import uuid

from fastapi import Depends

from common.database.db_session_manager import DB_SESSION_MNG
from common.database.model.models import items
from common.enums import DBWRType, ErrorType
from common.logger import LOG
from crud.item_crud import IItemCRUD, ItemCRUD
from router.v1.item.protocol import ItemData, Res_DeleteItem, Res_Item, Res_ItemList


class ItemService:
    """상품 비즈니스 로직. company_id 로 소유권을 확인한다(멀티테넌트)."""

    def __init__(self, item_crud: IItemCRUD = Depends(ItemCRUD)):
        self.item_crud = item_crud

    async def _fetch_owned(self, company_uuid: uuid.UUID, item_id: uuid.UUID):
        """item 조회 + 소유권 확인. (ErrorType, item|None) 반환."""
        err_type, item = await DB_SESSION_MNG.execute_lambda(
            items.DBType(),
            DBWRType.DB_READ.value,
            lambda s: self.item_crud.get_by_id(s, item_id),
        )
        if err_type != ErrorType.SUCCESS or item is None:
            return ErrorType.ITEM_NOT_FOUND, None
        if item.company_id != company_uuid:
            return ErrorType.ITEM_NOT_FOUND, None
        return ErrorType.SUCCESS, item

    async def list_items(self, company_id: str, search, category, page: int, size: int) -> Res_ItemList:
        res = Res_ItemList(page=page, size=size)
        company_uuid = uuid.UUID(company_id)
        skip = (page - 1) * size

        err_type, rows, total = await DB_SESSION_MNG.execute_lambda(
            items.DBType(),
            DBWRType.DB_READ.value,
            lambda s: self.item_crud.search(s, company_uuid, search, category, skip, size),
        )
        if err_type != ErrorType.SUCCESS:
            res.result.SetResult(err_type)
            return res
        res.items = [ItemData.model_validate(r) for r in rows]
        res.total = total
        return res

    async def get_item(self, company_id: str, item_id: str) -> Res_Item:
        res = Res_Item()
        err_type, item = await self._fetch_owned(uuid.UUID(company_id), uuid.UUID(item_id))
        if err_type != ErrorType.SUCCESS:
            res.result.SetResult(err_type)
            return res
        res.item = ItemData.model_validate(item)
        return res

    async def create_item(self, company_id: str, user_id: str, data: dict) -> Res_Item:
        res = Res_Item()
        item = items(**data, company_id=uuid.UUID(company_id), user_id=uuid.UUID(user_id))
        err_type = await DB_SESSION_MNG.execute_lambda_run(
            [items.DBType()],
            [lambda s: self.item_crud.add_item(s, item)],
        )
        if err_type != ErrorType.SUCCESS:
            res.result.SetResult(err_type)
            return res
        # 서버 기본값(created_at/updated_at)은 insert 후 Python 객체에 실리지 않으므로 재조회한다.
        return await self.get_item(company_id, str(item.item_id))

    async def update_item(self, company_id: str, item_id: str, data: dict) -> Res_Item:
        res = Res_Item()
        company_uuid = uuid.UUID(company_id)
        item_uuid = uuid.UUID(item_id)

        # 소유권 확인
        err_type, _ = await self._fetch_owned(company_uuid, item_uuid)
        if err_type != ErrorType.SUCCESS:
            res.result.SetResult(err_type)
            return res

        err_type = await DB_SESSION_MNG.execute_lambda_run(
            [items.DBType()],
            [lambda s: self.item_crud.update_item(s, item_uuid, data)],
        )
        if err_type != ErrorType.SUCCESS:
            res.result.SetResult(err_type)
            return res

        # 갱신 후 재조회
        return await self.get_item(company_id, item_id)

    async def delete_item(self, company_id: str, item_id: str) -> Res_DeleteItem:
        res = Res_DeleteItem()
        company_uuid = uuid.UUID(company_id)
        item_uuid = uuid.UUID(item_id)

        err_type, _ = await self._fetch_owned(company_uuid, item_uuid)
        if err_type != ErrorType.SUCCESS:
            res.result.SetResult(err_type)
            return res

        err_type = await DB_SESSION_MNG.execute_lambda_run(
            [items.DBType()],
            [lambda s: self.item_crud.soft_delete(s, item_uuid)],
        )
        if err_type != ErrorType.SUCCESS:
            res.result.SetResult(err_type)
        return res