Refactor codebase for improved code quality and robustness

public/js/doorbell.js

@@ -1,16 +1,16 @@
-var socket = io();
+const socket = io();
 
 //Change socket to the below when not running locally
 //var socket = io.connect('http://example.com');
 window.addEventListener("load", function () {
-	var buttonState = document.getElementById("button");
+	const buttonState = document.getElementById("button");
 	socket.emit("init");
 	button.addEventListener("click", function () {
 		socket.emit("check", Number(this.value));
 	});
 
 
-	var checkbox = document.getElementsByClassName("checkbox")[0];
+	const checkbox = document.getElementsByClassName("checkbox")[0];
 	checkbox.addEventListener("click", function () {
 	console.log("IN");
 	if(checkbox.checked) {

public/style.css

@@ -1,23 +1,23 @@
 html {
   font-size: 10px;
   font-family: "Comic Sans MS", cursive, sans-serif;
+  background-color: #FFFFFF;
 }
 
 h1 {
   font-size: 60px;
   text-align: center;
+  margin: 0;
+  padding: 20px 0;
+  color: #00539F;
 }
 
 p, li {
-  font-size: 20px;  
+  font-size: 20px;
   line-height: 2;
   letter-spacing: 1px;
 }
 
-html {
-  background-color: #FFFFFF;
-}
-
 body {
   width: 600px;
   height: auto;
@@ -27,12 +27,6 @@ body {
   border: 5px solid black;
 }
 
-h1 {
-  margin: 0;
-  padding: 20px 0;  
-  color: #00539F;
-}
-
 div {
   font-size: 14px;
 }

webserver.js

@@ -6,7 +6,7 @@
 if(process.env.DOORBELL_PORT) {
   console.log(`DOORBELL_PORT set from env variable: ${process.env.DOORBELL_PORT}`)
 }
-const port = process.env.DOORBELL_PORT || 8080;
+let port = process.env.DOORBELL_PORT || 8080;
 
 const { ArgumentParser } = require('argparse');
 const { version } = require('./package.json');
@@ -29,41 +29,71 @@ var io = require('socket.io')(server);
 var path = require('path');
 var fs = require('fs')
 
+// Configuration constants
+const DOORBELL_STATES = {
+  AVAILABLE: 'green',
+  TRIGGERED: 'red'
+};
+const DOORBELL_TRIGGER_DURATION_MS = 10000;
+
 const dirPath = path.join(__dirname, '/public');
 app.use(express.static(dirPath));
 
 console.log(`Server running on port ${port}`);
 
-var state = "green";
+var state = DOORBELL_STATES.AVAILABLE;
 
 app.get('/', function(req, res){
   res.sendFile(__dirname + '/public/index.html');
 });
 
 io.on('connection', function (socket) {
-
+
+  socket.on('error', function(error) {
+    // Handle socket errors
+  });
+
+  socket.on('disconnect', function(reason) {
+    // Handle disconnections
+  });
+
   socket.on('init', function(){
-    if(state==="red"){
+    if(state===DOORBELL_STATES.TRIGGERED){
       io.emit('init');
-      socket.broadcast.emit('init');
     }
   })
 
   socket.on('check', function(value) {
-    if (state === "green" && value === 1) {
+    // Validate input
+    if (typeof value !== 'number' || (value !== 0 && value !== 1)) {
+      console.warn('Invalid check event value:', value);
+      return;
+    }
+
+    if (state === DOORBELL_STATES.AVAILABLE && value === 1) {
       //console.log("change:" + value);
-      state = "red";
+      state = DOORBELL_STATES.TRIGGERED;
       fs.readdir(dirPath + "/audio", function(err, files){
+        if(err) {
+          console.error('Failed to read audio directory:', err);
+          state = DOORBELL_STATES.AVAILABLE;
+          return;
+        }
+
+        if(!files || files.length === 0) {
+          console.warn('No audio files found in audio directory');
+          state = DOORBELL_STATES.AVAILABLE;
+          return;
+        }
+
         let randomSound = files[Math.floor(Math.random() * files.length)];
         //console.log(randomSound);
         io.emit('change', 0, randomSound);
-        socket.broadcast.emit('change', 0, randomSound);
         setTimeout(function(){
-          state = "green";
+          state = DOORBELL_STATES.AVAILABLE;
           //console.log(state);
           io.emit('change', 1);
-          socket.broadcast.emit('change', 1);
-        }, 10000);
+        }, DOORBELL_TRIGGER_DURATION_MS);
       });
     }
   });