"""In-memory event bus for local development and testing."""

import asyncio
import logging
from collections import defaultdict
from collections.abc import Awaitable, Callable

from .base import EventBus, EventPayload

logger = logging.getLogger(__name__)


class MemoryEventBus(EventBus):
    """In-memory event bus implementation for local development"""

    def __init__(self) -> None:
        self.handlers: dict[
            str, list[Callable[[str, EventPayload], Awaitable[None]]]
        ] = defaultdict(list)
        self.running = False

    async def publish(self, topic: str, payload: EventPayload) -> bool:
        """Publish event to topic"""
        try:
            if not self.running:
                logger.warning(
                    "Event bus not running, skipping publish to topic: %s", topic
                )
                return False

            handlers = self.handlers.get(topic, [])
            if not handlers:
                logger.debug("No handlers for topic: %s", topic)
                return True

            # Execute all handlers concurrently
            tasks = [handler(topic, payload) for handler in handlers]
            await asyncio.gather(*tasks, return_exceptions=True)

            logger.debug(
                "Published event to topic %s with %d handlers", topic, len(handlers)
            )
            return True
        except Exception as e:
            logger.error("Failed to publish event to topic %s: %s", topic, e)
            return False

    async def subscribe(
        self, topic: str, handler: Callable[[str, EventPayload], Awaitable[None]]
    ) -> None:
        """Subscribe to topic with handler"""
        self.handlers[topic].append(handler)
        logger.debug("Subscribed handler to topic: %s", topic)

    async def start(self) -> None:
        """Start the event bus"""
        self.running = True
        logger.info("Memory event bus started")

    async def stop(self) -> None:
        """Stop the event bus"""
        self.running = False
        self.handlers.clear()
        logger.info("Memory event bus stopped")