"""
Celery configuration and app initialization
"""
import logging
import os

from celery import Celery
from celery.signals import worker_process_init
from app.config import settings

logger = logging.getLogger(__name__)

# Create Celery app
celery_app = Celery(
    'mulita',
    broker=settings.celery_broker_url,
    backend=settings.celery_result_backend,
    include=[
        'app.tasks.scan',
        'app.tasks.thumbs',
        'app.tasks.vision',
        'app.services.metadata',   # extract_metadata lives here
    ]
)

# Configure Celery
celery_app.conf.update(
    task_serializer='json',
    accept_content=['json'],
    result_serializer='json',
    timezone='UTC',
    enable_utc=True,
    # Robust acknowledgment: keep message in broker until task succeeds.
    task_acks_late=True,
    task_reject_on_worker_lost=True,
    # Global time limits — individual tasks can override via decorator.
    task_soft_time_limit=300,   # 5 min — raises SoftTimeLimitExceeded
    task_time_limit=600,        # 10 min — SIGKILL
    # Explicit routes for every task name. Wildcard patterns don't match
    # short names produced by @shared_task(name='...').
    task_routes={
        # Vision queue — GPU/CPU-bound inference
        'embed_photo': {'queue': 'vision'},
        'ocr_photo': {'queue': 'vision'},
        'detect_objects': {'queue': 'vision'},
        'extract_faces': {'queue': 'vision'},
        'classify_content': {'queue': 'vision'},
        'vision_fanout': {'queue': 'vision'},
        'recluster_faces': {'queue': 'vision'},
        # High-priority queue — thumbnails & duplicates
        'generate_thumbnails': {'queue': 'high'},
        'regenerate_all_thumbnails': {'queue': 'high'},
        'backfill_phashes': {'queue': 'high'},
        'regroup_duplicates': {'queue': 'high'},
        'incremental_regroup_duplicates': {'queue': 'high'},
        # Low-priority queue — scans
        'scan_folder': {'queue': 'low'},
        'scan_all_source_roots': {'queue': 'low'},
        'backfill_gps': {'queue': 'low'},
        # Dedicated watcher queue
        'watch_folders': {'queue': 'watcher'},
    },
    task_default_queue='default',
    task_default_exchange='default',
    task_default_exchange_type='direct',
    task_default_routing_key='default',
    broker_connection_retry_on_startup=True,
)


@worker_process_init.connect
def _warmup_vision_models(**kwargs):
    """Pre-load vision models in the worker process so the first task
    doesn't pay cold-start latency. Only runs on the vision queue."""
    # The worker name contains the queue — only warm up vision workers.
    worker_queues = os.environ.get("CELERY_QUEUES", "")
    if "vision" not in worker_queues:
        # Heuristic: check the celery command line for -Q vision
        import sys
        if "vision" not in " ".join(sys.argv):
            return
    try:
        from app.services.vision.registry import registry
        registry.warmup()
    except Exception:
        logger.exception("Vision model warmup failed")