"""Celery configuration with separate queue lanes.

Queues:
  import      — filesystem import path (FC-2)
  ml          — WD14 + SigLIP inference (FC-2; runs in the ml-worker image)
  thumbnail   — image and video thumbnail generation (FC-2)
  download    — gallery-dl tasks (FC-3)
  scan        — periodic source checks (FC-3) — kept separate so long imports
                don't starve the scheduler
  maintenance — pHash recomputation, centroid rebuild, etc. (FC-2/FC-3)
  default     — anything not explicitly routed
"""

from celery import Celery

from .config import get_config


def make_celery() -> Celery:
    cfg = get_config()
    app = Celery(
        "fabledcurator",
        broker=cfg.celery_broker_url,
        backend=cfg.celery_result_backend,
        include=[
            "backend.app.tasks.smoke",
            "backend.app.tasks.scan",
            "backend.app.tasks.import_file",
            "backend.app.tasks.thumbnail",
            "backend.app.tasks.maintenance",
            "backend.app.tasks.ml",
        ],
    )
    app.conf.update(
        task_default_queue="default",
        task_routes={
            "backend.app.tasks.import_file.*": {"queue": "import"},
            "backend.app.tasks.ml.*": {"queue": "ml"},
            "backend.app.tasks.thumbnail.*": {"queue": "thumbnail"},
            "backend.app.tasks.download.*": {"queue": "download"},
            "backend.app.tasks.scan.*": {"queue": "scan"},
            "backend.app.tasks.maintenance.*": {"queue": "maintenance"},
        },
        # Heavy ML tasks need fair dispatch — see ImageRepo's precedent.
        task_acks_late=True,
        worker_prefetch_multiplier=1,
        broker_connection_retry_on_startup=True,
        beat_schedule={
            "recover-interrupted-tasks": {
                "task": "backend.app.tasks.maintenance.recover_interrupted_tasks",
                "schedule": 300.0,  # every 5 minutes
            },
            "cleanup-old-tasks": {
                "task": "backend.app.tasks.maintenance.cleanup_old_tasks",
                "schedule": 86400.0,  # daily
            },
            "ml-backfill-daily": {
                "task": "backend.app.tasks.ml.backfill",
                "schedule": 86400.0,
            },
            "recompute-centroids-daily": {
                "task": "backend.app.tasks.ml.recompute_centroids",
                "schedule": 86400.0,
            },
            "apply-allowlist-sweep-daily": {
                "task": "backend.app.tasks.ml.apply_allowlist_tags",
                "schedule": 86400.0,
            },
        },
        timezone="UTC",
    )
    return app


celery = make_celery()