#include "lts_drag_icon.h"

#include <QDrag>
#include <QDragEnterEvent>
#include <QDragLeaveEvent>
#include <QDropEvent>
#include <QMimeData>
#include <QAction>
#include <QVBoxLayout>
#include <QLabel>
#include <QPixmap>
#include <QToolButton>
#include <QButtonGroup>
#include <QPainter>

namespace LtsWidgets
{

class LtsToolButton : public QToolButton
{
  Q_OBJECT
public:
  explicit LtsToolButton(QWidget *parent)
    : QToolButton(parent)
    , m_sameWidgetDrop(false)
    , m_isDraggable(true)
    , m_startPos(QPoint())
  {
    setAutoFillBackground(false);
    setToolButtonStyle(Qt::ToolButtonTextUnderIcon);
  }

  virtual ~LtsToolButton() = default;

  void mousePressEvent(QMouseEvent *event) override;
  void mouseReleaseEvent(QMouseEvent *event) override;
  void mouseMoveEvent(QMouseEvent *event) override;
  void dragEnterEvent(QDragEnterEvent *event) override;
  void setSameWidgetDrop(bool drop) { m_sameWidgetDrop = drop; }
  bool sameWidgetDrop() const { return m_sameWidgetDrop; }
  void setDraggable(bool isDraggable) { m_isDraggable = isDraggable; }
  void dropEvent(QDropEvent *event) override
  {
    emit newDropEvent(event);
    QToolButton::dropEvent(event);
  }
  void addMimeData(const QString &mimeType, const QByteArray &data);
  bool removeMimeData(const QString &mimeType);
  void removeAllMimeData() { m_mimeData.clear(); }

protected:
  void initButton();

signals:
  void newDropEvent(QDropEvent *e);
  void dropSuc();

private:
  void performDrag(QMouseEvent *event);
  bool        m_sameWidgetDrop;
  bool        m_isDraggable;
  QPoint      m_startPos;
  QMap<QString, QByteArray> m_mimeData;

};



LtsDragIcon::LtsDragIcon(QWidget *parent)
  : QWidget(parent)
  , m_lay(nullptr)
  , m_toolButton(nullptr)
  , m_icon()
  , m_dragLabel(new QLabel(this))
  , m_text()
  , m_style(ButtonStyle::eAll)
  , m_forceFixedSize(false)
  , m_isDraggable(true)
  , m_dropHandlerKey(0L)
  , m_buttonSize(ButtonSize::eDefault)
  , m_showDragIcon(true)
{
  setAutoFillBackground(false);
  initButton();
}


void LtsDragIcon::setStyleToButton()
{
  if (nullptr == m_toolButton) return;

  switch (m_style)
  {
  case ButtonStyle::eIconOnly:
  {
    setSizePolicy(QSizePolicy::Fixed, QSizePolicy::Fixed);
    m_toolButton->setSizePolicy(QSizePolicy::Minimum, QSizePolicy::Minimum);
    setFixedSize(QSize(static_cast<int>(m_buttonSize), static_cast<int>(m_buttonSize)));
    m_toolButton->setToolButtonStyle(Qt::ToolButtonIconOnly);
  } break;

  case ButtonStyle::eTextOnly:
  {
    setSizePolicy(QSizePolicy::Minimum, QSizePolicy::Fixed);
    m_toolButton->setSizePolicy(QSizePolicy::MinimumExpanding, QSizePolicy::Minimum);
    setFixedSize( QSize(QWIDGETSIZE_MAX,QWIDGETSIZE_MAX) );
    m_toolButton->setToolButtonStyle(Qt::ToolButtonTextOnly);
    layout()->setSizeConstraint( QLayout::SetDefaultConstraint );
  } break;

  case ButtonStyle::eTextNextToIcon:
  {
    setSizePolicy(QSizePolicy::Minimum, QSizePolicy::Fixed);
    m_toolButton->setSizePolicy(QSizePolicy::MinimumExpanding, QSizePolicy::Minimum);
    setFixedSize( QSize(QWIDGETSIZE_MAX,QWIDGETSIZE_MAX) );
    m_toolButton->setToolButtonStyle(Qt::ToolButtonTextUnderIcon);
    layout()->setSizeConstraint( QLayout::SetDefaultConstraint );
  } break;

  default: break;
  }

} 


void LtsDragIcon::initButton()
{
  setMinimumSize(static_cast<int>(m_buttonSize), static_cast<int>(m_buttonSize));

  delete m_toolButton;
  delete m_lay;
  delete layout();

  m_toolButton = new LtsToolButton(this);
  m_toolButton->setDraggable(m_isDraggable);
  connect(m_toolButton, &LtsToolButton::clicked, this, &LtsDragIcon::clicked);
  connect(m_toolButton, &LtsToolButton::toggled, this, &LtsDragIcon::toggled);
  connect(m_toolButton, &LtsToolButton::newDropEvent, this, &LtsDragIcon::newDropEvent);
  connect(m_toolButton, &LtsToolButton::dropSuc, this, &LtsDragIcon::dropSuc);

  m_toolButton->setIcon(modifyIcon(m_icon));
  m_toolButton->setText(m_text);
  generateToolTip();
  m_toolButton->setIconSize(QSize(static_cast<int>(m_buttonSize), static_cast<int>(m_buttonSize)));


  QVBoxLayout *box = new QVBoxLayout(this);
  box->setMargin(0);
  box->setSpacing(0);
  box->addWidget(m_toolButton);

  this->setLayout(box);

  m_toolButton->setToolButtonStyle(Qt::ToolButtonTextUnderIcon);

  if (m_forceFixedSize)
  {
    m_toolButton->setSizePolicy(QSizePolicy::Minimum, QSizePolicy::Minimum);
    setFixedSize(QSize(static_cast<int>(m_buttonSize), static_cast<int>(m_buttonSize)));
  }
  else
  {
    m_toolButton->setSizePolicy(QSizePolicy::MinimumExpanding, QSizePolicy::Minimum);
    setSizePolicy(QSizePolicy::MinimumExpanding, QSizePolicy::Minimum);
  }

  setStyleToButton();
}

void LtsDragIcon::addToButtonGroup(QButtonGroup *btnGrp, int btnGrpId)
{
  btnGrp->addButton(m_toolButton, btnGrpId);
}


void LtsDragIcon::setIcon(const QIcon &icon)
{
  m_icon = icon;
  (m_toolButton) ? m_toolButton->setIcon(modifyIcon(m_icon)) : initButton();
}


void LtsDragIcon::setMenu(QMenu *menu)
{
  if (nullptr == m_toolButton)
    initButton();
  m_toolButton->setMenu(menu);
}

QMenu *LtsDragIcon::menu() const
{
  if (nullptr == m_toolButton)
    return nullptr;

  return m_toolButton->menu();
}


void LtsDragIcon::setText(const QString &text)
{
  m_text = text;
  (m_toolButton) ? generateToolTip() : initButton();
}

void LtsDragIcon::setContext(const QString &context)
{
  m_context = context;
  generateToolTip();
}

void LtsDragIcon::generateToolTip()
{
  if (!m_toolButton || m_text.isEmpty())
    return;

  QString text(m_text);
  if (!m_context.isEmpty())
    text.prepend(m_context + QLatin1String(" - "));

  m_toolButton->setText(m_text);
  m_toolButton->setToolTip(text);
}

bool LtsDragIcon::isCheckable()
{
  return (m_toolButton) ? m_toolButton->isCheckable() : false;
}

void LtsDragIcon::setDraggable(bool draggable)
{
  m_isDraggable = draggable;
  m_toolButton->setDraggable(m_isDraggable);
}

void LtsDragIcon::setCheckable(bool checkable)
{
  m_toolButton->setCheckable(checkable);
}

bool LtsDragIcon::isChecked() const
{
  return (m_toolButton) ? m_toolButton->isChecked() : false;
}

void LtsDragIcon::setChecked(bool checked)
{
  if (nullptr == m_toolButton)
    initButton();
  m_toolButton->setChecked(checked);
}

void LtsDragIcon::setSameWidgetDrop(bool drop)
{
  if (nullptr == m_toolButton)
    initButton();
  m_toolButton->setSameWidgetDrop(drop);
}

bool LtsDragIcon::sameWidgetDrop() const
{
  if (nullptr == m_toolButton)
    return false;
  return m_toolButton->sameWidgetDrop();
}

void LtsDragIcon::addMimeData(const QString &mimeType, const QByteArray &data)
{
  if (nullptr == m_toolButton)
    initButton();
  m_toolButton->addMimeData(mimeType, data);
}

bool LtsDragIcon::removeMimeData(const QString &mimeType)
{
  if (nullptr == m_toolButton)
    initButton();
  return m_toolButton->removeMimeData(mimeType);
}

void LtsDragIcon::removeAllMimeData()
{
  if (nullptr == m_toolButton)
    initButton();
  m_toolButton->removeAllMimeData();
}

void LtsDragIcon::setAcceptDrops(bool on)
{
  if (nullptr == m_toolButton)
    initButton();
  m_toolButton->setAcceptDrops(on);
}

void LtsDragIcon::dragEnterEvent(QDragEnterEvent *e)
{
  if (m_toolButton)
    m_toolButton->dragEnterEvent(e);
}
void LtsDragIcon::dropEvent(QDropEvent *e)
{
  QWidget::dropEvent(e);
}

void LtsDragIcon::setButtonStyle(ButtonStyle style)
{
  m_style = style;
  setStyleToButton();
}

void LtsDragIcon::setIconSize(ButtonSize buttonSize)
{
  m_buttonSize = buttonSize;
  (m_toolButton) ? m_toolButton->setIconSize(QSize(static_cast<int>(m_buttonSize), static_cast<int>(m_buttonSize))) : initButton();
}

void LtsDragIcon::setForceFixedSize(bool force)
{
  m_forceFixedSize = force;
  initButton();
}

void LtsDragIcon::setButtonVisible(bool visible)
{
  if (nullptr == m_toolButton)
    initButton();
  m_toolButton->setVisible(visible);
}

bool LtsDragIcon::buttonVisible() const
{
  if (nullptr == m_toolButton)
    return false;
  return m_toolButton->isVisible();
}

void LtsDragIcon::setAction(QAction *action)
{
  QIcon icon = action->icon();
  if(!icon.isNull())
    m_icon = icon;
  m_toolButton->setDefaultAction(action);
  this->setObjectName(action->objectName());
}

void LtsDragIcon::changeEvent(QEvent *event)
{
  if (event->type() == QEvent::EnabledChange)
    emit enabledChanged(isEnabled());
}



void LtsToolButton::mousePressEvent(QMouseEvent *event)
{
  if (event->button() == Qt::LeftButton)
    m_startPos = event->pos();
  QToolButton::mousePressEvent(event);
}


void LtsToolButton::mouseReleaseEvent(QMouseEvent *event)
{
  QToolButton::mouseReleaseEvent(event);
}

void LtsToolButton::mouseMoveEvent(QMouseEvent *event)
{
  if (!m_isDraggable)
    return;
  if (event->buttons() & Qt::LeftButton) {
    int distance = (event->pos() - m_startPos).manhattanLength();
    if (distance >= 5)
    {
      this->setDown(false);
      performDrag(event);
      return;
    }
  }
  QToolButton::mouseMoveEvent(event);
}

void LtsToolButton::performDrag(QMouseEvent *)
{
  QWidget *item = this;
  if (item)
  {

    LtsDragIcon *dragIcon = nullptr;
    QString      name;

    while (dragIcon == nullptr)
    {
      if ((!item->objectName().isEmpty()) && (name.isNull()))
      {
        name = item->objectName();
      }
      item = item->parentWidget();
      if (nullptr == item) return; 
      dragIcon = dynamic_cast<LtsDragIcon*>(item);
    }
    QMimeData *mimeData = new QMimeData();
    mimeData->setText(name);
    for(auto it = m_mimeData.cbegin(); it != m_mimeData.cend(); ++it)
      mimeData->setData(it.key(), it.value());


    if (dragIcon->dropHandlerKey() != 0L)
    {
      QByteArray data = QByteArray(QByteArray::number(dragIcon->dropHandlerKey()));
      mimeData->setData(QLatin1String("DropHandlerPtr"),data);
    }

    QDrag *drag = new QDrag(item);

    drag->setMimeData(mimeData);

    QAction *action = defaultAction();

    if ((action) && (dragIcon->showDragIcon()))
    {
      drag->setPixmap(action->icon().pixmap(16,16) );
    }
    else
    {
      drag->setPixmap(dragIcon->icon().pixmap(16, 16));
    }
    Qt::DropAction drop = drag->exec(Qt::CopyAction | Qt::MoveAction);
    if (drop == Qt::MoveAction || drop == Qt::CopyAction )
      emit dropSuc();
  }

}

void LtsToolButton::dragEnterEvent(QDragEnterEvent *event)
{
  QWidget *source =
      qobject_cast<QWidget *>(event->source());
  if (source && source != this) {
    event->setDropAction(Qt::MoveAction);
    event->accept();
  }
  QWidget::dragEnterEvent(event);
}

void LtsToolButton::addMimeData(const QString &mimeType, const QByteArray &data)
{
  m_mimeData.insert(mimeType,data);
}

bool LtsToolButton::removeMimeData(const QString &mimeType)
{
  return (m_mimeData.remove(mimeType) > 0);
}

#define SIZE 40

QIcon LtsDragIcon::modifyIcon(const QIcon &icon)
{
  if (m_modification.isEmpty())
    return icon;

  QPixmap iconImage(icon.pixmap(SIZE*0.8, SIZE*0.8));
  QPainter painter(&iconImage);

  painter.save();
  painter.setRenderHints(QPainter::TextAntialiasing | QPainter::Antialiasing | QPainter::HighQualityAntialiasing | QPainter::SmoothPixmapTransform);
  painter.setBrush(QColor("red"));
  painter.setPen(QPen(QColor("red"), 3));

  QFont f;
  f.setFamily(QStringLiteral("Monospace"));
  f.setPointSize(12);
  f.setBold(true);
  painter.setFont(f);

  painter.drawText(QRect(0, 0, 28, 28), m_modification); 
  painter.restore();

  return iconImage;
}

} 


#include "lts_drag_icon.moc"