from fastapi import APIRouter, Depends, HTTPException, Query
from sqlalchemy.ext.asyncio import AsyncSession
from sqlalchemy import select, func, update
from app.core.database import get_db
from app.core.deps import get_current_user
from app.models.models import User, Notification
from app.schemas.schemas import NotificationResponse, NotificationListResponse

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


@router.get("", response_model=NotificationListResponse)
async def list_notifications(
    page: int = Query(1, ge=1),
    size: int = Query(20, ge=1, le=100),
    unread_only: bool = False,
    user: User = Depends(get_current_user),
    db: AsyncSession = Depends(get_db),
):
    q = select(Notification).where(Notification.user_id == user.id)
    if unread_only:
        q = q.where(Notification.is_read == 0)
    total_q = select(func.count(Notification.id)).where(Notification.user_id == user.id)
    total = (await db.execute(total_q)).scalar()
    q = q.order_by(Notification.created_at.desc()).offset((page - 1) * size).limit(size)
    items = (await db.execute(q)).scalars().all()
    unread = (await db.execute(
        select(func.count(Notification.id)).where(
            Notification.user_id == user.id, Notification.is_read == 0
        )
    )).scalar()
    return NotificationListResponse(
        items=[NotificationResponse.model_validate(n) for n in items],
        total=total,
        unread=unread,
    )


@router.put("/{notification_id}/read")
async def mark_read(
    notification_id: int,
    user: User = Depends(get_current_user),
    db: AsyncSession = Depends(get_db),
):
    result = await db.execute(
        select(Notification).where(
            Notification.id == notification_id,
            Notification.user_id == user.id
        )
    )
    n = result.scalar_one_or_none()
    if not n:
        raise HTTPException(status_code=404, detail="通知不存在")
    n.is_read = 1
    await db.commit()
    return {"message": "已标记已读"}


@router.put("/read-all")
async def mark_all_read(
    user: User = Depends(get_current_user),
    db: AsyncSession = Depends(get_db),
):
    await db.execute(
        update(Notification).where(
            Notification.user_id == user.id,
            Notification.is_read == 0
        ).values(is_read=1)
    )
    await db.commit()
    return {"message": "全部已读"}


@router.delete("/{notification_id}")
async def delete_notification(
    notification_id: int,
    user: User = Depends(get_current_user),
    db: AsyncSession = Depends(get_db),
):
    result = await db.execute(
        select(Notification).where(
            Notification.id == notification_id,
            Notification.user_id == user.id
        )
    )
    n = result.scalar_one_or_none()
    if not n:
        raise HTTPException(status_code=404, detail="通知不存在")
    await db.delete(n)
    await db.commit()
    return {"message": "已删除"}