Switch from virtualdom to React

src/renderer/lib/torrent-poster.js

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+module.exports = torrentPoster
+
+var captureVideoFrame = require('./capture-video-frame')
+var path = require('path')
+
+function torrentPoster (torrent, cb) {
+  // First, try to use a poster image if available
+  var posterFile = torrent.files.filter(function (file) {
+    return /^poster\.(jpg|png|gif)$/.test(file.name)
+  })[0]
+  if (posterFile) return torrentPosterFromImage(posterFile, torrent, cb)
+
+  // Second, try to use the largest video file
+  // Filter out file formats that the <video> tag definitely can't play
+  var videoFile = getLargestFileByExtension(torrent, ['.mp4', '.m4v', '.webm', '.mov', '.mkv'])
+  if (videoFile) return torrentPosterFromVideo(videoFile, torrent, cb)
+
+  // Third, try to use the largest image file
+  var imgFile = getLargestFileByExtension(torrent, ['.gif', '.jpg', '.jpeg', '.png'])
+  if (imgFile) return torrentPosterFromImage(imgFile, torrent, cb)
+
+  // TODO: generate a waveform from the largest sound file
+  // Finally, admit defeat
+  return cb(new Error('Cannot generate a poster from any files in the torrent'))
+}
+
+function getLargestFileByExtension (torrent, extensions) {
+  var files = torrent.files.filter(function (file) {
+    var extname = path.extname(file.name).toLowerCase()
+    return extensions.indexOf(extname) !== -1
+  })
+  if (files.length === 0) return undefined
+  return files.reduce(function (a, b) {
+    return a.length > b.length ? a : b
+  })
+}
+
+function torrentPosterFromVideo (file, torrent, cb) {
+  var index = torrent.files.indexOf(file)
+
+  var server = torrent.createServer(0)
+  server.listen(0, onListening)
+
+  function onListening () {
+    var port = server.address().port
+    var url = 'http://localhost:' + port + '/' + index
+    var video = document.createElement('video')
+    video.addEventListener('canplay', onCanPlay)
+
+    video.volume = 0
+    video.src = url
+    video.play()
+
+    function onCanPlay () {
+      video.removeEventListener('canplay', onCanPlay)
+      video.addEventListener('seeked', onSeeked)
+
+      video.currentTime = Math.min((video.duration || 600) * 0.03, 60)
+    }
+
+    function onSeeked () {
+      video.removeEventListener('seeked', onSeeked)
+
+      var buf = captureVideoFrame(video)
+
+      // unload video element
+      video.pause()
+      video.src = ''
+      video.load()
+
+      server.destroy()
+
+      if (buf.length === 0) return cb(new Error('Generated poster contains no data'))
+
+      cb(null, buf, '.jpg')
+    }
+  }
+}
+
+function torrentPosterFromImage (file, torrent, cb) {
+  var extname = path.extname(file.name)
+  file.getBuffer((err, buf) => cb(err, buf, extname))
+}