#ifndef COVEREDIT_H
#define COVEREDIT_H

#include "./previousvaluehandling.h"

#include <tagparser/tag.h>

#include <QWidget>
#include <QGraphicsScene>
#include <QGraphicsView>

#include <memory>

QT_FORWARD_DECLARE_CLASS(QEvent)
QT_FORWARD_DECLARE_CLASS(QGraphicsTextItem)
QT_FORWARD_DECLARE_CLASS(QGraphicsPixmapItem)
QT_FORWARD_DECLARE_CLASS(QGraphicsRectItem)

namespace Media {
class Tag;
class TagValue;
DECLARE_ENUM_CLASS(KnownField, unsigned int);
}

namespace QtGui {

DECLARE_ENUM_CLASS(PreviousValueHandling, int);

namespace Ui {
class PicturePreviewSelection;
}

class PicturePreviewScene : public QGraphicsScene
{
    Q_OBJECT

public:
    PicturePreviewScene(QObject *parent = nullptr);

signals:
    void displayRequested();

protected:
    void mousePressEvent(QGraphicsSceneMouseEvent *mouseEvent);
};

inline PicturePreviewScene::PicturePreviewScene(QObject *parent) :
    QGraphicsScene(parent)
{
}

class PicturePreview : public QGraphicsView
{
    Q_OBJECT

public:
    PicturePreview(QWidget *parent = nullptr);

signals:
    void displayRequested();

protected:
    void mousePressEvent(QMouseEvent *mouseEvent);
};

inline PicturePreview::PicturePreview(QWidget *parent) :
    QGraphicsView(parent)
{
}

class PicturePreviewSelection : public QWidget
{
    Q_OBJECT

public:
    explicit PicturePreviewSelection(Media::Tag *tag = nullptr, Media::KnownField field = Media::KnownField::Invalid, QWidget *parent = nullptr);
    ~PicturePreviewSelection();
    
    Media::Tag *tag() const;
    Media::KnownField field() const;

public slots:
    void setTagField(Media::Tag *tag, Media::KnownField field, PreviousValueHandling previousValueHandling = PreviousValueHandling::Clear);
    void setValue(const Media::TagValue &value, PreviousValueHandling previousValueHandling = PreviousValueHandling::Clear);

    void apply();
    void clear();
    void addOfSelectedType();
    void addOfSelectedType(const QString &path);
    void removeSelected();
    void extractSelected();
    void displaySelected();
    void changeMimeTypeOfSelected();
    void setCoverButtonsHidden(bool hideCoverButtons);

signals:
    void pictureChanged();

protected:
    void changeEvent(QEvent *event);
    void resizeEvent(QResizeEvent *event);
    void dragEnterEvent(QDragEnterEvent *event);
    void dropEvent(QDropEvent *event);
    void mouseDoubleClickEvent(QMouseEvent *event);
    bool eventFilter(QObject *watched, QEvent *event);

private slots:
    void typeSwitched(int index);
    void updateDescription(int newIndex);
    void updateDescription(int lastIndex, int newIndex);
    void updatePreview(int index);
    void showContextMenu();

private:
    void setup(PreviousValueHandling previousValueHandling = PreviousValueHandling::Clear);

    std::unique_ptr<Ui::PicturePreviewSelection> m_ui;
    PicturePreviewScene *m_scene;
    QGraphicsTextItem *m_textItem;
    QPixmap m_pixmap;
    QGraphicsPixmapItem *m_pixmapItem;
    QGraphicsRectItem *m_rectItem;
    Media::Tag *m_tag;
    Media::KnownField m_field;
    QList<Media::TagValue> m_values;
    int m_currentTypeIndex;
};

/*!
 * \brief Returns the tied tag if one is assigned; returns nullptr otherwise.
 *
 * This might have been set initially using the constructor or using the setTagField() method.
 */
inline Media::Tag *PicturePreviewSelection::tag() const
{
    return m_tag;
}

/*!
 * \brief Returns the field. This is commonly KnownField::Cover.
 */
inline Media::KnownField PicturePreviewSelection::field() const
{
    return m_field;
}

/*!
 * \brief Sets the specified \a tag, \a field and \a previousValueHandling.
 *
 * If \a tag is nullptr the widget is disabled. The widget will be re-setup.
 */
inline void PicturePreviewSelection::setTagField(Media::Tag *tag, Media::KnownField field, PreviousValueHandling previousValueHandling)
{
    m_tag = tag;
    m_field = field;
    setup(previousValueHandling);
}

}

#endif // COVEREDIT_H