const Discord = require('discord.js');
require('dotenv').config();
const tts = require('google-tts-api');
const fetch = require('node-fetch');
const fs = require('fs');
const sha1 = require('sha1');

let joinedVoiceChannels = [];

const bot = new Discord.Client();

bot.on('message', (message) => {
    console.log("I got a message", message);
})

bot.on('ready', async () => {
    console.log("Bot initialized and listening");
    const guild  = await bot.guilds.fetch(process.env.GUILD);
    const channel = await bot.channels.fetch(process.env.CHANNEL);
    await joinChannel(channel);
    
    speak(channel, `Hi! I'm alive. It is now ${new Date().toLocaleTimeString()} on ${new Date().toLocaleDateString()}`);
})

bot.on('voiceStateUpdate', async (oldState, newState) => {
    if (newState.member.user.bot) return;
    if (oldState.channel && newState.channel) return;
    const channel = oldState.channel || newState.channel;
    if (!channel) return;
    if (channel.members.array().length < 2) {
        return await leaveChannel(channel);
    }
    await joinChannel(channel);
    let joined = false;
    if (!oldState.channel) {
        joined = true;
    }

    let username = newState.member.displayName;
    let str = "";
    if (!joined) {
        str = username + " left the channel";
    } else {
        str = username + " joined the channel";
    }
    speak(channel, str);
})


bot.login(process.env.TOKEN);

function isInVoiceChannel(channel) {
    return joinedVoiceChannels.includes(channel);
}

function getConnectionForVoiceChannel(channel) {
    return bot.voice.connections.find((conn) => conn.channel === channel);
}

async function generateVoice(string) {
    const hash = sha1(string);
    const filepath = process.env.VOICE_TMP_PATH + hash + ".mp3";
    if (!fs.existsSync(filepath)) {
        const url = tts.getAudioUrl(string, {lang: "en-us"});
        console.log("Generated url: " + url);
        const data = await fetch(url);
        const contents = await data.arrayBuffer();
        const buf = Buffer.from(contents);
        fs.writeFileSync(filepath, buf);
    }
    return filepath;
}

async function joinChannel(channel) {
    if (!isInVoiceChannel(channel)) {
        const res = await channel.join();
        joinedVoiceChannels.push(channel);
    }
}

async function leaveChannel(channel) {
    if (joinedVoiceChannels.includes(channel)) {
        joinedVoiceChannels = joinedVoiceChannels.filter((chan) => chan !== channel);
        await channel.leave();
    }
}

async function speak(channel, message) {
    const conn = getConnectionForVoiceChannel(channel);
    const filepath = await generateVoice(message);
    if (conn) conn.play(filepath);
}