server.js

const express = require('express');
const http = require('http');
const socketIO = require('socket.io');
const fs = require('fs');
const path = require('path');

const app = express();
const server = http.createServer(app);
const io = socketIO(server);

// Set Content-Security-Policy header to allow resources from self and inline scripts/styles for development
app.use((req, res, next) => {
  res.setHeader('Content-Security-Policy', "default-src 'self'; img-src 'self' data:; script-src 'self' 'unsafe-inline'; style-src 'self' 'unsafe-inline'; connect-src 'self' ws://localhost:3000 ws://127.0.0.1:3000;");
  next();
});

// Serve static files from the public folder
app.use(express.static('public'));

// In-memory message history and user tracking
let messageHistory = [];
const users = {};
const rooms = {};
const MESSAGE_FILE = path.join(__dirname, 'messages.json');
const MAX_HISTORY = 100;

// Load message history from file
function loadMessages() {
  try {
    const data = fs.readFileSync(MESSAGE_FILE, 'utf8');
    messageHistory = JSON.parse(data);
  } catch (e) {
    messageHistory = [];
  }
}

// Save message history to file
function saveMessages() {
  fs.writeFileSync(MESSAGE_FILE, JSON.stringify(messageHistory.slice(-MAX_HISTORY), null, 2));
}

// Emoji replacement (simple)
function emojify(text) {
  const emojiMap = {
    ':smile:': '😄', ':sad:': '😢', ':heart:': '❤️', ':thumbsup:': '👍', ':fire:': '🔥', ':laugh:': '😂', ':cry:': '😭', ':star:': '⭐', ':100:': '💯', ':clap:': '👏', ':wave:': '👋', ':ok:': '👌', ':wink:': '😉', ':angry:': '😠', ':sunglasses:': '😎', ':party:': '🥳', ':thinking:': '🤔', ':sleep:': '😴', ':poop:': '💩', ':rocket:': '🚀'
  };
  return text.replace(/:[a-z0-9_]+:/g, m => emojiMap[m] || m);
}

loadMessages();

// WebSocket logic
io.on('connection', (socket) => {
  let username = '';
  let currentRoom = 'main';

  // Join default room
  socket.join(currentRoom);

  // Send message history
  socket.emit('message history', messageHistory.filter(m => m.room === currentRoom));

  // Handle username set
  socket.on('set username', (name) => {
    username = name || 'Anonymous';
    users[socket.id] = { username, room: currentRoom };
    socket.to(currentRoom).emit('system message', `${username} joined the chat`);
    socket.emit('system message', `Welcome, ${username}!`);
  });

  // Handle room join
  socket.on('join room', (room) => {
    socket.leave(currentRoom);
    socket.to(currentRoom).emit('system message', `${username} left the room`);
    currentRoom = room;
    socket.join(room);
    users[socket.id].room = room;
    socket.emit('message history', messageHistory.filter(m => m.room === room));
    socket.to(room).emit('system message', `${username} joined the room`);
  });

  // Typing status
  socket.on('typing', (isTyping) => {
    socket.to(currentRoom).emit('typing', { username, isTyping });
  });

  // Chat message
  socket.on('chat message', (msg) => {
    if (!username) return;
    const message = {
      username,
      text: emojify(msg),
      time: new Date().toISOString(),
      room: currentRoom
    };
    messageHistory.push(message);
    saveMessages();
    io.to(currentRoom).emit('chat message', message);
  });

  // Disconnect
  socket.on('disconnect', () => {
    if (username) {
      socket.to(currentRoom).emit('system message', `${username} left the chat`);
    }
    delete users[socket.id];
  });
});

const PORT = 3000;
server.listen(PORT, () => {
  console.log(`Server running at http://localhost:${PORT}`);
});