from __future__ import annotations

from celery import Celery

from govoplan_core.core.campaigns import CAPABILITY_CAMPAIGNS_DELIVERY_TASKS, CampaignDeliveryTaskProvider
from govoplan_core.core.module_management import load_startup_enabled_modules, startup_candidate_module_ids
from govoplan_core.core.modules import ModuleContext
from govoplan_core.core.runtime import configure_runtime
from govoplan_core.settings import settings
from govoplan_core.db.session import configure_database
from govoplan_core.server.registry import available_module_manifests, build_platform_registry

configure_database(settings.database_url)

celery = Celery(
    "multimailer",
    broker=settings.redis_url,
    backend=settings.redis_url,
)

celery.conf.update(
    task_default_queue="default",
    task_routes={
        "multimailer.send_email": {"queue": "send_email"},
        "multimailer.append_sent": {"queue": "append_sent"},
    },
    worker_prefetch_multiplier=1,
    task_acks_late=True,
    task_reject_on_worker_lost=True,
)


@celery.task(name="multimailer.ping")
def ping():
    return "pong"


def _campaign_delivery_tasks() -> CampaignDeliveryTaskProvider:
    raw_enabled_modules = load_startup_enabled_modules(settings.enabled_modules)
    candidate_modules = startup_candidate_module_ids(settings.enabled_modules, raw_enabled_modules)
    available_modules = available_module_manifests(enabled_modules=candidate_modules, ignore_load_errors=True)
    enabled_modules = load_startup_enabled_modules(settings.enabled_modules, available=available_modules)
    registry = build_platform_registry(enabled_modules)
    context = ModuleContext(registry=registry, settings=settings)
    configure_runtime(context)
    registry.configure_capability_context(context)
    capability = registry.require_capability(CAPABILITY_CAMPAIGNS_DELIVERY_TASKS)
    if not isinstance(capability, CampaignDeliveryTaskProvider):
        raise RuntimeError("Campaign delivery task capability is invalid")
    return capability


@celery.task(name="multimailer.send_email", bind=True, max_retries=0)
def send_email(self, job_id: str):
    """Send one explicitly queued campaign job.

    SMTP failures are persisted but are not retried implicitly. A worker-loss
    redelivery is safe because the delivery service converts an unfinished
    SMTP attempt into ``outcome_unknown`` instead of transmitting again.
    """

    from govoplan_core.db.session import get_database

    with get_database().SessionLocal() as session:
        return dict(_campaign_delivery_tasks().send_campaign_job(session, job_id=job_id, enqueue_imap_task=True))


@celery.task(name="multimailer.append_sent", bind=True, max_retries=None)
def append_sent(self, job_id: str):
    """Append the exact sent MIME to the configured IMAP Sent folder."""

    from govoplan_core.db.session import get_database

    with get_database().SessionLocal() as session:
        try:
            return dict(_campaign_delivery_tasks().append_sent_for_job(session, job_id=job_id))
        except Exception as exc:
            if getattr(exc, "temporary", None) is True:
                raise self.retry(exc=exc, countdown=300)
            raise