import json
import uuid
from datetime import datetime, timezone

from auth.authenticate import login_required
from base.redis import redis
from base.resolvers import mutation


@mutation.field("updateChat")
@login_required
async def update_chat(_, info, chat_new: dict):
    """
    updating chat
    requires info["request"].user.slug to be in chat["admins"]

    :param info: GraphQLInfo with request
    :param chat_new: dict with chat data
    :return: Result { error chat }
    """
    user = info.context["request"].user
    chat_id = chat_new["id"]
    chat = await redis.execute("GET", f"chats/{chat_id}")
    if not chat:
        return {
            "error": "chat not exist"
        }
    chat = dict(json.loads(chat))
    if user.slug in chat["admins"]:
        chat.update({
            "title": chat_new.get("title", chat["title"]),
            "description": chat_new.get("description", chat["description"]),
            "updatedAt": int(datetime.now(tz=timezone.utc).timestamp()),
            "admins": chat_new.get("admins", chat["admins"]),
            "users": chat_new.get("users", chat["users"])
        })
    await redis.execute("SET", f"chats/{chat.id}", json.dumps(chat))
    await redis.execute("COMMIT")

    return {
        "error": None,
        "chat": chat
    }


@mutation.field("createChat")
@login_required
async def create_chat(_, info, title="", members=[]):
    user = info.context["request"].user
    chat_id = str(uuid.uuid4())
    if user.slug not in members:
        members.append(user.slug)
    chat = {
        "title": title,
        "createdAt": int(datetime.now(tz=timezone.utc).timestamp()),
        "updatedAt": int(datetime.now(tz=timezone.utc).timestamp()),
        "createdBy": user.slug,
        "id": chat_id,
        "users": members,
        "admins": [user.slug, ]
    }
    # double creation protection
    cids = await redis.execute("SMEMBERS", f"chats_by_user/{user.slug}")
    for cid in cids:
        c = await redis.execute("GET", F"chats/{cid.decode('utf-8')}")
        isc = [x for x in c["users"] if x not in chat["users"]]
        if isc == [] and chat["title"] == c["title"]:
            return {
                "error": "chat was created before",
                "chat": chat
            }

    for m in members:
        await redis.execute("SADD", f"chats_by_user/{m}", chat_id)
    await redis.execute("SET", f"chats/{chat_id}", json.dumps(chat))
    await redis.execute("SET", f"chats/{chat_id}/next_message_id", str(0))
    await redis.execute("COMMIT")
    return {
        "error": None,
        "chat": chat
    }


@mutation.field("deleteChat")
@login_required
async def delete_chat(_, info, chat_id: str):
    user = info.context["request"].user
    chat = await redis.execute("GET", f"/chats/{chat_id}")
    if chat:
        chat = dict(json.loads(chat))
        if user.slug in chat['admins']:
            await redis.execute("DEL", f"chats/{chat_id}")
            await redis.execute("SREM", "chats_by_user/" + user, chat_id)
            await redis.execute("COMMIT")
    else:
        return {
            "error": "chat not exist"
        }