import express from 'express';
import { google } from 'googleapis';
import open from 'open';
import fs from 'fs';
import path from 'path';
import { tokenManager } from './tokenManager.js';
(await import('dotenv')).config({
path: './Downloader/secret/config.env',
debug: true
});
const app = express();
const port = 3000;
const { CLIENT_ID, CLIENT_SECRET, REDIRECT_URI } = process.env,
manager = new tokenManager({ clientId: CLIENT_ID, clientSecret: CLIENT_SECRET, redirectUri: REDIRECT_URI, tokenPath: 'Downloader/secret/token.json' });
const oauth2Client = manager.getAuthClient();
// scope to read playlist items/liked videos
const SCOPES = ['https://www.googleapis.com/auth/youtube.readonly'];
let downloadStatus = 'idle'; // can be: 'idle', 'in-progress', 'completed', 'error'
//#region oauth flow
app.get('/auth', async (_req, res) => {
const t = manager.loadToken();
if (t) return res.redirect('/choose-playlist');
// generate auth url
const authUrl = oauth2Client.generateAuthUrl({
access_type: 'offline',
scope: SCOPES
});
// automatically open the url in the default browser
const c = await open(authUrl).catch((err) => {
console.error('error opening browser:', err);
return res.status(500).send('failed to open browser for oauth.');
});
c.on('close', () => res.redirect('/choose-playlist'))
});
app.get('/oauth2callback', async (req, res) => {
try {
const code = req.query.code;
const { tokens } = await oauth2Client.getToken(code);
oauth2Client.setCredentials(tokens);
manager.saveToken(tokens);
// close the window
res.sendStatus(200);
} catch (err) {
console.error('error retrieving token:', err);
res.status(500).send('error retrieving token.');
}
});
//#endregion
//#region youtube stuffs
async function getAllPlaylists(auth) {
const youtube = google.youtube('v3');
let playlists = [];
let nextPageToken = null;
do {
const response = await youtube.playlists.list({
auth,
part: 'snippet',
mine: true,
maxResults: 50,
pageToken: nextPageToken
});
if (response.data.items) {
playlists = playlists.concat(response.data.items);
}
nextPageToken = response.data.nextPageToken;
} while (nextPageToken);
return playlists;
}
async function getPlaylistItems(playlistId, auth) {
const youtube = google.youtube('v3');
let items = [];
let nextPageToken = null;
do {
const response = await youtube.playlistItems.list({
auth,
part: 'snippet,contentDetails',
playlistId,
maxResults: 50,
pageToken: nextPageToken
});
if (response.data.items) {
items = items.concat(response.data.items);
}
nextPageToken = response.data.nextPageToken;
} while (nextPageToken);
return items.map(o => `https://music.youtube.com/watch?v=${o.id}`);
}
//#endregion
//#region routes
app.get('/choose-playlist', async (_req, res) => {
try {
if (!oauth2Client.credentials || !oauth2Client.credentials.access_token) {
const t = manager.loadToken();
if (!t) return res.redirect('/auth');
}
const playlists = await getAllPlaylists(oauth2Client);
let html = `
choose playlist
choose a playlist to download
`;
res.send(html);
} catch (err) {
console.error('error fetching playlists:', err);
res.status(500).send('error fetching playlists.');
}
});
/**
* called when the user has selected a playlist from the popup
* fetch all items, write them to a json file, and update the status
*/
app.get('/download-playlist', async (req, res) => {
try {
if (!oauth2Client.credentials || !oauth2Client.credentials.access_token) {
return res
.status(401)
.send('error: oauth2 client not authorized. go to /auth first.');
}
const { playlistId } = req.query;
if (!playlistId) {
return res
.status(400)
.send('missing playlist id. please choose a playlist.');
}
// set status to in-progress
downloadStatus = 'in-progress';
// fetch the playlist items
const items = await getPlaylistItems(playlistId, oauth2Client);
// create a data folder if it doesn't exist
const dataDir = path.join(process.cwd(), 'data');
if (!fs.existsSync(dataDir)) {
fs.mkdirSync(dataDir);
}
const outFile = path.join(dataDir, `playlist_${playlistId}.json`);
fs.writeFileSync(outFile, JSON.stringify(items, null, 2), 'utf8');
downloadStatus = 'completed';
res.send(`
download complete