From df04af0f38583120d5ba5c620a848e12c933331d Mon Sep 17 00:00:00 2001
From: Gabe Kangas <gabek@real-ity.com>
Date: Thu, 6 Aug 2020 10:55:33 -0700
Subject: [PATCH] Websocket refactor: Pull it out of the UI and support
 callbacks (#104)

* Websocket refactor: Pull it out of the UI and support listeners

* Changes required for Safari to be happy with modules

* Move to explicit ad-hoc callback registration
---
 webroot/index.html                    |  16 +--
 webroot/js/app.js                     |  82 ++++++---------
 webroot/js/chat/socketMessageTypes.js |  11 ++
 webroot/js/message.js                 |  38 +++----
 webroot/js/player.js                  |  29 ++++++
 webroot/js/utils.js                   |  67 +-----------
 webroot/js/websocket.js               | 142 ++++++++++++++++++++++++++
 7 files changed, 246 insertions(+), 139 deletions(-)
 create mode 100644 webroot/js/chat/socketMessageTypes.js
 create mode 100644 webroot/js/websocket.js

diff --git a/webroot/index.html b/webroot/index.html
index a7e356dd4..b9e112ee8 100644
--- a/webroot/index.html
+++ b/webroot/index.html
@@ -181,16 +181,16 @@
 
   <script src="js/usercolors.js"></script>
   <script src="js/utils.js?v=2"></script>
-  <script src="js/message.js?v=2"></script>
+  <script type="module" src="js/message.js?v=2"></script>
   <script src="js/social.js"></script>
   <script src="js/components.js"></script>
-  <script src="js/player.js"></script>
-  <script src="js/app.js?v=2"></script>
-  <script>
-    (function () {
-      const app = new Owncast();
-      app.init();
-    })();
+  <script type="module">
+      import Owncast from './js/app.js';
+
+      (function () {
+        const app = new Owncast();
+        app.init();
+      })();
   </script>
 
   <noscript>
diff --git a/webroot/js/app.js b/webroot/js/app.js
index f2e9d2101..e4582adf9 100644
--- a/webroot/js/app.js
+++ b/webroot/js/app.js
@@ -1,14 +1,33 @@
+import Websocket from './websocket.js';
+import { MessagingInterface, Message } from './message.js';
+import SOCKET_MESSAGE_TYPES from './chat/socketMessageTypes.js';
+import { OwncastPlayer } from './player.js';
+
+const MESSAGE_OFFLINE = 'Stream is offline.';
+const MESSAGE_ONLINE = 'Stream is online';
+
+const TEMP_IMAGE = 'data:image/gif;base64,R0lGODlhAQABAIAAAAAAAP///yH5BAEAAAAALAAAAAABAAEAAAIBRAA7';
+
+const LOCAL_TEST = window.location.href.indexOf('localhost:') >= 0;
+
+const URL_PREFIX = LOCAL_TEST ? 'http://localhost:8080' : ''; 
+const URL_CONFIG = `${URL_PREFIX}/config`;
+const URL_STATUS = `${URL_PREFIX}/status`;
+const URL_CHAT_HISTORY = `${URL_PREFIX}/chat`;
+
+const TIMER_STATUS_UPDATE = 5000; // ms
+const TIMER_DISABLE_CHAT_AFTER_OFFLINE = 5 * 60 * 1000; // 5 mins
+const TIMER_STREAM_DURATION_COUNTER = 1000;
+
 class Owncast {
   constructor() {
     this.player;    
 
-    this.websocket = null;
     this.configData;
     this.vueApp;
     this.messagingInterface = null;
 
     // timers
-    this.websocketReconnectTimer = null;
     this.playerRestartTimer = null;
     this.offlineTimer = null;
     this.statusTimer = null;
@@ -23,7 +42,6 @@ class Owncast {
     // bindings
     this.vueAppMounted = this.vueAppMounted.bind(this);
     this.setConfigData = this.setConfigData.bind(this);
-    this.setupWebsocket = this.setupWebsocket.bind(this);
     this.getStreamStatus = this.getStreamStatus.bind(this);
     this.getExtraUserContent = this.getExtraUserContent.bind(this);
     this.updateStreamStatus = this.updateStreamStatus.bind(this);
@@ -40,7 +58,7 @@ class Owncast {
 
   init() {
     this.messagingInterface = new MessagingInterface();
-    this.websocket = this.setupWebsocket();
+    this.setupWebsocket();
 
     this.vueApp = new Vue({
       el: '#app-container',
@@ -109,53 +127,17 @@ class Owncast {
 
   // websocket for messaging
   setupWebsocket() {
-    var ws = new WebSocket(URL_WEBSOCKET);  
-    ws.onopen = (e) => {
-      if (this.websocketReconnectTimer) {
-        clearTimeout(this.websocketReconnectTimer);
-      }
-
-      // If we're "online" then enable the chat.
-      if (this.streamStatus && this.streamStatus.online) {
-        this.messagingInterface.enableChat();
-      }
-    };
-    ws.onclose = (e) => {
-      // connection closed, discard old websocket and create a new one in 5s
-      this.websocket = null;
-      this.messagingInterface.disableChat();
-      this.handleNetworkingError('Websocket closed.');
-      this.websocketReconnectTimer = setTimeout(this.setupWebsocket, TIMER_WEBSOCKET_RECONNECT);
-    };
-    // On ws error just close the socket and let it re-connect again for now.
-    ws.onerror = e => {
-      this.handleNetworkingError(`Socket error: ${JSON.parse(e)}`);
-      ws.close();
-    };
-    ws.onmessage = (e) => {
-      const model = JSON.parse(e.data);
-
-      // Send PONGs
-      if (model.type === SOCKET_MESSAGE_TYPES.PING) {
-        this.sendPong(ws);
-        return;
-      } else if (model.type === SOCKET_MESSAGE_TYPES.CHAT) {
-        const message = new Message(model);
-        this.addMessage(message);
-      } else if (model.type === SOCKET_MESSAGE_TYPES.NAME_CHANGE) {
-        this.addMessage(model);
-      }
-    };
-    this.websocket = ws;
-    this.messagingInterface.setWebsocket(this.websocket);
+    this.websocket = new Websocket();
+    this.websocket.addListener('rawWebsocketMessageReceived', this.receivedWebsocketMessage.bind(this));
+    this.messagingInterface.send = this.websocket.send;
   };
 
-  sendPong(ws) {
-    try {
-      const pong = { type: SOCKET_MESSAGE_TYPES.PONG };
-      ws.send(JSON.stringify(pong));
-    } catch (e) {
-      console.log('PONG error:', e);
+  receivedWebsocketMessage(model) {
+    if (model.type === SOCKET_MESSAGE_TYPES.CHAT) {
+      const message = new Message(model);
+      this.addMessage(message);
+    } else if (model.type === SOCKET_MESSAGE_TYPES.NAME_CHANGE) {
+      this.addMessage(model);
     }
   }
 
@@ -349,3 +331,5 @@ class Owncast {
     this.handlePlayerEnded();
   };
 };
+
+export default Owncast;
\ No newline at end of file
diff --git a/webroot/js/chat/socketMessageTypes.js b/webroot/js/chat/socketMessageTypes.js
new file mode 100644
index 000000000..54116e1b0
--- /dev/null
+++ b/webroot/js/chat/socketMessageTypes.js
@@ -0,0 +1,11 @@
+/**
+ * These are the types of messages that we can handle with the websocket.
+ * Mostly used by `websocket.js` but if other components need to handle
+ * different types then it can import this file.
+ */
+export default {
+  CHAT: 'CHAT',
+  PING: 'PING',
+  NAME_CHANGE: 'NAME_CHANGE',
+  PONG: 'PONG'
+}
\ No newline at end of file
diff --git a/webroot/js/message.js b/webroot/js/message.js
index 4f2645f1b..cd1c81460 100644
--- a/webroot/js/message.js
+++ b/webroot/js/message.js
@@ -1,3 +1,13 @@
+import SOCKET_MESSAGE_TYPES from './chat/socketMessageTypes.js';
+
+const KEY_USERNAME = 'owncast_username';
+const KEY_AVATAR = 'owncast_avatar';
+const KEY_CHAT_DISPLAYED = 'owncast_chat';
+const KEY_CHAT_FIRST_MESSAGE_SENT = 'owncast_first_message_sent';
+const CHAT_INITIAL_PLACEHOLDER_TEXT = 'Type here to chat, no account necessary.';
+const CHAT_PLACEHOLDER_TEXT = 'Message';
+const CHAT_PLACEHOLDER_OFFLINE = 'Chat is offline.';
+
 class Message {
 	constructor(model) {
 		this.author = model.author;
@@ -36,7 +46,6 @@ class Message {
 
 class MessagingInterface {
 	constructor() {
-		this.websocket = null;
 		this.chatDisplayed = false;
 		this.username = '';
 		this.messageCharCount = 0;
@@ -89,11 +98,6 @@ class MessagingInterface {
 			window.addEventListener("orientationchange", setVHvar);
 			this.tagAppContainer.classList.add('touch-screen');
 		}
-
-	}
-
-	setWebsocket(socket) {
-		this.websocket = socket;
 	}
 
 	initLocalStates() {
@@ -188,9 +192,7 @@ class MessagingInterface {
 			image: image,
 		};
 
-		const jsonMessage = JSON.stringify(nameChange);
-
-		this.websocket.send(jsonMessage)
+		this.send(nameChange);
 	}
 
 	handleMessageInputKeydown(event) {
@@ -252,15 +254,7 @@ class MessagingInterface {
 			image: this.imgUsernameAvatar.src,
 			type: SOCKET_MESSAGE_TYPES.CHAT,
 		});
-		const messageJSON = JSON.stringify(message);
-		if (this.websocket) {
-			try {
-				this.websocket.send(messageJSON);
-			} catch(e) {
-				console.log('Message send error:', e);
-				return;
-			}
-		}
+		this.send(message);
 
 		// clear out things.
 		this.formMessageInput.value = '';
@@ -298,4 +292,10 @@ class MessagingInterface {
 			jumpToBottom(this.scrollableMessagesContainer);
 		}
 	}
-}
\ No newline at end of file
+
+	send(messageJSON) {
+		console.error('MessagingInterface send() is not linked to the websocket component.');
+	}
+}
+
+export { Message, MessagingInterface }
\ No newline at end of file
diff --git a/webroot/js/player.js b/webroot/js/player.js
index 35442aa83..890bc2833 100644
--- a/webroot/js/player.js
+++ b/webroot/js/player.js
@@ -1,5 +1,33 @@
 // https://docs.videojs.com/player
 
+const VIDEO_ID = 'video';
+const LOCAL_TEST = window.location.href.indexOf('localhost:') >= 0;
+const URL_PREFIX = LOCAL_TEST ? 'http://localhost:8080' : ''; 
+const URL_STREAM = `${URL_PREFIX}/hls/stream.m3u8`;
+
+// Video setup
+const VIDEO_SRC = {
+  src: URL_STREAM,
+  type: 'application/x-mpegURL',
+};
+const VIDEO_OPTIONS = {
+  autoplay: false,
+  liveui: true, // try this
+  preload: 'auto',
+  html5: {
+    vhs: {
+      // used to select the lowest bitrate playlist initially. This helps to decrease playback start time. This setting is false by default.
+      enableLowInitialPlaylist: true,
+
+    }
+  },
+  liveTracker: {
+    trackingThreshold: 0,
+  },
+  sources: [VIDEO_SRC],
+};
+
+
 class OwncastPlayer {
   constructor() {
     window.VIDEOJS_NO_DYNAMIC_STYLE = true; // style override
@@ -124,3 +152,4 @@ class OwncastPlayer {
 
 }
 
+export { OwncastPlayer };
\ No newline at end of file
diff --git a/webroot/js/utils.js b/webroot/js/utils.js
index f6c43801c..ba09ca479 100644
--- a/webroot/js/utils.js
+++ b/webroot/js/utils.js
@@ -1,75 +1,12 @@
 
 const LOCAL_TEST = window.location.href.indexOf('localhost:') >= 0;
-
-
 const URL_PREFIX = LOCAL_TEST ? 'http://localhost:8080' : ''; 
-const URL_STATUS = `${URL_PREFIX}/status`;
-const URL_CHAT_HISTORY = `${URL_PREFIX}/chat`;
-const URL_STREAM = `${URL_PREFIX}/hls/stream.m3u8`;
-const URL_WEBSOCKET = LOCAL_TEST
-  ? 'wss://goth.land/entry'
-  : `${location.protocol === 'https:' ? 'wss' : 'ws'}://${location.host}/entry`;
 
 const POSTER_DEFAULT = `${URL_PREFIX}/img/logo.png`;
 const POSTER_THUMB = `${URL_PREFIX}/thumbnail.jpg`;
 
-const URL_CONFIG = `${URL_PREFIX}/config`;
-
 const URL_OWNCAST = 'https://github.com/gabek/owncast'; // used in footer
 
-
-// Webscoket setup
-const SOCKET_MESSAGE_TYPES = {
-	CHAT: 'CHAT',
-  PING: 'PING',
-  NAME_CHANGE: 'NAME_CHANGE',
-  PONG: 'PONG'
-}
-
-// Video setup
-const VIDEO_ID = 'video';
-const VIDEO_SRC = {
-  src: URL_STREAM,
-  type: 'application/x-mpegURL',
-};
-const VIDEO_OPTIONS = {
-  autoplay: false,
-  liveui: true, // try this
-  preload: 'auto',
-  html5: {
-    vhs: {
-      // used to select the lowest bitrate playlist initially. This helps to decrease playback start time. This setting is false by default.
-      enableLowInitialPlaylist: true,
-
-    }
-  },
-  liveTracker: {
-    trackingThreshold: 0,
-  },
-  sources: [VIDEO_SRC],
-};
-
-// local storage keys for chat
-const KEY_USERNAME = 'owncast_username';
-const KEY_AVATAR = 'owncast_avatar';
-const KEY_CHAT_DISPLAYED = 'owncast_chat';
-const KEY_CHAT_FIRST_MESSAGE_SENT = 'owncast_first_message_sent';
-
-const TIMER_STATUS_UPDATE = 5000; // ms
-const TIMER_WEBSOCKET_RECONNECT = 5000; // ms
-const TIMER_DISABLE_CHAT_AFTER_OFFLINE = 5 * 60 * 1000; // 5 mins
-const TIMER_STREAM_DURATION_COUNTER = 1000;
-
-const TEMP_IMAGE = 'data:image/gif;base64,R0lGODlhAQABAIAAAAAAAP///yH5BAEAAAAALAAAAAABAAEAAAIBRAA7';
-
-const MESSAGE_OFFLINE = 'Stream is offline.';
-const MESSAGE_ONLINE = 'Stream is online';
-
-const CHAT_INITIAL_PLACEHOLDER_TEXT = 'Type here to chat, no account necessary.';
-const CHAT_PLACEHOLDER_TEXT = 'Message';
-const CHAT_PLACEHOLDER_OFFLINE = 'Chat is offline.';
-
-
 function getLocalStorage(key) {
   try {
     return localStorage.getItem(key);
@@ -182,3 +119,7 @@ function setVHvar() {
   document.documentElement.style.setProperty('--vh', `${vh}px`);
   console.log("== new vh", vh)
 }
+
+function doesObjectSupportFunction(object, functionName) {
+  return typeof object[functionName] === "function";
+}
\ No newline at end of file
diff --git a/webroot/js/websocket.js b/webroot/js/websocket.js
new file mode 100644
index 000000000..bc4efd1d9
--- /dev/null
+++ b/webroot/js/websocket.js
@@ -0,0 +1,142 @@
+import SOCKET_MESSAGE_TYPES from './chat/socketMessageTypes.js';
+
+const LOCAL_TEST = window.location.href.indexOf('localhost:') >= 0;
+const URL_WEBSOCKET = LOCAL_TEST
+  ? 'wss://goth.land/entry'
+  : `${location.protocol === 'https:' ? 'wss' : 'ws'}://${location.host}/entry`;
+
+const TIMER_WEBSOCKET_RECONNECT = 5000; // ms
+
+const CALLBACKS = {
+  RAW_WEBSOCKET_MESSAGE_RECEIVED: 'rawWebsocketMessageReceived',
+  WEBSOCKET_CONNECTED: 'websocketConnected',
+  WEBSOCKET_DISCONNECTED: 'websocketDisconnected',
+}
+
+class Websocket {
+
+  constructor() {
+    this.websocket = null;
+    this.websocketReconnectTimer = null;
+
+    this.websocketConnectedListeners = [];
+    this.websocketDisconnectListeners = [];
+    this.rawMessageListeners = [];
+
+    this.send = this.send.bind(this);
+
+    const ws = new WebSocket(URL_WEBSOCKET);
+    ws.onopen = this.onOpen.bind(this);
+    ws.onclose = this.onClose.bind(this);
+    ws.onerror = this.onError.bind(this);
+    ws.onmessage = this.onMessage.bind(this);
+
+    this.websocket = ws;
+  }
+
+  // Other components should register for websocket callbacks.
+  addListener(type, callback) {
+    if (type == CALLBACKS.WEBSOCKET_CONNECTED) {
+      this.websocketConnectedListeners.push(callback);
+    } else if (type == CALLBACKS.WEBSOCKET_DISCONNECTED) {
+      this.websocketDisconnectListeners.push(callback);
+    } else if (type == CALLBACKS.RAW_WEBSOCKET_MESSAGE_RECEIVED) {
+      this.rawMessageListeners.push(callback);
+    }
+  }
+
+  
+  // Interface with other components
+
+  // Outbound: Other components can pass an object to `send`.
+  send(message) {
+    // Sanity check that what we're sending is a valid type.
+    if (!message.type || !SOCKET_MESSAGE_TYPES[message.type]) {
+      console.warn(`Outbound message: Unknown socket message type: "${message.type}" sent.`);
+    }
+    
+    const messageJSON = JSON.stringify(message);
+    this.websocket.send(messageJSON);
+  }
+
+  // Private methods
+
+  // Fire the callbacks of the listeners.
+
+  notifyWebsocketConnectedListeners(message) {
+    this.websocketConnectedListeners.forEach(function (callback) {
+      callback(message);
+    });
+  }
+
+  notifyWebsocketDisconnectedListeners(message) {
+    this.websocketDisconnectListeners.forEach(function (callback) {
+      callback(message);
+    });
+  }
+
+
+  notifyRawMessageListeners(message) {
+    this.rawMessageListeners.forEach(function (callback) {
+      callback(message);
+    });
+  }
+
+  // Internal websocket callbacks
+
+  onOpen(e) {
+    if (this.websocketReconnectTimer) {
+      clearTimeout(this.websocketReconnectTimer);
+    }
+
+    this.notifyWebsocketConnectedListeners();
+  }
+
+  onClose(e) {
+    // connection closed, discard old websocket and create a new one in 5s
+    this.websocket = null;
+    this.notifyWebsocketDisconnectedListeners();
+    this.handleNetworkingError('Websocket closed.');
+    this.websocketReconnectTimer = setTimeout(this.setupWebsocket, TIMER_WEBSOCKET_RECONNECT);
+  }
+
+  // On ws error just close the socket and let it re-connect again for now.
+  onError(e) {
+    this.handleNetworkingError(`Socket error: ${JSON.parse(e)}`);
+    this.websocket.close();
+  }
+
+  /*
+  onMessage is fired when an inbound object comes across the websocket.
+  If the message is of type `PING` we send a `PONG` back and do not
+  pass it along to listeners.
+  */
+  onMessage(e) {
+    try {
+      var model = JSON.parse(e.data);
+    } catch (e) {
+      console.log(e)
+    }
+    
+    // Send PONGs
+    if (model.type === SOCKET_MESSAGE_TYPES.PING) {
+      this.sendPong();
+      return;
+    }
+
+    // Notify any of the listeners via the raw socket message callback.
+    this.notifyRawMessageListeners(model);
+  }
+
+  // Reply to a PING as a keep alive.
+  sendPong() {
+    const pong = { type: SOCKET_MESSAGE_TYPES.PONG };
+    this.send(pong);
+  }
+
+  handleNetworkingError(error) {
+    console.error(`Websocket Error: ${error}`)
+  };
+}
+
+export default Websocket;
\ No newline at end of file