improved synchronization

schema.ts

@@ -2,30 +2,46 @@
 
 // Firestore
 const collection = {
-  rooms: {
+  rooms: [
-    roomId: {
+    {
-      createdAt: 'timestamp',
+      roomId: {
-      ownerId: 'userId',
+        createdAt: 'timestamp',
-      messages: {
+        ownerId: 'userId',
-        messageId: {
+        messages: [
-          createdAt: 'timestamp',
+          {
-          content: 'Message content',
+            messageId: {
-          senderId: 'userId',
+              createdAt: 'timestamp',
-        },
+              content: 'Message content',
-      },
+              senderId: 'userId',
-      playlist: {
+            },
-        videoId: {
+          },
-          createdAt: 'timestamp',
+        ],
-          url: 'https://youtube.com',
+        playlist: [
-        },
+          {
+            videoId: {
+              createdAt: 'timestamp',
+              url: 'https://youtube.com',
+            },
+          },
+        ],
+        states: [
+          {
+            stateId: {
+              time: 'timestamp',
+              isPlaying: true,
+            },
+          },
+        ],
       },
     },
-  },
+  ],
-  users: {
+  users: [
-    userId: {
+    {
-      name: 'Anonymous',
+      userId: {
+        name: 'Anonymous',
+      },
     },
-  },
+  ],
 };
 
 // Realtime Database - needed for tracking user presence

src/components/Chatbox.css

@@ -13,12 +13,18 @@ ion-textarea {
   align-items: center;
   justify-content: center;
   display: flex;
+  padding-left: 0;
 }
 
 .send-button {
   width: 100%;
 }
 
+.message-col {
+  white-space: normal;
+  padding: 10px;
+}
+
 .message-input {
   height: 100%;
   border: 1px solid #999;

src/components/Chatbox.tsx

@@ -19,7 +19,7 @@ const Chat: React.FC<ChatboxProps> = ({ roomId, userId }) => {
         createdAt: timestamp,
         senderId: userId,
         content: message,
-        type: 'user',
+        type: 'chat',
       });
     }
 

src/components/Messages.css

@@ -2,7 +2,6 @@ ion-col {
   padding: 6px;
   border-radius: 5px;
   margin-bottom: 4px;
-  white-space: pre-wrap;
   max-width: 70%;
 }
 

src/components/Messages.tsx

@@ -1,5 +1,5 @@
-import { IonCol, IonGrid, IonRow, IonContent } from '@ionic/react';
+import { IonCol, IonContent, IonGrid, IonRow } from '@ionic/react';
-import React, { useEffect, useState } from 'react';
+import React, { useEffect, useRef, useState } from 'react';
 import { currTime, db } from '../services/firebase';
 import './Messages.css';
 
@@ -22,6 +22,7 @@ const Messages: React.FC<MessagesProps> = ({ roomId, userId }) => {
   ]); // All received messages
   const [prevMessages, setPrevMessages] = useState<Message[]>([]); // Track previous messages
   const [newMessages, setNewMessages] = useState<Message[]>([]); // Newly retrieved messages
+  const contentRef = useRef<HTMLIonContentElement>(null);
 
   // Only update array containing all messages ('chats') when there are new messages
   useEffect(() => {
@@ -45,13 +46,15 @@ const Messages: React.FC<MessagesProps> = ({ roomId, userId }) => {
         for (const change of changes) {
           if (change.type === 'added') {
             const data = change.doc.data();
-            const user = await db.collection('users').doc(data?.senderId).get();
+            const user = await db.collection('users').doc(data.senderId).get();
-            newMsgs.push({
+            if (data.type !== 'updateState') {
-              id: change.doc.id,
+              newMsgs.push({
-              senderId: data?.senderId,
+                id: change.doc.id,
-              sender: user.data()?.name,
+                senderId: data.senderId,
-              content: data?.content,
+                sender: user.data()?.name,
-            });
+                content: data.content,
+              });
+            }
           }
         }
 
@@ -67,7 +70,7 @@ const Messages: React.FC<MessagesProps> = ({ roomId, userId }) => {
 
   // Always scroll to most recent chat message (bottom)
   useEffect(() => {
-    let content = document.querySelector('ion-content');
+    let content = contentRef.current;
 
     // Set timeout because DOM doesn't update immediately after 'chats' state is updated
     setTimeout(() => {
@@ -76,7 +79,7 @@ const Messages: React.FC<MessagesProps> = ({ roomId, userId }) => {
   }, [chats]);
 
   return (
-    <IonContent class="message-card">
+    <IonContent class="message-card" ref={contentRef}>
       <IonGrid class="message-grid">
         {chats.map((chat) => {
           return (

src/components/RoomHeader.tsx

@@ -4,14 +4,14 @@ import React, { useState } from 'react';
 import { db, timestamp } from '../services/firebase';
 import './RoomHeader.css';
 
-type VideoInputProps = {
+type RoomHeaderProps = {
   roomId: string;
   userId: string;
   ownerId: string;
   videoId: string;
 };
 
-const VideoInput: React.FC<VideoInputProps> = ({ roomId, userId, ownerId, videoId }) => {
+const RoomHeader: React.FC<RoomHeaderProps> = ({ roomId, userId, ownerId, videoId }) => {
   const [videoUrl, setVideoUrl] = useState('');
 
   const onSubmit = async () => {
@@ -25,7 +25,7 @@ const VideoInput: React.FC<VideoInputProps> = ({ roomId, userId, ownerId, videoI
           createdAt: timestamp,
           senderId: userId,
           content: 'changed the video',
-          type: 'system',
+          type: 'change',
         });
       }
 
@@ -61,4 +61,4 @@ const VideoInput: React.FC<VideoInputProps> = ({ roomId, userId, ownerId, videoI
   );
 };
 
-export default VideoInput;
+export default RoomHeader;

src/components/VideoPlayer.tsx

@@ -1,92 +1,141 @@
 import React, { useEffect, useRef, useState } from 'react';
 import ReactPlayer from 'react-player';
 import { db, timestamp } from '../services/firebase';
-import { secondsToTimestamp, timestampToSeconds } from '../services/utilities';
+import { secondsToTimestamp, SYNC_MARGIN } from '../services/utilities';
 
 type VideoPlayerProps = {
   ownerId: string;
   userId: string;
   roomId: string;
+  stateId: string;
 };
 
-const VideoPlayer: React.FC<VideoPlayerProps> = ({ ownerId, userId, roomId }) => {
+const VideoPlayer: React.FC<VideoPlayerProps> = ({ ownerId, userId, roomId, stateId }) => {
   const player = useRef<ReactPlayer>(null);
   const [playing, setPlaying] = useState(false);
   const [videoUrl, setVideoUrl] = useState('');
 
-  // Send video playing message to database when owner plays video
+  // Update database on play (owner only)
   const onPlay = async () => {
+    setPlaying(true);
     if (ownerId === userId) {
-      const currTime = player?.current?.getCurrentTime();
+      const currTime = player.current?.getCurrentTime();
       if (currTime !== undefined) {
-        await db
+        const roomRef = db.collection('rooms').doc(roomId);
-          .collection('rooms')
+        await roomRef.collection('messages').add({
-          .doc(roomId)
+          createdAt: timestamp,
-          .collection('messages')
+          senderId: userId,
-          .add({
+          content: 'started playing the video from ' + secondsToTimestamp(currTime),
-            createdAt: timestamp,
+          type: 'play',
-            senderId: userId,
+        });
-            content: 'started playing the video from ' + secondsToTimestamp(currTime),
+
-            type: 'play',
+        await roomRef.collection('states').doc(stateId).update({
-          });
+          time: currTime,
+          isPlaying: true,
+        });
       }
     }
   };
 
+  // Update database on pause (owner only)
   const onPause = async () => {
+    setPlaying(false);
     if (ownerId === userId) {
-      const currTime = player?.current?.getCurrentTime();
+      const currTime = player.current?.getCurrentTime();
       if (currTime !== undefined) {
-        await db
+        const roomRef = db.collection('rooms').doc(roomId);
-          .collection('rooms')
+        await roomRef.collection('messages').add({
-          .doc(roomId)
+          createdAt: timestamp,
-          .collection('messages')
+          senderId: userId,
-          .add({
+          content: 'paused the video at ' + secondsToTimestamp(currTime),
-            createdAt: timestamp,
+          type: 'pause',
-            senderId: userId,
+        });
-            content: 'paused the video at ' + secondsToTimestamp(currTime),
+
-            type: 'pause',
+        await roomRef.collection('states').doc(stateId).update({
-          });
+          time: currTime,
+          isPlaying: false,
+        });
       }
     }
   };
 
-  // Listen for video interactions
+  // Request an update after buffering is finished (member only)
+  const onBufferEnd = () => {
+    if (ownerId !== userId) {
+      db.collection('rooms').doc(roomId).collection('messages').add({
+        createdAt: timestamp,
+        senderId: userId,
+        type: 'updateState',
+      });
+    }
+  };
+
+  // Listen for video state updates (member only)
   useEffect(() => {
-    const videoUnsubscribe = db
+    if (ownerId !== userId) {
-      .collection('rooms')
+      const stateRef = db.collection('rooms').doc(roomId).collection('states');
-      .doc(roomId)
+      const stateUnsubscribe = stateRef.onSnapshot((querySnapshot) => {
-      .collection('messages')
-      .where('type', 'in', ['play', 'pause'])
-      .onSnapshot((querySnapshot) => {
         const changes = querySnapshot.docChanges();
         const change = changes[changes.length - 1];
-        if (change?.type === 'added') {
+        if (change.type === 'modified') {
           const data = change.doc.data();
-          if (userId !== data.senderId) {
+          const currTime = player.current?.getCurrentTime();
-            // Match video timestamp of received message
+          if (currTime !== undefined) {
-            const arr = data.content.split(' ');
+            setPlaying(data.isPlaying);
-            const timestamp = arr[arr.length - 1];
+            if (!data.isPlaying) {
-            player.current?.seekTo(timestampToSeconds(timestamp));
+              player.current?.seekTo(data.time);
-
+            }
-            if (data.type === 'play') {
+
-              setPlaying(true);
+            // Continue requesting an update on the video state, until synced
-            } else {
+            if (Math.abs(currTime - data.time) > SYNC_MARGIN / 1000 && data.isPlaying) {
-              setPlaying(false);
+              player.current?.seekTo(data.time);
+              console.log('diff: ' + Math.abs(currTime - data.time));
+              db.collection('rooms').doc(roomId).collection('messages').add({
+                createdAt: timestamp,
+                senderId: userId,
+                type: 'updateState',
+              });
             }
           }
         }
       });
 
-    return () => {
+      return () => {
-      videoUnsubscribe();
+        stateUnsubscribe();
-    };
+      };
-  }, [roomId, userId]);
+    }
+  }, [ownerId, userId, roomId]);
+
+  // Listen for video updateState requests (owner only)
+  useEffect(() => {
+    if (ownerId === userId) {
+      const roomRef = db.collection('rooms').doc(roomId);
+      const videoUnsubscribe = roomRef
+        .collection('messages')
+        .where('type', '==', 'updateState')
+        .onSnapshot((querySnapshot) => {
+          const changes = querySnapshot.docChanges();
+          const change = changes[changes.length - 1];
+          if (change?.type === 'added') {
+            const currTime = player.current?.getCurrentTime();
+            if (currTime !== undefined) {
+              roomRef.collection('states').doc(stateId).update({
+                time: currTime,
+                isPlaying: true,
+              });
+            }
+          }
+        });
+
+      return () => {
+        videoUnsubscribe();
+      };
+    }
+  }, [ownerId, roomId, userId, stateId]);
 
   // Listen for video URL changes
   useEffect(() => {
     const urlRef = db.collection('rooms').doc(roomId).collection('playlist');
-
     const urlUnsubscribe = urlRef.onSnapshot((querySnapshot) => {
       const changes = querySnapshot.docChanges();
       for (const change of changes) {
@@ -108,6 +157,7 @@ const VideoPlayer: React.FC<VideoPlayerProps> = ({ ownerId, userId, roomId }) =>
       height="100%"
       controls={true}
       onPlay={onPlay}
+      onBufferEnd={onBufferEnd}
       onPause={onPause}
       playing={playing}
       muted={true}

src/pages/Home.tsx

@@ -18,11 +18,17 @@ const Home: React.FC = () => {
       ownerId: userId,
     });
 
-    await db.collection('rooms').doc(roomId.id).collection('playlist').add({
+    const roomRef = db.collection('rooms').doc(roomId.id);
+    await roomRef.collection('playlist').add({
       createdAt: timestamp,
       url: 'https://www.youtube.com/watch?v=ksHOjnopT_U',
     });
 
+    await roomRef.collection('states').add({
+      time: 0,
+      isPlaying: false,
+    });
+
     await rtdb.ref('/rooms/' + roomId.id).set({ userCount: 0 });
     await rtdb.ref('/available/' + roomId.id).set({ name: 'Room Name', createdAt: new Date().toISOString() });
     const path = '/room/' + roomId.id;

src/pages/Room.tsx

@@ -18,6 +18,7 @@ const Room: React.FC<RouteComponentProps<{ roomId: string }>> = ({ match }) => {
   const [loading, setLoading] = useState(true);
   const [userCount, setUserCount] = useState(0);
   const [videoId, setVideoId] = useState('');
+  const [stateId, setStateId] = useState('');
 
   // Verify that the roomId exists in db
   useEffect(() => {
@@ -27,13 +28,18 @@ const Room: React.FC<RouteComponentProps<{ roomId: string }>> = ({ match }) => {
       if (!room.exists) {
         history.push('/');
       } else {
-        setValidRoom(true);
-        setOwnerId(room.data()?.ownerId);
-
         // Set videoId for RoomHeader component
         const playlistSnapshot = await roomRef.collection('playlist').get();
         const vidId = playlistSnapshot.docs[0].id;
         setVideoId(vidId);
+
+        // Set stateId for VideoPlayer component
+        const stateSnapshot = await roomRef.collection('states').get();
+        const vidStateId = stateSnapshot.docs[0].id;
+        setStateId(vidStateId);
+
+        setOwnerId(room.data()?.ownerId);
+        setValidRoom(true);
       }
     };
 
@@ -145,7 +151,7 @@ const Room: React.FC<RouteComponentProps<{ roomId: string }>> = ({ match }) => {
         <IonGrid class="room-grid">
           <IonRow class="room-row">
             <IonCol size="12" sizeLg="9" class="player-col">
-              <VideoPlayer ownerId={ownerId} userId={userId} roomId={roomId}></VideoPlayer>
+              <VideoPlayer ownerId={ownerId} userId={userId} roomId={roomId} stateId={stateId}></VideoPlayer>
             </IonCol>
             <IonCol size="12" sizeLg="3" class="chat-col">
               <Chat roomId={roomId} userId={userId}></Chat>

src/services/utilities.ts

@@ -44,6 +44,20 @@ const animals = [
   'Zebra',
 ];
 
+// const links: { [index: string]: RegExp } = {
+//   MATCH_URL_YOUTUBE: /(?:youtu\.be\/|youtube(?:-nocookie)?\.com\/(?:embed\/|v\/|watch\?v=|watch\?.+&v=))((\w|-){11})|youtube\.com\/playlist\?list=|youtube\.com\/user\//,
+//   MATCH_URL_SOUNDCLOUD: /(?:soundcloud\.com|snd\.sc)\/[^.]+$/,
+//   MATCH_URL_VIMEO: /vimeo\.com\/.+/,
+//   MATCH_URL_FACEBOOK: /^https?:\/\/(www\.)?facebook\.com.*\/(video(s)?|watch|story)(\.php?|\/).+$/,
+//   MATCH_URL_STREAMABLE: /streamable\.com\/([a-z0-9]+)$/,
+//   MATCH_URL_WISTIA: /(?:wistia\.com|wi\.st)\/(?:medias|embed)\/(.*)$/,
+//   MATCH_URL_TWITCH_VIDEO: /(?:www\.|go\.)?twitch\.tv\/videos\/(\d+)($|\?)/,
+//   MATCH_URL_TWITCH_CHANNEL: /(?:www\.|go\.)?twitch\.tv\/([a-zA-Z0-9_]+)($|\?)/,
+//   MATCH_URL_DAILYMOTION: /^(?:(?:https?):)?(?:\/\/)?(?:www\.)?(?:(?:dailymotion\.com(?:\/embed)?\/video)|dai\.ly)\/([a-zA-Z0-9]+)(?:_[\w_-]+)?$/,
+//   MATCH_URL_MIXCLOUD: /mixcloud\.com\/([^/]+\/[^/]+)/,
+//   MATCH_URL_VIDYARD: /vidyard.com\/(?:watch\/)?([a-zA-Z0-9-]+)/,
+// };
+
 export const generateAnonName = (): string => {
   const adj: string = adjectives[Math.floor(Math.random() * 20)];
   const animal: string = animals[Math.floor(Math.random() * 20)];
@@ -66,3 +80,5 @@ export const timestampToSeconds = (timestamp: string): number => {
   }
   return +arr[0] * 60 + +arr[1];
 };
+
+export const SYNC_MARGIN = 3000; // in milliseconds