#pragma once

#include "ltstimeline_export.h"
#include "timeline_view.h"

#include <QtCore/QModelIndex>
#include <QtCore/QPoint>
#include <QtCore/QVector>

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};
};

} // namespace LtsTimeline