Add support for multiple downloads with multiple URLs (#14)

These updates significantly enhance the project's capabilities, particularly by adding support for multiple downloads. The introduction of the temppath module, along with the cache management functions for caching the given multiple URLs from command line, provides a more efficient and streamlined experience for users.

Signed-off-by: Ryuu Mitsuki <dhefam31@gmail.com>

index.js

@@ -15,7 +15,7 @@
  * A type definition for the filtered options object, which is returned from {@link filterOptions} function.
  *
  * @typedef  {Object} FilteredOptions
- * @property {string} url - The URL(s) to be processed.
+ * @property {string} urls - A list of URLs to be processed.
  * @property {string} batchFile - The path to the batch file containing YouTube URLs.
  * @property {number} version - A number counter to show the version. 1 shows this module version only, 2 shows all dependencies' version.
  * @property {boolean} copyright - A boolean flag to show the copyright information.
@@ -30,7 +30,14 @@
 
 const fs = require('fs');      // File system module
 const path = require('path');  // Path module
+const { EOL } = require('os');
+const { promisify } = require('util');
 const { ArgumentParser } = require('argparse');
+const {
+  getTempPath,
+  createTempPath: _createTempPath
+} = require('@mitsuki31/temppath');
+const createTempPath = promisify(_createTempPath);
 
 const {
   defaultOptions: defaultAudioConvOptions,
@@ -44,6 +51,10 @@ const ytmp3 = require('./lib/ytmp3');
 const pkg = require('./package.json');
 
 const DEFAULT_BATCH_FILE = path.join(__dirname, 'downloads.txt');
+// Windows: "C:\Users\...\AppData\Local\Temp\ytmp3-js"
+// Linux: "/home/usr/tmp/ytmp3-js"
+// Termux Android: "/data/data/com.termux/files/usr/tmp/ytmp3-js"
+const TEMPDIR = path.join(path.dirname(getTempPath()), 'ytmp3-js');
 const author = {
   name: pkg.author.split(' <')[0],
   email: /<(\w+@[a-z0-9.]+)>/m.exec(pkg.author)[1],
@@ -54,14 +65,17 @@ const __version__ = (() => {
   // eslint-disable-next-line prefer-const
   let [ ver, rel ] = (pkg.version || '0.0.0-dev').split('-');
   rel = (rel && rel.length !== 0)
-    ? rel.charAt(0).toUpperCase() + rel.substr(1)  // Capitalize first letter
+    ? rel.charAt(0).toUpperCase() + rel.substring(1)  // Capitalize first letter
     : 'Stable';
   return `\x1b[1m[${pkg.name.toUpperCase()}] v${ver} \x1b[2m${rel}\x1b[0m\n`;
 })();
 
 const __copyright__ = `${pkg.name} - Copyright (c) 2023-${
   new Date().getFullYear()} ${author.name} (${author.website})\n`;
 
+/** Store the file path of cached multiple download URLs. */
+let multipleDlCache = null;
+
 /**
  * Initializes the argument parser for command-line options.
  *
@@ -240,15 +254,19 @@ async function filterOptions({ options }) {
   delete optionsCopy.quiet;
 
   // Extract and resolve the download options from configuration file if given
-  const dlOptionsFromConfig = optionsCopy.config
-    ? await /* may an ES module */ importConfig(optionsCopy.config)
+  let dlOptionsFromConfig = optionsCopy.config
+    ? importConfig(optionsCopy.config)
     : {};
+  // Await the download options if it is a promise
+  if (dlOptionsFromConfig instanceof Promise) {
+    dlOptionsFromConfig = await dlOptionsFromConfig;
+  }
   const acOptionsFromConfig = dlOptionsFromConfig.converterOptions || {};
   delete optionsCopy.config;  // No longer needed
   delete dlOptionsFromConfig.converterOptions;  // No longer needed
 
   return Object.freeze({
-    url: optionsCopy.URL,
+    urls: optionsCopy.URL,
     batchFile: optionsCopy.file,
     version: optionsCopy.version,
     copyright: optionsCopy.copyright,
@@ -272,6 +290,47 @@ async function filterOptions({ options }) {
   });
 }
 
+/**
+ * Creates a cache file for URLs to be downloaded.
+ *
+ * This function creates a temporary file in the system's temporary directory
+ * containing a list of URLs to be downloaded using the
+ * {@link module:ytmp3~batchDownload `ytmp3.batchDownload`} function.
+ *
+ * @param {string[]} urls - URLs to be written to cache file
+ * @returns {Promise<string>} The path to the cache file for later deletion
+ */
+async function createCache(urls) {
+  const cache = await createTempPath(TEMPDIR, {
+    asFile: true,
+    ext: 'dl',
+    maxLen: 20
+  });
+  // Create write stream for cache file
+  const cacheStream = fs.createWriteStream(cache);
+
+  // Write URLs to cache
+  urls.forEach(url => cacheStream.write(`${url}${EOL}`));
+
+  // Close the write stream
+  cacheStream.end();
+  return cache;
+}
+
+/**
+ * Deletes the cache file if it exists
+ *
+ * @returns {Promise<boolean>} `true` if the cache file is deleted successfully
+ */
+async function deleteCache() {
+  if (!multipleDlCache) return false;
+  if (fs.existsSync(multipleDlCache)) {
+    // Delete the parent directory of the cache file
+    await fs.promises.rm(path.dirname(multipleDlCache), { recursive: true, force: true });
+  }
+  return true;
+}
+
 
 /**
  * Main function.
@@ -280,7 +339,7 @@ async function filterOptions({ options }) {
  */
 async function main() {
   const {
-    url,
+    urls,
     batchFile,
     version,
     copyright,
@@ -319,7 +378,7 @@ async function main() {
 
   let downloadSucceed = false;
   try {
-    if ((!url || (url && !url.length)) && !batchFile) {
+    if ((!urls || (urls && !urls.length)) && !batchFile) {
       const defaultBatchFileBase = path.basename(DEFAULT_BATCH_FILE);
       log.info(`\x1b[2mNo URL and batch file specified, searching \x1b[93m${
         defaultBatchFileBase}\x1b[0m\x1b[2m ...\x1b[0m`);
@@ -331,22 +390,24 @@ async function main() {
       }
       log.info('\x1b[95mMode: \x1b[97mBatch Download\x1b[0m');
       downloadSucceed = !!await ytmp3.batchDownload(DEFAULT_BATCH_FILE, downloadOptions);
-    } else if ((!url || (url && !url.length)) && batchFile) {
+    } else if ((!urls || (urls && !urls.length)) && batchFile) {
       log.info('\x1b[95mMode: \x1b[97mBatch Download\x1b[0m');
       downloadSucceed = !!await ytmp3.batchDownload(batchFile, downloadOptions);
-    } else if (url.length && !batchFile) {
-      if (Array.isArray(url) && url.length > 1) {
+    } else if (urls.length && !batchFile) {
+      if (Array.isArray(urls) && urls.length > 1) {
         log.info('\x1b[95mMode: \x1b[97mMultiple Downloads\x1b[0m');
-        console.log(url);  // FIXME
-        // TODO: Add support for multiple downloads
-        log.warn('Currently multiple downloads from URLs are not suppported');
-        process.exit(0);
+        multipleDlCache = await createCache(urls);
+        downloadSucceed = !!await ytmp3.batchDownload(multipleDlCache, downloadOptions);
+        await deleteCache();
       } else {
         log.info('\x1b[95mMode: \x1b[97mSingle Download\x1b[0m');
-        downloadSucceed = !!await ytmp3.singleDownload(url[0], downloadOptions);
+        downloadSucceed = !!await ytmp3.singleDownload(urls[0], downloadOptions);
       }
     }
   } catch (dlErr) {
+    // Prevent the cache file still exists when an error occurs
+    await deleteCache();
+
     log.error(dlErr.message);
     console.error(dlErr.stack);
     process.exit(1);

package.json

@@ -36,6 +36,7 @@
   },
   "dependencies": {
     "@distube/ytdl-core": "^4.13.5",
+    "@mitsuki31/temppath": "^0.5.0",
     "argparse": "^2.0.1",
     "fluent-ffmpeg": "^2.1.3"
   },