from __future__ import annotations

from slack_sdk.errors import SlackApiError
from slack_sdk.web.async_client import AsyncWebClient

from yuxi.channels.adapters.slack.dm_cache import DmChannelCache
from yuxi.utils.logging_config import logger


async def resolve_channel_id(
    client: AsyncWebClient,
    target: str,
    dm_cache: DmChannelCache | None = None,
) -> str | None:
    if target.startswith("C") or target.startswith("G") or target.startswith("D"):
        return target

    if target.startswith("U"):
        if dm_cache:
            cached = dm_cache.get(target)
            if cached:
                return cached
        try:
            result = await client.conversations_open(users=[target])
            if not result.get("ok"):
                return None
            channel_id = result.get("channel", {}).get("id", "")
            if channel_id and dm_cache:
                dm_cache.put(target, channel_id)
            return channel_id
        except SlackApiError as e:
            logger.warning(f"Failed to resolve DM channel for user {target}: {e}")
            return None

    try:
        result = await client.users_lookupByEmail(email=target)
        if result.get("ok"):
            user = result.get("user", {})
            user_id = user.get("id", "")
            if user_id:
                if dm_cache:
                    cached = dm_cache.get(user_id)
                    if cached:
                        return cached
                conv_result = await client.conversations_open(users=[user_id])
                if conv_result.get("ok"):
                    channel_id = conv_result.get("channel", {}).get("id", "")
                    if channel_id and dm_cache:
                        dm_cache.put(user_id, channel_id)
                    return channel_id
    except SlackApiError:
        pass

    return None