from lexorank import lexorank
from sqlalchemy import select, insert, update, delete
from sqlalchemy.orm import selectinload

from models import DealService as DealServiceModel, User, Deal, DealProduct, Product, GroupBillRequest
from models.deal_group import DealGroup, deal_relations
from schemas.group import *
from services.base import BaseService
from services.deal import DealService


class DealGroupService(BaseService):
    async def get_deals_by_group_id(self, group_id) -> list[Deal]:
        group: DealGroup | None = await self.session.scalar(
            select(DealGroup)
            .where(DealGroup.id == group_id)
            .options(
                selectinload(DealGroup.deals).selectinload(Deal.products).selectinload(DealProduct.services),
                selectinload(DealGroup.deals).selectinload(Deal.products)
                .selectinload(DealProduct.product).selectinload(Product.barcodes),
                selectinload(DealGroup.deals).selectinload(Deal.services).selectinload(DealServiceModel.service),
                selectinload(DealGroup.deals).selectinload(Deal.status_history),
                selectinload(DealGroup.deals).selectinload(Deal.group).selectinload(DealGroup.deals),
                selectinload(DealGroup.deals).joinedload(Deal.client),
                selectinload(DealGroup.deals).joinedload(Deal.shipping_warehouse),
            )
        )
        return group.deals if group else []

    async def create_group_model(self) -> DealGroup:
        group = DealGroup(
            name='',
            lexorank=lexorank.middle(lexorank.Bucket.BUCEKT_0).__str__(),
        )
        self.session.add(group)
        await self.session.flush()
        return group

    async def create_group(self, user: User, request: DealCreateGroupRequest) -> DealCreateGroupResponse:
        try:
            group = await self.create_group_model()

            for deal_id in [request.dragging_deal_id, request.hovered_deal_id]:
                insert_stmt = insert(deal_relations).values({
                    'deal_id': deal_id,
                    'group_id': group.id
                })
                await self.session.execute(insert_stmt)
            # changing status if needed on draggable deal
            dragging_deal = await self.session.scalar(
                select(Deal).where(Deal.id == request.dragging_deal_id)
            )
            dropped_deal = await self.session.scalar(
                select(Deal).where(Deal.id == request.hovered_deal_id)
            )
            if dragging_deal.current_status_id != dropped_deal.current_status_id:
                deal_service = DealService(self.session)
                await deal_service.change_status(dragging_deal, dropped_deal.current_status_id, user)
            await self.session.commit()
            return DealCreateGroupResponse(ok=True, message="Группа успешно создана")
        except Exception as e:
            return DealCreateGroupResponse(ok=False, message=str(e))

    async def update_group(self, request: DealGroupUpdateRequest) -> DealGroupUpdateResponse:
        try:
            group = await self.session.scalar(
                select(DealGroup).where(DealGroup.id == request.data.id)
            )
            if not group:
                return DealGroupUpdateResponse(ok=False, message="Группа не найдена")
            # update by dictionary
            request_dict = request.data.model_dump()
            request_dict.pop("bill_request", None)

            update_stmt = (
                update(DealGroup)
                .where(DealGroup.id == request.data.id)
                .values(**request_dict)
            )
            await self.session.execute(update_stmt)
            await self.session.commit()
            return DealGroupUpdateResponse(ok=True, message="Группа успешно обновлена")
        except Exception as e:
            await self.session.rollback()
            return DealGroupUpdateResponse(ok=False, message=str(e))

    async def complete_group(self, group_id: int) -> list[Deal]:
        deals = await self.get_deals_by_group_id(group_id)
        for deal in deals:
            deal.is_completed = True
        return deals

    async def delete_group(self, group_id: int) -> None:
        deals = await self.get_deals_by_group_id(group_id)
        for deal in deals:
            deal.is_deleted = True
        await self.session.commit()

    async def change_group_status(
            self,
            user: User,
            request: DealGroupChangeStatusRequest,
    ) -> DealGroupChangeStatusResponse:
        try:
            # getting all deals in group
            deals = await self.session.scalars(
                select(deal_relations.c.deal_id)
                .where(deal_relations.c.group_id == request.group_id)
            )

            deal_service = DealService(self.session)
            for deal_id in deals:
                deal = await self.session.scalar(
                    select(Deal).where(Deal.id == deal_id)
                )
                await deal_service.change_status(deal, request.new_status, user)
            await self.session.commit()
            return DealGroupChangeStatusResponse(ok=True, message="Статус группы успешно изменен")
        except Exception as e:
            await self.session.rollback()
            return DealGroupChangeStatusResponse(ok=False, message=str(e))

    async def add_deal(self, user: User, request: DealAddToGroupRequest) -> DealAddToGroupResponse:
        try:
            group_bill_request = await self.session.get(GroupBillRequest, request.group_id)
            if group_bill_request:
                raise Exception("Нельзя добавить сделку, так как на группу выставлен счёт.")

            # changing status if needed
            deal_id = await self.session.scalar(
                select(deal_relations.c.deal_id)
                .where(deal_relations.c.group_id == request.group_id)
            )
            group_deal_status = await self.session.scalar(
                select(Deal.current_status_id)
                .where(Deal.id == deal_id)
            )
            request_deal = await self.session.scalar(
                select(Deal).where(Deal.id == request.deal_id)
            )
            if group_deal_status != request_deal.current_status_id:
                await DealService(self.session).change_status(request_deal, group_deal_status, user)
            insert_stmt = insert(deal_relations).values({
                'deal_id': request.deal_id,
                'group_id': request.group_id
            })
            await self.session.execute(insert_stmt)
            await self.session.commit()

            return DealAddToGroupResponse(ok=True, message="Сделка успешно добавлена в группу")
        except Exception as e:
            await self.session.rollback()
            return DealAddToGroupResponse(ok=False, message=str(e))

    async def remove_deal(self, request: DealRemoveFromGroupRequest) -> DealRemoveFromGroupResponse:
        try:
            delete_stmt = (
                delete(deal_relations)
                .where(
                    deal_relations.c.deal_id == request.deal_id,
                )
            )
            await self.session.execute(delete_stmt)
            await self.session.commit()
            return DealRemoveFromGroupResponse(ok=True, message="Сделка успешно удалена из группы")
        except Exception as e:
            await self.session.rollback()
            return DealRemoveFromGroupResponse(ok=False, message=str(e))