Ability to programmatically control embeds (#776)

* first stab at jschannel based player api

* semicolon purge

* more method-level docs; consolidate definitions

* missing definitions

* better match peertube's class conventions

* styling for embed tester

* basic docs

* add `getVolume`

* document the test-embed feature

1 files changed, 251 insertions, 55 deletions

diff --git a/client/src/standalone/videos/embed.ts b/client/src/standalone/videos/embed.ts
index d8db2a119..e9baf64d0 100644
--- a/client/src/standalone/videos/embed.ts
+++ b/client/src/standalone/videos/embed.ts
@@ -17,100 +17,296 @@ import 'core-js/es6/set'
 // For google bot that uses Chrome 41 and does not understand fetch
 import 'whatwg-fetch'
 
-import * as videojs from 'video.js'
+import * as vjs from 'video.js'
+import * as Channel from 'jschannel'
 
 import { VideoDetails } from '../../../../shared'
 import { addContextMenu, getVideojsOptions, loadLocale } from '../../assets/player/peertube-player'
+import { PeerTubeResolution } from '../player/definitions';
 
-function getVideoUrl (id: string) {
-  return window.location.origin + '/api/v1/videos/' + id
-}
+/**
+ * Embed API exposes control of the embed player to the outside world via 
+ * JSChannels and window.postMessage
+ */
+class PeerTubeEmbedApi {
+  constructor(
+    private embed : PeerTubeEmbed
+  ) {
+  }
 
-function loadVideoInfo (videoId: string): Promise<Response> {
-  return fetch(getVideoUrl(videoId))
-}
+  private channel : Channel.MessagingChannel
+  private isReady = false
+  private resolutions : PeerTubeResolution[] = null
 
-function removeElement (element: HTMLElement) {
-  element.parentElement.removeChild(element)
-}
+  initialize() {
+    this.constructChannel()
+    this.setupStateTracking()
 
-function displayError (videoElement: HTMLVideoElement, text: string) {
-  // Remove video element
-  removeElement(videoElement)
+    // We're ready!
 
-  document.title = 'Sorry - ' + text
+    this.notifyReady()
+  }
+  
+  private get element() {
+    return this.embed.videoElement
+  }
 
-  const errorBlock = document.getElementById('error-block')
-  errorBlock.style.display = 'flex'
+  private constructChannel() {
+    let channel = Channel.build({ window: window.parent, origin: '*', scope: this.embed.scope })
+    
+    channel.bind('play', (txn, params) => this.embed.player.play())
+    channel.bind('pause', (txn, params) => this.embed.player.pause())
+    channel.bind('seek', (txn, time) => this.embed.player.currentTime(time))
+    channel.bind('setVolume', (txn, value) => this.embed.player.volume(value))
+    channel.bind('getVolume', (txn, value) => this.embed.player.volume())
+    channel.bind('isReady', (txn, params) => this.isReady)
+    channel.bind('setResolution', (txn, resolutionId) => this.setResolution(resolutionId))
+    channel.bind('getResolutions', (txn, params) => this.resolutions)
+    channel.bind('setPlaybackRate', (txn, playbackRate) => this.embed.player.playbackRate(playbackRate))
+    channel.bind('getPlaybackRate', (txn, params) => this.embed.player.playbackRate())
+    channel.bind('getPlaybackRates', (txn, params) => this.embed.playerOptions.playbackRates)
 
-  const errorText = document.getElementById('error-content')
-  errorText.innerHTML = text
-}
+    this.channel = channel
+  }
 
-function videoNotFound (videoElement: HTMLVideoElement) {
-  const text = 'This video does not exist.'
-  displayError(videoElement, text)
-}
+  private setResolution(resolutionId : number) {
+    if (resolutionId === -1 && this.embed.player.peertube().isAutoResolutionForbidden()) 
+      return
+
+    // Auto resolution
+    if (resolutionId === -1) {
+      this.embed.player.peertube().enableAutoResolution()
+      return
+    }
+
+    this.embed.player.peertube().disableAutoResolution()
+    this.embed.player.peertube().updateResolution(resolutionId)
+  }
+
+  /**
+   * Let the host know that we're ready to go!
+   */
+  private notifyReady() {
+    this.isReady = true
+    this.channel.notify({ method: 'ready', params: true })
+  }
+
+  private setupStateTracking() {
+    
+    let currentState : 'playing' | 'paused' | 'unstarted' = 'unstarted'
+
+    setInterval(() => {
+      let position = this.element.currentTime
+      let volume = this.element.volume
+
+      this.channel.notify({
+        method: 'playbackStatusUpdate',
+        params: {
+          position,
+          volume,
+          playbackState: currentState,
+        }
+      })
+    }, 500)
+
+    this.element.addEventListener('play', ev => {
+      currentState = 'playing'
+      this.channel.notify({ method: 'playbackStatusChange', params: 'playing' })
+    })
+
+    this.element.addEventListener('pause', ev => {
+      currentState = 'paused'
+      this.channel.notify({ method: 'playbackStatusChange', params: 'paused' })
+    })
+
+    // PeerTube specific capabilities
+
+    this.embed.player.peertube().on('autoResolutionUpdate', () => this.loadResolutions())
+    this.embed.player.peertube().on('videoFileUpdate', () => this.loadResolutions())
+  }
+
+  private loadResolutions() {
+    let resolutions = []
+    let currentResolutionId = this.embed.player.peertube().getCurrentResolutionId()
+
+    for (const videoFile of this.embed.player.peertube().videoFiles) {
+      let label = videoFile.resolution.label
+      if (videoFile.fps && videoFile.fps >= 50) {
+        label += videoFile.fps
+      }
 
-function videoFetchError (videoElement: HTMLVideoElement) {
-  const text = 'We cannot fetch the video. Please try again later.'
-  displayError(videoElement, text)
+      resolutions.push({
+        id: videoFile.resolution.id,
+        label,
+        src: videoFile.magnetUri,
+        active: videoFile.resolution.id === currentResolutionId
+      })
+    }
+
+    this.resolutions = resolutions
+    this.channel.notify({
+      method: 'resolutionUpdate',
+      params: this.resolutions
+    })
+  }
 }
 
-const urlParts = window.location.href.split('/')
-const lastPart = urlParts[urlParts.length - 1]
-const videoId = lastPart.indexOf('?') === -1 ? lastPart : lastPart.split('?')[0]
+class PeerTubeEmbed {
+  constructor(
+    private videoContainerId : string
+  ) {
+    this.videoElement = document.getElementById(videoContainerId) as HTMLVideoElement
+  }
 
-loadLocale(window.location.origin, videojs, navigator.language)
-  .then(() => loadVideoInfo(videoId))
-  .then(async response => {
+  videoElement : HTMLVideoElement
+  player : any
+  playerOptions : any
+  api : PeerTubeEmbedApi = null
+  autoplay : boolean = false
+  controls : boolean = true
+  muted : boolean = false
+  loop : boolean = false
+  enableApi : boolean = false
+  startTime : number = 0
+  scope : string = 'peertube'
+
+  static async main() {
     const videoContainerId = 'video-container'
-    const videoElement = document.getElementById(videoContainerId) as HTMLVideoElement
+    const embed = new PeerTubeEmbed(videoContainerId)
+    await embed.init()
+  }
+  
+  getVideoUrl (id: string) {
+    return window.location.origin + '/api/v1/videos/' + id
+  }
 
-    if (!response.ok) {
-      if (response.status === 404) return videoNotFound(videoElement)
+  loadVideoInfo (videoId: string): Promise<Response> {
+    return fetch(this.getVideoUrl(videoId))
+  }
 
-      return videoFetchError(videoElement)
-    }
+  removeElement (element: HTMLElement) {
+    element.parentElement.removeChild(element)
+  }
 
-    const videoInfo: VideoDetails = await response.json()
+  displayError (videoElement: HTMLVideoElement, text: string) {
+    // Remove video element
+    this.removeElement(videoElement)
+
+    document.title = 'Sorry - ' + text
+
+    const errorBlock = document.getElementById('error-block')
+    errorBlock.style.display = 'flex'
+
+    const errorText = document.getElementById('error-content')
+    errorText.innerHTML = text
+  }
+
+  videoNotFound (videoElement: HTMLVideoElement) {
+    const text = 'This video does not exist.'
+    this.displayError(videoElement, text)
+  }
+
+  videoFetchError (videoElement: HTMLVideoElement) {
+    const text = 'We cannot fetch the video. Please try again later.'
+    this.displayError(videoElement, text)
+  }
+
+  getParamToggle (params: URLSearchParams, name: string, defaultValue: boolean) {
+    return params.has(name) ? (params.get(name) === '1' || params.get(name) === 'true') : defaultValue
+  }
 
-    let autoplay = false
-    let startTime = 0
+  getParamString (params: URLSearchParams, name: string, defaultValue: string) {
+    return params.has(name) ? params.get(name) : defaultValue
+  }
 
+  private initializeApi() {
+    if (!this.enableApi)
+      return
+
+    this.api = new PeerTubeEmbedApi(this)
+    this.api.initialize()
+  }
+
+  async init() {
+    try {
+      await this.initCore()
+    } catch (e) {
+      console.error(e)
+    }
+  }
+
+  private loadParams() {
     try {
       let params = new URL(window.location.toString()).searchParams
-      autoplay = params.has('autoplay') && (params.get('autoplay') === '1' || params.get('autoplay') === 'true')
+
+      this.autoplay = this.getParamToggle(params, 'autoplay', this.autoplay)
+      this.controls = this.getParamToggle(params, 'controls', this.controls)
+      this.muted = this.getParamToggle(params, 'muted', this.muted)
+      this.loop = this.getParamToggle(params, 'loop', this.loop)
+      this.enableApi = this.getParamToggle(params, 'api', this.enableApi)
+      this.scope = this.getParamString(params, 'scope', this.scope)
 
       const startTimeParamString = params.get('start')
       const startTimeParamNumber = parseInt(startTimeParamString, 10)
-      if (isNaN(startTimeParamNumber) === false) startTime = startTimeParamNumber
+      if (isNaN(startTimeParamNumber) === false) 
+        this.startTime = startTimeParamNumber
     } catch (err) {
       console.error('Cannot get params from URL.', err)
     }
+  }
+
+  private async initCore() {
+    const urlParts = window.location.href.split('/')
+    const lastPart = urlParts[urlParts.length - 1]
+    const videoId = lastPart.indexOf('?') === -1 ? lastPart : lastPart.split('?')[0]
+
+    await loadLocale(window.location.origin, vjs, navigator.language)
+    let response = await this.loadVideoInfo(videoId)
+
+    if (!response.ok) {
+      if (response.status === 404) 
+        return this.videoNotFound(this.videoElement)
+
+      return this.videoFetchError(this.videoElement)
+    }
+
+    const videoInfo: VideoDetails = await response.json()
+
+    this.loadParams()
 
     const videojsOptions = getVideojsOptions({
-      autoplay,
+      autoplay: this.autoplay,
+      controls: this.controls,
+      muted: this.muted,
+      loop: this.loop,
+      startTime : this.startTime,
+
       inactivityTimeout: 1500,
-      videoViewUrl: getVideoUrl(videoId) + '/views',
-      playerElement: videoElement,
+      videoViewUrl: this.getVideoUrl(videoId) + '/views',
+      playerElement: this.videoElement,
       videoFiles: videoInfo.files,
       videoDuration: videoInfo.duration,
       enableHotkeys: true,
       peertubeLink: true,
       poster: window.location.origin + videoInfo.previewPath,
-      startTime,
       theaterMode: false
     })
-    videojs(videoContainerId, videojsOptions, function () {
-      const player = this
 
-      player.dock({
-        title: videoInfo.name,
-        description: player.localize('Uses P2P, others may know your IP is downloading this video.')
-      })
+    this.playerOptions = videojsOptions
+    this.player = vjs(this.videoContainerId, videojsOptions, () => {
 
-      addContextMenu(player, window.location.origin + videoInfo.embedPath)
+      window['videojsPlayer'] = this.player
+
+      if (this.controls) {
+        (this.player as any).dock({
+          title: videoInfo.name,
+          description: this.player.localize('Uses P2P, others may know your IP is downloading this video.')
+        })
+      }
+      addContextMenu(this.player, window.location.origin + videoInfo.embedPath)
+      this.initializeApi()
     })
-  })
-  .catch(err => console.error(err))
+  }
+}
+
+PeerTubeEmbed.main()