import os
from pathlib import Path

import asyncio
from celery import Celery
from celery.signals import worker_init, worker_shutdown
from celery.utils.log import get_task_logger

from auto_transcoder.model import MediaDAO, RedisManager
from auto_transcoder.services import transcode_media

redis_manager: RedisManager | None = None
logger = get_task_logger(__name__)

celery_app = Celery('auto_transcoder', config_source='auto_transcoder.celeryconfig')

@worker_init.connect
def setup_worker(**kwargs):
    global redis_manager
    redis_manager = RedisManager(os.environ.get("REDIS_URL", "redis://localhost:6379/0"))

@worker_shutdown.connect
def teardown_worker(**kwargs):
    asyncio.run(__teardown_worker())

async def __teardown_worker():
    global redis_manager
    if redis_manager:
        await redis_manager.close()
        redis_manager = None

@celery_app.task(ignore_result=True)
def transcode_media_task(inode: int, recycle_bin_path: str | None = None):
    async def process(inode: int, recycle_bin_path: str | None = None):
        global redis_manager
        if not redis_manager:
            raise RuntimeError("RedisManager is not initialized")
        async with redis_manager as manager:
            media_dao = MediaDAO(manager)
            media_dto = await media_dao.get_media_by_inode(inode)
            if not media_dto.is_transcoded:
                logger.info(f"Transcoding media with inode {inode}")
                new_medias = await transcode_media(media_dto, Path.from_uri(recycle_bin_path) if recycle_bin_path else None)
                if new_medias:
                    await asyncio.gather(
                        media_dao.batch_set_media(new_medias),
                        media_dao.delete_media(media_dto),
                    )
    asyncio.run(process(inode, recycle_bin_path))