Misc file moving and cleanup

- Rename JS/CSS for main.html to be consistent (main.js, main.css)
- Add hx.js module to reduce virtual-dom boilerplate
- Move state.js into renderer/lib.js where it belongs
- Rename torrent-list.js -> home.js for consistency
- Rename create-torrent-page.js -> create-torrent.js for consistency

renderer/views/create-torrent.js

@@ -0,0 +1,159 @@
+module.exports = CreateTorrentPage
+
+var createTorrent = require('create-torrent')
+var path = require('path')
+var prettyBytes = require('prettier-bytes')
+
+var {dispatch, dispatcher} = require('../lib/dispatcher')
+var hx = require('../lib/hx')
+
+function CreateTorrentPage (state) {
+  var info = state.location.current()
+
+  // Preprocess: exclude .DS_Store and other dotfiles
+  var files = info.files
+    .filter((f) => !f.name.startsWith('.'))
+    .map((f) => ({name: f.name, path: f.path, size: f.size}))
+  if (files.length === 0) return CreateTorrentErrorPage()
+
+  // First, extract the base folder that the files are all in
+  var pathPrefix = info.folderPath
+  if (!pathPrefix) {
+    pathPrefix = files.map((x) => x.path).reduce(findCommonPrefix)
+    if (!pathPrefix.endsWith('/') && !pathPrefix.endsWith('\\')) {
+      pathPrefix = path.dirname(pathPrefix)
+    }
+  }
+
+  // Sanity check: show the number of files and total size
+  var numFiles = files.length
+  var totalBytes = files
+    .map((f) => f.size)
+    .reduce((a, b) => a + b, 0)
+  var torrentInfo = `${numFiles} files, ${prettyBytes(totalBytes)}`
+
+  // Then, use the name of the base folder (or sole file, for a single file torrent)
+  // as the default name. Show all files relative to the base folder.
+  var defaultName, basePath
+  if (files.length === 1) {
+    // Single file torrent: /a/b/foo.jpg -> torrent name "foo.jpg", path "/a/b"
+    defaultName = files[0].name
+    basePath = pathPrefix
+  } else {
+    // Multi file torrent: /a/b/{foo, bar}.jpg -> torrent name "b", path "/a"
+    defaultName = path.basename(pathPrefix)
+    basePath = path.dirname(pathPrefix)
+  }
+  var maxFileElems = 100
+  var fileElems = files.slice(0, maxFileElems).map(function (file) {
+    var relativePath = files.length === 0 ? file.name : path.relative(pathPrefix, file.path)
+    return hx`<div>${relativePath}</div>`
+  })
+  if (files.length > maxFileElems) {
+    fileElems.push(hx`<div>+ ${maxFileElems - files.length} more</div>`)
+  }
+  var trackers = createTorrent.announceList.join('\n')
+  var collapsedClass = info.showAdvanced ? 'expanded' : 'collapsed'
+
+  return hx`
+    <div class='create-torrent'>
+      <h2>Create torrent ${defaultName}</h2>
+      <p class="torrent-info">
+        ${torrentInfo}
+      </p>
+      <p class='torrent-attribute'>
+        <label>Path:</label>
+        <div class='torrent-attribute'>${pathPrefix}</div>
+      </p>
+      <div class='expand-collapse ${collapsedClass}' onclick=${handleToggleShowAdvanced}>
+        ${info.showAdvanced ? 'Basic' : 'Advanced'}
+      </div>
+      <div class="create-torrent-advanced ${collapsedClass}">
+        <p class='torrent-attribute'>
+          <label>Comment:</label>
+          <textarea class='torrent-attribute torrent-comment'></textarea>
+        </p>
+        <p class='torrent-attribute'>
+          <label>Trackers:</label>
+          <textarea class='torrent-attribute torrent-trackers'>${trackers}</textarea>
+        </p>
+        <p class='torrent-attribute'>
+          <label>Private:</label>
+          <input type='checkbox' class='torrent-is-private' value='torrent-is-private'>
+        </p>
+        <p class='torrent-attribute'>
+          <label>Files:</label>
+          <div>${fileElems}</div>
+        </p>
+      </div>
+      <p class="float-right">
+        <button class='button-flat light' onclick=${handleCancel}>Cancel</button>
+        <button class='button-raised' onclick=${handleOK}>Create Torrent</button>
+      </p>
+    </div>
+  `
+
+  function handleOK () {
+    var announceList = document.querySelector('.torrent-trackers').value
+      .split('\n')
+      .map((s) => s.trim())
+      .filter((s) => s !== '')
+    var isPrivate = document.querySelector('.torrent-is-private').checked
+    var comment = document.querySelector('.torrent-comment').value.trim()
+    var options = {
+      // We can't let the user choose their own name if we want WebTorrent
+      // to use the files in place rather than creating a new folder.
+      // If we ever want to add support for that:
+      // name: document.querySelector('.torrent-name').value
+      name: defaultName,
+      path: basePath,
+      files: files,
+      announce: announceList,
+      private: isPrivate,
+      comment: comment
+    }
+    dispatch('createTorrent', options)
+  }
+
+  function handleCancel () {
+    dispatch('back')
+  }
+
+  function handleToggleShowAdvanced () {
+    // TODO: what's the clean way to handle this?
+    // Should every button on every screen have its own dispatch()?
+    info.showAdvanced = !info.showAdvanced
+    dispatch('update')
+  }
+}
+
+function CreateTorrentErrorPage () {
+  return hx`
+    <div class='create-torrent'>
+      <h2>Create torrent</h2>
+      <p class="torrent-info">
+        <p>
+          Sorry, you must select at least one file that is not a hidden file.
+        </p>
+        <p>
+          Hidden files, starting with a . character, are not included.
+        </p>
+      </p>
+      <p class="float-right">
+        <button class='button-flat light' onclick=${dispatcher('back')}>
+          Cancel
+        </button>
+      </p>
+    </div>
+  `
+}
+
+// Finds the longest common prefix
+function findCommonPrefix (a, b) {
+  for (var i = 0; i < a.length && i < b.length; i++) {
+    if (a.charCodeAt(i) !== b.charCodeAt(i)) break
+  }
+  if (i === a.length) return a
+  if (i === b.length) return b
+  return a.substring(0, i)
+}