#include "track_drag_handler.h"

#include "track_content_widget.h"
#include "track_entry.h"
#include "tools.h"

#include "track_widget.h"
#include "script_timeline.h"

#include <LtsWidgets/lts_message_dialog.h>

#include <QDragEnterEvent>
#include <QDropEvent>
#include <QDrag>
#include <QMimeData>
#include <QGuiApplication>
#include <QApplication>

#include <QDebug>


namespace LtsScriptTimeline
{

void DragHandler::dragEnterEvent(QDragEnterEvent *event)
{
  if (m_tcw->isMultiLineMultiSelectionMode()) // in multiline selection mode, ignore enter events from other tracks
  {
    if (event->source() != m_tcw)
    {
      event->ignore();
      return;
    }
    else
    {
      for (const auto &tcw : qAsConst(m_tcwCorresponding))
        tcw->dragEnter(tcw->selectedItemsToData(tcw->m_tools->getTime(m_dragStartPos.x())));
    }
  }

  m_tcw->dragEnd();

  if (!event->mimeData()->hasFormat(TrackContentWidget::mime))
    return;

  if (m_tcw->dragEnter(event->mimeData()->data(TrackContentWidget::mime)))
    event->acceptProposedAction();
}


void DragHandler::dragLeaveEvent(QDragLeaveEvent *event)
{
  if (m_tcw->isMultiLineMultiSelectionMode())
  {
    event->ignore();
    for (const auto &tcw : qAsConst(m_tcwCorresponding))
      tcw->dragEnd();
  }

  m_tcw->dragEnd();
}


void DragHandler::dropEvent(QDropEvent *event)
{
  int dropPos = event->pos().x();
  int dropTime = m_tcw->m_tools->getTime(dropPos, m_tcw->m_isFilter) - m_tcw->m_dragOffsetTime;

  /*
   * If set, check other track content widget for collisions to avoid parallel topics of same type,
   * since not all topics can be played on both screens at the same time.
   */
  for (const auto &tcw : qAsConst(m_tcwCorresponding))
  {
    bool hasParallelTopicsOfSameType = TrackContentWidget::checkForParallelTopics(tcw, m_tcw->m_preview, dropTime);

    if (hasParallelTopicsOfSameType)
    {
      new LtsWidgets::LtsMessageDialogNew(m_tcw, TrackContentWidget::parallelError(), QObject::tr("Error"));
      break;
    }
  }

  if (m_tcw->dragDrop(dropPos))
    event->acceptProposedAction();
  else
    emit m_tcw->signalMultiLineMultiSelectionDone(0);
}


void DragHandler::dragMoveEvent(QDragMoveEvent *event)
{
  int pos = event->pos().x();

  if (m_tcw->dragMove(pos))
    event->acceptProposedAction();

  // only called from the master
  if (m_tcw->isMultiLineMultiSelectionMode())
    emit m_tcw->signalMultiLineMultiSelectionMove(pos);
}


void DragHandler::mousePressEvent(QMouseEvent *event)
{
  if (event->buttons() != Qt::LeftButton)
    return;
  m_dragStartPos = event->pos();
}


void DragHandler::mouseMoveEvent(QMouseEvent *event) // before a drag is started - drag is started here
{
  if (event->buttons() != Qt::LeftButton)
    return;

  QPoint cursorPos = m_tcw->mapFromGlobal(event->globalPos());

  // check if it's a drag *pun unintended*
  if (!m_tcw->m_mainSelected /* only allow drag if there was ANY te under the cursor */
      || ((cursorPos - m_dragStartPos).manhattanLength() < QApplication::startDragDistance()
          && (m_dragStartPos - cursorPos).manhattanLength() < QApplication::startDragDistance()))
    return;

  QVector<TrackEntry *> selected = m_tcw->getSelectedEntries();

  if (selected.isEmpty())
    return;

  int cursorPosTime = m_tcw->m_tools->getTime(m_dragStartPos.x());

  QMimeData *mimeData = new QMimeData();
  mimeData->setData(TrackContentWidget::mime, m_tcw->selectedItemsToData(cursorPosTime));

  QDrag *drag = new QDrag(m_tcw);
  drag->setMimeData(mimeData);

  if (m_tcw->isMultiLineMultiSelectionMode())
    emit m_tcw->signalMultiLineMultiSelectionStart(cursorPosTime);

  QVector<TrackEntry *> selectedOld = m_tcw->m_selected; // copy list, only delete OLD selection [NOTE: m_selected has to be fetched BEFORE exec(), otherwise m_select has changed (due to new / moved TEs!)

  if (drag->exec(Qt::MoveAction) == Qt::MoveAction)
  {
    if (!m_tcw->isMultiLineMultiSelectionMode())
    {
      // move action - TEs were moved
      for (auto i = selectedOld.begin(); i != selectedOld.end(); ++i)
        emit m_tcw->signalTrackEntryDeleted((*i)->m_topicId); // triggers the deletion of old filters
      qDeleteAll(selectedOld);
    }
  }
  else // user pressed escape while dragging
  {
    emit m_tcw->signalMultiLineMultiSelectionDone(-1);
  }
}


void DragHandler::keyPressEvent(QKeyEvent *event)
{
  switch (event->key())
  {
    case Qt::Key_Left:
    {
      emit m_tcw->signalMoveAll(-1);
      break;
    }

    case Qt::Key_Right:
    {
      emit m_tcw->signalMoveAll(1);
      break;
    }

    default:
    {
      break;
    }
  }
}

} // namespace LtsScriptTimeline