youtube-music/src/plugins/discord/main.ts

import { app, dialog, ipcMain } from 'electron';
import { Client as DiscordClient } from '@xhayper/discord-rpc';
import { dev } from 'electron-is';

import { SetActivity } from '@xhayper/discord-rpc/dist/structures/ClientUser';

import registerCallback, { type SongInfo } from '@/providers/song-info';

import { createBackend } from '@/utils';

import type { DiscordPluginConfig } from './index';


// Application ID registered by @th-ch/youtube-music dev team
const clientId = '1177081335727267940';

export interface Info {
  rpc: DiscordClient;
  ready: boolean;
  autoReconnect: boolean;
  lastSongInfo?: SongInfo;
}

const info: Info = {
  rpc: new DiscordClient({
    clientId,
  }),
  ready: false,
  autoReconnect: true,
  lastSongInfo: undefined,
};

/**
 * @type {(() => void)[]}
 */
const refreshCallbacks: (() => void)[] = [];

const resetInfo = () => {
  info.ready = false;
  clearTimeout(clearActivity);
  if (dev()) {
    console.log('discord disconnected');
  }

  for (const cb of refreshCallbacks) {
    cb();
  }
};

const connectTimeout = () => new Promise((resolve, reject) => setTimeout(() => {
  if (!info.autoReconnect || info.rpc.isConnected) {
    return;
  }

  info.rpc.login().then(resolve).catch(reject);
}, 5000));
const connectRecursive = () => {
  if (!info.autoReconnect || info.rpc.isConnected) {
    return;
  }

  connectTimeout().catch(connectRecursive);
};

let window: Electron.BrowserWindow;
export const connect = (showError = false) => {
  if (info.rpc.isConnected) {
    if (dev()) {
      console.log('Attempted to connect with active connection');
    }

    return;
  }

  info.ready = false;

  // Startup the rpc client
  info.rpc.login().catch((error: Error) => {
    resetInfo();
    if (dev()) {
      console.error(error);
    }

    if (info.autoReconnect) {
      connectRecursive();
    } else if (showError) {
      dialog.showMessageBox(window, {
        title: 'Connection failed',
        message: error.message || String(error),
        type: 'error',
      });
    }
  });
};

let clearActivity: NodeJS.Timeout | undefined;

export const clear = () => {
  if (info.rpc) {
    info.rpc.user?.clearActivity();
  }

  clearTimeout(clearActivity);
};

export const registerRefresh = (cb: () => void) => refreshCallbacks.push(cb);
export const isConnected = () => info.rpc !== null;

export const backend = createBackend<{
  config?: DiscordPluginConfig;
  updateActivity: (songInfo: SongInfo, config: DiscordPluginConfig) => void;
}, DiscordPluginConfig>({
  /**
   * We get multiple events
   * Next song: PAUSE(n), PAUSE(n+1), PLAY(n+1)
   * Skip time: PAUSE(N), PLAY(N)
   */
  updateActivity: (songInfo, config) => {
    if (songInfo.title.length === 0 && songInfo.artist.length === 0) {
      return;
    }

    info.lastSongInfo = songInfo;

    // Stop the clear activity timout
    clearTimeout(clearActivity);

    // Stop early if discord connection is not ready
    // do this after clearTimeout to avoid unexpected clears
    if (!info.rpc || !info.ready) {
      return;
    }

    // Clear directly if timeout is 0
    if (songInfo.isPaused && config.activityTimoutEnabled && config.activityTimoutTime === 0) {
      info.rpc.user?.clearActivity().catch(console.error);
      return;
    }

    // Song information changed, so lets update the rich presence
    // @see https://discord.com/developers/docs/topics/gateway#activity-object
    // not all options are transfered through https://github.com/discordjs/RPC/blob/6f83d8d812c87cb7ae22064acd132600407d7d05/src/client.js#L518-530
    const hangulFillerUnicodeCharacter = '\u3164'; // This is an empty character
    if (songInfo.title.length < 2) {
      songInfo.title += hangulFillerUnicodeCharacter.repeat(2 - songInfo.title.length);
    }
    if (songInfo.artist.length < 2) {
      songInfo.artist += hangulFillerUnicodeCharacter.repeat(2 - songInfo.title.length);
    }

    const activityInfo: SetActivity = {
      details: songInfo.title,
      state: songInfo.artist,
      largeImageKey: songInfo.imageSrc ?? '',
      largeImageText: songInfo.album ?? '',
      buttons: [
        ...(config.playOnYouTubeMusic ? [{ label: 'Play on YouTube Music', url: songInfo.url ?? '' }] : []),
        ...(config.hideGitHubButton ? [] : [{
          label: 'View App On GitHub',
          url: 'https://github.com/th-ch/youtube-music'
        }]),
      ],
    };

    if (songInfo.isPaused) {
      // Add a paused icon to show that the song is paused
      activityInfo.smallImageKey = 'paused';
      activityInfo.smallImageText = 'Paused';
      // Set start the timer so the activity gets cleared after a while if enabled
      if (config.activityTimoutEnabled) {
        clearActivity = setTimeout(() => info.rpc.user?.clearActivity().catch(console.error), config.activityTimoutTime ?? 10_000);
      }
    } else if (!config.hideDurationLeft) {
      // Add the start and end time of the song
      const songStartTime = Date.now() - ((songInfo.elapsedSeconds ?? 0) * 1000);
      activityInfo.startTimestamp = songStartTime;
      activityInfo.endTimestamp
        = songStartTime + (songInfo.songDuration * 1000);
    }

    info.rpc.user?.setActivity(activityInfo).catch(console.error);
  },
  async start({ window: win, getConfig }) {
    this.config = await getConfig();

    info.rpc.on('connected', () => {
      if (dev()) {
        console.log('discord connected');
      }

      for (const cb of refreshCallbacks) {
        cb();
      }
    });

    info.rpc.on('ready', () => {
      info.ready = true;
      if (info.lastSongInfo && this.config) {
        this.updateActivity(info.lastSongInfo, this.config);
      }
    });

    info.rpc.on('disconnected', () => {
      resetInfo();

      if (info.autoReconnect) {
        connectTimeout();
      }
    });

    info.autoReconnect = this.config.autoReconnect;

    window = win;

    // If the page is ready, register the callback
    win.once('ready-to-show', () => {
      let lastSongInfo: SongInfo;
      registerCallback((songInfo) => {
        lastSongInfo = songInfo;
        if (this.config) this.updateActivity(songInfo, this.config);
      });
      connect();
      let lastSent = Date.now();
      ipcMain.on('timeChanged', (_, t: number) => {
        const currentTime = Date.now();
        // if lastSent is more than 5 seconds ago, send the new time
        if (currentTime - lastSent > 5000) {
          lastSent = currentTime;
          if (lastSongInfo) {
            lastSongInfo.elapsedSeconds = t;
            if (this.config) this.updateActivity(lastSongInfo, this.config);
          }
        }
      });
    });
    app.on('window-all-closed', clear);
  },
  stop() {
    resetInfo();
  },
  onConfigChange(newConfig) {
    this.config = newConfig;
    info.autoReconnect = newConfig.autoReconnect;
    if (info.lastSongInfo) {
      this.updateActivity(info.lastSongInfo, newConfig);
    }
  },
});