"""Сервис для работы с каналами."""
from typing import List, Optional
from sqlalchemy import select
from app.models.channel import Channel, BotChannel
from app.models.bot import Bot
from app.db.session import async_session_maker

class ChannelService:
    """Сервис для работы с каналами."""

    @staticmethod
    async def get_user_channels(user_id: int) -> List[Channel]:
        """Получает список каналов пользователя."""
        async with async_session_maker() as session:
            stmt = select(Channel).where(Channel.owner_id == user_id)
            result = await session.execute(stmt)
            return list(result.scalars().all())

    @staticmethod
    async def get_channel(channel_id: int) -> Optional[Channel]:
        """Получает канал по ID."""
        async with async_session_maker() as session:
            stmt = select(Channel).where(Channel.id == channel_id)
            result = await session.execute(stmt)
            return result.scalars().first()

    @staticmethod
    async def get_bot_channels(bot_id: int) -> List[Channel]:
        """Получает список каналов бота."""
        async with async_session_maker() as session:
            stmt = select(Channel).where(Channel.bot_id == bot_id)
            result = await session.execute(stmt)
            return list(result.scalars().all())

    @staticmethod
    async def add_channel(
        owner_id: int, 
        bot_id: int, 
        chat_id: int, 
        title: Optional[str] = None, 
        username: Optional[str] = None
    ) -> Channel:
        """Добавляет новый канал."""
        async with async_session_maker() as session:
            channel = Channel(
                owner_id=owner_id,
                bot_id=bot_id,
                chat_id=chat_id,
                title=title,
                username=username
            )
            session.add(channel)
            await session.commit()
            await session.refresh(channel)
            return channel

    @staticmethod
    async def update_channel(
        channel_id: int,
        title: Optional[str] = None,
        username: Optional[str] = None
    ) -> bool:
        """Обновляет данные канала."""
        async with async_session_maker() as session:
            stmt = select(Channel).where(Channel.id == channel_id)
            result = await session.execute(stmt)
            channel = result.scalars().first()
            
            if not channel:
                return False
                
            if title is not None:
                channel.title = title
            if username is not None:
                channel.username = username
                
            await session.commit()
            return True

    @staticmethod
    async def delete_channel(channel_id: int) -> bool:
        """Удаляет канал."""
        async with async_session_maker() as session:
            stmt = select(Channel).where(Channel.id == channel_id)
            result = await session.execute(stmt)
            channel = result.scalars().first()
            
            if not channel:
                return False
                
            await session.delete(channel)
            await session.commit()
            return True