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

from app.media.models import Attachment
from app.messages.models import Message


async def create_attachment(
    db: AsyncSession,
    *,
    message_id: int,
    file_url: str,
    file_type: str,
    file_size: int,
) -> Attachment:
    attachment = Attachment(
        message_id=message_id,
        file_url=file_url,
        file_type=file_type,
        file_size=file_size,
    )
    db.add(attachment)
    await db.flush()
    return attachment


async def get_attachment_by_id(db: AsyncSession, attachment_id: int) -> Attachment | None:
    return await db.get(Attachment, attachment_id)


async def list_chat_attachments(
    db: AsyncSession,
    *,
    chat_id: int,
    limit: int = 100,
    before_id: int | None = None,
) -> list[tuple[Attachment, Message]]:
    stmt = (
        select(Attachment, Message)
        .join(Message, Message.id == Attachment.message_id)
        .where(Message.chat_id == chat_id)
        .order_by(Attachment.id.desc())
        .limit(limit)
    )
    if before_id is not None:
        stmt = stmt.where(Attachment.id < before_id)
    result = await db.execute(stmt)
    return [(row[0], row[1]) for row in result.all()]