from __future__ import annotations

from dataclasses import dataclass
from typing import Any, Awaitable, Callable, Dict, List, Optional

from core.error_handler import capture_errors


Subscriber = Callable[[Any], Awaitable[None]]
Requester = Callable[[Any], Awaitable[Any]]


@dataclass
class BusMessage:
    topic: str
    data: Any


class MessageBus:
    def __init__(self) -> None:
        self._topics: Dict[str, List[Subscriber]] = {}
        self._services: Dict[str, Any] = {}
        self._requests: Dict[str, Requester] = {}

    def subscribe(self, topic: str, handler: Subscriber) -> None:
        handlers = self._topics.setdefault(topic, [])
        handlers.append(capture_errors(handler))

    async def publish(self, topic: str, data: Any) -> None:
        for handler in list(self._topics.get(topic, [])):
            await handler(data)

    def register_request_handler(self, topic: str, handler: Requester) -> None:
        self._requests[topic] = handler

    async def request(self, topic: str, data: Any) -> Optional[Any]:
        handler = self._requests.get(topic)
        if not handler:
            return None
        return await handler(data)

    def register_service(self, name: str, service: Any) -> None:
        self._services[name] = service

    def get_service(self, name: str) -> Any:
        return self._services.get(name)