backend/app/worker/tasks.py

import logging
import socket
import os
from datetime import datetime, UTC
from celery.exceptions import SoftTimeLimitExceeded
from app.worker.celery_app import celery_app
from app.core.processor import process_file
from app.db.database import SessionLocal
from app.models.user_model import User
from app.models.job_model import Job

logger = logging.getLogger(__name__)

@celery_app.task(
    bind=True,
    max_retries=3,
    soft_time_limit=300,
    time_limit=360,
    retry_backoff=True,
    retry_backoff_max=600,
    acks_late=True,
    reject_on_worker_lost=True
)

def process_file_task(self, file_id: int):
    worker_id = socket.gethostname()
    logger.info(f"Starting Celery worker process for file_id: {file_id}")
    db = SessionLocal()
    job = db.query(Job).filter(Job.job_id == self.request.id).first()

    if not job:
        job = Job(
            job_id=self.request.id,
            file_id=file_id,
            status="QUEUED",
            worker_id=worker_id
        )
        db.add(job)

    job.status = "PROCESSING"
    job.started_at = datetime.now(UTC)
    db.commit()

    logger.info(f"Starting Celery worker process for file_id: {file_id}")
    try:
        from app.models.file_model import File
        db_file = db.query(File).filter(File.id == file_id).first()
        
        if not db_file:
            logger.info(f"File {file_id} not found (possibly user deleted account). Aborting task.")
            job.status = "CANCELLED"
            job.finished_at = datetime.now(UTC)
            db.commit()
            return

        if db_file.filetype and db_file.filetype.startswith('video/'):
            from app.services.video_processor import process_video_pipeline
            process_video_pipeline(file_id, db_file.filepath, db)
        else:
            process_file(file_id, db)

        job.status = "COMPLETED"
        job.finished_at = datetime.now(UTC)
        logger.info(f"Successfully processed file_id: {file_id}")
        db.commit()

    except SoftTimeLimitExceeded as exc:
        logger.error(f"Task for file_id {file_id} timed out. Requeuing...")
        job.status = "FAILED"
        job.error_message = "SoftTimeLimitExceeded"
        job.finished_at = datetime.now(UTC)
        db.commit()
        db.close()
        raise self.retry(exc=exc)

    except Exception as exc:
        logger.error(f"Error processing file_id {file_id}: {exc}. Retrying...")
        job.status  = "FAILED"
        job.error_message = str(exc)
        job.finished_at = datetime.now(UTC)
        db.commit()
        db.close()
        raise self.retry(exc=exc)
    
    except BaseException as exc:
        job.status = "FAILED"
        job.error_message = f"CRITICAL WORKER DEATH {type(exc).__name__}"
        db.commit()
        raise
        
    finally:
        db.close()

@celery_app.task
def delete_guest_file_task(file_id: int):
    db = SessionLocal()
    try:
        from app.models.file_model import File
        db_file = db.query(File).filter(File.id == file_id).first()
        from app.core.storage import active_storage
        if db_file:
            if db_file.filepath:
                active_storage.delete(db_file.filepath)
            if db_file.heatmap_path:
                active_storage.delete(db_file.heatmap_path)

            db.delete(db_file)
            db.commit()
            logger.info(f"Guest file {file_id} wiped from servers after 15 minutes.")
        
    except Exception as e:
        logger.error(f"Failed to auto-delete guest file {file_id}: {e}")
    finally:
        db.close()