from fastapi import APIRouter, Depends
from sqlalchemy.ext.asyncio import AsyncSession
from sqlalchemy import select, func

from app.database import get_db
from app.models.notification import Notification
from app.models.user import User
from app.schemas.notification import NotificationOut
from app.deps import get_current_user

router = APIRouter(prefix="/notifications", tags=["notifications"])


@router.get("", response_model=list[NotificationOut])
async def list_notifications(
    db: AsyncSession = Depends(get_db),
    current_user: User = Depends(get_current_user),
):
    result = await db.execute(
        select(Notification)
        .where(Notification.user_id == current_user.id)
        .order_by(Notification.created_at.desc())
        .limit(30)
    )
    return result.scalars().all()


@router.get("/unread-count")
async def unread_count(
    db: AsyncSession = Depends(get_db),
    current_user: User = Depends(get_current_user),
):
    count = await db.scalar(
        select(func.count()).where(
            Notification.user_id == current_user.id,
            Notification.is_read == False,  # noqa: E712
        )
    )
    return {"count": count or 0}


@router.post("/{notif_id}/read", status_code=204)
async def mark_read(
    notif_id: int,
    db: AsyncSession = Depends(get_db),
    current_user: User = Depends(get_current_user),
):
    result = await db.execute(
        select(Notification).where(
            Notification.id == notif_id,
            Notification.user_id == current_user.id,
        )
    )
    notif = result.scalar_one_or_none()
    if notif and not notif.is_read:
        notif.is_read = True
        try:
            await db.commit()
        except Exception:
            await db.rollback()
            raise


@router.post("/read-all", status_code=204)
async def mark_all_read(
    db: AsyncSession = Depends(get_db),
    current_user: User = Depends(get_current_user),
):
    result = await db.execute(
        select(Notification).where(
            Notification.user_id == current_user.id,
            Notification.is_read == False,  # noqa: E712
        )
    )
    notifs = result.scalars().all()
    for n in notifs:
        n.is_read = True
    try:
        await db.commit()
    except Exception:
        await db.rollback()
        raise