from os import getenv
import sys

import asyncio
from commands import answer, await_n, bot_commands
import config

import discord
from discord.ext import commands


class Cupido(commands.Bot):
    def __init__(self, *args, **kwargs):
        super().__init__(*args, **kwargs)
        self.meta_channel = None
        self.lobby_channel = None
        self.pair_channels = []
        self.task = None

    async def await_coroutine(self, co):
        if self.task is not None:
            return 'already running'
        self.task = asyncio.create_task(co)
        try:
            result = await self.task
        except asyncio.CancelledError:
            self.task = None
            return 'cancelled'
        finally:
            self.task = None
        return result

    async def cancel_coroutine(self):
        if self.task is not None:
            self.task.cancel()

    async def on_ready(self):
        print(f'the bot {config.NAME} is logged in as "{self.user}"')

    async def create_category(self, ctx):
        category = await ctx.guild.create_category(config.CATEGORY_CHANNEL_NAME)
        await answer(ctx, f'info: category created "{category}" ({category.id})')
        return category

    async def create_lobby(self, ctx):
        lobby = await ctx.guild.create_voice_channel(
            config.LOBBY_CHANNEL_NAME,
            topic=config.LOBBY_CHANNEL_TOPIC,
            category=self.meta_channel,
        )
        await answer(ctx, f'info: voice channel created "{lobby}" ({lobby.id})')
        return lobby

    def get_meta_channel(self, ctx):
        return self.meta_channel or discord.utils.get(ctx.guild.categories, name=config.CATEGORY_CHANNEL_NAME)

    def get_lobby_channel(self, ctx, meta_channel):
        return (self.lobby_channel
                or discord.utils.get(
                    ctx.guild.voice_channels,
                    name=config.LOBBY_CHANNEL_NAME,
                    category=meta_channel
                ))

    def get_pair_channels_no_cache(self, ctx, meta_channel):
        return sorted((channel for channel in ctx.guild.voice_channels
                       if channel.category == meta_channel
                       and channel.name.isdigit()),
                      key=lambda c: c.name)

    def get_pair_channels(self, ctx, meta_channel):
        return self.pair_channels or self.get_pair_channels_no_cache(ctx, meta_channel)

    async def try_delete_channel(self, channel):
        try:
            await channel.delete()
            return True
        except discord.errors.NotFound:
            return False

    async def send_panel(self, ctx, user):
        pass

    async def destroy_pair_channels(self, ctx, meta_channel):
        await await_n(map(self.try_delete_channel, self.get_pair_channels_no_cache(ctx, meta_channel)))
        self.pair_channels = []

    async def create_pair_channels(self, ctx, meta_channel, n):
        await self.destroy_pair_channels(ctx, meta_channel)
        futures = []
        for i in range(1, n + 1):
            futures.append(ctx.guild.create_voice_channel(str(i), category=meta_channel))
        return await await_n(futures)

    async def get_channels(self, ctx):
        meta_channel = self.get_meta_channel(ctx)
        lobby_channel = self.get_lobby_channel(ctx, meta_channel)
        if meta_channel is None or lobby_channel is None:
            await answer(ctx, 'error: cannot start shuffling, you need to initialize channels')
            return None
        return meta_channel, lobby_channel


def main():
    token = getenv(config.TOKEN_ENV_VAR)
    if token is None:
        print('error: no token was given')
        sys.exit(1)
    bot = Cupido(activity=discord.Game(name=config.GAME_STATUS), command_prefix=config.COMMAND_PREFIX, case_insensitive=True)
    bot.remove_command('help')
    for cmd in bot_commands:
        bot.add_command(cmd)
    bot.run(token)


if __name__ == '__main__':
    while True:
        try:
            main()
        except KeyboardInterrupt:
            break
        except Exception as e:
            print(f'[DEBUG] encountered exception: {type(e)}: {e}')
            if e.args == ('Event loop is closed',):
                print('[DEBUG] quit...')
                break
            print('[DEBUG] restarting...')