import asyncio
import json
import logging
from typing import Any, Dict, List, Optional, Union

from models.chat import ChatPayload
from resolvers.chats import create_chat
from services.auth import login_required
from services.core import CacheStorage
from services.rediscache import redis
from services.schema import query


logger = logging.getLogger('[resolvers.load] ')
logger.setLevel(logging.DEBUG)


async def get_unread_counter(chat_id: str, member_id: int) -> int:
    unread = await redis.execute('LLEN', f'chats/{chat_id}/unread/{member_id}')
    if isinstance(unread, int):
        return unread
    else:
        return 0


# NOTE: not an API handler
async def load_messages(chat_id: str, limit: int = 5, offset: int = 0, ids: Optional[List[int]] = None):
    """load :limit messages for :chat_id with :offset"""
    logger.info('load_messages')
    messages = []
    try:
        message_ids = [] + (ids or [])
        if limit:
            mids = await redis.execute('LRANGE', f'chats/{chat_id}/message_ids', offset, offset + limit)
            if isinstance(mids, list):
                message_ids.extend(mids)
        if message_ids:
            message_keys = [f'chats/{chat_id}/messages/{mid}' for mid in message_ids]
            messages = await redis.execute('MGET', *message_keys)
            if isinstance(messages, list):
                messages = [json.loads(m) if isinstance(m, str) else m for m in messages]
                replies = []
                for m in messages:
                    if m:
                        reply_to = m.get('reply_to')
                        if reply_to:
                            reply_to = int(reply_to)
                            if reply_to not in message_ids:
                                replies.append(reply_to)
                if replies:
                    more_messages = await load_messages(chat_id, offset, limit, replies)
                    if isinstance(more_messages, list):
                        messages.extend(more_messages)
    except Exception as ex:
        logger.error(ex)
        import traceback

        traceback.print_exc()
    return messages


@query.field('load_chats')
@login_required
async def load_chats(_, info, limit: int = 50, offset: int = 0) -> Dict[str, Union[List[Dict[str, Any]], None]]:
    """load :limit chats of current user with :offset"""
    logger.info('load_chats')
    author_id = info.context['author_id']
    chats = []
    try:
        if author_id:
            logger.debug('got author', author_id)
            cids = await redis.execute('SMEMBERS', f'chats_by_author/{author_id}')
            logger.debug('got cids', cids)
            members_online = (await redis.execute('SMEMBERS', 'authors-online')) or []  # to show online status
            logger.debug('members online', members_online)
            if isinstance(cids, set):
                # TODO: add sort by chat.created_at with in-memory caching chats service
                cids = list(cids)[offset : (offset + limit)]
                lock = asyncio.Lock()
                if len(cids) == 0:
                    logger.debug(f'no chats for user with id={author_id}')
                    r = await create_chat(None, info, members=[2])  # member with id = 2 is discours
                    logger.debug(f"created chat: {r['chat_id']}")
                    cids.append(r['chat']['id'])

                logger.debug(f"getting data for {len(cids)} user's chats")
                for cid in cids:
                    async with lock:
                        chat_str = await redis.execute('GET', f'chats/{cid}')
                        if isinstance(chat_str, str):
                            logger.debug(f'redis GET by {cid}: {chat_str}')
                            c: ChatPayload = json.loads(chat_str)
                            c['messages'] = (await load_messages(cid, 5, 0)) or []
                            c['unread'] = await get_unread_counter(cid, author_id)
                            member_ids = c['members'].copy()
                            c['members'] = []
                            for member_id in member_ids:
                                a = CacheStorage.authors_by_id.get(str(member_id))
                                if a:
                                    a['online'] = a.get('id') in members_online
                                    c['members'].append(a)
                                else:
                                    logger.error(f'cant find author by id {member_id}')
                            chats.append(c)

                        else:
                            logger.error(f'cant find chat by id {cid}')
    except Exception:
        import traceback

        traceback.print_exc()
    return {'chats': chats, 'error': None}


@query.field('load_messages_by')
@login_required
async def load_messages_by(_, info, by, limit: int = 10, offset: int = 0):
    """load :limit messages of :chat_id with :offset"""
    logger.info('load_messages_by')
    author_id = info.context['author_id']
    author_chats = await redis.execute('SMEMBERS', f'chats_by_author/{author_id}')
    try:
        if isinstance(author_chats, set):
            author_chats = list(author_chats)
            messages = []
            by_chat = by.get('chat')
            if by_chat in author_chats:
                chat = await redis.execute('GET', f'chats/{by_chat}')
                if not chat:
                    return {'messages': [], 'error': 'chat not exist'}
                # everyone's messages in filtered chat
                messages = await load_messages(by_chat, limit, offset)
                if isinstance(messages, list):
                    sorted_messages = [m for m in messages if m and m.get('created_at')]
                    return {
                        'messages': sorted(
                            sorted_messages,
                            key=lambda m: m.get('created_at'),
                        ),
                        'error': None,
                    }

    except Exception as exc:
        logger.error(exc)
        import traceback

        traceback.print_exc()
    return {'error': 'Cannot get messages of this chat'}