// RDP: Windows nutzt das eingebaute mstsc.exe, Linux (Arch/CachyOS) FreeRDP (xfreerdp3 / xfreerdp / sdl-freerdp3 / wlfreerdp3).
// Verbindungen laufen entweder eingebettet im MrTerm-Tab (siehe rdp-embed.js) oder im eigenen Fenster.
const { spawn, execFile, execFileSync } = require('child_process');
const fs = require('fs');
const os = require('os');
const path = require('path');
const i18n = require('../i18n');

function which(bin) {
  try {
    execFileSync(process.platform === 'win32' ? 'where' : 'which', [bin], { stdio: 'ignore' });
    return true;
  } catch { return false; }
}

// Eingebettet geht nur der X11-Client (unterstützt /parent-window)
function linuxClient(pref, embedded) {
  if (embedded) return ['xfreerdp3', 'xfreerdp'].find(which);
  const candidates = pref && pref !== 'auto'
    ? [pref]
    : process.env.WAYLAND_DISPLAY
      ? ['sdl-freerdp3', 'wlfreerdp3', 'xfreerdp3', 'wlfreerdp', 'xfreerdp']
      : ['xfreerdp3', 'sdl-freerdp3', 'xfreerdp'];
  return candidates.find(which);
}

function detect(settings) {
  if (process.platform === 'win32') return { available: true, client: 'mstsc', embedClient: 'mstsc' };
  const c = linuxClient(settings.rdpClientLinux);
  const e = linuxClient(null, true);
  return c ? { available: true, client: c, embedClient: e || null } : { available: false, hint: 'sudo pacman -S freerdp' };
}

const userOf = (host) => (host.domain ? `${host.domain}\\${host.username || ''}` : host.username || '');

// ---------- Windows: .rdp-Datei + temporäre Anmeldedaten
function writeRdpFile(host, size) {
  const port = Number(host.port) || 3389;
  const target = port === 3389 ? host.address : `${host.address}:${port}`;
  const user = userOf(host);
  const w = size?.width || host.rdpWidth;
  const hgt = size?.height || host.rdpHeight;
  const lines = [
    `full address:s:${target}`,
    user && `username:s:${user}`,
    `screen mode id:i:${!size && host.rdpFullscreen ? 2 : 1}`,
    w && `desktopwidth:i:${w}`,
    hgt && `desktopheight:i:${hgt}`,
    'dynamic resolution:i:1',
    // Standard: Auflösung folgt der Fenstergröße (Windows 8.1 / Server 2012 R2 und neuer). "smart sizing" würde stattdessen nur skalieren.
    `smart sizing:i:${host.rdpResize === 'scale' ? 1 : 0}`,
    'displayconnectionbar:i:0',
    `redirectclipboard:i:${host.rdpClipboard === false ? 0 : 1}`,
    `redirectdrives:i:${host.rdpDrives ? 1 : 0}`,
    `audiomode:i:${host.rdpAudio === false ? 2 : 0}`,
    'prompt for credentials:i:0',
    'authentication level:i:2',
    'autoreconnection enabled:i:1',
  ].filter(Boolean);
  const file = path.join(os.tmpdir(), `mrterm-${host.id || 'quick'}-${Date.now()}.rdp`);
  fs.writeFileSync(file, lines.join('\r\n'), 'utf16le');
  setTimeout(() => fs.rm(file, () => {}), 60000);
  return file;
}

// Legt Anmeldedaten kurzzeitig im Windows-Anmeldeinformationsspeicher ab, damit mstsc ohne Rückfrage verbindet.
function withWinCredentials(host, run) {
  const user = userOf(host);
  if (!(host.password && user)) return run();
  execFile('cmdkey', [`/generic:TERMSRV/${host.address}`, `/user:${user}`, `/pass:${host.password}`], () => {
    run();
    setTimeout(() => execFile('cmdkey', [`/delete:TERMSRV/${host.address}`], () => {}), 20000);
  });
}

// ---------- Linux: FreeRDP-Argumente
function freerdpArgs(host, size) {
  const port = Number(host.port) || 3389;
  const args = [`/v:${host.address}:${port}`, '/cert:tofu', '+auto-reconnect'];
  if (host.username) args.push(`/u:${host.username}`);
  if (host.domain) args.push(`/d:${host.domain}`);
  const resize = host.rdpResize === 'scale' ? '/smart-sizing' : '/dynamic-resolution';
  if (size) args.push(`/size:${size.width}x${size.height}`, resize);
  else if (host.rdpFullscreen) args.push('/f');
  else if (host.rdpWidth && host.rdpHeight) args.push(`/size:${host.rdpWidth}x${host.rdpHeight}`, resize);
  else args.push(resize);
  if (host.rdpClipboard !== false) args.push('+clipboard');
  if (host.rdpDrives) args.push(`/drive:home,${os.homedir()}`);
  if (host.rdpAudio !== false) args.push('/sound');
  args.push(`/title:${host.label || host.address}`);
  // Passwort über stdin statt Kommandozeile (nicht in `ps` sichtbar)
  if (host.password) args.push('/from-stdin');
  return args;
}

// Externes Fenster
function launch(host, settings) {
  if (process.platform === 'win32') {
    const file = writeRdpFile(host);
    withWinCredentials(host, () => spawn('mstsc.exe', [file], { detached: true, stdio: 'ignore' }).unref());
    return { client: 'mstsc' };
  }
  const client = linuxClient(settings.rdpClientLinux);
  if (!client) throw new Error(i18n.t('No FreeRDP found. Install with: sudo pacman -S freerdp'));
  const p = spawn(client, freerdpArgs(host), { detached: true, stdio: [host.password ? 'pipe' : 'ignore', 'ignore', 'pipe'] });
  if (host.password) { p.stdin.write(host.password + '\n'); p.stdin.end(); }
  let err = '';
  p.stderr.on('data', (d) => { err = (err + d).slice(-4000); });
  p.unref();
  return { client, process: p, getErr: () => err };
}

module.exports = { detect, launch, linuxClient, writeRdpFile, withWinCredentials, freerdpArgs };