import logging
from decimal import Decimal
from enum import Enum
from typing import Optional

from src.ez_lan_manager.services.AccountingService import AccountingService
from src.ez_lan_manager.services.DatabaseService import DatabaseService
from src.ez_lan_manager.services.UserService import UserService
from src.ez_lan_manager.types.CateringOrder import CateringOrder, CateringOrderStatus, CateringMenuItemsWithAmount
from src.ez_lan_manager.types.CateringMenuItem import CateringMenuItem, CateringMenuItemCategory

logger = logging.getLogger(__name__.split(".")[-1])


class CateringErrorType(Enum):
    INCLUDES_DISABLED_ITEM = 0
    INSUFFICIENT_FUNDS = 1
    GENERIC = 99


class CateringError(Exception):
    def __init__(self, message: str, error_type: CateringErrorType = CateringErrorType.GENERIC) -> None:
        self.message = message
        self.error_type = error_type


class CateringService:
    def __init__(self, db_service: DatabaseService, accounting_service: AccountingService, user_service: UserService):
        self._db_service = db_service
        self._accounting_service = accounting_service
        self._user_service = user_service
        self.cached_cart: dict[int, list[CateringMenuItem]] = {}

    # ORDERS

    async def place_order(self, menu_items: CateringMenuItemsWithAmount, user_id: int,
                          is_delivery: bool = True) -> CateringOrder:
        for menu_item in menu_items:
            if menu_item.is_disabled:
                raise CateringError("Order includes disabled items", CateringErrorType.INCLUDES_DISABLED_ITEM)

        user = await self._user_service.get_user(user_id)
        if not user:
            raise CateringError("User does not exist")

        total_price = sum([item.price * quantity for item, quantity in menu_items.items()], Decimal(0))
        if await self._accounting_service.get_balance(user_id) < total_price:
            raise CateringError("Insufficient funds", CateringErrorType.INSUFFICIENT_FUNDS)

        order = await self._db_service.add_new_order(menu_items, user_id, is_delivery)
        if order:
            await self._accounting_service.remove_balance(user_id, total_price, f"CATERING - {order.order_id}")
        logger.info(
            f"User '{order.customer.user_name}' (ID:{order.customer.user_id}) ordered from catering for {self._accounting_service.make_euro_string_from_decimal(total_price)}")
        # await self.cancel_order(order)  # ToDo: Check if commented out before commit. Un-comment to auto-cancel every placed order
        return order

    async def update_order_status(self, order_id: int, new_status: CateringOrderStatus) -> bool:
        if new_status == CateringOrderStatus.CANCELED:
            # Cancelled orders need to be refunded
            raise CateringError("Orders cannot be canceled this way, use CateringService.cancel_order")
        return await self._db_service.change_order_status(order_id, new_status)

    async def get_orders(self) -> list[CateringOrder]:
        return await self._db_service.get_orders()

    async def get_orders_for_user(self, user_id: int) -> list[CateringOrder]:
        return await self._db_service.get_orders(user_id=user_id)

    async def get_orders_by_status(self, status: CateringOrderStatus) -> list[CateringOrder]:
        return await self._db_service.get_orders(status=status)

    async def cancel_order(self, order: CateringOrder) -> bool:
        change_result = await self._db_service.change_order_status(order.order_id, CateringOrderStatus.CANCELED)
        if change_result:
            await self._accounting_service.add_balance(order.customer.user_id, order.price,
                                                       f"CATERING REFUND - {order.order_id}")
            return True
        return False

    # MENU ITEMS

    async def get_menu(self, category: Optional[CateringMenuItemCategory] = None) -> list[CateringMenuItem]:
        items = await self._db_service.get_menu_items()
        if not category:
            return items
        return list(filter(lambda item: item.category == category, items))

    async def get_menu_item_by_id(self, menu_item_id: int) -> CateringMenuItem:
        item = await self._db_service.get_menu_item(menu_item_id)
        if not item:
            raise CateringError("Menu item not found")
        return item

    async def add_menu_item(self, name: str, info: str, price: Decimal, category: CateringMenuItemCategory,
                            is_disabled: bool = False) -> CateringMenuItem:
        if new_item := await self._db_service.add_menu_item(name, info, price, category, is_disabled):
            return new_item
        raise CateringError(f"Could not add item '{name}' to the menu.")

    async def remove_menu_item(self, menu_item_id: int) -> bool:
        return await self._db_service.delete_menu_item(menu_item_id)

    async def change_menu_item(self, updated_item: CateringMenuItem) -> bool:
        return await self._db_service.update_menu_item(updated_item)

    async def disable_menu_item(self, menu_item_id: int) -> bool:
        try:
            item = await self.get_menu_item_by_id(menu_item_id)
        except CateringError:
            return False
        item.is_disabled = True
        return await self._db_service.update_menu_item(item)

    async def enable_menu_item(self, menu_item_id: int) -> bool:
        try:
            item = await self.get_menu_item_by_id(menu_item_id)
        except CateringError:
            return False
        item.is_disabled = False
        return await self._db_service.update_menu_item(item)

    async def disable_menu_items_by_category(self, category: CateringMenuItemCategory) -> bool:
        items = await self.get_menu(category=category)
        return all([self.disable_menu_item(item.item_id) for item in items])

    async def enable_menu_items_by_category(self, category: CateringMenuItemCategory) -> bool:
        items = await self.get_menu(category=category)
        return all([self.enable_menu_item(item.item_id) for item in items])

    # CART

    def save_cart(self, user_id: Optional[int], cart: list[CateringMenuItem]) -> None:
        if user_id:
            self.cached_cart[user_id] = cart

    def get_cart(self, user_id: Optional[int]) -> list[CateringMenuItem]:
        if user_id is None:
            return []
        try:
            return self.cached_cart[user_id]
        except KeyError:
            return []