import datetime

from sqlalchemy import select

from models import User
from models.deal import *
from schemas.deal import *
from services.base import BaseService


class DealService(BaseService):

    async def _get_deal_by_id(self, deal_id) -> Deal:
        return await self.session.get(Deal, deal_id)

    async def create(self, request: DealCreateRequest) -> DealCreateResponse:
        deal = Deal(
            name=request.name,
            created_at=datetime.datetime.now(),
            current_status=DealStatus.AWAITING_ACCEPTANCE
        )
        self.session.add(deal)
        await self.session.commit()
        return DealCreateResponse(ok=True)

    async def change_status(self, request: DealChangeStatusRequest, user: User) -> DealChangeStatusResponse:
        # Changing current status
        deal = await self._get_deal_by_id(request.deal_id)
        from_status = deal.current_status
        deal.current_status = request.new_status

        # Append status history
        status_change = DealStatusHistory(
            deal_id=request.deal_id,
            user_id=user.id,
            changed_at=datetime.datetime.now(),
            from_status=from_status,
            to_status=request.new_status
        )
        self.session.add(status_change)
        await self.session.commit()
        return DealChangeStatusResponse(ok=True)