Consolidated the server into the project

Added npm scripts to build and launch the whole project

server/ts/app.ts

@@ -0,0 +1,102 @@
+import WebSocket from 'ws';
+import Coordinates from './coordinates';
+
+const wss = new WebSocket.Server({ port: 8081 });
+const receivers: WebSocket[] = [];
+let sender: WebSocket | null = null;
+
+const paths = [] as Coordinates[][];
+
+let currentPath = [] as Coordinates[];
+
+wss.on('connection', ws => {
+    console.log('CONNECTION incoming');
+    ws.once('message', message => {
+        const str = message.toString();
+        switch (str) {
+            case 'SENDER':
+                setSender(ws);
+                break;
+            case 'RECEIVER':
+                addReceiver(ws)
+                break;
+            default:
+                console.log('Unknown register code: ' + str);
+                break;
+        }
+    });
+});
+
+console.log('READY');
+
+function addReceiver(ws: WebSocket) {
+    console.log('RECEIVER registered');
+    for (const path of paths) {
+        ws.send('START');
+        path.forEach(c => ws.send(JSON.stringify(c)));
+        ws.send('STOP');
+    }
+
+    receivers.push(ws);
+
+    ws.onclose = () => {
+        // Remove receiver when connection closes
+        for (const [i, recv] of receivers.entries()) {
+            if (ws === recv) {
+                receivers.splice(i, 1);
+            }
+        }
+    };
+}
+
+function setSender(ws: WebSocket) {
+    console.log('SENDER is being registered')
+    if (sender) {
+        console.log('Removing current sender...')
+        sender.close();
+        clearPaths();
+    }
+
+    sender = ws;
+    ws.on('message', msg => processMessage(msg));
+}
+
+function processMessage(message: WebSocket.Data) {
+    const text = message.toString();
+    switch (text) {
+        case 'START':
+            startPath();
+            break;
+        case 'STOP':
+            finishPath();
+            break;
+        default:
+            processCoordinates(text);
+            break;
+    }
+}
+
+function processCoordinates(text: string) {
+    console.log('COORDINATES received: ' + text);
+
+    console.log('SENDING to ' + receivers.length, 'clients');
+    receivers.forEach(r => r.send(text));
+
+    currentPath.push(JSON.parse(text));
+}
+
+function startPath() {
+    currentPath = [];
+    receivers.forEach(r => r.send('START'));
+}
+
+function finishPath() {
+    paths.push(currentPath);
+    receivers.forEach(r => r.send("STOP"));
+}
+
+function clearPaths() {
+    paths.splice(0, paths.length);
+    receivers.forEach(r => r.send('CLEAR'));
+    console.log('Paths have been cleared');
+}

server/ts/coordinates.ts

@@ -0,0 +1,9 @@
+export default class Coordinates {
+    public x: number;
+    public y: number;
+
+    constructor(x: number, y: number) {
+        this.x = x;
+        this.y = y;
+    }
+}