import datetime

from sqlalchemy import select
from sqlalchemy.ext.asyncio import AsyncSession

from db.models import User
from db.models.transactions import BalanceTransaction, BalanceTxType
from schemas.users import NewUserDTO


class UserRepository:
    async def get_users(self, session: AsyncSession) -> list[User]:
        stmt = select(User)
        res = await session.execute(stmt)

        return list(res.scalars().all())

    async def get_user_by_id(self, session: AsyncSession, user_id: int) -> User | None:
        stmt = select(User).where(User.id == user_id)
        result = await session.execute(stmt)

        return result.scalar_one_or_none()

    async def create_user(self, session: AsyncSession, user_data: NewUserDTO) -> User:
        user = User(
            id=user_data.id,
            referal_id=user_data.referal,
            subscription_link=user_data.link,
        )
        session.add(user)
        await session.commit()

        return user

    async def update_user_topic(
        self, session: AsyncSession, user_id: int, thread_id: int
    ) -> User | None:
        user = await self.get_user_by_id(session, user_id=user_id)
        if not user:
            return None
        user.support_thread_id = thread_id

        await session.commit()
        return user

    async def update_user_link(self, session: AsyncSession, user_id: int, link: str) -> User | None:
        user = await self.get_user_by_id(session, user_id=user_id)
        if not user:
            return None
        user.subscription_link = link

        await session.commit()
        return user

    async def update_user_balance(
        self, session: AsyncSession, user_id: int, balance: int
    ) -> User | None:
        user = await self.get_user_by_id(session, user_id=user_id)
        if not user:
            return None
        user.balance = balance

        await session.commit()
        return user

    async def increase_user_balance(
        self,
        session: AsyncSession,
        user_id: int,
        amount: int,
        tx_type: BalanceTxType,
        description: str,
    ) -> User | None:
        user = await self.get_user_by_id(session, user_id=user_id)
        if not user:
            return None

        created_at = datetime.datetime.now(datetime.UTC)
        transaction = BalanceTransaction(
            user_id=user_id,
            amount=amount,
            tx_type=tx_type,
            balance_before=user.balance,
            balance_after=user.balance + amount,
            description=description,
            created_at=created_at,
        )

        user.balance += amount

        session.add(transaction)

        await session.commit()
        return user

    async def decrease_user_balance(
        self,
        session: AsyncSession,
        user_id: int,
        amount: int,
        tx_type: BalanceTxType,
        description: str,
    ) -> User | None:
        user = await self.get_user_by_id(session, user_id=user_id)
        if not user or user.balance < amount:
            return None

        created_at = datetime.datetime.now(datetime.timezone.UTC)
        transaction = BalanceTransaction(
            user_id=user_id,
            amount=amount,
            tx_type=tx_type,
            balance_before=user.balance,
            balance_after=user.balance + amount,
            description=description,
            created_at=created_at,
        )

        user.balance -= amount
        session.add(transaction)

        await session.commit()
        return user