"""
Firebase → Django mahsulotlarni sinxronlashtirish skripti.

Ishlatish:
    python sync_firebase_products.py
    python sync_firebase_products.py --dry-run        # haqiqatda saqlamaydi
    python sync_firebase_products.py --update         # mavjudlarni ham yangilaydi

Logika:
    - firestore_id bo'yicha tekshiradi
    - Mavjud bo'lsa — o'tkazib ketadi (--update bilan yangilaydi)
    - Yangi bo'lsa — create qiladi
"""

import os
import sys
import argparse
import django
import firebase_admin
from firebase_admin import credentials, firestore
from decimal import Decimal, InvalidOperation

# ── Django sozlash ───────────────────────────────────────────────────────────
BASE_DIR = os.path.dirname(os.path.abspath(__file__))
sys.path.insert(0, BASE_DIR)
os.environ.setdefault("DJANGO_SETTINGS_MODULE", "config.settings.local")

try:
    django.setup()
except Exception as e:
    print(f"[XATO] Django setup: {e}")
    sys.exit(1)

from core.apps.vendors.models import (
    VendorproductModel,
    CategoryModel,
    SectionModel,
)

# ── Firebase ulanish ─────────────────────────────────────────────────────────
CERT_PATH = os.path.join(BASE_DIR, "fondexuzb-firebase-adminsdk-fbsvc-7b0e2d6200.json")

if not os.path.exists(CERT_PATH):
    print(f"[XATO] Firebase credentials topilmadi: {CERT_PATH}")
    sys.exit(1)

if not firebase_admin._apps:
    cred = credentials.Certificate(CERT_PATH)
    firebase_admin.initialize_app(cred)

db = firestore.client()


# ── Yordamchi funksiyalar ────────────────────────────────────────────────────

def to_decimal(value, default=Decimal("0")):
    """Har qanday qiymatni Decimal'ga o'tkazadi."""
    try:
        return Decimal(str(value)).quantize(Decimal("0.01"))
    except (InvalidOperation, TypeError):
        return default


def to_int(value, default=-1):
    try:
        return int(value)
    except (TypeError, ValueError):
        return default


def get_category(firestore_id: str):
    """CategoryModel'ni firestore_id bo'yicha topadi."""
    if not firestore_id:
        return None
    return CategoryModel.objects.filter(firestore_id=firestore_id).first()


def get_section(firestore_id: str):
    """SectionModel'ni firestore_id bo'yicha topadi."""
    if not firestore_id:
        return None
    return SectionModel.objects.filter(firestore_id=firestore_id).first()


def build_product_data(doc_id: str, data: dict) -> dict:
    """Firebase hujjatidan Django model uchun dict yasaydi."""

    # product_specification: {"Og'irlik": "1 kg", "Hajm": "500 ml"} kabi
    spec = data.get("product_specification")
    if isinstance(spec, str):
        # Ba'zida JSON string sifatida keladi
        import json
        try:
            spec = json.loads(spec)
        except Exception:
            spec = None
    if not isinstance(spec, dict) or not spec:
        spec = None

    return dict(
        firestore_id=doc_id,
        vendor=data.get("vendorID") or data.get("vendor") or "",
        name=(data.get("name") or "").strip() or "—",
        description=data.get("description") or "",
        price=to_decimal(data.get("price", 0)),
        discount_price=to_decimal(data.get("disPrice", 0)),
        quantity=to_int(data.get("quantity", -1)),
        is_publish=bool(data.get("publish", True)),
        photos_json=data.get("photos") or None,
        product_specification=spec,
        # ForeignKey'lar ayrida to'ldiriladi
        _category_id=data.get("categoryID") or "",
        _section_id=data.get("section_id") or "",
    )


def sync_products(dry_run: bool = False, update: bool = False):
    print("Firebase vendor_products kolleksiyasi o'qilmoqda…")
    docs = list(db.collection("vendor_products").stream())
    print(f"Jami Firebase'da: {len(docs)} ta mahsulot\n")

    created = 0
    updated = 0
    skipped = 0
    errors = 0

    for doc in docs:
        doc_id = doc.id
        data = doc.to_dict() or {}

        if not data.get("name"):
            print(f"  [O'TKAZILDI] {doc_id} — nomi yo'q")
            skipped += 1
            continue

        try:
            product_data = build_product_data(doc_id, data)
            category_fid = product_data.pop("_category_id")
            section_fid = product_data.pop("_section_id")

            exists = VendorproductModel.objects.filter(firestore_id=doc_id).first()

            if exists and not update:
                skipped += 1
                continue

            # ForeignKey topish
            category = get_category(category_fid)
            section = get_section(section_fid)

            if exists and update:
                for field, val in product_data.items():
                    setattr(exists, field, val)
                exists.category = category
                exists.section = section
                if not dry_run:
                    exists.save()
                print(f"  [YANGILANDI] {doc_id} — {product_data['name']}")
                updated += 1
            else:
                if not dry_run:
                    VendorproductModel.objects.create(
                        **product_data,
                        category=category,
                        section=section,
                    )
                print(f"  [YARATILDI]  {doc_id} — {product_data['name']}")
                created += 1

        except Exception as e:
            print(f"  [XATO] {doc_id}: {e}")
            errors += 1

    print("\n" + "=" * 50)
    print(f"Yaratildi : {created}")
    print(f"Yangilandi: {updated}")
    print(f"O'tkazildi: {skipped}")
    print(f"Xatolar   : {errors}")
    if dry_run:
        print("\n[DRY-RUN] Hech narsa saqlanmadi.")


# ── Entry point ───────────────────────────────────────────────────────────────

if __name__ == "__main__":
    parser = argparse.ArgumentParser(description="Firebase → Django mahsulot sync")
    parser.add_argument(
        "--dry-run",
        action="store_true",
        help="Haqiqatda DB'ga yozmaydi, faqat natijalari ko'rsatadi",
    )
    parser.add_argument(
        "--update",
        action="store_true",
        help="Mavjud mahsulotlarni ham yangilaydi (default: o'tkazib ketadi)",
    )
    args = parser.parse_args()

    sync_products(dry_run=args.dry_run, update=args.update)