discord-playback-bot/bot.js

/*
  shred.ing-discord - audio streaming c2+util
  Copyright 2025 Corwin Brust <corwin@bru.st>

This program is free software; you can redistribute it and/or modify
it under the terms of the GNU Public License as published by
the Free Software Foundation, either version 3 of the License, or (at
your option) any later version.

This program is distributed in the hope that it will be useful,
but WITHOUT ANY WARRANTY; without even the implied warranty of
MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
GNU General Public License for more details.

You should have received a copy of the GNU Public License
along with this program.  If not, see <https://www.gnu.org/licenses/>.

  Commentary:

  Thanks to numerious kind folks on IRC on SO, as well ihis helpful post
  that turned me onto Eris: https://www.toptal.com/chatbot/how-to-make-a-discord-bot
*/

const fs = require('fs');
//const eris = require('eris');
const eris = require("@projectdysnomia/dysnomia");


const configEnvVar = 'SHRED_BOT_CONFIG';
const configFile = process.env.hasOwnProperty( configEnvVar )
      ? process.env[ configEnvVar ]
      : '/opt/shred.ing/discord-channels-simple.json';

const shredConfig = JSON.parse( fs.readFileSync( configFile ) );

function writeConfig() { fs.writeFileSync( configFile, JSON.stringify( shredConfig ) ) }

const uri = shredConfig.uri;

const bot = new eris.Client(fs.readFileSync(shredConfig.tokenFile).toString(), {
    seedVoiceConnections: true,
    reconnectDelay: 17000
});
bot.on('error', err => console.debug({
    what:"error",
    where:"bot",
    error:err
}));
process.on("unhandledRejection", err => console.debug({
    what:"unhandledRejection",
    where:"process",
    error:err
}));
process.on("uncaughtException", err => console.debug({
    what:"uncaughtException",
    where:"process",
    error:err
}));


const joinAndPlay = function (msg) {
    _internal_join_and_play( msg.member.voiceState.channelID, msg.channel.id);
};

let activeChannels = {};

const _internal_join_and_play = function( joinID, msgID ) {
    bot.joinVoiceChannel(joinID).catch((err) => {
	if(msgID) {
	    bot.createMessage(msgID, "Error joining voice channel: " + err.message);
	}
	console.debug({
	    what:"catch",
	    where:"join",
	    joinID:joinID,
	    msgID:msgID,
	    error:err
	});
    }).then((connection) => {

      const ac = { playing: false, timer: false };

      ac.stop = function() { connection.stopPlaying(); };
      ac.play = function() {
	connection.play( uri, { voiceDataTimeout: 17000 });
	ac.playing = true
      };
      ac.before = function() {
	if (connection.playing) { // Stop playing if the connection is playing something
	  connection.stopPlaying();
	}
      };
      ac.when = function() {
	  //if(msgID) bot.createMessage(msgID, `Now playing **${uri}**`);
      },
      ac.after = function() {
	ac.playing = false;
	  //console.log(`Finished in ${ joinID }`);
      },

      ac.cancel = function() {
	if(ac.timer) clearInterval( ac.timer );
	if(ac.playing) ac.stop();
      };

      ac.start = function() {
	ac.before();
	ac.play();
	ac.when();
	connection.once("end", () => { ac.after() });
      };

      ac.maybeStart = function() {
	try {
	  if(! ac.playing ) {
	    ac.start();
	  }
	} catch(err) {
	    console.debug({
		what:"catch",
		where:"maybeStart",
		error:err
	    });
	}
      };
      activeChannels[ joinID ] = ac;
      ac.timer = setInterval( ac.maybeStart, 100 );
    });
};

const doAutoJoin = function () {
    const autoJoin = shredConfig.autoJoin;
    for(var i = 0; i < autoJoin.length; ++i) {
	try {
	//console.debug({autoJoin:autoJoin[i],botGuilds:bot.guilds,chanGet:bot.guilds.get( autoJoin[i].guild )});
	    //const vc = bot.guilds.get( autoJoin[i].guild ).channels.get( autoJoin[i].channel );
	    //_internal_join_and_play( vc.id );
	    _internal_join_and_play( autoJoin[i].channel );
	}
	catch (err) {
	    console.debug({
		what:"catch",
		where:"doAutoJoin",
		guild:auoJoin[i].guild,
		id:autoJoin[i].channel,
		error:err
	    });
	}
    }
};

let title = null;
let trackUri = '';
function formatArtist(artist,album,year) {
    var rv = '';
    if(album) {
	rv = rv ? rv + ' ' + album : album;
    }
    if(year && album != year) {
	rv = rv ? `${rv}, *${year}*` : year
    }
    if(artist) {
	rv = rv ? (rv.includes('(')?`__${artist}__, ${rv}` : `__${artist}__ (${rv})`) : artist;
    }
    return rv;
}
function formatTrackTitle(meta) {
    if(! meta) return '';

    const {title,artist,album,date,year,filename} = meta;
    const who = formatArtist(artist,album,year||date);
    const fileUri
	  = 'https://f.shred.ing/'
	  + encodeURI(
	      filename.replace('/spokes/gw11/storage/ftp/music/','')
	  );
    //console.log({title:title,who:who,fUri:fileUri,artist:artist,album:album,date:date,year:year,fname:filename});
    const rv = title +' '+ formatArtist(artist,album,year||date);
    return [rv,fileUri];
}
const setStatus = async function() {
    try {
	const response = await fetch( shredConfig.titleUri );
	if(!response.ok) {
	    console.debug({
		what:"request.ok",
		where:"setStatus",
		error:err
	    });
	}
	const json = await response.json();
	if(json) {
	    let [newTitle,newLink] = formatTrackTitle(Object.fromEntries( json ));
	    if(newTitle && newTitle != title) {
		//console.log("Playing[discord]: " + newTitle + ' at ' + newLink);
		title = newTitle;
		trackUri = newLink;
		bot.editStatus("online", [ { name: title, type: 0, url: newLink}]);
	    }
	}
    } catch (err) {
	console.debug({
	    what:"catch",
	    where:"setStatus",
	    error:err
	});
    }
};
let timer = setInterval( setStatus, 10000 );

// Every time a message is sent anywhere the bot is present,
// this event will fire and we will check if the bot was mentioned.
// If it was, the bot will attempt to respond with "Present".
bot.on('messageCreate', async (msg) => {
   const botWasMentioned = msg.mentions.find(
       mentionedUser => mentionedUser.id === bot.user.id,
   );

   if (botWasMentioned) {
       try {
	   if( msg.content.indexOf( 'stop' ) != -1) {
	       // request to stop
	       if(! msg.member.voiceState.channelID ) {
		   // user is not in a voice channel
		    bot.createMessage(msg.channel.id, "You are not in a voice channel.");
	       } else {
		   const chan = bot.guilds.get( msg.guildID ).channels.get( msg.member.voiceState.channelID );
		   if(chan.id && activeChannels[ chan.id ]) activeChannels[ chan.id ].cancel()
		   chan.leave();
	       }
	   } else if( msg.content.indexOf( 'join' ) != -1) {
	       // request to join a channel
	       if(! msg.member.voiceState.channelID ) {
		   // user is not in a voice channel
		    bot.createMessage(msg.channel.id, "You are not in a voice channel.");
	       } else {
		   joinAndPlay( msg );
	       }
	   } else if( msg.content.indexOf( 'reconnect' ) != -1) {
	       // request to join a channel
	       if( msg.member.voiceState.channelID)
		   joinAndPlay( msg );
	   } else {
	       // treat everything else a request for current track title
	       await msg.channel.createMessage(title +"\n\n[Download/Permalink]("+ trackUri +")\n");
	   }
       } catch (err) {
           // There are various reasons why sending a message may fail.
           // The API might time out or choke and return a 5xx status,
           // or the bot may not have permission to send the
           // message (403 status).
	   console.debug({
	       what:"replyMessageError",
	       where:"messageCreate",
	       error:err
	   })
       }
   }
});

let autoJoinTimer;
function setAutoJoinTimeout( waitTime ) {
    if(autoJoinTimer) return;
    autoJoinTimer = setTimeout( () => {
	autoJoinTimer=null;
	doAutoJoin();
    }, waitTime );
    return autoJoinTimer;
}

bot.connect();

setAutoJoinTimeout( 1000 );