from typing import List, Optional

from fastapi import APIRouter, Depends, HTTPException, Query, BackgroundTasks
from sqlalchemy.orm import Session
from app.core.database import get_db
from app.api.deps import get_current_user
from app.tasks.background_tasks import process_marketplace_import
from middleware.decorators import rate_limit
from models.api_models import MarketplaceImportJobResponse, MarketplaceImportRequest
from models.database_models import User, MarketplaceImportJob, Shop
from datetime import datetime
import logging

router = APIRouter()
logger = logging.getLogger(__name__)


# Enhanced Statistics with Marketplace Support
@router.get("/stats", response_model=StatsResponse)
def get_stats(db: Session = Depends(get_db), current_user: User = Depends(get_current_user)):
    """Get comprehensive statistics with marketplace data (Protected)"""

    # Use more efficient queries with proper indexes
    total_products = db.query(Product).count()

    unique_brands = db.query(Product.brand).filter(
        Product.brand.isnot(None),
        Product.brand != ""
    ).distinct().count()

    unique_categories = db.query(Product.google_product_category).filter(
        Product.google_product_category.isnot(None),
        Product.google_product_category != ""
    ).distinct().count()

    # New marketplace statistics
    unique_marketplaces = db.query(Product.marketplace).filter(
        Product.marketplace.isnot(None),
        Product.marketplace != ""
    ).distinct().count()

    unique_shops = db.query(Product.shop_name).filter(
        Product.shop_name.isnot(None),
        Product.shop_name != ""
    ).distinct().count()

    # Stock statistics
    total_stock_entries = db.query(Stock).count()
    total_inventory = db.query(func.sum(Stock.quantity)).scalar() or 0

    return StatsResponse(
        total_products=total_products,
        unique_brands=unique_brands,
        unique_categories=unique_categories,
        unique_marketplaces=unique_marketplaces,
        unique_shops=unique_shops,
        total_stock_entries=total_stock_entries,
        total_inventory_quantity=total_inventory
    )


@router.get("/marketplace-stats", response_model=List[MarketplaceStatsResponse])
def get_marketplace_stats(db: Session = Depends(get_db), current_user: User = Depends(get_current_user)):
    """Get statistics broken down by marketplace (Protected)"""

    # Query to get stats per marketplace
    marketplace_stats = db.query(
        Product.marketplace,
        func.count(Product.id).label('total_products'),
        func.count(func.distinct(Product.shop_name)).label('unique_shops'),
        func.count(func.distinct(Product.brand)).label('unique_brands')
    ).filter(
        Product.marketplace.isnot(None)
    ).group_by(Product.marketplace).all()

    return [
        MarketplaceStatsResponse(
            marketplace=stat.marketplace,
            total_products=stat.total_products,
            unique_shops=stat.unique_shops,
            unique_brands=stat.unique_brands
        ) for stat in marketplace_stats
    ]