YouTube playlist downloader

9 files changed, 74 insertions, 4 deletions

diff --git a/man/http-music-crawl-http.1 b/man/http-music-crawl-http.1
index 003e8f7..62bbc24 100644
--- a/man/http-music-crawl-http.1
+++ b/man/http-music-crawl-http.1
@@ -5,7 +5,7 @@ http-music-crawl-http - create a playlist file using an HTTP-based directory lis
 
 .SH SYNOPSIS
 .B http-music-crawl-http
-\fIdownloadURL\fR
+<download URL>
 [opts...]
 
 .SH DESCRIPTION
diff --git a/man/http-music-crawl-itunes.1 b/man/http-music-crawl-itunes.1
index e1f39d5..383c80d 100644
--- a/man/http-music-crawl-itunes.1
+++ b/man/http-music-crawl-itunes.1
@@ -5,7 +5,7 @@ http-music-crawl-itunes - create a playlist file using an iTunes library
 
 .SH SYNOPSIS
 .B http-music crawl-itunes
-[libraryPath]
+[library path]
 
 .SH DESCRIPTION
 \fBhttp-music-crawl-itunes\fR is a command line utility used to generate a
diff --git a/man/http-music-crawl-youtube.1 b/man/http-music-crawl-youtube.1
new file mode 100644
index 0000000..58a03f5
--- /dev/null
+++ b/man/http-music-crawl-youtube.1
@@ -0,0 +1,13 @@
+.TH HTTP-MUSIC-CRAWL-YOUTUBE 1
+
+.SH NAME
+http-music-crawl-youtube - create a playlist file from a YouTube playlist URL
+
+.SH SYNOPSIS
+.B http-music crawl-youtube
+<youtube playlist URL>
+
+.SH DESCRIPTION
+\fBhttp-music-crawl-youtube\fR is a simple utility that creates a playlist file from a YouTube playlist, given its URL.
+It requires the \fByoutube-dl\fR command line utility to download tracks.
+(It's also necessary to have youtube-dl to play them.)
diff --git a/man/http-music.1 b/man/http-music.1
index 12970bc..634f014 100644
--- a/man/http-music.1
+++ b/man/http-music.1
@@ -42,6 +42,10 @@ Creates a playlist from a directory on the local machine.
 Creates a playlist from the iTunes Shared Library.
 
 .TP
+.BR crawl-youtube
+Creates a playlist from a YouTube playlist URL.
+
+.TP
 .BR download-playlist
 Downloads each item in a playlist into a directory.
 
diff --git a/package.json b/package.json
index c66f894..57ef8aa 100644
--- a/package.json
+++ b/package.json
@@ -16,7 +16,8 @@
     "./man/http-music.1",
     "./man/http-music-play.1",
     "./man/http-music-crawl-http.1",
-    "./man/http-music-crawl-itunes.1"
+    "./man/http-music-crawl-itunes.1",
+    "./man/http-music-crawl-youtube.1"
   ],
   "dependencies": {
     "cheerio": "^1.0.0-rc.1",
diff --git a/src/cli.js b/src/cli.js
index d88ddc0..4bc64ab 100755
--- a/src/cli.js
+++ b/src/cli.js
@@ -18,6 +18,7 @@ async function main(args) {
     case 'crawl-http': script = require('./crawl-http'); break
     case 'crawl-local': script = require('./crawl-local'); break
     case 'crawl-itunes': script = require('./crawl-itunes'); break
+    case 'crawl-youtube': script = require('./crawl-youtube'); break
     case 'download-playlist': script = require('./download-playlist'); break
 
     default:
diff --git a/src/crawl-http.js b/src/crawl-http.js
index 29c59d2..e776b9c 100755
--- a/src/crawl-http.js
+++ b/src/crawl-http.js
@@ -142,7 +142,6 @@ function getHTMLLinks(text) {
 async function main(args) {
   if (args.length === 0) {
     console.log("Usage: crawl-http http://.../example/path/ [opts]")
-    process.exit(1)
     return
   }
 
diff --git a/src/crawl-youtube.js b/src/crawl-youtube.js
new file mode 100644
index 0000000..823fef7
--- /dev/null
+++ b/src/crawl-youtube.js
@@ -0,0 +1,49 @@
+'use strict'
+
+const { spawn } = require('child_process')
+const promisifyProcess = require('./promisify-process')
+
+async function crawl(url) {
+  const ytdl = spawn('youtube-dl', [
+    '-j', // Output as JSON
+    '--flat-playlist',
+    url
+  ])
+
+  const items = []
+
+  ytdl.stdout.on('data', data => {
+    const lines = data.toString().trim().split('\n')
+
+    items.push(...lines.map(JSON.parse))
+  })
+
+  // Don't show logging.
+  await promisifyProcess(ytdl, false)
+
+  return {
+    items: items.map(item => {
+      return {
+        name: item.title,
+        downloaderArg: 'https://youtube.com/watch?v=' + item.id
+      }
+    })
+  }
+}
+
+async function main(args) {
+  // TODO: Error message if none is passed.
+
+  if (args.length === 0) {
+    console.error("Usage: crawl-youtube <playlist URL>")
+  } else {
+    console.log(JSON.stringify(await crawl(args[0]), null, 2))
+  }
+}
+
+module.exports = main
+
+if (require.main === module) {
+  main(process.argv.slice(2))
+    .catch(err => console.error(err))
+}
diff --git a/todo.txt b/todo.txt
index 4382526..52c2a94 100644
--- a/todo.txt
+++ b/todo.txt
@@ -225,3 +225,6 @@ TODO: Make iTunes crawler prefer album artist over artist.
       (Done!)
 
 TODO: Make iTunes crawler take into account track numbers.
+
+TODO: Make a YouTube playlist crawler.
+      (Done!)