from typing import Any

from fastapi import APIRouter, Depends, HTTPException, status
from sqlalchemy.orm import Session

from app import crud, models, schemas
from app.api import deps

router = APIRouter()


@router.get("/", response_model=schemas.Cart)
def read_user_cart(
    db: Session = Depends(deps.get_db),
    current_user: models.User = Depends(deps.get_current_active_user),
) -> Any:
    """
    Get current user's cart with all items.
    """
    cart = crud.cart.get_cart_with_items(db, user_id=current_user.id)
    if not cart:
        # Create a new cart for the user if it doesn't exist
        cart = crud.cart.create(db, obj_in=schemas.CartCreate(user_id=current_user.id))
    return cart


@router.post("/items", response_model=schemas.CartItem)
def add_cart_item(
    *,
    db: Session = Depends(deps.get_db),
    item_in: schemas.CartItemCreate,
    current_user: models.User = Depends(deps.get_current_active_user),
) -> Any:
    """
    Add item to cart. If item already exists, update quantity.
    """
    # Verify the product exists and is active
    product = crud.product.get(db, id=item_in.product_id)
    if not product or not product.is_active:
        raise HTTPException(
            status_code=status.HTTP_404_NOT_FOUND,
            detail="Product not found or inactive",
        )

    # Check if product is in stock
    if product.stock < item_in.quantity:
        raise HTTPException(
            status_code=status.HTTP_400_BAD_REQUEST,
            detail=f"Not enough stock. Available: {product.stock}",
        )

    # Get or create user's cart
    cart = crud.cart.get_or_create_cart(db, user_id=current_user.id)

    # Add or update cart item
    cart_item = crud.cart_item.create_or_update_cart_item(
        db, cart_id=cart.id, product_id=item_in.product_id, quantity=item_in.quantity
    )

    return cart_item


@router.put("/items/{product_id}", response_model=schemas.CartItem)
def update_cart_item(
    *,
    db: Session = Depends(deps.get_db),
    product_id: int,
    item_in: schemas.CartItemUpdate,
    current_user: models.User = Depends(deps.get_current_active_user),
) -> Any:
    """
    Update cart item quantity.
    """
    # Verify the product exists and is active
    product = crud.product.get(db, id=product_id)
    if not product or not product.is_active:
        raise HTTPException(
            status_code=status.HTTP_404_NOT_FOUND,
            detail="Product not found or inactive",
        )

    # Check if product is in stock
    if product.stock < item_in.quantity:
        raise HTTPException(
            status_code=status.HTTP_400_BAD_REQUEST,
            detail=f"Not enough stock. Available: {product.stock}",
        )

    # Get user's cart
    cart = crud.cart.get_by_user_id(db, user_id=current_user.id)
    if not cart:
        raise HTTPException(
            status_code=status.HTTP_404_NOT_FOUND,
            detail="Cart not found",
        )

    # Update cart item
    cart_item = crud.cart_item.create_or_update_cart_item(
        db, cart_id=cart.id, product_id=product_id, quantity=item_in.quantity
    )

    return cart_item


@router.delete("/items/{product_id}", status_code=status.HTTP_204_NO_CONTENT, response_model=None)
def remove_cart_item(
    *,
    db: Session = Depends(deps.get_db),
    product_id: int,
    current_user: models.User = Depends(deps.get_current_active_user),
) -> None:
    """
    Remove item from cart.
    """
    # Get user's cart
    cart = crud.cart.get_by_user_id(db, user_id=current_user.id)
    if not cart:
        raise HTTPException(
            status_code=status.HTTP_404_NOT_FOUND,
            detail="Cart not found",
        )

    # Remove cart item
    crud.cart_item.remove_cart_item(db, cart_id=cart.id, product_id=product_id)


@router.delete("/", status_code=status.HTTP_204_NO_CONTENT, response_model=None)
def clear_cart(
    *,
    db: Session = Depends(deps.get_db),
    current_user: models.User = Depends(deps.get_current_active_user),
) -> None:
    """
    Clear all items from cart.
    """
    # Get user's cart
    cart = crud.cart.get_by_user_id(db, user_id=current_user.id)
    if not cart:
        raise HTTPException(
            status_code=status.HTTP_404_NOT_FOUND,
            detail="Cart not found",
        )

    # Clear cart
    crud.cart_item.clear_cart(db, cart_id=cart.id)