#data_loader

import os
import re
import json
import csv
import codecs
import requests
import PyPDF2
from docx import Document
import openpyxl
from bs4 import BeautifulSoup

# ? Normalize utility
def normalize_prompt(text):
    text = text.strip().lower()
    text = re.sub(r"[;:,.!?]+$", "", text)
    text = re.sub(r"[^\w\s]", "", text)
    #text = re.sub(r"\b(what|actually|please|tell|me|about|can|you|explain|is|the|do)\b", "", text)
    text = re.sub(r"\b(what|actually|please|tell|me|about|can|you|explain|is|the|do|does|give|show)\b(?!\w)", "", text)
    return re.sub(r"\s+", " ", text).strip()

# ? Output cleanup for SQL responses
def clean_sql_output(raw_text):
    try:
        decoded = codecs.decode(raw_text.strip(), 'unicode_escape')
        return decoded.replace(";;", ";").replace("\n\n\n", "\n\n").strip()
    except Exception as e:
        print("?? Cleaning error:", e)
        return raw_text.strip()

# ? Existing basic rule loader
def load_rules(file_path="data/train_data.txt"):
    data = {}
    if os.path.exists(file_path):
        with open(file_path, "r", encoding="utf-8") as file:
            for line in file:
                if "=" in line:
                    key, value = line.strip().split("=", 1)
                    data[key.strip().lower()] = clean_sql_output(value)
    return data

# ? Domain routing logic
def detect_domain(prompt):
    prompt = prompt.lower()
    if any(word in prompt for word in ["salary", "financial", "transaction", "ledger"]):
        return "data/finance.txt"
    elif any(word in prompt for word in ["employee", "hr", "hiring"]):
        return "data/hr.txt"
    elif any(word in prompt for word in ["sale", "customer", "order"]):
        return "data/sales.txt"
    else:
        return None

def load_rules_by_domain(prompt):
    domain_file = detect_domain(prompt)
    if domain_file and os.path.exists(domain_file):
        domain_rules = load_rules(domain_file)
        if prompt in domain_rules:
            return domain_rules[prompt]
    return None

# ? Extended loaders for structured files
def load_txt(path):
    pairs = []
    with open(path, 'r', encoding='utf-8') as f:
        for line in f:
            if '=' in line:
                prompt, answer = line.split('=', 1)
                pairs.append((normalize_prompt(prompt), answer.strip()))
    return pairs

def load_json(path):
    pairs = []
    with open(path, 'r', encoding='utf-8') as f:
        for entry in json.load(f):
            pairs.append((normalize_prompt(entry['prompt']), entry['answer'].strip()))
    return pairs

def load_csv(path):
    pairs = []
    with open(path, newline='', encoding='utf-8') as csvfile:
        reader = csv.DictReader(csvfile)
        for row in reader:
            if 'prompt' in row and 'answer' in row:
                pairs.append((normalize_prompt(row['prompt']), row['answer'].strip()))
    return pairs

def load_pdf(path):
    pairs = []
    with open(path, 'rb') as f:
        reader = PyPDF2.PdfReader(f)
        text = "\n".join([p.extract_text() for p in reader.pages if p.extract_text()])
        for line in text.split("\n"):
            if '=' in line:
                prompt, answer = line.split('=', 1)
                pairs.append((normalize_prompt(prompt), answer.strip()))
    return pairs



def load_docx(path):
    pairs = []
    doc = Document(path)
    for para in doc.paragraphs:
        if "=" in para.text:
            prompt, answer = para.text.split("=", 1)
            pairs.append((normalize_prompt(prompt), answer.strip()))
    return pairs

def load_xlsx(path):
    pairs = []
    wb = openpyxl.load_workbook(path)
    for sheet in wb.worksheets:
        for row in sheet.iter_rows(values_only=True):
            if not row or len(row) < 2:
                continue
            prompt, answer = row[0], row[1]
            if isinstance(prompt, str) and isinstance(answer, str) and "=" not in prompt:
                pairs.append((normalize_prompt(prompt), answer.strip()))
            elif isinstance(prompt, str) and "=" in prompt:
                p, a = prompt.split("=", 1)
                pairs.append((normalize_prompt(p), a.strip()))
    return pairs



# ? Load from GitHub/HuggingFace (TXT/JSON)
def fetch_text_from_url(url):
    try:
        resp = requests.get(url, timeout=10)
        resp.raise_for_status()
        return resp.text
    except Exception as e:
        print(f"?? Error reading remote file {url}: {e}")
        return ""
# ? Dispatcher for local files
def load_prompts_from_file(path):
    if path.endswith('.txt'):
        return load_txt(path)
    elif path.endswith('.json'):
        return load_json(path)
    elif path.endswith('.csv'):
        return load_csv(path)
    elif path.endswith('.pdf'):
        return load_pdf(path)
    elif path.endswith('.docx'):
        return load_docx(path)
    elif path.endswith('.xlsx'):
        return load_xlsx(path)
    else:
        print(f"? Unsupported format: {path}")
        return []

def load_prompts_from_url(url):
    pairs = []
    text = fetch_text_from_url(url)
    if not text:
        return []

    if url.endswith(".txt"):
        for line in text.splitlines():
            if '=' in line:
                prompt, answer = line.split('=', 1)
                pairs.append((normalize_prompt(prompt), answer.strip()))
    elif url.endswith(".json"):
        try:
            data = json.loads(text)
            for entry in data:
                pairs.append((normalize_prompt(entry['prompt']), entry['answer'].strip()))
        except Exception as e:
            print(f"?? JSON parsing failed: {e}")
    return pairs

def load_prompt_pairs(path):
    import json, csv
    import requests
    import io
    import PyPDF2

    def is_url(p): return p.startswith("http")
    ext = path.split(".")[-1].lower()
    data = []

    if is_url(path):
        response = requests.get(path)
        response.raise_for_status()
        content = response.content

        if ext == "json":
            parsed = json.loads(content.decode("utf-8"))
            for entry in parsed:
                data.append((normalize_prompt(entry['prompt']), entry['answer'].strip()))
        elif ext == "csv":
            reader = csv.DictReader(io.StringIO(content.decode("utf-8")))
            for row in reader:
                data.append((normalize_prompt(row['prompt']), row['answer'].strip()))
        elif ext == "txt":
            for line in content.decode("utf-8", errors="replace").splitlines():
                if "=" in line:
                    p, a = line.split("=", 1)
                    data.append((normalize_prompt(p), a.strip()))
        elif ext == "pdf":
            reader = PyPDF2.PdfReader(io.BytesIO(content))
            for page in reader.pages:
                text = page.extract_text()
                if text:
                    for line in text.splitlines():
                        if "=" in line:
                            p, a = line.split("=", 1)
                            data.append((normalize_prompt(p), a.strip()))
    else:
        with open(path, "r", encoding="utf-8", errors="replace") as f:
            lines = f.readlines()
            for line in lines:
                line = line.strip()
                if "=" in line:
                    p, a = line.split("=", 1)
                    data.append((normalize_prompt(p), a.strip()))

    return data


def list_files_from_github_folder(github_folder_url):
    try:
        html = requests.get(github_folder_url).text
        soup = BeautifulSoup(html, "lxml")
        links = soup.select("a.js-navigation-open")
        raw_base = github_folder_url.replace("github.com", "raw.githubusercontent.com").replace("/blob", "")
        file_links = []
        for link in links:
            href = link.get("href", "")
            if any(href.endswith(ext) for ext in [".txt", ".json", ".csv", ".pdf", ".docx", ".xlsx"]):
                file_links.append(f"https://{raw_base.split('/', 2)[-1].split('/')[0]}/{href.split('/', 2)[-1]}")
        return file_links
    except Exception as e:
        print("⚠️ GitHub scan error:", e)
        return []