import logging
from dataclasses import dataclass, field

from django.db import transaction

logger = logging.getLogger(__name__)


@dataclass
class EventDefinition:
    name: str
    description: str = ""
    example_payload: dict = field(default_factory=dict)
    schema: dict = field(default_factory=dict)


class EventRegistry:
    _events: dict[str, EventDefinition] = {}

    @classmethod
    def register(cls, event_name, *, description="", example_payload=None, schema=None):
        cls._events[event_name] = EventDefinition(
            name=event_name,
            description=description,
            example_payload=example_payload or {},
            schema=schema or {},
        )
        logger.debug(f"Event registered: {event_name}")

    @classmethod
    def emit(cls, event_name, payload: dict):
        from django.db.models import Q

        from .models import OutboundSubscription

        active_subs = OutboundSubscription.objects.filter(
            Q(event_name=event_name) | Q(event_name="*"),
            is_active=True,
            endpoint__is_active=True,
        ).select_related("endpoint")

        with transaction.atomic():
            for sub in active_subs:
                transaction.on_commit(
                    lambda sid=sub.id, en=event_name, pl=payload, pt=sub.payload_template: __import__(  # type: ignore[misc]
                        "infrasynth.webhooks.dispatch", fromlist=["deliver_webhook"]
                    ).deliver_webhook.delay(sid, en, pl, pt)
                )

    @classmethod
    def get_registered_events(cls) -> dict[str, EventDefinition]:
        return dict(cls._events)