////////////////////////////////////////////////////////////////////////
//
// Copyright (C) 2011-2021 The Octave Project Developers
//
// See the file COPYRIGHT.md in the top-level directory of this
// distribution or <https://octave.org/copyright/>.
//
// This file is part of Octave.
//
// Octave is free software: you can redistribute it and/or modify it
// under the terms of the GNU General Public License as published by
// the Free Software Foundation, either version 3 of the License, or
// (at your option) any later version.
//
// Octave is distributed in the hope that it will be useful, but
// WITHOUT ANY WARRANTY; without even the implied warranty of
// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
// GNU General Public License for more details.
//
// You should have received a copy of the GNU General Public License
// along with Octave; see the file COPYING.  If not, see
// <https://www.gnu.org/licenses/>.
//
////////////////////////////////////////////////////////////////////////

#if defined (HAVE_CONFIG_H)
#  include "config.h"
#endif

#include <QEvent>
#include <QFrame>
#include <QLabel>
#include <QMouseEvent>
#include <QTimer>

#include "Canvas.h"
#include "Container.h"
#include "ContextMenu.h"
#include "Panel.h"
#include "QtHandlesUtils.h"

#include "octave-qobject.h"

#include "graphics.h"
#include "interpreter.h"

namespace octave
{

  static int
  frameStyleFromProperties (const uipanel::properties& pp)
  {
    if (pp.bordertype_is ("none"))
      return QFrame::NoFrame;
    else if (pp.bordertype_is ("etchedin"))
      return (QFrame::Box | QFrame::Sunken);
    else if (pp.bordertype_is ("etchedout"))
      return (QFrame::Box | QFrame::Raised);
    else if (pp.bordertype_is ("beveledin"))
      return (QFrame::Panel | QFrame::Sunken);
    else if (pp.bordertype_is ("beveledout"))
      return (QFrame::Panel | QFrame::Raised);
    else
      return (QFrame::Panel | QFrame::Plain);
  }

  static void
  setupPalette (const uipanel::properties& pp, QPalette& p)
  {
    p.setColor (QPalette::Window,
                Utils::fromRgb (pp.get_backgroundcolor_rgb ()));
    p.setColor (QPalette::WindowText,
                Utils::fromRgb (pp.get_foregroundcolor_rgb ()));
    p.setColor (QPalette::Light,
                Utils::fromRgb (pp.get_highlightcolor_rgb ()));
    p.setColor (QPalette::Dark,
                Utils::fromRgb (pp.get_shadowcolor_rgb ()));
  }

  static int
  borderWidthFromProperties (const uipanel::properties& pp)
  {
    int bw = 0;

    if (! pp.bordertype_is ("none"))
      {
        bw = octave::math::round (pp.get_borderwidth ());
        if (pp.bordertype_is ("etchedin") || pp.bordertype_is ("etchedout"))
          bw *= 2;
      }

    return bw;
  }

  Panel*
  Panel::create (octave::base_qobject& oct_qobj, octave::interpreter& interp,
                 const graphics_object& go)
  {
    Object *parent = parentObject (interp, go);

    if (parent)
      {
        Container *container = parent->innerContainer ();

        if (container)
          return new Panel (oct_qobj, interp, go, new QFrame (container));
      }

    return nullptr;
  }

  Panel::Panel (octave::base_qobject& oct_qobj, octave::interpreter& interp,
                const graphics_object& go, QFrame *frame)
    : Object (oct_qobj, interp, go, frame), m_container (nullptr),
      m_title (nullptr), m_blockUpdates (false),
      m_previous_bbox (Matrix (1, 4, 0))
  {
    uipanel::properties& pp = properties<uipanel> ();

    frame->setObjectName ("UIPanel");
    frame->setAutoFillBackground (true);
    Matrix bb = pp.get_boundingbox (false);
    frame->setGeometry (octave::math::round (bb(0)), octave::math::round (bb(1)),
                        octave::math::round (bb(2)), octave::math::round (bb(3)));
    frame->setFrameStyle (frameStyleFromProperties (pp));
    frame->setLineWidth (octave::math::round (pp.get_borderwidth ()));
    QPalette pal = frame->palette ();
    setupPalette (pp, pal);
    frame->setPalette (pal);

    m_container = new Container (frame, oct_qobj, interp);
    m_container->canvas (m_handle);

    connect (m_container, SIGNAL (interpeter_event (const fcn_callback&)),
             this, SIGNAL (interpeter_event (const fcn_callback&)));

    connect (m_container, SIGNAL (interpeter_event (const meth_callback&)),
             this, SIGNAL (interpeter_event (const meth_callback&)));

    if (frame->hasMouseTracking ())
      {
        for (auto *w : frame->findChildren<QWidget*> ())
          w->setMouseTracking (true);
      }

    QString title = Utils::fromStdString (pp.get_title ());
    if (! title.isEmpty ())
      {
        m_title = new QLabel (title, frame);
        m_title->setAutoFillBackground (true);
        m_title->setContentsMargins (4, 0, 4, 0);
        m_title->setPalette (pal);
        m_title->setFont (Utils::computeFont<uipanel> (pp, bb(3)));
      }

    frame->installEventFilter (this);
    m_container->installEventFilter (this);

    graphics_object fig (go.get_ancestor ("figure"));
    if (! fig.get ("keypressfcn").isempty ())
      m_container->canvas (m_handle)->addEventMask (Canvas::KeyPress);

    if (! fig.get ("keyreleasefcn").isempty ())
      m_container->canvas (m_handle)->addEventMask (Canvas::KeyRelease);

    if (pp.is_visible ())
      QTimer::singleShot (0, frame, &QFrame::show);
    else
      frame->hide ();
  }

  Panel::~Panel (void)
  { }

  bool
  Panel::eventFilter (QObject *watched, QEvent *xevent)
  {
    if (! m_blockUpdates)
      {
        gh_manager& gh_mgr = m_interpreter.get_gh_manager ();

        if (watched == qObject ())
          {
            switch (xevent->type ())
              {
              case QEvent::Resize:
                {
                  octave::autolock guard (gh_mgr.graphics_lock ());

                  graphics_object go = object ();

                  if (go.valid_object ())
                    {
                      if (m_title)
                        {
                          const uipanel::properties& pp =
                            Utils::properties<uipanel> (go);

                          if (pp.fontunits_is ("normalized"))
                            {
                              QFrame *frame = qWidget<QFrame> ();

                              m_title->setFont (Utils::computeFont<uipanel>
                                                (pp, frame->height ()));
                              m_title->resize (m_title->sizeHint ());
                            }
                        }
                      updateLayout ();
                    }
                }
                break;

              case QEvent::MouseButtonPress:
                {
                  QMouseEvent *m = dynamic_cast<QMouseEvent *> (xevent);

                  if (m->button () == Qt::RightButton)
                    {
                      octave::autolock guard (gh_mgr.graphics_lock ());

                      graphics_object go = object ();

                      if (go.valid_object ())
                        ContextMenu::executeAt (m_interpreter,
                                                go.get_properties (),
                                                m->globalPos ());
                    }
                }
                break;

              default:
                break;
              }
          }
        else if (watched == m_container)
          {
            switch (xevent->type ())
              {
              case QEvent::Resize:
                if (qWidget<QWidget> ()->isVisible ())
                  {
                    octave::autolock guard (gh_mgr.graphics_lock ());

                    graphics_object go = object ();

                    if (go.valid_object ())
                      go.get_properties ().update_boundingbox ();
                  }
                break;

              default:
                break;
              }
          }
      }

    return false;
  }

  void
  Panel::update (int pId)
  {
    uipanel::properties& pp = properties<uipanel> ();
    QFrame *frame = qWidget<QFrame> ();

    m_blockUpdates = true;

    switch (pId)
      {
      case uipanel::properties::ID_POSITION:
        {
          Matrix bb = pp.get_boundingbox (false);
          if (m_previous_bbox(0) != bb(0) || m_previous_bbox(1) != bb(1)
              || m_previous_bbox(2) != bb(2) || m_previous_bbox(3) != bb(3))
            {
              frame->setGeometry (octave::math::round (bb(0)),
                                  octave::math::round (bb(1)),
                                  octave::math::round (bb(2)),
                                  octave::math::round (bb(3)));
              updateLayout ();
            }
          m_previous_bbox = bb;
        }
        break;

      case uipanel::properties::ID_BORDERWIDTH:
        frame->setLineWidth (octave::math::round (pp.get_borderwidth ()));
        updateLayout ();
        break;

      case uipanel::properties::ID_BACKGROUNDCOLOR:
      case uipanel::properties::ID_FOREGROUNDCOLOR:
      case uipanel::properties::ID_HIGHLIGHTCOLOR:
      case uipanel::properties::ID_SHADOWCOLOR:
        {
          QPalette pal = frame->palette ();

          setupPalette (pp, pal);
          frame->setPalette (pal);
          if (m_title)
            m_title->setPalette (pal);
        }
        break;

      case uipanel::properties::ID_TITLE:
        {
          QString title = Utils::fromStdString (pp.get_title ());

          if (title.isEmpty ())
            {
              if (m_title)
                delete m_title;
              m_title = nullptr;
            }
          else
            {
              if (! m_title)
                {
                  QPalette pal = frame->palette ();

                  m_title = new QLabel (title, frame);
                  m_title->setAutoFillBackground (true);
                  m_title->setContentsMargins (4, 0, 4, 0);
                  m_title->setPalette (pal);
                  m_title->setFont (Utils::computeFont<uipanel> (pp));
                  m_title->show ();
                }
              else
                {
                  m_title->setText (title);
                  m_title->resize (m_title->sizeHint ());
                }
            }
          updateLayout ();
        }
        break;

      case uipanel::properties::ID_TITLEPOSITION:
        updateLayout ();
        break;

      case uipanel::properties::ID_BORDERTYPE:
        frame->setFrameStyle (frameStyleFromProperties (pp));
        updateLayout ();
        break;

      case uipanel::properties::ID_FONTNAME:
      case uipanel::properties::ID_FONTSIZE:
      case uipanel::properties::ID_FONTWEIGHT:
      case uipanel::properties::ID_FONTANGLE:
        if (m_title)
          {
            m_title->setFont (Utils::computeFont<uipanel> (pp));
            m_title->resize (m_title->sizeHint ());
            updateLayout ();
          }
        break;

      case uipanel::properties::ID_VISIBLE:
        frame->setVisible (pp.is_visible ());
        updateLayout ();
        break;

      default:
        break;
      }

    m_blockUpdates = false;
  }

  void
  Panel::redraw (void)
  {
    update (uipanel::properties::ID_POSITION);

    Canvas *canvas = m_container->canvas (m_handle);

    if (canvas)
      canvas->redraw ();
  }

  void
  Panel::updateLayout (void)
  {
    uipanel::properties& pp = properties<uipanel> ();
    QFrame *frame = qWidget<QFrame> ();

    Matrix bb = pp.get_boundingbox (true);
    int bw = borderWidthFromProperties (pp);

    frame->setFrameRect (QRect (octave::math::round (bb(0)) - bw,
                                octave::math::round (bb(1)) - bw,
                                octave::math::round (bb(2)) + 2*bw, octave::math::round (bb(3)) + 2*bw));
    m_container->setGeometry (octave::math::round (bb(0)),
                              octave::math::round (bb(1)),
                              octave::math::round (bb(2)), octave::math::round (bb(3)));

    if (m_blockUpdates)
      pp.update_boundingbox ();

    if (m_title)
      {
        QSize sz = m_title->sizeHint ();
        int offset = 5;

        if (pp.titleposition_is ("lefttop"))
          m_title->move (bw+offset, 0);
        else if (pp.titleposition_is ("righttop"))
          m_title->move (frame->width () - bw - offset - sz.width (), 0);
        else if (pp.titleposition_is ("leftbottom"))
          m_title->move (bw+offset, frame->height () - sz.height ());
        else if (pp.titleposition_is ("rightbottom"))
          m_title->move (frame->width () - bw - offset - sz.width (),
                         frame->height () - sz.height ());
        else if (pp.titleposition_is ("centertop"))
          m_title->move (frame->width () / 2 - sz.width () / 2, 0);
        else if (pp.titleposition_is ("centerbottom"))
          m_title->move (frame->width () / 2 - sz.width () / 2,
                         frame->height () - sz.height ());
      }
  }

  void
  Panel::do_connections (const QObject *receiver, const QObject* /* emitter */)
  {
    Object::do_connections (receiver);
    Object::do_connections (receiver, m_container->canvas (m_handle));
  }

};