import express from 'express';
import { createServer } from 'http';
import { Server } from 'socket.io';
import { fileURLToPath } from 'url';
import { dirname, join } from 'path';

const __dirname = dirname(fileURLToPath(import.meta.url));
const app = express();
const httpServer = createServer(app);
const io = new Server(httpServer, {
  cors: { origin: '*' }
});

app.use(express.static(join(__dirname, '../client')));

const CHANNEL_NAMES = {
  1: 'Europa 1', 2: 'Europa 2', 3: 'Europa 3', 4: 'Funker TG',
  8: 'Notruf', 9: 'Notruf', 19: 'Bande (LKW/Auto)', 27: 'WW Band'
};

const channels = Array.from({ length: 40 }, (_, i) => ({
  id: i + 1,
  users: []
}));

const usedNames = new Set();

function makeUniqueName(name) {
  let finalName = name;
  let counter = 1;
  while (usedNames.has(finalName.toLowerCase())) {
    finalName = `${name}${counter}`;
    counter++;
  }
  usedNames.add(finalName.toLowerCase());
  return finalName;
}

io.on('connection', (socket) => {
  let currentChannel = null;
  let username = '';

  socket.on('check_name', (name, callback) => {
    if (!name || name.trim().length < 2) {
      callback({ available: false, message: 'Mindestens 2 Zeichen' });
      return;
    }
    if (usedNames.has(name.toLowerCase())) {
      callback({ available: false, suggested: makeUniqueName(name) });
    } else {
      callback({ available: true });
    }
  });

  socket.on('join', ({ name, channel }) => {
    username = makeUniqueName(name);
    currentChannel = channel;

    if (currentChannel) {
      channels[currentChannel - 1].users.push({ id: socket.id, name: username, isTransmitting: false });
    }

    socket.emit('init', { channels, CHANNEL_NAMES, myName: username });
    socket.broadcast.emit('user_update', { name: username, channel: currentChannel, joined: true });
  });

  socket.on('join_channel', ({ channel }) => {
    socket.join(`channel-${channel}`);
    if (currentChannel && currentChannel !== channel) {
      socket.leave(`channel-${currentChannel}`);
      channels[currentChannel - 1].users = channels[currentChannel - 1].users.filter(u => u.id !== socket.id);
    }
    currentChannel = channel;
    if (!channels[channel - 1].users.find(u => u.id === socket.id)) {
      channels[channel - 1].users.push({ id: socket.id, name: username, isTransmitting: false });
    }
    io.emit('channel_update', { channels });
  });

  socket.on('leave_channel', () => {
    if (currentChannel) {
      socket.leave(`channel-${currentChannel}`);
      channels[currentChannel - 1].users = channels[currentChannel - 1].users.filter(u => u.id !== socket.id);
      currentChannel = null;
      io.emit('channel_update', { channels });
    }
  });

  socket.on('transmitting', (isTransmitting) => {
    if (currentChannel) {
      const user = channels[currentChannel - 1].users.find(u => u.id === socket.id);
      if (user) user.isTransmitting = isTransmitting;
      io.emit('channel_update', { channels });
    }
  });

  socket.on('audio', (audioData) => {
    if (currentChannel) {
      socket.broadcast.to(`channel-${currentChannel}`).emit('audio', audioData);
    }
  });

  socket.on('slang', ({ channel, text, user }) => {
    io.to(`channel-${channel}`).emit('slang', { text, user });
  });

  socket.on('disconnect', () => {
    if (username) {
      usedNames.delete(username.toLowerCase());
    }
    if (currentChannel) {
      channels[currentChannel - 1].users = channels[currentChannel - 1].users.filter(u => u.id !== socket.id);
      io.emit('channel_update', { channels });
      io.emit('user_update', { name: username, channel: currentChannel, joined: false });
    }
  });
});

const PORT = process.env.PORT || 3001;
httpServer.listen(PORT, () => {
  console.log(`WebCB Server läuft auf http://localhost:${PORT}`);
});