// TODO: hdr

#include "lts_global_wait_dialog.h"
#include "lts_progress_dialog_helper.h"
#include "lts_overlay_loading.h"
#include "lts_dialog.h"
#include "lts_frameless_dialog.h"

#include <QCoreApplication>
#include <QTimer>
//#include <QDebug>

#ifdef Q_OS_UNIX
#include <execinfo.h> // backtrace(..)
#include <dlfcn.h> // dladdr(..)
#include <cxxabi.h> // demangle
#endif


namespace LtsWidgets
{

LtsGlobalWaitDialog::~LtsGlobalWaitDialog()
{
  delete m_progressDialog;
}


LtsGlobalWaitDialog::LtsGlobalWaitDialog()
  : m_waitingCount(0)
  , m_visible(true)
  , m_progressDialog(new LtsProgressDialogHelper(nullptr))
  , m_hideTimer(new QTimer(this)) // avoids blinking windows by waiting a little until the wait window will be hidden
{
  m_hideTimer->setSingleShot(true);
  m_hideTimer->setInterval(500);
  connect(m_hideTimer, &QTimer::timeout,
          this, &LtsGlobalWaitDialog::hideIt);
}


void LtsGlobalWaitDialog::unarm()
{
  m_armed = false;
  hideIt(); // force hide it (don't worry, does nothing if now shown)
}


void LtsGlobalWaitDialog::rearm()
{
  m_armed = true;
  setVisible(true); // show again (if some component is still waiting)
}


void LtsGlobalWaitDialog::setVisible(bool visible)
{
  if (m_waitingCount > 0 && visible)
    showIt();

  if (m_waitingCount < 1 && !visible)
    hideIt();
}


void LtsGlobalWaitDialog::showIt()
{
  if (m_progressDialog->isShown())
    return;

  m_hideTimer->stop();
  if (m_armed)
  {
    m_progressDialog->slotShowWaitForReplyWindow();
  }
}


void LtsGlobalWaitDialog::hideIt()
{
  if (!m_progressDialog->isShown())
    return;

  m_hideTimer->stop();
  m_progressDialog->slotStopWaitForReplyWindow();
}


void bt()
{
#ifdef Q_OS_UNIX
  void *callstack[128];
  const int nMaxFrames = sizeof(callstack) / sizeof(callstack[0]);
  int nFrames = backtrace(callstack, nMaxFrames);
  char **symbols = backtrace_symbols(callstack, nFrames);

  for (int i = 1; i < nFrames; i++)
  {
    QString address(QStringLiteral("0x%1").arg(QString::number(*(quintptr *)callstack[i], 16)));
    QString function;
    int offset = -1; // aka. invalid

    Dl_info info;
    if (dladdr(callstack[i], &info) && info.dli_sname)
    {
      char *demangled = nullptr;
      int status = -1;
      if (info.dli_sname[0] == '_')
        demangled = abi::__cxa_demangle(info.dli_sname, nullptr, 0, &status);

      function = QString::fromUtf8(status == 0 ? demangled : info.dli_sname == 0 ? symbols[i] : info.dli_sname);
      offset = (char *)callstack[i] - (char *)info.dli_saddr;

      free(demangled);
    }
    else
    {
      function = QString::fromUtf8(symbols[i]);
    }

    //qWarning() << "frame" << i << address << function << offset;
  }

  free(symbols);

//  if (nFrames == nMaxFrames)
//    qWarning() << "[BACKTRACE TRUNCATED]";
#endif
}


void LtsGlobalWaitDialog::wait(QWidget *parent, const QString &customText)
{
  m_progressDialog->setParentWidget(parent);
  if (m_waitingCount < 1 && m_visible) // nothing is waiting
    showIt();

  setCustomText(customText);

  m_waitingCount++; // count even if not visible !

  //qWarning() << "LtsGlobalWaitDialog ++" << m_waitingCount;

  //bt();
}


void LtsGlobalWaitDialog::setCustomText(const QString &customText)
{
  m_progressDialog->setCustomText(customText);
}


void LtsGlobalWaitDialog::done()
{
  if (m_waitingCount == 0)
  {
    //qWarning() << "LtsGlobalWaitDialog: called done() while there is nothing waiting!";
    m_hideTimer->start();
    return;
  }

  Q_ASSERT(m_waitingCount > 0);

  m_waitingCount--;
  //qWarning() << "LtsGlobalWaitDialog --" << m_waitingCount;

  if (m_waitingCount == 0) // no more waiting classes
    m_hideTimer->start();
}

static LtsGlobalWaitDialog *s_gwdInstance = nullptr;
void LtsGlobalWaitDialog::cleanupGwdInstance()
{
  delete s_gwdInstance;
  s_gwdInstance = nullptr;
}

LtsGlobalWaitDialog *LtsGlobalWaitDialog::getInstance()
{
  if (!s_gwdInstance)
  {
    s_gwdInstance = new LtsGlobalWaitDialog;
    qAddPostRoutine(&LtsGlobalWaitDialog::cleanupGwdInstance);
  }
  return s_gwdInstance;
}
} // namespace LtsWidgets


/// Waiter
Waiter::Waiter(const QString &customText)
{
  LtsWidgets::LtsGlobalWaitDialog::getInstance()->wait(nullptr, customText);
}


Waiter::Waiter(LtsWidgets::LtsDialog *parent, const QString &customText)
  : m_parent(parent)
{
  m_oldClosableState = m_parent->isClosable();
  m_parent->setClosable(false);
  m_parent->setCurrentlyBlocking(true);
  auto *wait = new LtsWidgets::LtsOverlayLoading;
  wait->setText(customText.isEmpty() ? QObject::tr("Waiting for server reply...") : customText);
  m_parent->setOverlay(wait);
  m_loadingOverlay = wait;
}


Waiter::~Waiter()
{
  if (m_loadingOverlay == nullptr)
  {
    LtsWidgets::LtsGlobalWaitDialog::getInstance()->done();
    return;
  }

  m_parent->setClosable(m_oldClosableState);
  m_parent->setCurrentlyBlocking(false);
  m_loadingOverlay->deleteLater();
}