const { app, BrowserWindow, ipcMain } = require('electron');
const path = require('path');
const fs = require('fs');
const dgram = require('dgram');

let mainWindow;
let servers = [];

const configPath = path.join(app.getPath('userData'), 'servers.json');

function loadConfig() {
  try {
    if (fs.existsSync(configPath)) {
      const data = fs.readFileSync(configPath, 'utf8');
      servers = JSON.parse(data).servers || [];
    }
  } catch (e) {
    servers = [];
  }
}

function saveConfig() {
  fs.writeFileSync(configPath, JSON.stringify({ servers }, null, 2));
}

function createWindow() {
  mainWindow = new BrowserWindow({
    width: 1200,
    height: 800,
    webPreferences: {
      preload: path.join(__dirname, 'preload.js'),
      contextIsolation: true,
      nodeIntegration: false
    }
  });

  mainWindow.loadFile('index.html');
}

app.whenReady().then(() => {
  loadConfig();
  createWindow();
});

ipcMain.handle('get-servers', () => servers);

ipcMain.handle('save-server', (event, server) => {
  const index = servers.findIndex(s => s.id === server.id);
  if (index >= 0) {
    servers[index] = server;
  } else {
    server.id = Date.now().toString();
    servers.push(server);
  }
  saveConfig();
  return servers;
});

ipcMain.handle('delete-server', (event, id) => {
  servers = servers.filter(s => s.id !== id);
  saveConfig();
  return servers;
});

ipcMain.handle('rcon-send', async (event, { address, port, password, command }) => {
  const msgStr = 'rcon ' + password + ' ' + command + '\n';
  const packet = Buffer.alloc(4 + Buffer.byteLength(msgStr));
  packet.writeUInt32LE(0xFFFFFFFF, 0);
  packet.write(msgStr, 4);

  return new Promise((resolve) => {
    const socket = dgram.createSocket('udp4');
    let responseBuffer = '';
    let done = false;

    const finish = (success, response) => {
      if (!done) {
        done = true;
        clearTimeout(timeout);
        socket.removeAllListeners();
        try { socket.close(); } catch (e) {}
        resolve({ success, response: success ? response : null, error: success ? null : response });
      }
    };

    const timeout = setTimeout(() => {
      finish(false, 'Timeout waiting for response');
    }, 5000);

    socket.on('message', (msg) => {
      const buf = Buffer.from(msg);
      let start = 0;
      if (buf.length >= 4 && buf[0] === 0xFF && buf[1] === 0xFF && buf[2] === 0xFF && buf[3] === 0xFF) {
        start = 4;
      }
      let data = buf.slice(start).toString('ascii');
      if (data.startsWith('print')) {
        data = data.slice(5);
        if (data.charCodeAt(0) === 10) data = data.slice(1);
      }
      responseBuffer += data;
      if (responseBuffer.length > 0) {
        finish(true, responseBuffer.trim());
      }
    });

    socket.on('error', (err) => {
      finish(false, err.message);
    });

    socket.on('close', () => {
      if (!done) {
        finish(true, responseBuffer.trim());
      }
    });

    socket.send(packet, 0, packet.length, port, address, (err) => {
      if (err) {
        finish(false, err.message);
      }
    });
  });
});