const { app, BrowserWindow, ipcMain, dialog, shell, clipboard, Menu } = require('electron');
const path = require('path');
const fs = require('fs');
const os = require('os');
const crypto = require('crypto');
const { utils: sshUtils } = require('ssh2');
const { Store } = require('./store');
const { SshManager } = require('./ssh');
const rdp = require('./rdp');
const { Updater } = require('./updater');
const { createEmbed, embedSupported } = require('./rdp-embed');

let win;
const store = new Store();

// Unter Linux muss MrTerm für eingebettete RDP-Tabs als X11-Client laufen (unter Wayland via XWayland).
// Die Wahl wird unverschlüsselt in launch.json gespeichert, weil sie vor dem Start des Fensters gebraucht wird.
const launchFile = path.join(app.getPath('userData'), 'launch.json');
function readLaunch() { try { return JSON.parse(fs.readFileSync(launchFile, 'utf8')); } catch { return {}; } }
if (process.platform === 'linux' && readLaunch().x11 !== false) app.commandLine.appendSwitch('ozone-platform', 'x11');
const pendingSecrets = new Map();

function send(channel, ...args) {
  if (win && !win.isDestroyed()) win.webContents.send(channel, ...args);
}

async function confirmHostKey(target, fingerprint, known) {
  if (process.env.MRTERM_SMOKE) return true;
  const changed = !!known;
  const r = await dialog.showMessageBox(win, {
    type: changed ? 'warning' : 'question',
    title: changed ? 'Host-Schlüssel hat sich geändert!' : 'Unbekannter Host',
    message: changed
      ? `WARNUNG: Der Host-Schlüssel von ${target.host}:${target.port} hat sich geändert. Das kann auf einen Man-in-the-Middle-Angriff hindeuten.`
      : `Die Echtheit von ${target.host}:${target.port} kann nicht bestätigt werden.`,
    detail: `Fingerprint:\n${fingerprint}${changed ? `\n\nBisher gespeichert:\n${known.fingerprint}` : ''}`,
    buttons: [changed ? 'Trotzdem verbinden & ersetzen' : 'Vertrauen & verbinden', 'Abbrechen'],
    defaultId: changed ? 1 : 0,
    cancelId: 1,
  });
  return r.response === 0;
}

function askSecret(sessionId, req) {
  return new Promise((resolve) => {
    const reqId = crypto.randomUUID();
    pendingSecrets.set(reqId, resolve);
    send('secret:request', { reqId, sessionId, ...req });
  });
}

const ssh = new SshManager(store, confirmHostKey, askSecret);
const updater = new Updater(store, send);

function createWindow() {
  win = new BrowserWindow({
    width: 1360,
    height: 860,
    minWidth: 900,
    minHeight: 560,
    backgroundColor: '#14161d',
    icon: path.join(__dirname, '..', '..', 'assets', 'icon.png'),
    frame: false,
    titleBarStyle: process.platform === 'darwin' ? 'hiddenInset' : 'hidden',
    webPreferences: {
      preload: path.join(__dirname, '..', 'preload.js'),
      contextIsolation: true,
      nodeIntegration: false,
      sandbox: true,
    },
  });
  Menu.setApplicationMenu(null);
  win.loadFile(path.join(__dirname, '..', 'renderer', 'index.html'));
  win.on('maximize', () => send('win:state', true));
  // Eingebettete RDP-Fenster (Windows: owned windows) beim Verschieben/Größenändern mitführen
  const followRdp = () => { for (const s of rdpSessions.values()) { try { s.emb.reposition(); } catch {} } };
  win.on('move', followRdp);
  win.on('resize', followRdp);
  win.on('restore', followRdp);
  win.on('unmaximize', () => send('win:state', false));
  win.webContents.setWindowOpenHandler(({ url }) => { shell.openExternal(url); return { action: 'deny' }; });
}

function handle(channel, fn) {
  ipcMain.handle(channel, async (_e, ...args) => {
    try { return { ok: true, value: await fn(...args) }; }
    catch (e) { return { ok: false, error: e.message || String(e) }; }
  });
}

// ---------- Fenster ----------
ipcMain.on('win:min', () => win.minimize());
ipcMain.on('win:max', () => (win.isMaximized() ? win.unmaximize() : win.maximize()));
ipcMain.on('win:close', () => win.close());

// ---------- Vault ----------
handle('vault:get', () => ({ ...store.get(), encrypted: store.encrypted, platform: process.platform }));
handle('vault:upsert', (col, item) => store.upsert(col, item));
handle('vault:remove', (col, id) => store.remove(col, id));
handle('vault:settings', (s) => {
  store.setSettings(s);
  if ('rdpEmbed' in s) fs.writeFileSync(launchFile, JSON.stringify({ ...readLaunch(), x11: s.rdpEmbed !== false }));
});
handle('vault:forgetHost', (id) => { delete store.get().knownHosts[id]; store.save(); });
handle('vault:export', async () => {
  const r = await dialog.showSaveDialog(win, { defaultPath: 'mrterm-backup.json', filters: [{ name: 'JSON', extensions: ['json'] }] });
  if (r.canceled) return false;
  fs.writeFileSync(r.filePath, JSON.stringify(store.get(), null, 2), { mode: 0o600 });
  return r.filePath;
});
handle('vault:import', async () => {
  const r = await dialog.showOpenDialog(win, { filters: [{ name: 'JSON', extensions: ['json'] }], properties: ['openFile'] });
  if (r.canceled) return false;
  const data = JSON.parse(fs.readFileSync(r.filePaths[0], 'utf8'));
  for (const col of ['groups', 'hosts', 'keys', 'snippets', 'forwards'])
    for (const item of data[col] || []) store.upsert(col, item);
  return true;
});

// Import aus ~/.ssh/config
handle('vault:importSshConfig', () => {
  const file = path.join(os.homedir(), '.ssh', 'config');
  if (!fs.existsSync(file)) throw new Error('~/.ssh/config nicht gefunden');
  const entries = [];
  let cur = null;
  for (const raw of fs.readFileSync(file, 'utf8').split(/\r?\n/)) {
    const line = raw.trim();
    if (!line || line.startsWith('#')) continue;
    const [k, ...rest] = line.split(/\s+/);
    const v = rest.join(' ');
    if (k.toLowerCase() === 'host') {
      cur = v.includes('*') ? null : { label: v, address: v, port: 22, protocol: 'ssh' };
      if (cur) entries.push(cur);
    } else if (cur) {
      const key = k.toLowerCase();
      if (key === 'hostname') cur.address = v;
      else if (key === 'user') cur.username = v;
      else if (key === 'port') cur.port = Number(v);
      else if (key === 'identityfile') cur._identity = v.replace(/^~/, os.homedir());
    }
  }
  let n = 0;
  for (const e of entries) {
    if (store.get().hosts.some((h) => h.address === e.address && h.username === e.username && Number(h.port) === e.port)) continue;
    if (e._identity && fs.existsSync(e._identity)) {
      const pk = fs.readFileSync(e._identity, 'utf8');
      let key = store.get().keys.find((k) => k.privateKey === pk);
      if (!key) key = store.upsert('keys', { label: path.basename(e._identity), privateKey: pk, publicKey: readPub(e._identity) });
      e.keyId = key.id;
    }
    delete e._identity;
    store.upsert('hosts', e);
    n++;
  }
  return n;
});

function readPub(p) {
  try { return fs.readFileSync(p + '.pub', 'utf8').trim(); } catch { return ''; }
}

// ---------- Schlüssel ----------
handle('key:generate', ({ type, bits, comment, passphrase }) => {
  const opts = { comment: comment || `${os.userInfo().username}@mrterm` };
  if (type === 'rsa') opts.bits = Number(bits) || 4096;
  if (passphrase) { opts.passphrase = passphrase; opts.cipher = 'aes256-cbc'; }
  const k = sshUtils.generateKeyPairSync(type === 'rsa' ? 'rsa' : type === 'ecdsa' ? 'ecdsa' : 'ed25519', opts);
  return { privateKey: k.private, publicKey: k.public };
});
handle('key:parse', ({ privateKey, passphrase }) => {
  const k = sshUtils.parseKey(privateKey, passphrase || undefined);
  if (k instanceof Error) throw k;
  const key = Array.isArray(k) ? k[0] : k;
  return { type: key.type, publicKey: `${key.type} ${key.getPublicSSH().toString('base64')} ${key.comment || ''}`.trim() };
});
handle('key:pickFile', async () => {
  const r = await dialog.showOpenDialog(win, { defaultPath: path.join(os.homedir(), '.ssh'), properties: ['openFile', 'showHiddenFiles'] });
  if (r.canceled) return null;
  return { name: path.basename(r.filePaths[0]), content: fs.readFileSync(r.filePaths[0], 'utf8'), publicKey: readPub(r.filePaths[0]) };
});

// ---------- SSH-Terminal ----------
function hostWithOverrides(hostOrId) {
  if (typeof hostOrId === 'string') {
    const h = store.resolveHost(hostOrId);
    if (!h) throw new Error('Host nicht gefunden');
    return h;
  }
  return hostOrId; // Quick-Connect: temporärer Host
}

handle('ssh:open', async (sessionId, hostRef, size) => {
  const host = hostWithOverrides(hostRef);
  if (host.id) store.addHistory({ hostId: host.id, at: Date.now() });
  await ssh.openShell(sessionId, host, size, (type, payload) => send('ssh:event', sessionId, type, payload));
  return true;
});
ipcMain.on('ssh:write', (_e, id, data) => ssh.write(id, data));
ipcMain.on('ssh:resize', (_e, id, cols, rows) => ssh.resize(id, cols, rows));
ipcMain.on('ssh:close', (_e, id) => ssh.close(id));
ipcMain.on('secret:reply', (_e, reqId, value) => {
  pendingSecrets.get(reqId)?.(value);
  pendingSecrets.delete(reqId);
});

// ---------- SFTP ----------
handle('sftp:open', (sessionId, hostRef) => ssh.openSftp(sessionId, hostWithOverrides(hostRef)));
handle('sftp:list', (id, dir) => ssh.sftpList(id, dir));
handle('sftp:op', (id, op, a, b) => ssh.sftpOp(id, op, a, b));
handle('sftp:transfer', async (id, dir, localPath, remotePath, transferId) => {
  let last = 0;
  await ssh.transfer(id, dir, localPath, remotePath, (done, total) => {
    const now = Date.now();
    if (now - last > 100 || done === total) { last = now; send('sftp:progress', transferId, done, total, dir === 'download' ? remotePath : localPath); }
  });
  return true;
});
handle('sftp:close', (id) => ssh.close(id));

// Lokales Dateisystem (für den Dual-Pane-SFTP-Browser)
handle('local:home', () => os.homedir());
handle('local:list', (dir) => fs.readdirSync(dir, { withFileTypes: true }).map((d) => {
  let st = {};
  try { st = fs.statSync(path.join(dir, d.name)); } catch {}
  return { name: d.name, isDir: d.isDirectory() || (d.isSymbolicLink() && st.isDirectory?.()), size: st.size || 0, mtime: st.mtimeMs || 0 };
}));
handle('local:join', (...p) => path.join(...p));
handle('local:parent', (p) => path.dirname(p));
handle('local:roots', () => {
  if (process.platform !== 'win32') return ['/'];
  return 'CDEFGHIJKLMNOPQRSTUVWXYZ'.split('').map((l) => `${l}:\\`).filter((d) => fs.existsSync(d));
});
handle('local:op', (op, a, b) => {
  if (op === 'mkdir') return fs.mkdirSync(a, { recursive: true });
  if (op === 'rename') return fs.renameSync(a, b);
  if (op === 'delete') return shell.trashItem(a);
  if (op === 'open') return shell.openPath(a);
});

// ---------- Port-Forwarding ----------
handle('fw:start', (id) => {
  const fw = store.get().forwards.find((f) => f.id === id);
  if (!fw) throw new Error('Regel nicht gefunden');
  return ssh.startForward(fw, (ev) => send('fw:event', id, ev));
});
handle('fw:stop', (id) => ssh.stopForward(id));
handle('fw:active', () => ssh.activeForwards());

// ---------- RDP ----------
handle('rdp:detect', () => rdp.detect(store.get().settings));
handle('rdp:launch', (hostId) => {
  const host = hostWithOverrides(hostId);
  if (host.id) store.addHistory({ hostId: host.id, at: Date.now() });
  const r = rdp.launch(host, store.get().settings);
  if (r.process) {
    r.process.on('exit', (code) => { if (code && code !== 0 && code !== 12) send('toast', `RDP beendet (Code ${code}): ${r.getErr().split('\n').filter(Boolean).slice(-1)[0] || ''}`, 'error'); });
    r.process.on('error', (e) => send('toast', 'RDP-Start fehlgeschlagen: ' + e.message, 'error'));
  }
  return r.client;
});

// Eingebettete RDP-Sitzungen (Anzeige im Tab)
const rdpSessions = new Map();
handle('rdp:embedSupported', () => {
  const s = embedSupported();
  if (s.ok && process.platform === 'linux' && !rdp.linuxClient(null, true)) return { ok: false, reason: 'xfreerdp3 fehlt (sudo pacman -S freerdp)' };
  return s;
});
handle('rdp:open', async (id, hostRef, bounds) => {
  const host = hostWithOverrides(hostRef);
  if (host.id) store.addHistory({ hostId: host.id, at: Date.now() });
  const emb = createEmbed(win.getNativeWindowHandle());
  const sess = { emb, cancelled: false };
  rdpSessions.set(id, sess);
  const size = { width: bounds.width, height: bounds.height };
  let proc;
  if (process.platform === 'win32') {
    const file = rdp.writeRdpFile(host, size);
    proc = await new Promise((resolve) => rdp.withWinCredentials(host, () => resolve(emb.start({ rdpFile: file }))));
  } else {
    proc = emb.start({ client: rdp.linuxClient(null, true), args: rdp.freerdpArgs(host, size), password: host.password });
  }
  proc.on('error', (e) => send('rdp:event', id, 'exit', { code: -1, message: e.message }));
  proc.on('exit', (code) => {
    const err = (emb.err || '').split('\n').filter((l) => /ERROR|error/.test(l)).slice(-1)[0] || '';
    if (rdpSessions.get(id) === sess) send('rdp:event', id, 'exit', { code, message: err });
    rdpSessions.delete(id);
  });
  const ok = await emb.attach(bounds, () => sess.cancelled);
  if (ok) {
    if (sess.hidden) emb.hide();
    send('rdp:event', id, 'attached');
  }
  return ok;
});
ipcMain.on('rdp:bounds', (_e, id, b) => { try { rdpSessions.get(id)?.emb.setBounds(b); } catch {} });
ipcMain.on('rdp:show', (_e, id) => { const s = rdpSessions.get(id); if (s) { s.hidden = false; try { s.emb.show(); s.emb.focus(); } catch {} } });
ipcMain.on('rdp:hide', (_e, id) => { const s = rdpSessions.get(id); if (s) { s.hidden = true; try { s.emb.hide(); } catch {} } });
ipcMain.on('rdp:focus', (_e, id) => { try { rdpSessions.get(id)?.emb.focus(); } catch {} });
ipcMain.on('rdp:close', (_e, id) => {
  const s = rdpSessions.get(id);
  if (!s) return;
  s.cancelled = true;
  rdpSessions.delete(id);
  s.emb.kill();
});
handle('rdp:detach', (id) => {
  const s = rdpSessions.get(id);
  if (!s) return false;
  if (process.platform !== 'win32') return false;
  s.emb.detach();
  rdpSessions.delete(id); // läuft als eigenständiges Fenster weiter
  return true;
});

// ---------- Import aus anderen Programmen (z. B. Devolutions RDM) ----------
handle('import:pickFile', async (title, extensions) => {
  const r = await dialog.showOpenDialog(win, { title, filters: [{ name: title, extensions }, { name: 'Alle Dateien', extensions: ['*'] }], properties: ['openFile'] });
  if (r.canceled) return null;
  const buf = fs.readFileSync(r.filePaths[0]);
  // UTF-16-Exporte (BOM) erkennen
  const text = buf[0] === 0xff && buf[1] === 0xfe ? buf.toString('utf16le') : buf.toString('utf8');
  return { name: path.basename(r.filePaths[0]), content: text.replace(/^/, '') };
});
// entries: [{ folder: ['A','B'], host?: {...} }] – Ordner werden per Pfad angelegt bzw. wiederverwendet
handle('vault:bulkImport', (entries) => {
  const groups = store.get().groups;
  const ensure = (parts) => {
    let parent = null;
    for (const label of parts) {
      let g = groups.find((x) => (x.parentId || null) === parent && x.label.toLowerCase() === label.toLowerCase());
      if (!g) { g = { id: crypto.randomUUID(), label, parentId: parent, createdAt: Date.now() }; groups.push(g); }
      parent = g.id;
    }
    return parent;
  };
  let hosts = 0, skipped = 0;
  for (const e of entries) {
    const groupId = ensure(e.folder || []);
    if (!e.host) continue;
    const dup = store.get().hosts.find((h) => h.address === e.host.address && (h.groupId || null) === groupId && (h.label || '') === (e.host.label || '') && (h.protocol || 'ssh') === e.host.protocol);
    if (dup) { skipped++; continue; }
    store.get().hosts.push({ ...e.host, id: crypto.randomUUID(), groupId, createdAt: Date.now(), updatedAt: Date.now() });
    hosts++;
  }
  store.save();
  return { hosts, skipped, groups: groups.length };
});

// ---------- Updates ----------
handle('update:check', () => updater.check());
handle('update:download', () => updater.download());
handle('update:install', () => updater.install());
handle('app:version', () => app.getVersion());

handle('clipboard:write', (t) => clipboard.writeText(t));
handle('clipboard:read', () => clipboard.readText());
handle('shell:open', (url) => shell.openExternal(url));

app.whenReady().then(() => {
  store.load();
  createWindow();
  if (store.get().settings.updateAutoCheck && app.isPackaged) {
    setTimeout(() => updater.check().then((r) => { if (r.available) send('update:available', r); }).catch(() => {}), 6000);
  }
});
app.on('window-all-closed', () => { ssh.closeAll(); app.quit(); });

// Smoke-Test: MRTERM_SMOKE=<pfad.png> startet, loggt Renderer-Meldungen, speichert einen Screenshot und beendet.
if (process.env.MRTERM_SMOKE) {
  app.whenReady().then(() => {
    win.webContents.on('console-message', (e) => console.log('[renderer]', e.level, e.message));
    setTimeout(async () => {
      if (process.env.MRTERM_SMOKE_JS) await win.webContents.executeJavaScript(process.env.MRTERM_SMOKE_JS).catch((e) => console.log('js error', e));
      setTimeout(async () => {
        fs.writeFileSync(process.env.MRTERM_SMOKE, (await win.webContents.capturePage()).toPNG());
        app.quit();
      }, 1500);
    }, 2500);
  });
}