init

server/package-lock.json

@@ -0,0 +1,36 @@
+{
+  "name": "chat-server",
+  "version": "1.0.0",
+  "lockfileVersion": 3,
+  "requires": true,
+  "packages": {
+    "": {
+      "name": "chat-server",
+      "version": "1.0.0",
+      "dependencies": {
+        "ws": "^8.16.0"
+      }
+    },
+    "node_modules/ws": {
+      "version": "8.21.0",
+      "resolved": "https://registry.npmjs.org/ws/-/ws-8.21.0.tgz",
+      "integrity": "sha512-Vsp28b7DRcimFQvrqu2Wek3z1iYxDCWqHYB8Qsnk/S4RfaCQzPGPyBNuVjJV3cd6UiKtUtp6sNM77gWvzcCH+g==",
+      "license": "MIT",
+      "engines": {
+        "node": ">=10.0.0"
+      },
+      "peerDependencies": {
+        "bufferutil": "^4.0.1",
+        "utf-8-validate": ">=5.0.2"
+      },
+      "peerDependenciesMeta": {
+        "bufferutil": {
+          "optional": true
+        },
+        "utf-8-validate": {
+          "optional": true
+        }
+      }
+    }
+  }
+}

server/package.json

@@ -0,0 +1,12 @@
+{
+  "name": "chat-server",
+  "version": "1.0.0",
+  "description": "WebSocket chat server with file sharing",
+  "main": "server.js",
+  "scripts": {
+    "start": "node server.js"
+  },
+  "dependencies": {
+    "ws": "^8.16.0"
+  }
+}

server/server.js

@@ -0,0 +1,129 @@
+const fs = require('fs');
+const path = require('path');
+const { WebSocketServer } = require('ws');
+
+const PORT = parseInt(process.env.PORT, 10) || 8080;
+const MAX_FILE_SIZE = parseInt(process.env.MAX_FILE_SIZE, 10) || 10 * 1024 * 1024;
+
+const usersPath = path.join(__dirname, process.env.USERS_FILE || 'users.json');
+let validUsers;
+try {
+  validUsers = JSON.parse(fs.readFileSync(usersPath, 'utf-8'));
+  console.log(`Loaded ${validUsers.length} users from users.json`);
+} catch (err) {
+  console.error('Failed to load users.json:', err.message);
+  process.exit(1);
+}
+
+function authenticate(login, password) {
+  return validUsers.find(u => u.login === login && u.password === password) || null;
+}
+
+const wss = new WebSocketServer({ port: PORT });
+console.log(`WebSocket server running on ws://localhost:${PORT}`);
+
+wss.on('connection', (ws, req) => {
+  const clientIp = req.socket.remoteAddress;
+  console.log(`New connection from ${clientIp}`);
+
+  let authenticated = false;
+  let userLogin = null;
+
+  ws.on('message', (data) => {
+    let parsed;
+    try {
+      parsed = JSON.parse(data.toString());
+    } catch (e) {
+      ws.send(JSON.stringify({ type: 'error', message: 'Invalid JSON' }));
+      return;
+    }
+
+    if (!authenticated) {
+      if (parsed.type === 'auth') {
+        const user = authenticate(parsed.login, parsed.password);
+        if (user) {
+          authenticated = true;
+          userLogin = parsed.login;
+          console.log(`User authenticated: ${userLogin}`);
+          ws.send(JSON.stringify({ type: 'auth_result', success: true }));
+          broadcast({
+            type: 'system',
+            text: `${userLogin} joined the chat`
+          }, null);
+        } else {
+          console.log(`Auth failed for login: ${parsed.login}`);
+          ws.send(JSON.stringify({
+            type: 'auth_result',
+            success: false,
+            reason: 'Invalid login or password'
+          }));
+        }
+      } else {
+        ws.send(JSON.stringify({ type: 'error', message: 'Authenticate first' }));
+      }
+      return;
+    }
+
+    if (parsed.type === 'text') {
+      if (!parsed.text || typeof parsed.text !== 'string') {
+        ws.send(JSON.stringify({ type: 'error', message: 'Invalid text message' }));
+        return;
+      }
+      console.log(`Text from ${userLogin}: ${parsed.text.substring(0, 50)}`);
+      broadcast({
+        type: 'text',
+        from: userLogin,
+        timestamp: Date.now(),
+        text: parsed.text
+      }, null);
+      return;
+    }
+
+    if (parsed.type === 'file') {
+      if (!parsed.filename || !parsed.mime || !parsed.data) {
+        ws.send(JSON.stringify({ type: 'error', message: 'Invalid file message' }));
+        return;
+      }
+      const size = Math.ceil((parsed.data.length * 3) / 4);
+      if (size > MAX_FILE_SIZE) {
+        ws.send(JSON.stringify({ type: 'error', message: 'File too large (max 10 MB)' }));
+        return;
+      }
+      console.log(`File from ${userLogin}: ${parsed.filename} (${parsed.mime}, ~${size} bytes)`);
+      broadcast({
+        type: 'file',
+        from: userLogin,
+        timestamp: Date.now(),
+        filename: parsed.filename,
+        mime: parsed.mime,
+        data: parsed.data
+      }, null);
+      return;
+    }
+
+    ws.send(JSON.stringify({ type: 'error', message: 'Unknown message type' }));
+  });
+
+  ws.on('close', (code, reason) => {
+    console.log(`Connection closed${userLogin ? ` for ${userLogin}` : ''} (code: ${code})`);
+    if (userLogin) {
+      broadcast({
+        type: 'system',
+        text: `${userLogin} left the chat`
+      }, null);
+    }
+  });
+
+  ws.on('error', (err) => {
+    console.error(`WebSocket error${userLogin ? ` for ${userLogin}` : ''}:`, err.message);
+  });
+});
+
+function broadcast(message, excludeWs) {
+  const json = JSON.stringify(message);
+  wss.clients.forEach(client => {
+    if (client !== excludeWs && client.readyState === 1) {
+      client.send(json);
+    }
+  });
+}

server/users.json

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+[
+  { "login": "alice", "password": "123" },
+  { "login": "bob", "password": "456" }
+]