/**
* @RDE_HEADER@
* FrameLess Dialog with alternatie basecolor
* $Id$
* $HeadURL$
* $Author$
*
* Created by Mike Wille, SLSE, 2016-03-09
*/

#include "lts_frameless_dialog.h"

#include <QApplication>
#include <QRect>
#include <QStyle>
#include <QSize>
#include <QScreen>
#include <QScroller>
#include <QScrollArea>
#include <QDesktopWidget>
#include <QShowEvent>
#include <QTimer>


namespace LtsWidgets
{
LtsFramelessDialog::LtsFramelessDialog(QWidget *parent, const Behaviour &behaviour)
  : QDialog(parent)
{
  // Qt-Bug? Qt::FramelessWindowHint in the underlying windows results in
  // mapToGlobal(QPoint(0,0)) == QPoint(0,0) when a popup window is show on top of it
  Qt::WindowFlags wf; // TODO: FIX WM AFTER FAT!! = Qt::FramelessWindowHint; // make frameless, composite manager drops the shadow
  // frameless dialogs cannot have (completety working) children dialogs => frames 4 fat

  switch (behaviour)
  {
    case Behaviour::Modal:
    {

#ifndef TABLET_MODE
      setModal(true);
      wf |= Qt::Dialog;
#else
      wf |= Qt::Window;
#endif
      wf |= Qt::WindowStaysOnTopHint;
      break;
    }

    case Behaviour::Popup:
      wf |= Qt::Popup;
      break;
  }

  setWindowFlags(wf);


  QTimer *t = new QTimer(this);
  t->setInterval(250);
  connect(t, &QTimer::timeout,
          this, [this]()
  {
    //qWarning() << "my pos" << QCursor::pos();
    //qWarning() << "my screen rect" << screenRectFromPoint(QCursor::pos());

    QSize s = size();
    setGeometry(QStyle::alignedRect(Qt::LeftToRight, Qt::AlignCenter, s, screenRectFromPoint(QCursor::pos())));
  });
  //t->start();    TODO: impl this!
}


LtsFramelessDialog::~LtsFramelessDialog()
{

}


QRect LtsFramelessDialog::screenRectFromPoint(const QPoint &pos) const
{
  const auto screens = QGuiApplication::screens();
  for (QScreen *screen : screens)
  {
    QRect s = screen->geometry().adjusted(-50, -50, 50, 50); // graceful offset for desktop managers

    bool contains = s.contains(pos);

    //qWarning() << "screen" << s << "   widget" << w << "   contains?" << contains;
    //qWarning() << "screen: x" << s.x() << "y" << s.y() << "h" << s.height() << "w" << s.width();
    //qWarning() << "widget: x" << w.x() << "y" << w.y() << "h" << w.height() << "w" << w.width();

    if (contains)
      return screen->geometry();
  }

  return QRect();
}


void LtsFramelessDialog::showEvent(QShowEvent *event)
{
  QDialog::showEvent(event);
  QTimer::singleShot(0, this, &LtsFramelessDialog::onUpdateGeometry);


#ifdef TABLET_MODE
  QList<QWidget *> scrollWidgets = findChildren<QWidget *>();

  for (auto i = scrollWidgets.begin(); i != scrollWidgets.end(); ++i)
  {
    QWidget *widget = *i;

    QVariant isConst = widget->property("const");
    if (isConst.isValid() && isConst.toBool())
      continue;

    addTouchScroll(widget);
  }
#endif
}


void LtsFramelessDialog::addTouchScroll(QWidget *widget)
{
  if (!widget)
    return;
  widget->setAttribute(Qt::WA_AcceptTouchEvents);

  QScrollArea *sca = qobject_cast<QScrollArea *>(widget);
  if (sca)
  {
    QScroller::grabGesture(sca->viewport(), QScroller::LeftMouseButtonGesture);
    return;
  }
}


void LtsFramelessDialog::onUpdateGeometry()
{
  QRect r;
  QWidget *p = parentWidget();

  if (p) // get the parent's window and center the dialog on the center of the parent's window
  {
    QWidget *window = p->window();
    QPoint global = window->mapToGlobal(QPoint(0,0));
    QSize size = window->size();

    r = QRect(global, size);
  }
  else // no parent - no alignment!
  {
    r = QGuiApplication::primaryScreen()->geometry();
  }

  QSize s = size();
  setGeometry(QStyle::alignedRect(Qt::LeftToRight, Qt::AlignCenter, s, r));
}

} // namespace LtsWidgets