video-accessibility/backend/app/tasks/ingest_and_ai.py

import asyncio
import os
import tempfile
from datetime import datetime

import ffmpeg
from celery import Task
from motor.motor_asyncio import AsyncIOMotorClient

from ..core.config import settings
from ..core.logging import get_logger
from ..models.job import JobStatus
from ..services.gcs import gcs_service, upload_vtt_to_gcs
from ..services.gemini import gemini_service
from ..services.websocket import connection_manager
from . import celery_app

logger = get_logger(__name__)


def broadcast_status_update(job_id: str, status: str, job_title: str = None, message: str = None, progress: int = None):
    """
    Helper function to broadcast job status updates via WebSocket
    Uses sync Redis client for Celery worker context
    """
    logger.info(f"🔊 ATTEMPTING TO BROADCAST: job_id={job_id}, status={status}, job_title={job_title}, message={message}")
    try:
        import redis as sync_redis
        from ..core.config import settings
        from ..services.websocket import JobStatusUpdate
        from datetime import datetime
        
        logger.info(f"🔊 About to create JobStatusUpdate for job {job_id}")
        
        # Create status update
        update = JobStatusUpdate(
            job_id=job_id,
            status=status,
            updated_at=datetime.utcnow(),
            job_title=job_title,
            message=message,
            progress=progress
        )
        
        logger.info(f"🔊 Created update object, now connecting to Redis: {settings.redis_url}")
        
        # Create synchronous Redis client
        redis_client = sync_redis.Redis.from_url(
            settings.redis_url,
            encoding="utf-8",
            decode_responses=True
        )
        
        logger.info(f"🔊 Redis client created, now publishing to channels")
        
        # Publish to channels
        result1 = redis_client.publish("job_status_updates", update.model_dump_json())
        result2 = redis_client.publish(f"job_status_updates:{job_id}", update.model_dump_json())
        
        logger.info(f"🔊 Published to channels - general: {result1} subscribers, job-specific: {result2} subscribers")
        
        # Close connection
        redis_client.close()
        
        logger.info(f"🔊 ✅ Successfully broadcasted status update for job {job_id}: {status}")
        
    except Exception as e:
        logger.error(f"🔊 ❌ Failed to broadcast status update for job {job_id}: {e}")
        import traceback
        logger.error(f"🔊 ❌ Full traceback: {traceback.format_exc()}")
        # Don't let WebSocket failures break the worker task


class AsyncTask(Task):
    """Base task class that supports async execution"""
    def __call__(self, *args, **kwargs):
        loop = asyncio.new_event_loop()
        asyncio.set_event_loop(loop)
        try:
            return loop.run_until_complete(self.run_async(*args, **kwargs))
        finally:
            loop.close()

    async def run_async(self, *args, **kwargs):
        raise NotImplementedError


class IngestAndAITask(AsyncTask):
    async def run_async(self, job_id: str):
        return await ingest_and_ai_task_impl(job_id)


@celery_app.task(bind=True, base=IngestAndAITask)
def ingest_and_ai_task(self, job_id: str):
    """
    Pipeline 1: Ingestion & AI Processing
    Task wrapper that delegates to async implementation
    """
    # This method is called by AsyncTask.__call__
    pass


async def ingest_and_ai_task_impl(job_id: str):
    """
    Pipeline 1: Ingestion & AI Processing
    1. Update status to 'ingesting'
    2. Probe video for metadata (duration, codec)
    3. Process with Gemini 2.5 Pro
    4. Generate VTT files
    5. Update status to 'pending_qc'
    """
    logger.info(f"Starting ingestion and AI processing for job {job_id}")

    # Connect to MongoDB
    client = AsyncIOMotorClient(settings.mongodb_uri)
    db = client[settings.mongodb_db]

    try:
        # Get job document to retrieve title for notifications
        job_doc = await db.jobs.find_one({"_id": job_id})
        if not job_doc:
            logger.error(f"Job {job_id} not found in database")
            return
        
        job_title = job_doc.get("title", "Untitled Job")
        logger.info(f"Processing job: {job_title}")

        # Update status to ingesting
        await db.jobs.update_one(
            {"_id": job_id},
            {
                "$set": {
                    "status": JobStatus.INGESTING.value,
                    "updated_at": datetime.utcnow()
                },
                "$push": {
                    "review.history": {
                        "at": datetime.utcnow(),
                        "status": JobStatus.INGESTING.value,
                        "by": "system"
                    }
                }
            }
        )

        # Get job details
        job_doc = await db.jobs.find_one({"_id": job_id})
        if not job_doc:
            raise ValueError(f"Job {job_id} not found")

        # Download video file temporarily for processing
        source_blob_path = job_doc["source"]["gcs_uri"].replace(f"gs://{settings.gcs_bucket}/", "")

        with tempfile.NamedTemporaryFile(suffix=".mp4", delete=False) as temp_file:
            temp_path = temp_file.name

            # Download from GCS
            blob = gcs_service.bucket.blob(source_blob_path)
            blob.download_to_filename(temp_path)

            try:
                # Update status to AI processing
                await db.jobs.update_one(
                    {"_id": job_id},
                    {
                        "$set": {
                            "status": JobStatus.AI_PROCESSING.value,
                            "updated_at": datetime.utcnow()
                        },
                        "$push": {
                            "review.history": {
                                "at": datetime.utcnow(),
                                "status": JobStatus.AI_PROCESSING.value,
                                "by": "system"
                            }
                        }
                    }
                )

                # Probe video for metadata
                duration = await _get_video_duration(temp_path)

                # Update source with duration
                await db.jobs.update_one(
                    {"_id": job_id},
                    {"$set": {"source.duration_s": duration}}
                )

                # Process with Gemini
                ai_result = await gemini_service.extract_accessibility(temp_path)

                # Final safety check for required fields
                required_fields = ["captions_vtt", "audio_description_vtt"]
                missing_fields = [field for field in required_fields if field not in ai_result]

                if missing_fields:
                    logger.error(f"Missing required fields after AI processing: {missing_fields}")
                    # Create fallback content for missing fields
                    if "audio_description_vtt" in missing_fields:
                        ai_result["audio_description_vtt"] = "WEBVTT\n\n00:00:00.000 --> 00:00:05.000\nVideo content with visual elements."
                        logger.info("Created fallback audio_description_vtt")

                # Get detected language from Gemini response
                detected_language = ai_result.get("language", "en")
                language_hint = job_doc["source"].get("language_hint")
                initial_language = job_doc["source"].get("language", "en")

                # Log if there's a mismatch between hint/initial and detected language
                if language_hint and language_hint != detected_language:
                    logger.warning(
                        f"Language mismatch for job {job_id}: "
                        f"hint={language_hint}, detected={detected_language}"
                    )
                elif initial_language != "auto" and initial_language != detected_language:
                    logger.info(
                        f"Language detection for job {job_id}: "
                        f"initial={initial_language}, detected={detected_language}"
                    )

                # Use detected language for output storage
                source_language = detected_language
                logger.info(f"Using detected language '{source_language}' for job {job_id}")

                # Upload VTT files to GCS using detected language
                captions_gcs_uri = await upload_vtt_to_gcs(
                    ai_result["captions_vtt"],
                    f"{job_id}/{source_language}/captions.vtt"
                )

                ad_gcs_uri = await upload_vtt_to_gcs(
                    ai_result["audio_description_vtt"],
                    f"{job_id}/{source_language}/ad.vtt"
                )

                # Update job with AI results, detected language, and outputs
                await db.jobs.update_one(
                    {"_id": job_id},
                    {
                        "$set": {
                            "status": JobStatus.PENDING_QC.value,
                            "source.language": source_language,  # Update with detected language
                            "source.detected_language": detected_language,
                            "ai.ingestion_json": ai_result,
                            "ai.confidence": ai_result["confidence"],
                            f"outputs.{source_language}": {
                                "captions_vtt_gcs": captions_gcs_uri,
                                "ad_vtt_gcs": ad_gcs_uri
                            },
                            "updated_at": datetime.utcnow()
                        },
                        "$push": {
                            "review.history": {
                                "at": datetime.utcnow(),
                                "status": JobStatus.PENDING_QC.value,
                                "by": "system"
                            }
                        }
                    }
                )
                
                # Broadcast status update
                broadcast_status_update(
                    job_id, 
                    JobStatus.PENDING_QC.value,
                    job_title=job_title,
                    message=f"{job_title} has completed AI processing and is ready for QC review"
                )

                logger.info(f"Successfully completed ingestion and AI processing for job {job_id}")

            finally:
                # Clean up temp file
                os.unlink(temp_path)

    except Exception as e:
        logger.error(f"Ingestion and AI processing failed for job {job_id}: {e}")

        # Update job with error
        await db.jobs.update_one(
            {"_id": job_id},
            {
                "$set": {
                    "error": {
                        "type": "ingestion_failure",
                        "message": str(e),
                        "timestamp": datetime.utcnow().isoformat()
                    },
                    "updated_at": datetime.utcnow()
                }
            }
        )

        raise

    finally:
        client.close()


async def _get_video_duration(video_path: str) -> float:
    """Get video duration using ffprobe"""
    try:
        probe = ffmpeg.probe(video_path)
        duration = float(probe['streams'][0]['duration'])
        return duration
    except Exception as e:
        logger.warning(f"Could not determine video duration: {e}")
        return 0.0