару.", 'warning') # Use warning

                photos_list = []
                if photos_files and any(f.filename for f in photos_files):
                    if HF_TOKEN_WRITE:
                        uploads_dir = 'uploads_temp'
                        os.makedirs(uploads_dir, exist_ok=True)
                        api = HfApi()
                        photo_limit = 10
                        uploaded_count = 0
                        for photo in photos_files:
                            if uploaded_count >= photo_limit:
                                flash(f"Загружено только первые {photo_limit} фото.", "warning")
                                break
                            if photo and photo.filename:
                                try:
                                    ext = os.path.splitext(photo.filename)[1].lower()
                                    if ext not in ['.jpg', '.jpeg', '.png', '.gif', '.webp']:
                                        flash(f"Файл {photo.filename} не является изображением и был пропущен.", "warning")
                                        continue

                                    safe_name = secure_filename(name.replace(' ', '_'))[:50]
                                    photo_filename = f"{safe_name}_{datetime.now().strftime('%Y%m%d%H%M%S%f')}{ext}"
                                    temp_path = os.path.join(uploads_dir, photo_filename)
                                    photo.save(temp_path)
                                    api.upload_file(
                                        path_or_fileobj=temp_path,
                                        path_in_repo=f"photos/{photo_filename}",
                                        repo_id=REPO_ID,
                                        repo_type="dataset",
                                        token=HF_TOKEN_WRITE,
                                        commit_message=f"Add photo for product {name}"
                                    )
                                    photos_list.append(photo_filename)
                                    os.remove(temp_path)
                                    uploaded_count += 1
                                except Exception as e:
                                    flash(f"Ошибка при загрузке фото {photo.filename}.", 'error')
                                    logging.error(f"HF upload error for {photo.filename}: {e}", exc_info=True)
                                    if os.path.exists(temp_path):
                                        try: os.remove(temp_path)
                                        except OSError: pass
                            elif photo and not photo.filename: # Handle empty file input case
                                 pass
                        try:
                             # Clean up temp directory if empty
                             if os.path.exists(uploads_dir) and not os.listdir(uploads_dir):
                                 os.rmdir(uploads_dir)
                        except OSError as e:
                            logging.warning(f"Could not remove temporary upload directory {uploads_dir}: {e}")
                    else:
                        flash("HF_TOKEN (write) не настроен. Фотографии не были загружены.", "warning")
                # Add placeholder if no photos uploaded/uploaded failed
                if not photos_list:
                    photos_list = ['placeholder.png']


                new_product = {
                    'id': uuid.uuid4().hex,
                    'name': name, 'price': price, 'description': description,
                    'category': category if category in categories else 'Без категории',
                    'photos': photos_list, 'colors': colors,
                    'stock': initial_stock,
                    'in_stock': initial_stock > 0,
                    'is_top': is_top,
                    'barcode': barcode # Save barcode
                }
                products.append(new_product)
                data['products'] = products # Update products reference
                save_data(data)
                flash(f"Товар '{name}' успешно добавлен.", 'success')

            elif action == 'edit_product':
                product_id = request.form.get('product_id')
                if not product_id:
                     flash("Ошибка редактирования: ID товара не передан.", 'error')
                     return redirect(redirect_url)

                product_to_edit = next((p for p in products if p['id'] == product_id), None)
                if not product_to_edit:
                    flash(f"Ошибка редактирования: товар с ID '{product_id}' не найден.", 'error')
                    return redirect(redirect_url)

                original_name = product_to_edit.get('name', 'N/A')
                original_barcode = product_to_edit.get('barcode', '')

                # Update fields if present in form
                product_to_edit['name'] = request.form.get('name', product_to_edit.get('name', '')).strip()
                price_str = request.form.get('price', str(product_to_edit.get('price', 0))).replace(',', '.')
                stock_str = request.form.get('stock', str(product_to_edit.get('stock', 0)))
                product_to_edit['description'] = request.form.get('description', product_to_edit.get('description', '')).strip()
                category = request.form.get('category')
                product_to_edit['category'] = category if category in categories else 'Без категории'
                product_to_edit['colors'] = [c.strip() for c in request.form.getlist('colors') if c.strip()]
                product_to_edit['is_top'] = 'is_top' in request.form
                new_barcode = request.form.get('barcode', '').strip()
                product_to_edit['barcode'] = new_barcode # Update barcode


                try:
                    stock = int(stock_str)
                    if stock < 0: stock = 0
                    product_to_edit['stock'] = stock
                    product_to_edit['in_stock'] = stock > 0 # Update in_stock status
                except ValueError:
                    flash(f"Неверный формат остатка для товара '{original_name}'. Остаток не изменен.", 'warning')

                try:
                    price = round(float(price_str), 2)
                    if price < 0: price = 0
                    product_to_edit['price'] = price
                except ValueError:
                    flash(f"Неверный формат цены для товара '{original_name}'. Цена не изменена.", 'warning')

                # Check for duplicate barcode *after* updating the product's barcode, but before saving
                if new_barcode and new_barcode != original_barcode:
                     if any(p.get('barcode') == new_barcode and p['id'] != product_id for p in products):
                         flash(f"Штрихкод '{new_barcode}' уже присвоен другому товару.", 'warning') # Use warning


                photos_files = request.files.getlist('photos')
                if photos_files and any(f.filename for f in photos_files):
                    if HF_TOKEN_WRITE:
                        uploads_dir = 'uploads_temp'
                        os.makedirs(uploads_dir, exist_ok=True)
                        api = HfApi()
                        new_photos_list = []
                        photo_limit = 10
                        uploaded_count = 0

                        old_photos = product_to_edit.get('photos', [])
                        # Attempt to delete old photos first
                        if old_photos and old_photos != ['placeholder.png']:
                            try:
                                logging.info(f"Attempting to delete old photos for {product_to_edit.get('name', 'Unknown')}: {old_photos}")
                                api.delete_files(
                                    repo_id=REPO_ID,
                                    paths_in_repo=[f"photos/{p}" for p in old_photos if p and p != 'placeholder.png'],
                                    repo_type="dataset",
                                    token=HF_TOKEN_WRITE,
                                    commit_message=f"Delete old photos for product {product_to_edit['name']}"
                                )
                                logging.info("Old photos deleted successfully.")
                            except Exception as e:
                                logging.error(f"Error deleting old photos {old_photos} from HF: {e}", exc_info=True)
                                flash("Не удалось удалить старые фотографии с сервера. Новые фото будут загружены.", "warning")
                                # Keep old photos in the list if deletion failed? Decide policy.
                                # For simplicity, we'll replace the list regardless, relying on HF's deduplication
                                # and hoping manual cleanup can happen later if needed.

                        # Upload new photos
                        for photo in photos_files:
                            if uploaded_count >= photo_limit:
                                flash(f"Загружено только первые {photo_limit} фото.", "warning")
                                break
                            if photo and photo.filename:
                                try:
                                    ext = os.path.splitext(photo.filename)[1].lower()
                                    if ext not in ['.jpg', '.jpeg', '.png', '.gif', '.webp']:
                                        flash(f"Файл {photo.filename} не является изображением и был пропущен.", "warning")
                                        continue

                                    safe_name = secure_filename(product_to_edit['name'].replace(' ', '_'))[:50]
                                    # Ensure unique filename using timestamp and UUID part
                                    photo_filename = f"{safe_name}_{datetime.now().strftime('%Y%m%d%H%M%S%f')}_{uuid.uuid4().hex[:4]}{ext}"
                                    temp_path = os.path.join(uploads_dir, photo_filename)
                                    photo.save(temp_path)

                                    api.upload_file(path_or_fileobj=temp_path, path_in_repo=f"photos/{photo_filename}",
                                                    repo_id=REPO_ID, repo_type="dataset", token=HF_TOKEN_WRITE,
                                                    commit_message=f"Update photo for product {product_to_edit['name']}")
                                    new_photos_list.append(photo_filename)
                                    os.remove(temp_path)
                                    uploaded_count += 1
                                except Exception as e:
                                    flash(f"Ошибка при загрузке нового фото {photo.filename}.", 'error')
                                    logging.error(f"HF upload error for {photo.filename}: {e}", exc_info=True)
                                    if os.path.exists(temp_path):
                                        try: os.remove(temp_path)
                                        except OSError: pass
                            elif photo and not photo.filename:
                                 pass # Ignore empty file inputs
                        try:
                             if os.path.exists(uploads_dir) and not os.listdir(uploads_dir):
                                 os.rmdir(uploads_dir)
                        except OSError as e:
                            logging.warning(f"Could not remove temporary upload directory {uploads_dir}: {e}")

                        product_to_edit['photos'] = new_photos_list if new_photos_list else ['placeholder.png'] # Replace with new list or placeholder
                        if new_photos_list:
                           flash("Фотографии товара успешно обновлены.", "success")
                        else:
                           flash("Новые фотографии не были выбраны или загружены. Старые фото удалены.", "warning")

                    else:
                        flash("HF_TOKEN (write) не настроен. Фотографии не были обновлены.", "warning")
                        # Keep existing photos if token is not set, as we can't delete old ones anyway
                        product_to_edit['photos'] = product_to_edit.get('photos', ['placeholder.png'])


                data['products'] = products # Update products reference (important after modification)
                save_data(data)
                flash(f"Товар '{product_to_edit.get('name', original_name)}' успешно обновлен.", 'success')

            elif action == 'delete_product':
                product_id = request.form.get('product_id')
                if not product_id:
                    flash("Ошибка удаления: ID товара не передан.", 'error')
                    return redirect(redirect_url)

                idx_to_delete = next((i for i, p in enumerate(products) if p['id'] == product_id), -1)

                if idx_to_delete == -1:
                    flash(f"Ошибка удаления: товар с ID '{product_id}' не найден.", 'error')
                    return redirect(redirect_url)

                deleted_product = products.pop(idx_to_delete)
                product_name = deleted_product.get('name', 'N/A')

                photos_to_delete = deleted_product.get('photos', [])
                if photos_to_delete and photos_to_delete != ['placeholder.png'] and HF_TOKEN_WRITE:
                    try:
                        logging.info(f"Attempting to delete photos for deleted product {product_name}: {photos_to_delete}")
                        api = HfApi()
                        api.delete_files(
                            repo_id=REPO_ID,
                            paths_in_repo=[f"photos/{p}" for p in photos_to_delete if p and p != 'placeholder.png'],
                            repo_type="dataset",
                            token=HF_TOKEN_WRITE,
                            commit_message=f"Delete photos for deleted product {product_name}"
                        )
                        logging.info("Photos deleted successfully from HF.")
                    except Exception as e:
                         flash(f"Не удалось удалить фото для товара '{product_name}' с сервера. Товар удален локально.", "warning")
                         logging.error(f"HF delete error for {product_name} photos: {e}", exc_info=True)
                elif photos_to_delete and photos_to_delete != ['placeholder.png'] and not HF_TOKEN_WRITE:
                    flash(f"Товар '{product_name}' удален локально, но фото не удалены с сервера (токен не задан).", "warning")


                data['products'] = products # Update products reference
                save_data(data)
                flash(f"Товар '{product_name}' удален.", 'success')

            elif action == 'adjust_stock':
                product_id = request.form.get('product_id')
                quantity_str = request.form.get('quantity')
                adjustment_type = request.form.get('adjustment_type')

                if not product_id or not quantity_str or not adjustment_type:
                    flash("Не все поля заполнены для корректировки остатка.", 'error')
                    return redirect(redirect_url)

                try:
                    quantity_change = int(quantity_str)
                    if quantity_change < 0:
                        raise ValueError("Количество не может быть отрицательным.")
                    if quantity_change == 0:
                        flash("Количество для корректировки должно быть больше 0.", 'warning')
                        return redirect(redirect_url)
                except ValueError:
                    flash("Неверное количество для корректировки остатка.", 'error')
                    return redirect(redirect_url)

                product = next((p for p in products if p['id'] == product_id), None)
                if not product:
                    flash(f"Товар с ID '{product_id}' не найден.", 'error')
                    return redirect(redirect_url)

                old_stock = product.get('stock', 0)
                if adjustment_type == 'add':
                    product['stock'] = old_stock + quantity_change
                    flash(f"Остаток для '{product['name']}' увеличен на {quantity_change}. Новый остаток: {product['stock']}.", 'success')
                elif adjustment_type == 'subtract':
                    if old_stock < quantity_change:
                        flash(f"Нельзя вычесть {quantity_change} со склада '{product['name']}'. Доступно: {old_stock}.", 'error')
                        return redirect(redirect_url)
                    product['stock'] = old_stock - quantity_change
                    flash(f"Остаток для '{product['name']}' уменьшен на {quantity_change}. Новый остаток: {product['stock']}.", 'success')
                else:
                    flash("Неверный тип корректировки остатка.", 'error')
                    return redirect(redirect_url)

                product['in_stock'] = product['stock'] > 0 # Update in_stock status
                save_data(data)
                return redirect(redirect_url)

            else:
                 flash(f"Неизвестное действие: {action}", 'warning')

            return redirect(redirect_url)

        except Exception as e:
             logging.error(f"Error processing admin action '{action}': {e}", exc_info=True)
             flash(f"Произошла внутренняя ошибка при выполнении действия '{action}'. Подробности в логе сервера.", 'error')
             return redirect(redirect_url)

    # GET request logic
    current_data = load_data()
    # Sort products for display
    display_products = sorted(current_data.get('products', []), key=lambda p: p.get('name', '').lower())
    # Sort categories for display
    display_categories = sorted(current_data.get('categories', []))
    orders = current_data.get('orders', {})
    # Sort orders by creation date, latest first
    display_orders = sorted(orders.values(), key=lambda o: o.get('created_at', ''), reverse=True)

    # Calculate statistics
    total_orders = len(orders)
    total_revenue = 0
    product_sales_count = Counter()

    # Include sales from 'completed' and 'new' statuses for total revenue/sales count
    for order_id, order_data in orders.items():
        # Use get() with default to avoid errors if keys are missing
        status = order_data.get('status')
        if status in ['completed', 'new']: # Consider both web orders ('new') and cashier sales ('completed') as revenue
            total_revenue += order_data.get('total_price', 0)
            for item in order_data.get('cart', []):
                # Use product name for stats, might be issues if names change
                product_sales_count[item.get('name', 'Unknown Product')] += item.get('quantity', 0)

    top_selling_products = product_sales_count.most_common(5)

    # Count products based on current stock
    products_in_stock_count = sum(1 for p in products if p.get('stock', 0) > 0)
    products_out_of_stock_count = sum(1 for p in products if p.get('stock', 0) <= 0)
    total_products_count = len(products)

    products_in_stock_percent = (products_in_stock_count / total_products_count * 100) if total_products_count > 0 else 0

    low_stock_threshold = 10
    # Low stock includes items in stock but below threshold
    low_stock_products = sorted([p for p in products if p.get('stock', 0) > 0 and p.get('stock', 0) < low_stock_threshold], key=lambda p: p['stock'])

    stats = {
        'total_orders': total_orders,
        'total_revenue': total_revenue,
        'total_products': total_products_count,
        'products_in_stock': products_in_stock_count,
        'products_out_of_stock': products_out_of_stock_count,
        'products_in_stock_percent': products_in_stock_percent,
        'top_selling_products': top_selling_products,
        'low_stock_products': low_stock_products
    }

    return render_template_string(
        ADMIN_TEMPLATE,
        products=display_products,
        categories=display_categories,
        display_orders=display_orders,
        stats=stats,
        repo_id=REPO_ID,
        currency_code=CURRENCY_CODE
    )

@app.route('/force_upload', methods=['POST'])
def force_upload():
    """Handler for manually triggering data upload to Hugging Face."""
    try:
        upload_db_to_hf()
        flash("Данные успешно загружены на Hugging Face.", 'success')
    except Exception as e:
        logging.error(f"Error during forced upload: {e}", exc_info=True)
        flash(f"Ошибка при загрузке на Hugging Face: {e}", 'error')
    return redirect(url_for('admin'))

@app.route('/force_download', methods=['POST'])
def force_download():
    """Handler for manually triggering data download from Hugging Face."""
    try:
        if download_db_from_hf():
            # Reload data into memory after successful download
            load_data()
            flash("Данные успешно скачаны с Hugging Face. Локальные файлы обновлены.", 'success')
        else:
            flash("Не удалось скачать данные с Hugging Face после нескольких попыток. Проверьте логи.", 'error')
    except Exception as e:
        logging.error(f"Error during forced download: {e}", exc_info=True)
        flash(f"Ошибка при скачивании с Hugging Face: {e}", 'error')
    return redirect(url_for('admin'))

@app.route('/sale')
def sale_register():
    """Cashier register page."""
    data = load_data()
    # Get all products, including out of stock, for display in the cashier interface
    all_products = sorted(data.get('products', []), key=lambda p: p.get('name', '').lower())

    # Ensure each product has a photos list (even if empty, for template consistency)
    for product in all_products:
         if not product.get('photos'):
              product['photos'] = ['placeholder.png'] # Add placeholder if no photos

    return render_template_string(
        SALE_TEMPLATE,
        all_products=all_products,
        repo_id=REPO_ID,
        currency_code=CURRENCY_CODE
    )

@app.route('/sale/new_session', methods=['POST'])
def new_sale_session():
    """Creates a new sale session."""
    session_id = uuid.uuid4().hex
    open_sale_sessions[session_id] = {
        'cart_items': [],
        'customer_name': '',
        'customer_contact': '',
        'created_at': datetime.now().strftime('%Y-%m-%d %H:%M:%S')
    }
    logging.info(f"New sale session created: {session_id}")
    # No flash here, handled by JS notification on the sale page
    return jsonify({"session_id": session_id, "active_sessions": list(open_sale_sessions.keys())}) # Return session list

@app.route('/sale/load_session/<session_id>')
def load_sale_session_api(session_id):
    """Loads details of a specific sale session."""
    sale_session = open_sale_sessions.get(session_id)
    if not sale_session:
        logging.warning(f"Sale session {session_id} not found during load attempt.")
        return jsonify({"error": "Сессия не найдена."}), 404

    # Reload product data from DB to get current stock levels for validation
    all_products_from_db = load_data()['products']
    products_map = {p['id']: p for p in all_products_from_db}

    current_sale_cart_formatted = []
    total_price = 0

    # Add stock info and photo_url to cart items for display/validation
    for item in sale_session['cart_items']:
        product_data = products_map.get(item['product_id'])
        # Skip items if product no longer exists in DB
        if not product_data:
            logging.warning(f"Product ID {item['product_id']} in session {session_id} cart not found in DB.")
            continue

        photo_filename = item.get('photo', 'placeholder.png')

        item_total = item['price'] * item['quantity']
        total_price += item_total
        current_sale_cart_formatted.append({
            "temp_id": item['temp_id'],
            "product_id": item['product_id'],
            "name": item['name'],
            "price": item['price'],
            "quantity": item['quantity'],
            "color": item['color'],
            "photo": photo_filename,
            "photo_url": f"https://huggingface.co/datasets/{REPO_ID}/resolve/main/photos/{photo_filename}" if photo_filename != 'placeholder.png' else "https://via.placeholder.com/60x60.png?text=N/A",
            "max_stock": product_data.get('stock', 0) # Include current stock from DB
        })

    # Prepare active sessions data structure including cart items counts for list display
    active_sessions_data = {}
    for s_id, s_data in open_sale_sessions.items():
         active_sessions_data[s_id] = {
            'id': s_id,
            'item_count': sum(item['quantity'] for item in s_data['cart_items']),
            'total_price': sum(item['price'] * item['quantity'] for item in s_data['cart_items']),
            'created_at': s_data.get('created_at', ''), # Include created_at for sorting
            'cart_items': s_data['cart_items'] # Include items list for local processing
         }


    return jsonify({
        "session_id": session_id,
        "customer_name": sale_session['customer_name'],
        "customer_contact": sale_session['customer_contact'],
        "current_sale_cart": current_sale_cart_formatted,
        "total_price": round(total_price, 2),
        "active_sessions_data": active_sessions_data # Send full session data
    })

@app.route('/sale/active_sessions')
def get_active_sale_sessions():
    """Returns a list of active sale sessions with summary info."""
    active_sessions_data = {}
    for s_id, s_data in open_sale_sessions.items():
        active_sessions_data[s_id] = {
            'id': s_id,
            'item_count': sum(item['quantity'] for item in s_data['cart_items']),
            'total_price': sum(item['price'] * item['quantity'] for item in s_data['cart_items']),
            'created_at': s_data.get('created_at', ''),
            'cart_items': s_data['cart_items'] # Include items list for local processing
        }
    return jsonify({"active_sessions_data": active_sessions_data})

@app.route('/sale/add_item', methods=['POST'])
def add_item_to_sale_session():
    """Adds an item to the current sale session cart."""
    data_req = request.get_json()
    session_id = data_req.get('session_id')
    product_id = data_req.get('product_id')
    quantity = int(data_req.get('quantity', 0))
    color = data_req.get('color', 'N/A')

    if not session_id or session_id not in open_sale_sessions:
        logging.warning(f"Add item failed: Session {session_id} not found.")
        return jsonify({"error": "Активная сессия не найдена."}), 404
    if quantity <= 0:
        return jsonify({"error": "Количество товара должно быть больше 0."}), 400

    all_data = load_data()
    product_in_db = next((p for p in all_data['products'] if p['id'] == product_id), None)
    if not product_in_db:
        logging.warning(f"Add item failed: Product {product_id} not found in DB.")
        return jsonify({"error": "Товар не найден в базе данных."}), 404

    sale_session = open_sale_sessions[session_id]

    # Calculate how much of this product (and color) is already in the current session
    current_qty_in_this_session = 0
    existing_item_in_session_index = -1
    for i, item in enumerate(sale_session['cart_items']):
        if item['product_id'] == product_id and item['color'] == color:
            current_qty_in_this_session = item['quantity']
            existing_item_in_session_index = i
            break

    proposed_new_qty_in_session = current_qty_in_this_session + quantity

    # Calculate total quantity of this product (and color) reserved across *all* open sessions
    total_reserved_across_sessions = 0
    for s_id, s_data in open_sale_sessions.items():
        for item_in_session in s_data['cart_items']:
            if item_in_session['product_id'] == product_id and item_in_session['color'] == color:
                 # If it's the item we are trying to update in the current session, use the proposed new qty
                 if s_id == session_id and item_in_session.get('temp_id') == sale_session['cart_items'][existing_item_in_session_index].get('temp_id') if existing_item_in_session_index != -1 else False:
                      total_reserved_across_sessions += proposed_new_qty_in_session
                 # Otherwise, use the quantity already in that session's item
                 elif not (s_id == session_id and existing_item_in_session_index != -1): # Don't double count the item being updated in the current session
                     total_reserved_across_sessions += item_in_session['quantity']
                 elif s_id != session_id:
                     total_reserved_across_sessions += item_in_session['quantity']

    # Refined stock check: Stock in DB must be >= total quantity across all open sessions *plus* the new quantity being added to *this* session.
    # Simpler check: The total quantity of THIS product/color in ALL open sessions *after* adding the new quantity must not exceed the stock.
    # The current total in the current session is `current_qty_in_this_session`. We are adding `quantity`. The new total in this session will be `proposed_new_qty_in_session`.
    # The total reserved in other sessions is `total_reserved_across_sessions` (calculated *without* the quantity in the current session's item).
    # So, the *total* across ALL sessions *if this addition succeeds* is `total_reserved_across_sessions + proposed_new_qty_in_session`.
    # Let's recalculate `total_reserved_across_sessions` to mean quantity in *other* sessions + quantity of *other items* in this session.
    total_reserved_excluding_this_specific_item = 0
    for s_id, s_data in open_sale_sessions.items():
        for item_in_session in s_data['cart_items']:
            if item_in_session['product_id'] == product_id and item_in_session['color'] == color:
                 # Exclude the quantity of the item we are potentially merging into in the current session
                 if s_id == session_id and existing_item_in_session_index != -1 and item_in_session.get('temp_id') == sale_session['cart_items'][existing_item_in_session_index].get('temp_id'):
                      continue
                 total_reserved_excluding_this_specific_item += item_in_session['quantity']

    effective_stock_available_for_this_addition = product_in_db['stock'] - total_reserved_excluding_this_specific_item;

    if effective_stock_available_for_this_addition < quantity:
        logging.warning(f"Stock insufficient for product {product_id} ('{product_in_db['name']}'/{color}) across sessions. Stock {product_in_db['stock']}, Reserved elsewhere {total_reserved_excluding_this_specific_item}, Attempted add {quantity}.")
        available_to_add = effective_stock_available_for_this_addition # Can be negative if over-reserved
        return jsonify({
            "error": f"Недостаточно товара '{product_in_db['name']}' (цвет: {color}) на складе. Доступно: {product_in_db['stock']} шт. (Из них {total_reserved_excluding_this_specific_item} шт. зарезервированы в других кассах/позициях этого чека). Вы можете добавить не более {max(0, available_to_add)} шт.",
            "max_quantity": max(0, available_to_add) # Return how many *can* be added
            }), 400


    photo_filename = product_in_db.get('photos')
    selected_photo = photo_filename[0] if photo_filename and len(photo_filename) > 0 else 'placeholder.png'

    if existing_item_in_session_index != -1:
        sale_session['cart_items'][existing_item_in_session_index]['quantity'] = proposed_new_qty_in_session
        logging.info(f"Updated item {existing_item_in_session_index} quantity in session {session_id} to {proposed_new_qty_in_session}")
    else:
        new_item_temp_id = uuid.uuid4().hex
        sale_session['cart_items'].append({
            "temp_id": new_item_temp_id, # Temporary ID for session management
            "product_id": product_id,
            "name": product_in_db['name'],
            "price": product_in_db['price'],
            "quantity": quantity,
            "color": color,
            "photo": selected_photo # Store just filename
        })
        logging.info(f"Added new item {new_item_temp_id} to session {session_id}")

    # Recalculate totals and format cart for response
    current_sale_cart_formatted = []
    total_price = 0
    # Reload product data from DB again to ensure stock info in response is fresh (paranoia)
    all_products_from_db_fresh = load_data()['products']
    products_map_fresh = {p['id']: p for p in all_products_from_db_fresh}

    for item in sale_session['cart_items']:
         product_data_fresh = products_map_fresh.get(item['product_id'])
         if not product_data_fresh: continue # Should not happen if checks above passed

         item_total = item['price'] * item['quantity']
         total_price += item_total
         current_sale_cart_formatted.append({
             "temp_id": item['temp_id'],
             "product_id": item['product_id'],
             "name": item['name'],
             "price": item['price'],
             "quantity": item['quantity'],
             "color": item['color'],
             "photo": item['photo'], # Use filename stored in session
             "photo_url": f"https://huggingface.co/datasets/{REPO_ID}/resolve/main/photos/{item['photo']}" if item['photo'] != 'placeholder.png' else "https://via.placeholder.com/60x60.png?text=No+Image",
             "max_stock": product_data_fresh.get('stock', 0) # Include current stock from DB
         })

    active_sessions_data = {}
    for s_id, s_data in open_sale_sessions.items():
         active_sessions_data[s_id] = {
            'id': s_id,
            'item_count': sum(item['quantity'] for item in s_data['cart_items']),
            'total_price': sum(item['price'] * item['quantity'] for item in s_data['cart_items']),
            'created_at': s_data.get('created_at', ''),
            'cart_items': s_data['cart_items'] # Include items list
         }


    return jsonify({
        "current_sale_cart": current_sale_cart_formatted,
        "total_price": round(total_price, 2),
        "active_sessions_data": active_sessions_data # Send full session data
    })

@app.route('/sale/remove_item', methods=['POST'])
def remove_item_from_sale_session():
    """Removes an item from the current sale session cart using its temporary ID."""
    data_req = request.get_json()
    session_id = data_req.get('session_id')
    temp_id = data_req.get('temp_id')

    if not session_id or session_id not in open_sale_sessions:
        logging.warning(f"Remove item failed: Session {session_id} not found.")
        return jsonify({"error": "Активная сессия не найдена."}), 404

    sale_session = open_sale_sessions[session_id]
    original_item_count = len(sale_session['cart_items'])
    sale_session['cart_items'] = [item for item in sale_session['cart_items'] if item['temp_id'] != temp_id]

    if len(sale_session['cart_items']) == original_item_count:
        logging.warning(f"Remove item failed: Item {temp_id} not found in session {session_id}.")
        return jsonify({"error": "Товар не найден в текущем чеке."}), 404

    logging.info(f"Removed item {temp_id} from session {session_id}")

    # Recalculate totals and format cart for response
    current_sale_cart_formatted = []
    total_price = 0
    all_products_from_db = load_data()['products']
    products_map = {p['id']: p for p in all_products_from_db}


    for item in sale_session['cart_items']:
        product_data = products_map.get(item['product_id'])
        if not product_data: continue # Should not happen

        item_total = item['price'] * item['quantity']
        total_price += item_total
        current_sale_cart_formatted.append({
             "temp_id": item['temp_id'],
             "product_id": item['product_id'],
             "name": item['name'],
             "price": item['price'],
             "quantity": item['quantity'],
             "color": item['color'],
             "photo": item['photo'], # Use filename stored in session
             "photo_url": f"https://huggingface.co/datasets/{REPO_ID}/resolve/main/photos/{item['photo']}" if item['photo'] != 'placeholder.png' else "https://via.placeholder.com/60x60.png?text=N/A",
             "max_stock": product_data.get('stock', 0) # Include current stock from DB
         })

    active_sessions_data = {}
    for s_id, s_data in open_sale_sessions.items():
         active_sessions_data[s_id] = {
            'id': s_id,
            'item_count': sum(item['quantity'] for item in s_data['cart_items']),
            'total_price': sum(item['price'] * item['quantity'] for item in s_data['cart_items']),
            'created_at': s_data.get('created_at', ''),
             'cart_items': s_data['cart_items'] # Include items list
         }


    return jsonify({
        "current_sale_cart": current_sale_cart_formatted,
        "total_price": round(total_price, 2),
        "active_sessions_data": active_sessions_data # Send full session data
    })

@app.route('/sale/update_item_quantity', methods=['POST'])
def update_item_quantity_in_sale():
    """Updates the quantity of an item in the current sale session cart."""
    data_req = request.get_json()
    session_id = data_req.get('session_id')
    temp_id = data_req.get('temp_id')
    new_quantity = int(data_req.get('new_quantity', 0))

    if not session_id or session_id not in open_sale_sessions:
        logging.warning(f"Update quantity failed: Session {session_id} not found.")
        return jsonify({"error": "Активная сессия не найдена."}), 404
    if new_quantity <= 0:
        return jsonify({"error": "Количество товара должно быть больше 0."}), 400

    sale_session = open_sale_sessions[session_id]

    item_to_update = None
    item_index = -1
    for i, item in enumerate(sale_session['cart_items']):
        if item['temp_id'] == temp_id:
            item_to_update = item
            item_index = i
            break

    if not item_to_update:
        logging.warning(f"Update quantity failed: Item {temp_id} not found in session {session_id}.")
        return jsonify({"error": "Товар не найден в текущем чеке."}), 404

    all_data = load_data()
    product_in_db = next((p for p in all_data['products'] if p['id'] == item_to_update['product_id']), None)
    if not product_in_db:
        logging.error(f"Update quantity failed: Product {item_to_update['product_id']} from session cart not found in DB.")
        return jsonify({"error": "Товар не найден в базе данных."}), 400

    current_product_id = item_to_update['product_id']
    current_color = item_to_update['color']

    # Calculate total quantity of this product (and color) reserved across *all* open sessions,
    # EXCLUDING the *old* quantity of the specific item we are updating.
    total_reserved_excluding_this_specific_item_old_qty = 0
    for s_id, s_data in open_sale_sessions.items():
        for item_in_session in s_data['cart_items']:
            if item_in_session['product_id'] == current_product_id and item_in_session['color'] == current_color:
                 if s_id == session_id and item_in_session['temp_id'] == temp_id:
                      continue # Exclude the item being updated
                 total_reserved_excluding_this_specific_item_old_qty += item_in_session['quantity']


    # The new total reserved across all sessions will be `total_reserved_excluding_this_specific_item_old_qty + new_quantity`
    new_total_reserved_across_sessions = total_reserved_excluding_this_specific_item_old_qty + new_quantity

    if product_in_db['stock'] < new_total_reserved_across_sessions:
        logging.warning(f"Update quantity failed: Stock insufficient for product {current_product_id} ('{product_in_db['name']}'/{current_color}) across sessions. Stock {product_in_db['stock']}, Reserved elsewhere/other items {total_reserved_excluding_this_specific_item_old_qty}, Attempted new total {new_total_reserved_across_sessions}.")
        available_qty = product_in_db['stock'] - total_reserved_excluding_this_specific_item_old_qty
        return jsonify({
            "error": f"Недостаточно товара '{product_in_db['name']}' (цвет: {current_color}) на складе. Доступно: {product_in_db['stock']} шт. (Из них {total_reserved_excluding_this_specific_item_old_qty} шт. зарезервированы в других кассах/позициях этого чека). Вы можете установить количество не более {max(0, available_qty)} шт.",
             "max_quantity": max(0, available_qty) # Return how many *can* be set
             }), 400

    # If validation passes, update the quantity
    sale_session['cart_items'][item_index]['quantity'] = new_quantity
    logging.info(f"Updated item {temp_id} quantity in session {session_id} to {new_quantity}")

    # Recalculate totals and format cart for response
    current_sale_cart_formatted = []
    total_price = 0
     # Reload product data from DB again to ensure stock info in response is fresh (paranoia)
    all_products_from_db_fresh = load_data()['products']
    products_map_fresh = {p['id']: p for p in all_products_from_db_fresh}

    for item in sale_session['cart_items']:
         product_data_fresh = products_map_fresh.get(item['product_id'])
         if not product_data_fresh: continue # Should not happen

         item_total = item['price'] * item['quantity']
         total_price += item_total
         current_sale_cart_formatted.append({
             "temp_id": item['temp_id'],
             "product_id": item['product_id'],
             "name": item['name'],
             "price": item['price'],
             "quantity": item['quantity'],
             "color": item['color'],
             "photo": item['photo'], # Use filename stored in session
             "photo_url": f"https://huggingface.co/datasets/{REPO_ID}/resolve/main/photos/{item['photo']}" if item['photo'] != 'placeholder.png' else "https://via.placeholder.com/60x60.png?text=N/A",
             "max_stock": product_data_fresh.get('stock', 0) # Include current stock from DB
         })

    active_sessions_data = {}
    for s_id, s_data in open_sale_sessions.items():
         active_sessions_data[s_id] = {
            'id': s_id,
            'item_count': sum(item['quantity'] for item in s_data['cart_items']),
            'total_price': sum(item['price'] * item['quantity'] for item in s_data['cart_items']),
            'created_at': s_data.get('created_at', ''),
             'cart_items': s_data['cart_items'] # Include items list
         }


    return jsonify({
        "current_sale_cart": current_sale_cart_formatted,
        "total_price": round(total_price, 2),
        "active_sessions_data": active_sessions_data # Send full session data
        })

@app.route('/sale/clear_session', methods=['POST'])
def clear_sale_session():
    """Clears all items from a specific sale session cart."""
    data_req = request.get_json()
    session_id = data_req.get('session_id')

    if not session_id or session_id not in open_sale_sessions:
        logging.warning(f"Clear session failed: Session {session_id} not found.")
        return jsonify({"error": "Активная сессия не найдена."}), 404

    open_sale_sessions[session_id]['cart_items'] = []
    open_sale_sessions[session_id]['customer_name'] = '' # Clear customer info too
    open_sale_sessions[session_id]['customer_contact'] = ''

    logging.info(f"Session {session_id} cart cleared.")

    active_sessions_data = {}
    for s_id, s_data in open_sale_sessions.items():
         active_sessions_data[s_id] = {
            'id': s_id,
            'item_count': sum(item['quantity'] for item in s_data['cart_items']),
            'total_price': sum(item['price'] * item['quantity'] for item in s_data['cart_items']),
            'created_at': s_data.get('created_at', ''),
             'cart_items': s_data['cart_items'] # Include items list
         }

    return jsonify({
        "current_sale_cart": [], # Return empty cart for the cleared session
        "total_price": 0.0,
        "active_sessions_data": active_sessions_data # Send updated session list
        })

@app.route('/sale/delete_session', methods=['POST'])
def delete_sale_session_api():
    """Deletes a specific sale session."""
    data_req = request.get_json()
    session_id = data_req.get('session_id')

    if not session_id or session_id not in open_sale_sessions:
        logging.warning(f"Delete session failed: Session {session_id} not found.")
        return jsonify({"error": "Сессия не найдена."}), 404

    del open_sale_sessions[session_id]
    logging.info(f"Session {session_id} deleted.")

    active_sessions_data = {}
    for s_id, s_data in open_sale_sessions.items():
         active_sessions_data[s_id] = {
            'id': s_id,
            'item_count': sum(item['quantity'] for item in s_data['cart_items']),
            'total_price': sum(item['price'] * item['quantity'] for item in s_data['cart_items']),
            'created_at': s_data.get('created_at', ''),
             'cart_items': s_data['cart_items'] # Include items list
         }

    return jsonify({"active_sessions_data": active_sessions_data}) # Send updated session list

@app.route('/sale/finalize_sale', methods=['POST'])
def finalize_sale():
    """Registers a sale as a completed order."""
    data_req = request.get_json()
    session_id = data_req.get('session_id')
    customer_name = data_req.get('customer_name', '').strip()
    customer_contact = data_req.get('customer_contact', '').strip()

    if not session_id or session_id not in open_sale_sessions:
        logging.warning(f"Finalize sale failed: Session {session_id} not found.")
        return jsonify({"error": "Активная сессия не найдена."}), 404

    sale_session = open_sale_sessions[session_id]
    if not sale_session['cart_items']:
        return jsonify({"error": "Чек пуст. Невозможно зарегистрировать продажу."}), 400

    db_data = load_data()
    products_map = {p['id']: p for p in db_data.get('products', [])}

    total_price = 0
    processed_sale_cart = []
    products_to_update_stock = {} # Dict to track stock changes {product_id: new_stock_level}

    # --- Stock Validation and Calculation ---
    # Recalculate the *total* quantity of each product/color combination across *all* sessions
    # This ensures we don't over-sell if the same item is in multiple open carts
    product_color_reserved_qty = Counter()
    for s_id, s_data in open_sale_sessions.items():
        for item_in_session in s_data['cart_items']:
            # Use a tuple (product_id, color) as the key for the counter
            key = (item_in_session['product_id'], item_in_session['color'])
            product_color_reserved_qty[key] += item_in_session['quantity']

    # Now, for the *current* sale session, validate against total reserved quantity
    for item in sale_session['cart_items']:
        product_id = item['product_id']
        quantity = int(item['quantity']) # Quantity in THIS item in THIS session
        color = item['color']

        product_in_db = products_map.get(product_id)
        if not product_in_db:
            logging.error(f"Finalize sale failed: Product {product_id} from session cart not found in DB.")
            return jsonify({"error": f"Товар '{item['name']}' не найден в базе данных."}), 400

        db_stock = product_in_db.get('stock', 0)
        reserved_total = product_color_reserved_qty[(product_id, color)] # Total reserved quantity for this item/color across ALL sessions

        # Check if the total reserved quantity for this item/color exceeds the stock in the DB
        if db_stock < reserved_total:
            logging.error(f"Finalize sale failed: Stock insufficient for product {product_id} ('{item['name']}'/{color}). DB Stock: {db_stock}, Total Reserved across sessions: {reserved_total}. Cannot finalize.")
            # Find how much of this item is in *this specific* session
            qty_in_current_session = next((i['quantity'] for i in sale_session['cart_items'] if i['product_id'] == product_id and i['color'] == color), 0)

            return jsonify({
                "error": f"Ошибка: Недостаточно товара '{item['name']}' (цвет: {color}) на складе. Доступно всего: {db_stock} шт. В текущей кассе: {qty_in_current_session} шт. Всего зарезервировано во всех кассах (включая эту): {reserved_total} шт. Пожалуйста, скорректируйте количество."
                }), 400 # Use 400 Bad Request for validation errors


        # Calculate the stock update based on the quantity sold in *this* specific session
        # The stock in the DB should be reduced by the quantity of this item *only* in the current session.
        # We build `products_to_update_stock` with the *final* stock level.
        # We need the current stock level *before* this sale. Let's reload data for this crucial step.
        fresh_db_data_for_stock_calc = load_data()
        fresh_products_map_for_stock_calc = {p['id']: p for p in fresh_db_data_for_stock_calc.get('products', [])}
        product_in_db_fresh = fresh_products_map_for_stock_calc.get(product_id) # Get the latest stock value

        if not product_in_db_fresh:
             logging.error(f"Finalize sale failed during stock calculation: Product {product_id} disappeared from DB.")
             return jsonify({"error": f"Внутренняя ошибка при расчете остатков для товара '{item['name']}'. Пожалуйста, попробуйте снова."}), 500


        current_stock_before_this_sale = product_in_db_fresh.get('stock', 0)
        stock_after_this_item_sale = current_stock_before_this_sale - quantity

        # Store the calculated final stock level for this product ID.
        # Note: If the same product ID appears with different colors, this dict will store the
        # *last* calculated stock for that ID. This is correct because stock is per product ID,
        # not per color variant in our current model. Each item sold, regardless of color, reduces the total stock.
        products_to_update_stock[product_id] = stock_after_this_item_sale


        total_price += item['price'] * quantity

        # Format the item for the order record
        photo_filename = item['photo'] # Use the photo filename stored in the session item

        processed_sale_cart.append({
            "product_id": product_id,
            "name": item['name'],
            "price": item['price'],
            "quantity": quantity,
            "color": item['color'],
            "photo": photo_filename,
            "photo_url": f"https://huggingface.co/datasets/{REPO_ID}/resolve/main/photos/{photo_filename}" if photo_filename != 'placeholder.png' else "https://via.placeholder.com/60x60.png?text=N/A"
        })

    # --- Create Order Record ---
    sale_id = f"SALE-{datetime.now().strftime('%Y%m%d%H%M%S')}-{uuid.uuid4().hex[:6]}"
    sale_timestamp = datetime.now().strftime('%Y-%m-%d %H:%M:%S')

    new_sale_record = {
        "id": sale_id,
        "created_at": sale_timestamp,
        "cart": processed_sale_cart,
        "total_price": round(total_price, 2),
        "user_info": "Admin Registered Sale (Cashier)",
        "status": "completed", # Mark cashier sales as 'completed'
        "customer_name": customer_name if customer_name else "Анонимный покупатель",
        "customer_contact": customer_contact if customer_contact else "Не указан"
    }

    # --- Apply Stock Updates and Save Data ---
    try:
        # Apply the calculated final stock levels to the data object loaded at the start of the request
        # This ensures we save the correct final state to data.json
        for prod_in_list in db_data['products']:
            if prod_in_list['id'] in products_to_update_stock:
                prod_in_list['stock'] = products_to_update_stock[prod_in_list['id']]
                prod_in_list['in_stock'] = prod_in_list['stock'] > 0

        if 'orders' not in db_data or not isinstance(db_data.get('orders'), dict):
            db_data['orders'] = {}
        db_data['orders'][sale_id] = new_sale_record

        save_data(db_data) # Save the updated data

        # --- Cleanup Session ---
        del open_sale_sessions[session_id] # Remove the completed session

        logging.info(f"Sale {sale_id} registered successfully and session {session_id} deleted.")

        # Prepare response with updated active sessions list
        active_sessions_data = {}
        for s_id, s_data in open_sale_sessions.items():
            active_sessions_data[s_id] = {
                'id': s_id,
                'item_count': sum(item['quantity'] for item in s_data['cart_items']),
                'total_price': sum(item['price'] * item['quantity'] for item in s_data['cart_items']),
                 'created_at': s_data.get('created_at', ''),
                 'cart_items': s_data['cart_items'] # Include items list
            }

        return jsonify({"order_id": sale_id, "active_sessions_data": active_sessions_data}), 201

    except Exception as e:
        logging.error(f"Failed to finalize sale {sale_id} or update stock: {e}", exc_info=True)
        # Note: Reverting stock perfectly on failure here is complex in this simple file-based DB.
        # It's safer to rely on the admin panel's stock adjustment if inconsistencies occur.
        return jsonify({"error": "Ошибка сервера при регистрации продажи. Пожалуйста, попробуйте позже."}), 500


if __name__ == '__main__':
    # Perform initial download before starting the app
    logging.info("Attempting initial database download from Hugging Face...")
    download_db_from_hf()
    logging.info("Initial download attempt finished. Loading data...")
    # Load data after download attempt (will load default if download failed)
    load_data()
    logging.info("Data loaded. Starting Flask application.")

    # Start periodic backup thread if write token is available
    if HF_TOKEN_WRITE:
        logging.info("HF_TOKEN (write) is set. Starting periodic backup thread.")
        backup_thread = threading.Thread(target=periodic_backup, daemon=True)
        backup_thread.start()
    else:
        logging.warning("HF_TOKEN (write) not set. Periodic backup is disabled.")

    # Run the Flask application
    port = int(os.environ.get('PORT', 7860)) # Default to 7860 for Hugging Face Spaces
    app.run(debug=False, host='0.0.0.0', port=port)