#pragma once

#include "timeline_view.h"

#include <LtsTimeline/ltstimeline_export.h>

#include <QPoint>
#include <QVector>
#include <QModelIndex>


class QDragEnterEvent;
class QDragMoveEvent;
class QDragLeaveEvent;
class QDropEvent;
class QMouseEvent;
class QKeyEvent;


namespace LtsTimeline
{

class Item;
class Track;
class TimelineView;
class ItemDelegate;


class LTSTIMELINE_EXPORT TimelineViewDragHandler
{
  friend class TimelineView;
  friend class ItemDelegate;

public:
  explicit TimelineViewDragHandler(TimelineView *view);
  virtual ~TimelineViewDragHandler();

  virtual void dragEnterEvent(QDragEnterEvent *e);
  virtual void dragMoveEvent(QDragMoveEvent *e);
  virtual void dragLeaveEvent(QDragLeaveEvent *e);
  virtual void dropEvent(QDropEvent *e);
  virtual void mouseMoveEvent(QMouseEvent *e);
  virtual void mousePressEvent(QMouseEvent *e);
  virtual void mouseReleaseEvent(QMouseEvent *e);
  virtual void keyPressEvent(QKeyEvent *e);

  virtual bool isActive() const;

  virtual int deltaX() const;
  virtual int deltaY() const;
  virtual qint64 deltaTime() const;

  
  const QVector<int> &dragItemIds() const { return m_dragItemIds; }
  const QModelIndex &dragStartIndex() const { return m_dragStartIndex; }
  qint64 dragStartTime() const { return m_dragStartTime; }
  const QPoint &dragStartPos() const { return m_dragStartPos; }
  const QPoint &dragPos() const { return m_dragPos; }

protected:
  virtual bool canDragItemsTo(const QPoint &point) const;
  virtual bool canMoveItemsTo(const QPoint &point) const;

  virtual void moveItemsLeft(const QVector<int> &itemIds, int dt);
  virtual void moveItemsRight(const QVector<int> &itemIds, int dt);

  int dragItemTrackId(const Item &item) const;
  void clear();

protected:
  TimelineView *m_view{nullptr};
  QVector<int> m_dragItemIds;
  QModelIndex m_dragStartIndex;
  qint64 m_dragStartTime{-1};
  QPoint m_dragStartPos;
  QPoint m_dragPos;

  int m_snapLinePos{-1};

};

}