server.py

import base64
import binascii
import hashlib
import json
import os
import re
import uuid
from datetime import date, datetime, timedelta, timezone
from decimal import Decimal, ROUND_HALF_UP, getcontext
from pathlib import Path
from typing import Any, Dict, List, Optional, Tuple

from flask import Flask, jsonify, request, send_from_directory

from db import (
    create_account,
    execute,
    fetch_all,
    fetch_one,
    fetch_business_logo,
    insert_invoice,
    search_clients,
    update_business,
    update_business_logo,
    upsert_client,
)

APP_ROOT = Path(__file__).parent.resolve()
DATA_DIR = Path(os.environ.get("DATA_DIR", APP_ROOT))
DATA_FILE = DATA_DIR / "web_invoice_store.json"
INVOICE_HISTORY_LIMIT = 200
MAX_LOGO_SIZE = 512 * 1024  # 512 KB
TOKEN_TTL = timedelta(hours=12)
ALLOWED_LOGO_MIME_TYPES = {"image/png", "image/jpeg"}

DATABASE_AVAILABLE = bool(os.environ.get("NEON_DATABASE_URL"))

VAT_RATES: Dict[str, Optional[Decimal]] = {
    "23": Decimal("0.23"),
    "8": Decimal("0.08"),
    "5": Decimal("0.05"),
    "0": Decimal("0.00"),
    "ZW": None,
    "NP": None,
}

DEFAULT_UNIT = "szt."
ALLOWED_UNITS = {"szt.", "godz."}
PASSWORD_MIN_LENGTH = 4

SESSION_TOKENS: Dict[str, Dict[str, Any]] = {}

ALLOWED_STATIC = {
    "index.html",
    "styles.css",
    "main.js",
    "favicon.ico",
    "Roboto-VariableFont_wdth,wght.ttf",
}


app = Flask(__name__, static_folder=str(APP_ROOT), static_url_path="")

getcontext().prec = 10


def _quantize(value: Decimal) -> Decimal:
    return value.quantize(Decimal("0.01"), rounding=ROUND_HALF_UP)


def _decimal(value: Any) -> Decimal:
    try:
        return Decimal(str(value))
    except Exception as error:  # pragma: no cover - defensive
        raise ValueError(f"Niepoprawna wartosc liczby: {value}") from error


def _format_decimal_str(value: Any, default: str = "0.00") -> str:
    if value in (None, ""):
        return default
    if isinstance(value, Decimal):
        return str(_quantize(value))
    try:
        return str(_quantize(Decimal(str(value))))
    except Exception:
        return str(value)


def hash_password(password: str) -> str:
    return hashlib.sha256(password.encode("utf-8")).hexdigest()


EMAIL_PATTERN = re.compile(r"^[A-Za-z0-9._%+-]+@[A-Za-z0-9.-]+\.[A-Za-z]{2,}$")


def normalize_email(raw_email: str) -> Tuple[str, str]:
    display_email = (raw_email or "").strip()
    if not display_email:
        raise ValueError("Email nie moze byc pusty.")
    if not EMAIL_PATTERN.fullmatch(display_email):
        raise ValueError("Podaj poprawny adres email.")
    return display_email.lower(), display_email


def sanitize_filename(filename: Optional[str]) -> str:
    if not filename:
        return "logo"
    name = str(filename).split("/")[-1].split("\\")[-1]
    sanitized = re.sub(r"[^A-Za-z0-9._-]", "_", name).strip("._")
    return sanitized or "logo"


def find_account_identifier(accounts: Dict[str, Any], identifier: str) -> Tuple[Optional[str], Optional[Dict[str, Any]]]:
    key = (identifier or "").strip().lower()
    if not key:
        return None, None
    account = accounts.get(key)
    if account:
        return key, account
    for login_key, candidate in accounts.items():
        candidate_login = (candidate.get("login") or "").strip().lower()
        candidate_email = (candidate.get("email") or "").strip().lower()
        if key in {candidate_login, candidate_email}:
            return login_key, candidate
    return None, None


def load_store() -> Dict[str, Any]:
    if not DATA_FILE.exists():
        return {"accounts": {}}
    try:
        with DATA_FILE.open("r", encoding="utf-8") as handle:
            data = json.load(handle)
    except json.JSONDecodeError:
        raise ValueError("Plik z danymi jest uszkodzony.")
    return data


def save_store(data: Dict[str, Any]) -> None:
    DATA_DIR.mkdir(parents=True, exist_ok=True)
    tmp_path = DATA_FILE.with_suffix(".tmp")
    with tmp_path.open("w", encoding="utf-8") as handle:
        json.dump(data, handle, ensure_ascii=False, indent=2)
    tmp_path.replace(DATA_FILE)


def get_account(data: Dict[str, Any], login_key: str) -> Dict[str, Any]:
    accounts = data.get("accounts") or {}
    account = accounts.get(login_key)
    if not account:
        raise KeyError("Nie znaleziono konta.")
    return account


def get_account_row(login_key: str) -> Dict[str, Any]:
    row = fetch_one("SELECT id, login FROM accounts WHERE login = %s", (login_key,))
    if not row:
        raise KeyError("Nie znaleziono konta.")
    return row


def get_business_profile(account_id: int) -> Optional[Dict[str, Any]]:
    return fetch_one(
        """
        SELECT company_name, owner_name, address_line, postal_code,
               city, tax_id, bank_account
        FROM business_profiles
        WHERE account_id = %s
        """,
        (account_id,),
    )


def require_auth() -> str:
    auth_header = request.headers.get("Authorization")
    if not auth_header or not auth_header.startswith("Bearer "):
        raise PermissionError("Brak tokenu.")
    token = auth_header.split(" ", 1)[1].strip()
    session = SESSION_TOKENS.get(token)
    if not session:
        raise PermissionError("Nieprawidlowy token.")
    if session["expires_at"] < datetime.utcnow():
        SESSION_TOKENS.pop(token, None)
        raise PermissionError("Token wygasl.")
    return session["login_key"]


@app.route("/")
def index() -> Any:
    return send_from_directory(app.static_folder, "index.html")


@app.route("/<path:filename>")
def static_files(filename: str) -> Any:
    if filename not in ALLOWED_STATIC:
        return jsonify({"error": "Nie ma takiego zasobu."}), 404
    return send_from_directory(app.static_folder, filename)


@app.route("/api/register", methods=["POST"])
def api_register() -> Any:
    payload = request.get_json(force=True)
    email = payload.get("email")
    password = payload.get("password")
    confirm = payload.get("confirm_password")
    business_fields = [
        "company_name",
        "owner_name",
        "address_line",
        "postal_code",
        "city",
        "tax_id",
        "bank_account",
    ]
    business_data: Dict[str, str] = {}

    for field in business_fields:
        value = (payload.get(field) or "").strip()
        if not value:
            return jsonify({"error": f"Pole {field} jest wymagane."}), 400
        business_data[field] = value

    if password != confirm:
        return jsonify({"error": "Hasla musza byc identyczne."}), 400
    if len(password or "") < PASSWORD_MIN_LENGTH:
        return jsonify({"error": "Haslo jest za krotkie."}), 400

    login_key, display_email = normalize_email(email)
    password_hash = hash_password(password)

    if DATABASE_AVAILABLE:
        if fetch_one("SELECT 1 FROM accounts WHERE login = %s", (login_key,)):
            return jsonify({"error": "Konto o podanym emailu juz istnieje."}), 400
        account_id = create_account(login_key, display_email, password_hash)
        update_business(account_id, business_data)
        return jsonify({"message": "Konto zostalo utworzone."})

    data = load_store()
    accounts = data.setdefault("accounts", {})
    if login_key in accounts:
        return jsonify({"error": "Konto o podanym emailu juz istnieje."}), 400

    accounts[login_key] = {
        "login": login_key,
        "email": display_email,
        "password_hash": password_hash,
        "business": business_data,
        "invoices": [],
        "logo": None,
        "created_at": datetime.utcnow().isoformat(timespec="seconds"),
    }
    save_store(data)
    return jsonify({"message": "Konto zostalo utworzone."})


@app.route("/api/login", methods=["POST"])
def api_login() -> Any:
    payload = request.get_json(force=True)
    identifier = payload.get("identifier") or payload.get("email")
    password = payload.get("password")
    if not identifier or not password:
        return jsonify({"error": "Podaj email/login i haslo."}), 400

    login_key, _ = normalize_email(identifier)

    if DATABASE_AVAILABLE:
        row = fetch_one(
            "SELECT id, password_hash FROM accounts WHERE login = %s",
            (login_key,),
        )
        if not row or row["password_hash"] != hash_password(password):
            return jsonify({"error": "Niepoprawne dane logowania."}), 401
        token = uuid.uuid4().hex
        SESSION_TOKENS[token] = {
            "login_key": login_key,
            "account_id": row["id"],
            "expires_at": datetime.utcnow() + TOKEN_TTL,
        }
        return jsonify({"token": token, "login": login_key})

    data = load_store()
    accounts = data.get("accounts") or {}
    login_key, account = find_account_identifier(accounts, login_key)
    if not account or account.get("password_hash") != hash_password(password):
        return jsonify({"error": "Niepoprawne dane logowania."}), 401
    token = uuid.uuid4().hex
    SESSION_TOKENS[token] = {
        "login_key": login_key,
        "expires_at": datetime.utcnow() + TOKEN_TTL,
    }
    return jsonify({"token": token, "login": account.get("login", login_key)})


@app.route("/api/logout", methods=["POST"])
def api_logout() -> Any:
    token = request.headers.get("Authorization", "").replace("Bearer ", "")
    SESSION_TOKENS.pop(token, None)
    return jsonify({"message": "Wylogowano."})


@app.route("/api/business", methods=["GET", "POST"])
def api_business() -> Any:
    try:
        login_key = require_auth()
    except PermissionError:
        return jsonify({"error": "Brak autoryzacji."}), 401

    data = load_store()
    account = data.get("accounts", {}).get(login_key)
    account_row = None
    if DATABASE_AVAILABLE:
        try:
            account_row = get_account_row(login_key)
        except KeyError:
            return jsonify({"error": "Nie znaleziono konta."}), 404

    if request.method == "GET":
        if DATABASE_AVAILABLE:
            profile = fetch_one(
                """

                SELECT company_name, owner_name, address_line, postal_code,

                       city, tax_id, bank_account

                FROM business_profiles

                WHERE account_id = %s

                """,
                (account_row["id"],),
            )
            return jsonify({"business": profile})
        if not account:
            return jsonify({"business": None})
        return jsonify({"business": account.get("business")})

    payload = request.get_json(force=True)
    required_fields = [
        "company_name",
        "owner_name",
        "address_line",
        "postal_code",
        "city",
        "tax_id",
        "bank_account",
    ]
    for field in required_fields:
        if not (payload.get(field) or "").strip():
            return jsonify({"error": f"Pole {field} jest wymagane."}), 400

    if DATABASE_AVAILABLE:
        update_business(account_row["id"], payload)
        return jsonify({"message": "Dane sprzedawcy zostaly zaktualizowane."})

    if not account:
        return jsonify({"error": "Nie znaleziono konta."}), 404
    account["business"] = payload
    save_store(data)
    return jsonify({"message": "Dane sprzedawcy zostaly zaktualizowane."})


@app.route("/api/clients", methods=["GET"])
def api_clients() -> Any:
    try:
        login_key = require_auth()
    except PermissionError:
        return jsonify({"error": "Brak autoryzacji."}), 401

    if not DATABASE_AVAILABLE:
        return jsonify({"clients": []})

    try:
        account_row = get_account_row(login_key)
    except KeyError:
        return jsonify({"error": "Nie znaleziono konta."}), 404

    search_term = (request.args.get("q") or "").strip()
    limit_param = request.args.get("limit", "10")
    try:
        limit_value = int(limit_param)
    except ValueError:
        limit_value = 10
    limit_value = max(1, min(25, limit_value))
    clients = search_clients(account_row["id"], search_term, limit_value)
    return jsonify({"clients": clients})


@app.route("/api/logo", methods=["GET", "POST", "DELETE"])
def api_logo() -> Any:
    try:
        login_key = require_auth()
    except PermissionError:
        return jsonify({"error": "Brak autoryzacji."}), 401

    account_row = None
    account = None
    data = None

    if DATABASE_AVAILABLE:
        try:
            account_row = get_account_row(login_key)
        except KeyError:
            return jsonify({"error": "Nie znaleziono konta."}), 404
    else:
        data = load_store()
        try:
            account = get_account(data, login_key)
        except KeyError:
            return jsonify({"error": "Nie znaleziono konta."}), 404

    if request.method == "GET":
        if DATABASE_AVAILABLE:
            logo_row = fetch_business_logo(account_row["id"])
            if not logo_row:
                return jsonify({"logo": None})
            mime_type = logo_row["mime_type"]
            encoded = logo_row["data"]
            data_url = f"data:{mime_type};base64,{encoded}" if mime_type and encoded else None
            return jsonify(
                {
                    "logo": {
                        "filename": None,
                        "mime_type": mime_type,
                        "data": encoded,
                        "data_url": data_url,
                        "uploaded_at": None,
                    }
                }
            )
        logo = account.get("logo") if account else None
        if not logo:
            return jsonify({"logo": None})
        encoded = logo.get("data")
        mime_type = logo.get("mime_type")
        data_url = None
        if encoded and mime_type:
            data_url = f"data:{mime_type};base64,{encoded}"
        return jsonify(
            {
                "logo": {
                    "filename": logo.get("filename"),
                    "mime_type": mime_type,
                    "data": encoded,
                    "data_url": data_url,
                    "uploaded_at": logo.get("uploaded_at"),
                }
            }
        )

    if request.method == "DELETE":
        if DATABASE_AVAILABLE:
            update_business_logo(account_row["id"], None, None)
            return jsonify({"message": "Logo zostalo usuniete."})
        if not account or data is None:
            return jsonify({"error": "Nie znaleziono konta."}), 404
        account["logo"] = None
        save_store(data)
        return jsonify({"message": "Logo zostalo usuniete."})

    payload = request.get_json(force=True)
    raw_content = (payload.get("content") or payload.get("data") or "").strip()
    if not raw_content:
        return jsonify({"error": "Brak danych logo."}), 400

    provided_mime = (payload.get("mime_type") or "").strip()
    filename = sanitize_filename(payload.get("filename"))

    if raw_content.startswith("data:"):
        try:
            header, encoded_content = raw_content.split(",", 1)
        except ValueError:
            return jsonify({"error": "Niepoprawny format danych logo."}), 400
        header = header.strip()
        if ";base64" not in header:
            return jsonify({"error": "Niepoprawny format danych logo (oczekiwano base64)."}), 400
        mime_type = header.split(";")[0].replace("data:", "", 1) or provided_mime
        base64_content = encoded_content.strip()
    else:
        mime_type = provided_mime
        base64_content = raw_content

    mime_type = (mime_type or "").lower()
    if mime_type not in ALLOWED_LOGO_MIME_TYPES:
        return jsonify({"error": "Dozwolone formaty logo to PNG lub JPG."}), 400

    try:
        logo_bytes = base64.b64decode(base64_content, validate=True)
    except (ValueError, binascii.Error):
        return jsonify({"error": "Nie udalo sie odczytac danych logo (base64)."}), 400

    if len(logo_bytes) > MAX_LOGO_SIZE:
        return jsonify({"error": f"Logo jest zbyt duze (maksymalnie {MAX_LOGO_SIZE // 1024} KB)."}), 400

    encoded_logo = base64.b64encode(logo_bytes).decode("ascii")
    stored_logo = {
        "filename": filename,
        "mime_type": mime_type,
        "data": encoded_logo,
        "uploaded_at": datetime.utcnow().isoformat(timespec="seconds"),
    }

    if DATABASE_AVAILABLE:
        update_business_logo(account_row["id"], stored_logo["mime_type"], stored_logo["data"])
        return jsonify({"logo": stored_logo})

    account["logo"] = stored_logo
    save_store(data)
    return jsonify({"logo": stored_logo})

def normalize_phone(phone: Optional[str]) -> Optional[str]:
    if not phone:
        return None
    digits = re.sub(r"[^\d+]", "", phone)
    return digits or None


def validate_client(payload: Dict[str, Any]) -> Dict[str, str]:
    client_payload = payload.get("client") or {}
    client = {
        "name": (client_payload.get("name") or payload.get("clientName") or "").strip(),
        "tax_id": (client_payload.get("tax_id") or payload.get("clientTaxId") or "").strip(),
        "address_line": (client_payload.get("address_line") or payload.get("clientAddress") or "").strip(),
        "postal_code": (client_payload.get("postal_code") or payload.get("clientPostalCode") or "").strip(),
        "city": (client_payload.get("city") or payload.get("clientCity") or "").strip(),
        "phone": normalize_phone(client_payload.get("phone") or payload.get("clientPhone")),
    }
    return client


def build_invoice(payload: Dict[str, Any], business: Dict[str, Any], client: Dict[str, str]) -> Dict[str, Any]:
    now = datetime.now()
    invoice_id = f"FV-{now.strftime('%Y%m%d-%H%M%S')}"
    issued_at = now.strftime("%Y-%m-%d %H:%M")
    sale_date = payload.get("sale_date") or payload.get("saleDate") or date.today().isoformat()
    payment_term = int(payload.get("payment_term") or payload.get("paymentTerm") or 14)
    items = payload.get("items") or []

    normalized_items: List[Dict[str, Any]] = []
    for item in items:
        name = (item.get("name") or "").strip()
        if not name:
            raise ValueError("Nazwa pozycji nie moze byc pusta.")
        quantity = _quantize(_decimal(item.get("quantity") or "0"))
        if quantity <= Decimal("0"):
            raise ValueError("Ilosc musi byc dodatnia.")
        unit = item.get("unit") or DEFAULT_UNIT
        vat_code = str(item.get("vat_code") or item.get("vat") or item.get("vatCode") or "23")
        if vat_code not in VAT_RATES:
            raise ValueError("Niepoprawna stawka VAT.")
        unit_price_raw = item.get("unit_price_gross")
        if unit_price_raw in (None, ""):
            unit_price_raw = item.get("unitPrice") or item.get("unit_price") or item.get("price")
        unit_price_gross = _quantize(_decimal(unit_price_raw or "0"))
        if unit_price_gross <= Decimal("0"):
            raise ValueError("Cena musi byc dodatnia.")
        vat_rate = VAT_RATES[vat_code]
        if vat_rate is None:
            unit_price_net = unit_price_gross
            vat_amount = Decimal("0.00")
        else:
            unit_price_net = _quantize(unit_price_gross / (Decimal("1.0") + vat_rate))
            vat_amount = _quantize(unit_price_gross - unit_price_net)
        net_total = _quantize(unit_price_net * quantity)
        vat_total = _quantize(vat_amount * quantity)
        gross_total = _quantize(unit_price_gross * quantity)
        normalized_items.append(
            {
                "name": name,
                "quantity": str(quantity),
                "unit": unit,
                "vat_code": vat_code,
                "vat_label": item.get("vatLabel") or vat_code,
                "unit_price_net": str(unit_price_net),
                "unit_price_gross": str(unit_price_gross),
                "net_total": str(net_total),
                "vat_amount": str(vat_amount),
                "gross_total": str(gross_total),
            }
        )

    totals = {"net": Decimal("0"), "vat": Decimal("0"), "gross": Decimal("0")}
    summary: Dict[str, Dict[str, Decimal]] = {}
    for item in normalized_items:
        totals["net"] += Decimal(item["net_total"])
        totals["vat"] += Decimal(item["vat_amount"])
        totals["gross"] += Decimal(item["gross_total"])
        label = item["vat_label"]
        summary.setdefault(label, {"net_total": Decimal("0"), "vat_total": Decimal("0"), "gross_total": Decimal("0")})
        summary[label]["net_total"] += Decimal(item["net_total"])
        summary[label]["vat_total"] += Decimal(item["vat_amount"])
        summary[label]["gross_total"] += Decimal(item["gross_total"])

    totals = {key: str(_quantize(value)) for key, value in totals.items()}
    summary_list = [
        {
            "vat_label": label,
            "net_total": str(_quantize(values["net_total"])),
            "vat_total": str(_quantize(values["vat_total"])),
            "gross_total": str(_quantize(values["gross_total"])),
        }
        for label, values in summary.items()
    ]

    exemption_note = (payload.get("exemption_note") or payload.get("exemptionNote") or "").strip()

    return {
        "invoice_id": invoice_id,
        "issued_at": issued_at,
        "sale_date": sale_date,
        "payment_term": payment_term,
        "items": normalized_items,
        "summary": summary_list,
        "totals": totals,
        "client": client,
        "business": business,
        "exemption_note": exemption_note,
    }


@app.route("/api/invoices", methods=["GET", "POST"])
def api_invoices() -> Any:
    try:
        login_key = require_auth()
    except PermissionError:
        return jsonify({"error": "Brak autoryzacji."}), 401

    if request.method == "GET":
        if DATABASE_AVAILABLE:
            try:
                account_row = get_account_row(login_key)
            except KeyError:
                return jsonify({"error": "Nie znaleziono konta."}), 404
            invoice_rows = fetch_all(
                """
                SELECT i.id,
                       i.invoice_number,
                       i.issued_at,
                       i.sale_date,
                       i.payment_term_days,
                       i.exemption_note,
                       i.total_net,
                       i.total_vat,
                       i.total_gross,
                       c.name AS client_name,
                       c.address_line AS client_address,
                       c.postal_code AS client_postal_code,
                       c.city AS client_city,
                       c.tax_id AS client_tax_id,
                       c.phone AS client_phone
                FROM invoices AS i
                LEFT JOIN clients AS c ON c.id = i.client_id
                WHERE i.account_id = %s
                ORDER BY i.issued_at DESC
                LIMIT %s
                """,
                (account_row["id"], INVOICE_HISTORY_LIMIT),
            )
            if not invoice_rows:
                return jsonify({"invoices": []})

            invoice_ids = [row["id"] for row in invoice_rows]
            items_map: Dict[int, List[Dict[str, Any]]] = {row_id: [] for row_id in invoice_ids}
            summary_map: Dict[int, List[Dict[str, str]]] = {row_id: [] for row_id in invoice_ids}

            if invoice_ids:
                item_rows = fetch_all(
                    """
                    SELECT invoice_id, line_no, name, quantity, unit,
                           vat_code, vat_label, unit_price_net,
                           unit_price_gross, net_total, vat_amount, gross_total
                    FROM invoice_items
                    WHERE invoice_id = ANY(%s)
                    ORDER BY line_no
                    """,
                    (invoice_ids,),
                )
                for item in item_rows:
                    items_map.setdefault(item["invoice_id"], []).append(
                        {
                            "name": item["name"],
                            "quantity": _format_decimal_str(item.get("quantity"), "0.00"),
                            "unit": item.get("unit") or DEFAULT_UNIT,
                            "vat_code": item.get("vat_code"),
                            "vat_label": item.get("vat_label") or item.get("vat_code"),
                            "unit_price_net": _format_decimal_str(item.get("unit_price_net")),
                            "unit_price_gross": _format_decimal_str(item.get("unit_price_gross")),
                            "net_total": _format_decimal_str(item.get("net_total")),
                            "vat_amount": _format_decimal_str(item.get("vat_amount")),
                            "gross_total": _format_decimal_str(item.get("gross_total")),
                        }
                    )

                summary_rows = fetch_all(
                    """
                    SELECT invoice_id, vat_label, net_total, vat_total, gross_total
                    FROM invoice_vat_summary
                    WHERE invoice_id = ANY(%s)
                    ORDER BY vat_label
                    """,
                    (invoice_ids,),
                )
                for entry in summary_rows:
                    summary_map.setdefault(entry["invoice_id"], []).append(
                        {
                            "vat_label": entry.get("vat_label"),
                            "net_total": _format_decimal_str(entry.get("net_total")),
                            "vat_total": _format_decimal_str(entry.get("vat_total")),
                            "gross_total": _format_decimal_str(entry.get("gross_total")),
                        }
                    )

            business_profile = get_business_profile(account_row["id"])
            invoices: List[Dict[str, Any]] = []
            for row in invoice_rows:
                issued_at_value = row.get("issued_at")
                sale_date_value = row.get("sale_date")
                if isinstance(issued_at_value, datetime):
                    issued_at = issued_at_value.strftime("%Y-%m-%d %H:%M")
                else:
                    issued_at = issued_at_value
                if hasattr(sale_date_value, "isoformat"):
                    sale_date = sale_date_value.isoformat()
                else:
                    sale_date = sale_date_value
                client = None
                if row.get("client_name"):
                    client = {
                        "name": row.get("client_name"),
                        "address_line": row.get("client_address"),
                        "postal_code": row.get("client_postal_code"),
                        "city": row.get("client_city"),
                        "tax_id": row.get("client_tax_id"),
                        "phone": row.get("client_phone"),
                    }
                invoices.append(
                    {
                        "invoice_id": row.get("invoice_number"),
                        "issued_at": issued_at,
                        "sale_date": sale_date,
                        "payment_term": row.get("payment_term_days"),
                        "exemption_note": row.get("exemption_note"),
                        "items": items_map.get(row["id"], []),
                        "summary": summary_map.get(row["id"], []),
                        "totals": {
                            "net": _format_decimal_str(row.get("total_net")),
                            "vat": _format_decimal_str(row.get("total_vat")),
                            "gross": _format_decimal_str(row.get("total_gross")),
                        },
                        "client": client,
                        "business": business_profile,
                    }
                )
            return jsonify({"invoices": invoices})

        data = load_store()
        try:
            account = get_account(data, login_key)
        except KeyError:
            return jsonify({"error": "Nie znaleziono konta."}), 404
        invoices = account.get("invoices", [])[:INVOICE_HISTORY_LIMIT]
        return jsonify({"invoices": invoices})

    payload = request.get_json(force=True)

    if DATABASE_AVAILABLE:
        try:
            account_row = get_account_row(login_key)
        except KeyError:
            return jsonify({"error": "Nie znaleziono konta."}), 404
        business = get_business_profile(account_row["id"])
        if not business:
            return jsonify({"error": "Ustaw dane sprzedawcy przed dodaniem faktury."}), 400

        client = validate_client(payload)
        try:
            invoice = build_invoice(payload, business, client)
        except ValueError as error:
            return jsonify({"error": str(error)}), 400

        client_id = upsert_client(
            account_row["id"],
            {
                "name": client["name"],
                "address_line": client["address_line"],
                "postal_code": client["postal_code"],
                "city": client["city"],
                "tax_id": client["tax_id"],
                "phone": client.get("phone"),
            },
        )
        insert_invoice(account_row["id"], client_id, invoice)
        return jsonify({"message": "Faktura zostala zapisana.", "invoice": invoice})

    data = load_store()
    try:
        account = get_account(data, login_key)
    except KeyError:
        return jsonify({"error": "Nie znaleziono konta."}), 404

    business = account.get("business")
    if not business:
        return jsonify({"error": "Ustaw dane sprzedawcy przed dodaniem faktury."}), 400

    client = validate_client(payload)
    try:
        invoice = build_invoice(payload, business, client)
    except ValueError as error:
        return jsonify({"error": str(error)}), 400

    invoices = account.setdefault("invoices", [])
    invoices.insert(0, invoice)
    account["invoices"] = invoices[:INVOICE_HISTORY_LIMIT]
    save_store(data)
    return jsonify({"message": "Faktura zostala zapisana.", "invoice": invoice})


@app.route("/api/invoices/<invoice_id>", methods=["PUT", "DELETE"])
def api_invoice_detail(invoice_id: str) -> Any:
    try:
        login_key = require_auth()
    except PermissionError:
        return jsonify({"error": "Brak autoryzacji."}), 401

    if DATABASE_AVAILABLE:
        try:
            account_row = get_account_row(login_key)
        except KeyError:
            return jsonify({"error": "Nie znaleziono konta."}), 404

        invoice_row = fetch_one(
            """
            SELECT id, issued_at
            FROM invoices
            WHERE account_id = %s AND invoice_number = %s
            """,
            (account_row["id"], invoice_id),
        )
        if not invoice_row:
            return jsonify({"error": "Nie znaleziono faktury."}), 404

        if request.method == "DELETE":
            execute("DELETE FROM invoice_items WHERE invoice_id = %s", (invoice_row["id"],))
            execute("DELETE FROM invoice_vat_summary WHERE invoice_id = %s", (invoice_row["id"],))
            execute("DELETE FROM invoices WHERE id = %s", (invoice_row["id"],))
            return jsonify({"message": "Faktura zostala usunieta."})

        payload = request.get_json(force=True)
        business = get_business_profile(account_row["id"])
        if not business:
            return jsonify({"error": "Ustaw dane sprzedawcy przed dodaniem faktury."}), 400

        client = validate_client(payload)
        try:
            invoice = build_invoice(payload, business, client)
        except ValueError as error:
            return jsonify({"error": str(error)}), 400

        invoice["invoice_id"] = invoice_id
        existing_issued_at = invoice_row.get("issued_at")
        if isinstance(existing_issued_at, datetime):
            invoice["issued_at"] = existing_issued_at.strftime("%Y-%m-%d %H:%M")
        elif existing_issued_at:
            invoice["issued_at"] = str(existing_issued_at)

        client_id = upsert_client(
            account_row["id"],
            {
                "name": client["name"],
                "address_line": client["address_line"],
                "postal_code": client["postal_code"],
                "city": client["city"],
                "tax_id": client["tax_id"],
                "phone": client.get("phone"),
            },
        )

        execute("DELETE FROM invoice_items WHERE invoice_id = %s", (invoice_row["id"],))
        execute("DELETE FROM invoice_vat_summary WHERE invoice_id = %s", (invoice_row["id"],))
        execute("DELETE FROM invoices WHERE id = %s", (invoice_row["id"],))
        insert_invoice(account_row["id"], client_id, invoice)
        return jsonify({"message": "Faktura zostala zaktualizowana.", "invoice": invoice})

    data = load_store()
    try:
        account = get_account(data, login_key)
    except KeyError:
        return jsonify({"error": "Nie znaleziono konta."}), 404

    invoices = account.get("invoices", [])
    invoice_index = next(
        (idx for idx, entry in enumerate(invoices) if entry.get("invoice_id") == invoice_id),
        None,
    )
    if invoice_index is None:
        return jsonify({"error": "Nie znaleziono faktury."}), 404

    if request.method == "DELETE":
        invoices.pop(invoice_index)
        save_store(data)
        return jsonify({"message": "Faktura zostala usunieta."})

    payload = request.get_json(force=True)
    business = account.get("business")
    if not business:
        return jsonify({"error": "Ustaw dane sprzedawcy przed dodaniem faktury."}), 400

    client = validate_client(payload)
    try:
        invoice = build_invoice(payload, business, client)
    except ValueError as error:
        return jsonify({"error": str(error)}), 400

    invoice["invoice_id"] = invoice_id
    existing_invoice = invoices[invoice_index]
    if existing_invoice.get("issued_at"):
        invoice["issued_at"] = existing_invoice.get("issued_at")
    invoices[invoice_index] = invoice
    save_store(data)
    return jsonify({"message": "Faktura zostala zaktualizowana.", "invoice": invoice})


@app.route("/api/invoices/summary", methods=["GET"])
def api_invoice_summary() -> Any:
    try:
        login_key = require_auth()
    except PermissionError:
        return jsonify({"error": "Brak autoryzacji."}), 401

    now = datetime.utcnow()
    last_month_start = now - timedelta(days=30)
    quarter_first_month = ((now.month - 1) // 3) * 3 + 1
    quarter_start = now.replace(month=quarter_first_month, day=1, hour=0, minute=0, second=0, microsecond=0)
    year_start = now.replace(month=1, day=1, hour=0, minute=0, second=0, microsecond=0)

    def normalize_issued_at(value: Any) -> Optional[datetime]:
        if isinstance(value, datetime):
            tzinfo = value.tzinfo
            if tzinfo is not None and tzinfo.utcoffset(value) is not None:
                return value.astimezone(timezone.utc).replace(tzinfo=None)
            return value
        if isinstance(value, str):
            candidate = value.strip()
            if not candidate:
                return None
            for fmt in ("%Y-%m-%d %H:%M", "%Y-%m-%dT%H:%M:%S", "%Y-%m-%d"):
                try:
                    return datetime.strptime(candidate, fmt)
                except ValueError:
                    continue
        return None

    def aggregate_from_rows(rows: List[Dict[str, Any]], start: datetime) -> Dict[str, Any]:
        count = 0
        gross_total = Decimal("0.00")
        for row in rows:
            issued_dt = normalize_issued_at(row.get("issued_at"))
            if issued_dt is None or issued_dt < start:
                continue
            try:
                gross_total += _decimal(row.get("total_gross") or "0")
            except ValueError:
                continue
            count += 1
        return {"count": count, "gross_total": str(_quantize(gross_total))}

    if DATABASE_AVAILABLE:
        try:
            account_row = get_account_row(login_key)
        except KeyError:
            return jsonify({"error": "Nie znaleziono konta."}), 404
        rows = fetch_all(
            """
            SELECT issued_at, total_gross
            FROM invoices
            WHERE account_id = %s
            """,
            (account_row["id"],),
        )
        summary = {
            "last_month": aggregate_from_rows(rows, last_month_start),
            "quarter": aggregate_from_rows(rows, quarter_start),
            "year": aggregate_from_rows(rows, year_start),
        }
        return jsonify({"summary": summary})

    data = load_store()
    try:
        account = get_account(data, login_key)
    except KeyError:
        return jsonify({"error": "Nie znaleziono konta."}), 404
    invoices = account.get("invoices", [])
    rows = [
        {
            "issued_at": invoice.get("issued_at"),
            "total_gross": (invoice.get("totals") or {}).get("gross", "0"),
        }
        for invoice in invoices
    ]

    summary = {
        "last_month": aggregate_from_rows(rows, last_month_start),
        "quarter": aggregate_from_rows(rows, quarter_start),
        "year": aggregate_from_rows(rows, year_start),
    }
    return jsonify({"summary": summary})


if __name__ == "__main__":
    port = int(os.environ.get("PORT", "5000"))
    app.run(host="0.0.0.0", port=port, debug=True)