"""
Discard API router
"""
import os
import logging
from fastapi import APIRouter, Depends, HTTPException
from sqlalchemy import select, and_
from sqlalchemy.ext.asyncio import AsyncSession

from app.database import get_db
from app.models import Photo

logger = logging.getLogger(__name__)

router = APIRouter()

@router.get("")
async def list_discarded(db: AsyncSession = Depends(get_db)):
    """List discarded photos"""
    result = await db.execute(
        select(Photo).where(Photo.is_discarded == True)
    )
    photos = result.scalars().all()
    return photos

@router.post("/restore")
async def restore_photos(photo_ids: list[str], db: AsyncSession = Depends(get_db)):
    """Restore photos from the discard pile"""
    result = await db.execute(
        select(Photo).where(and_(Photo.id.in_(photo_ids), Photo.is_discarded == True))
    )
    photos = result.scalars().all()

    for photo in photos:
        photo.is_discarded = False
        photo.discarded_at = None

    await db.commit()
    return {"status": "success", "restored": len(photos)}

@router.delete("/empty")
async def empty_discard(db: AsyncSession = Depends(get_db)):
    """Permanently delete all discarded photos and unlink their files from
    disk. Failures on individual files are logged but don't abort the batch.
    """
    result = await db.execute(
        select(Photo).where(Photo.is_discarded == True)
    )
    photos = result.scalars().all()

    deleted = 0
    file_errors = 0
    for photo in photos:
        try:
            if photo.filepath and os.path.exists(photo.filepath):
                os.unlink(photo.filepath)
        except OSError as e:
            file_errors += 1
            logger.error(f"Failed to unlink {photo.filepath}: {e}")
        await db.delete(photo)
        deleted += 1

    await db.commit()
    return {
        "status": "success",
        "deleted": deleted,
        "file_errors": file_errors,
    }