#include "vnc_server_manager.h"

#include <QRegularExpression>
#include <QScreen>
#include <QDir>

namespace LtsProjectionWorkstation
{

VncServerManager::VncServerManager(LOGGER_T &logger, QObject *parent)
  : QObject(parent)
  , m_logger(logger)
{
}


VncServerManager::~VncServerManager()
{
  stopScreens();
}

QList<QScreen *> sortScreen(const QList<QScreen *> &screens)
{
  auto ret(screens);
  
  auto doSortScreens = [](const QScreen *s1, const QScreen *s2) -> bool
  {
    const auto tl1 = s1->geometry().topLeft();
    const auto tl2 = s2->geometry().topLeft();
    if (tl1.y() > tl2.y())
      return true;
    if (tl1.y() < tl2.y())
      return false;
    return tl1.x() < tl2.x();
  };
  std::sort(ret.begin(), ret.end(), doSortScreens);
  return ret;
}

bool VncServerManager::init(const QList<QScreen *> &screens)
{
  killScreens();
  createPwdFile();

  const auto sortedScreens = sortScreen(screens);

  DEBUG_LOG(m_logger) << "Setup VNCScreens with " << screens.size() << " screens";

  int count = 1;

  static constexpr char VNC_START_ARGS[] = "-rfbauth,%1/.vnc/passwd,-clip,%2x%3+%4+%5,-loop100,-forever,-display,:0,-threads,-noxdamage";

  
  for (QScreen *screen : sortedScreens)
  {
    VncScreen vncScreen;
    
    vncScreen.geometry = screen->geometry();
    vncScreen.name     = QStringLiteral("Display%1").arg(count);
    vncScreen.proc = new QProcess(this);
    QString startArgs = QString::fromLatin1(VNC_START_ARGS).arg(QDir::home().absolutePath())
                        .arg(screen->geometry().width()).arg(screen->geometry().height())
                        .arg(screen->geometry().x()).arg(screen->geometry().y());

    vncScreen.proc->setProgram(QStringLiteral("x11vnc"));
    vncScreen.proc->setArguments(startArgs.split(QLatin1Char(',')));

    NOTICE_LOG(m_logger) << "Started VNC for Screen " << count << " with geometry "
                         << screen->geometry().width() << "," << screen->geometry().height() << "+"
                         << screen->geometry().x() << "+" << screen->geometry().y();

    m_vncScreens.push_back(vncScreen);
    count++;
  }

  DEBUG_LOG(m_logger) << m_vncScreens.size() << " VNCScreen(s) created - Setup completed.";
  return true;
}

void VncServerManager::startScreens()
{
  DEBUG_LOG(m_logger) << "Starting " << m_vncScreens.size() << " VNCScreen(s) ... ";
  for (const VncScreen &s : qAsConst(m_vncScreens))
  {
    connect(s.proc, &QProcess::readyReadStandardOutput,
            this, &VncServerManager::slotReadStandardOutput, Qt::UniqueConnection);
    connect(s.proc, &QProcess::errorOccurred,
            this, &VncServerManager::slotErrorOccured, Qt::UniqueConnection);
    s.proc->start();
  }
  for (const VncScreen &s : qAsConst(m_vncScreens))
  {
    if (!s.proc->waitForStarted(2000))
      ERROR_LOG(m_logger) << "Can not start process '" << s.proc->program() << "': "
                          << s.proc->errorString();
  }
  DEBUG_LOG(m_logger) << "Done";
}


void VncServerManager::stopScreens()
{
  DEBUG_LOG(m_logger) << "Stopping " << m_vncScreens.size() << " VNCScreen(s) ...";

  for (const VncScreen &s : qAsConst(m_vncScreens))
  {
    s.proc->disconnect(this);
    s.proc->terminate();
  }
  for (const VncScreen &s : qAsConst(m_vncScreens))
  {
    if (!s.proc->waitForFinished(2000))
      s.proc->kill();
  }
  DEBUG_LOG(m_logger) << "Done";
}


void VncServerManager::killScreens()
{
  DEBUG_LOG(m_logger) << "Killing all exisiting x11vnc processes ...";
  
  SingleShotProcess ssp(QStringLiteral("killall x11vnc"));
  ssp.execute();
  DEBUG_LOG(m_logger) << "Done";
}


void VncServerManager::createPwdFile()
{
  DEBUG_LOG(m_logger) << "(Re)creating x11vnc password-file ...";
  
  SingleShotProcess ssp(QStringLiteral("x11vnc -storepasswd ctc11de %1/.vnc/passwd")
                        .arg(QDir::home().absolutePath()));
  ssp.execute();
  DEBUG_LOG(m_logger) << "Done";
}


void VncServerManager::slotReadStandardOutput()
{
  QProcess *p = qobject_cast<QProcess *>(QObject::sender());
  if (!p)
    return;

  QString stdOut = QString::fromLocal8Bit(p->readAllStandardOutput());
  QRegularExpressionMatch match = QRegularExpression(QStringLiteral("PORT=(.*?)\\s")).match(stdOut);
  if (!match.hasMatch())
  {
    WARNING_LOG(m_logger) << "Could not retrieve port information from stdout of " << p->program();
    return;
  }
  const quint16 port = match.capturedRef(1).toInt();
  if (port == 0)
    return;
  for (VncScreen &screen : m_vncScreens)
  {
    if (screen.proc != p)
      continue;
    screen.port = port;
    disconnect(screen.proc, &QProcess::readyReadStandardOutput, nullptr, nullptr);
    break;
  }
}


void VncServerManager::slotErrorOccured()
{
  QProcess *p = qobject_cast<QProcess *>(QObject::sender());
  if (p)
    ERROR_LOG(m_logger) << p->errorString();
}




SingleShotProcess::SingleShotProcess(const QString &cmd, bool startImmediatly)
  : m_cmd(cmd)
{
  if (startImmediatly) execute();
}

bool SingleShotProcess::execute()
{
  m_process.start(m_cmd);
  return m_process.waitForFinished();
}



}