import asyncio
import os
import random
import string
from collections import AsyncIterable
from typing import Callable, AsyncGenerator, Optional, Any, Coroutine
import discord
import gtts


async def async_filter(fun: Callable, iterable: AsyncIterable) -> AsyncGenerator:
    async for val in iterable:
        if fun(val):
            yield val


def find_category(guild: discord.Guild, group: str) -> Optional[discord.CategoryChannel]:
    group = group.lower()
    for cat in guild.categories:
        if cat.name.lower() == group:
            return cat
    return None


async def find_role_case_insensitive(guild: discord.Guild, name: str, prefix: str = '') -> Optional[discord.Role]:
    for role in await guild.fetch_roles():
        if name.strip().lower() == role.name[len(prefix):].lower():
            return role
    return None


def link_channel(channel: discord.abc.GuildChannel, italic: bool = False) -> str:
    if italic:
        return '[*' + channel.name + '*](https://discord.com/channels/' + str(channel.guild.id) + '/' + str(
            channel.id) + ')'
    return '[' + channel.name + '](https://discord.com/channels/' + str(channel.guild.id) + '/' + str(channel.id) + ')'


def text_to_speech(text: str, lang: str = "de") -> (discord.AudioSource, Callable[[], None]):
    tts = gtts.gTTS(text, lang=lang)
    os.makedirs('temp', exist_ok=True)
    file_name = 'temp/' + ''.join(random.choice(string.ascii_lowercase) for i in range(12)) + '.mp3'
    tts.save(file_name)
    source = discord.PCMVolumeTransformer(
        discord.FFmpegPCMAudio(source=file_name, before_options='-v quiet', options='-filter:a "atempo=1.5"')
    )

    def destroy():
        os.remove(file_name)

    return source, destroy


async def connect_and_play(
        channel: discord.VoiceChannel, source: discord.AudioSource,
        after_play: Optional[Callable[[discord.DiscordException, discord.VoiceProtocol], Any]] = None
) -> Optional[discord.VoiceClient]:
    # noinspection PyTypeChecker
    client: discord.VoiceClient = await channel.connect()
    after_callback: Optional[Callable[[discord.DiscordException], Any]]
    if after_play is None:
        after_callback = None
    else:
        def callback(exc: discord.DiscordException) -> Any:
            after_play(exc, client)

        after_callback = callback

    client.play(source, after=after_callback)
    return client