Fix up selecting first player and some errors in the number generation.

static/css/style.css

@@ -4,3 +4,22 @@
     top: 0;
     padding: 12px;
 }
+
+#ready {
+    position: fixed;
+    bottom: 20px;
+    width: 100%;
+    display: flex;
+    align-items: center;
+    justify-content: center;
+}
+
+#ready-button {
+    font-size: 2em;
+    color: red;
+}
+
+#ready-button.active {
+    font-size: 2em;
+    color: green;
+}

static/js/dom.js

@@ -15,3 +15,24 @@ function updatePlayerDom() {
         }
     }
 }
+
+document.addEventListener("DOMContentLoaded", () => {
+    document.querySelector("#ready-button").addEventListener("click", async (ev) => {
+        let nowReady = ev.target.textContent === "Not ready";
+        us.ready = nowReady;
+
+        ev.target.classList.toggle("active");
+        ev.target.textContent = nowReady ? "Ready" : "Not ready";
+
+        socket.emit("message", {
+            type: "SYNC",
+            author: ID,
+            ready: nowReady,
+            name: "",
+        });
+
+        if (allPlayersReady()) {
+            await startPregame();
+        }
+    });
+});

static/js/index.js

@@ -3,6 +3,7 @@ const ID = window.crypto.randomUUID();
 const TIMEOUT = 30_000;
 
 let players = {};
+let us = null;
 
 const WAITING = 0;
 const PRE_GAME = 1;
@@ -38,6 +39,7 @@ document.addEventListener("DOMContentLoaded", () => {
         });
         // Create self
         players[ID] = new Player(ID, name);
+        us = players[ID];
     });
 
     socket.on("message", async (data) => {
@@ -64,7 +66,7 @@ document.addEventListener("DOMContentLoaded", () => {
                 break;
 
             case "RANDOM":
-                random.processCooperativeRandom(data);
+                await random.processCooperativeRandom(data);
                 break;
         }
     });
@@ -131,16 +133,7 @@ async function sync(data) {
     players[data.author].ready = data.ready;
 
     if (allPlayersReady()) {
-        game_state = PRE_GAME;
-        // Decide turn order. "Master" begins a cooperative rng process.
-        if (ID === Array.min(...Object.keys(players))) {
-            random.coopRandom(Object.keys(players).length, "first-player");
-        }
-
-        // Wait for value to populate
-        let player1 = await random.get("first-player");
-
-        console.log(player1);
+        await startPregame();
     }
 }
 
@@ -153,3 +146,13 @@ function allPlayersReady() {
 
     return true;
 }
+
+async function startPregame() {
+    console.log("All players ready.");
+
+    game_state = PRE_GAME;
+
+    let player1 = await random.get(Object.keys(players).length, "first-player");
+
+    console.log(player1);
+}

static/js/random.js

@@ -5,7 +5,7 @@ class RandomSession {
         this.cipherKeys = {};
         this.ourKey = CryptoJS.lib.WordArray.random(32).toString();
         // 32-bit as JavaScript does funny stuff at 64-bit levels.
-        this.ourNoise = CryptoJS.lib.WordArray.random(4).toString();
+        this.ourNoise = CryptoJS.lib.WordArray.random(4);
         this.finalValue = null;
         this.resolvers = [];
     }
@@ -17,33 +17,37 @@ class RandomSession {
 
 class Random {
     constructor() {
-        this.locked = false;
         this.sessions = {};
     }
 
-    get(sessionId) {
-        // Spin until lock frees.
-        while (this.locked);
+    async get(n, sessionId) {
+        if (this.sessions[sessionId] === undefined) {
+            this.initialiseSession(n, sessionId);
+        }
 
+        let promise;
+        await navigator.locks.request(`random-${sessionId}`, () => {
+            console.log("in lock now");
             if (this.sessions[sessionId].finalValue === null) {
                 let session = this.sessions[sessionId];
                 let resolver;
-            let promise = new Promise((resolve) => {
+                promise = new Promise((resolve) => {
                     resolver = resolve;
                 });
                 session.resolvers.push(resolver);
-            return promise;
             } else {
-            return new Promise((resolve) => {
+                promise = new Promise((resolve) => {
                     resolve(this.sessions[sessionId].finalValue);
                 });
             }
+        });
+        return promise;
     }
 
     /**
      * Start a cooperative random session.
      */
-    coopRandom(n, sessionId) {
+    initialiseSession(n, sessionId) {
         let session = new RandomSession(n);
         if (sessionId === undefined) {
             sessionId = window.crypto.randomUUID();
@@ -60,7 +64,7 @@ class Random {
             cipherText: session.cipherText(),
         });
 
-        return sessionId;
+        return session;
     }
 
     /**
@@ -68,28 +72,13 @@ class Random {
      *
      * @param data Packet received
      */
-    processCooperativeRandom(data) {
+    async processCooperativeRandom(data) {
         // Step 0: extract relevant information from data
         let session = this.sessions[data.session];
         const stage = data.stage;
 
         if (session === undefined) {
-            // Step 1: generate and encrypt our random value. 8 bytes = 64 bit integer
-            const noise = CryptoJS.lib.WordArray.random(8).toString();
-            console.log(`our noise: ${noise}`);
-
-            session = new RandomSession(data.range);
-            this.sessions[data.session] = session;
-
-            // Step 2: send our random value and wait for all responses
-            socket.emit("message", {
-                type: "RANDOM",
-                author: ID,
-                session: data.session,
-                stage: "CIPHERTEXT",
-                range: data.range,
-                cipherText: session.cipherText(),
-            });
+            session = this.initialiseSession(data.range, data.session);
         }
 
         if (stage === "CIPHERTEXT") {
@@ -117,22 +106,22 @@ class Random {
                 Object.keys(players).length - 1
             ) {
                 // Lock out wait calls as they may resolve to never-ending promises.
-                this.locked = true;
-
-                let total = 0;
+                await navigator.locks.request(`random-${data.session}`, () => {
+                    let total = parseInt(session.ourNoise, 16);
 
                     for (let participant of Object.keys(session.cipherKeys)) {
-                    total += CryptoJS.AES.decrypt(
+                        let decrypted = CryptoJS.AES.decrypt(
                             session.cipherTexts[participant],
                             session.cipherKeys[participant]
-                    );
+                        ).toString();
+
+                        total += parseInt(decrypted, 16);
                     }
 
                     session.finalValue = total % session.range;
 
                     this.resolve(data.session);
-
-                this.locked = false;
+                });
             }
         }
     }

static/js/shim.js

@@ -0,0 +1,3 @@
+Array.prototype.min = function () {
+    return this.reduce((min, val) => (min < val ? min : val));
+};

templates/index.html

@@ -7,6 +7,7 @@
 
         <script src="https://cdn.socket.io/4.5.4/socket.io.min.js"></script>
         <script src="https://cdnjs.cloudflare.com/ajax/libs/crypto-js/4.1.1/crypto-js.min.js"></script>
+        <script src="{{ url_for('static', filename='js/shim.js') }}"></script>
         <script src="{{ url_for('static', filename='js/index.js') }}"></script>
         <script src="{{ url_for('static', filename='js/player.js') }}"></script>
         <script src="{{ url_for('static', filename='js/dom.js') }}"></script>
@@ -20,5 +21,9 @@
         </ul>
     </div>
 
+    <div id="ready">
+        <button id="ready-button">Not ready</button>
+    </div>
+
     </body>
 </html>