#ifndef IMAGESCROLLAREAGL_H
#define IMAGESCROLLAREAGL_H

#include <memory>
#include <QObject>
#include <QOpenGLWidget>
#include <QOpenGLFunctions_3_3_Core>
#include <QOpenGLShaderProgram>
#include <QOpenGLBuffer>
#include <QOpenGLTexture>
#include <QOpenGLVertexArrayObject>
#include <QScrollBar>
#include <QTimer>
#include "rawimage.h"
#include "imageringlist.h"
#include "database.h"

struct ImageThumb
{
    QString name;
    QString path;
    QSize size;
    bool selected;
    bool dirty;
};

class ImageWidget : public QOpenGLWidget
{
    Q_OBJECT
    QOpenGLFunctions *f;
    QOpenGLFunctions_3_3_Core *f3;
    QTimer *m_updateTimer;
    std::unique_ptr<QOpenGLShaderProgram> m_program;
    std::unique_ptr<QOpenGLShaderProgram> m_thumbnailProgram;
    std::unique_ptr<QOpenGLBuffer> m_buffer;
    std::unique_ptr<QOpenGLBuffer> m_bufferSizes;
    std::unique_ptr<QOpenGLTexture> m_image;
    std::unique_ptr<QOpenGLVertexArrayObject> m_vao;
    std::unique_ptr<QOpenGLVertexArrayObject> m_vaoThumb;
    std::unique_ptr<QOpenGLPixelTransferOptions> m_transferOptions;
    std::unique_ptr<QOpenGLTexture> m_thumbnailTexture;
    int m_width, m_height;
    int m_imgWidth, m_imgHeight;
    int m_currentImg;
    float m_low;
    float m_mid;
    float m_high;
    float m_range;
    float m_dx, m_dy;
    float m_scale;
    bool m_blockRepaint;
    bool m_bwImg;
    bool m_invert;
    bool m_superpixel;
    bool m_showThumbnails;
    bool m_selecting;
    int m_thumbnailCount;
    QVector<ImageThumb> m_thumnails;
    Database *m_database;
public:
    explicit ImageWidget(Database *database, QWidget *parent = nullptr);
    ~ImageWidget() override;
    void setImage(const RawImage *image, int index);
    void setImage(const QPixmap &pixmap);
    void setScale(float scale);
    void blockRepaint(bool block);
    void allocateThumbnails(const QStringList &paths);
public slots:
    void setMTFParams(float low, float mid, float high);
    void setOffset(int dx, int dy);
    void superPixel(bool enable);
    void invert(bool enable);
    QImage renderToImage();
    void thumbnailLoaded(const Image *image);
    void showThumbnail(bool enable);
protected:
    void paintGL() override;
    void resizeGL(int w, int h) override;
    void initializeGL() override;
    void dragEnterEvent(QDragEnterEvent *event) override;
    void dropEvent(QDropEvent *event) override;
    void mousePressEvent(QMouseEvent *event) override;
    void mouseMoveEvent(QMouseEvent *event) override;
    void mouseReleaseEvent(QMouseEvent *event) override;
    void thumbSelect(QMouseEvent *event);
signals:
    void fileDropped(const QString &path);
};

class ImageScrollAreaGL : public QWidget
{
    Q_OBJECT
    QScrollBar *m_verticalScrollBar;
    QScrollBar *m_horizontalScrollBar;
    ImageWidget *m_imageWidget;
    int m_imgWidth, m_imgHeight;
    QPoint m_lastPos;
    float m_scale;
    bool m_bestFit;
    int m_thumbCount;
public:
    explicit ImageScrollAreaGL(Database *database, QWidget *parent = nullptr);
    ~ImageScrollAreaGL() override;
    void setImage(RawImage *image, int index);
    ImageWidget* imageWidget();
    void setThumbnails(int count);
protected:
    void updateScrollbars(bool zoom = false);
    void resizeEvent(QResizeEvent *event) override;
    void mouseMoveEvent(QMouseEvent *event) override;
    void mousePressEvent(QMouseEvent *event) override;
    void wheelEvent(QWheelEvent *event) override;
    void zoom(float delta);
public slots:
    void zoomIn();
    void zoomOut();
    void bestFit();
    void oneToOne();
protected slots:
    void scrollEvent();
};

#endif // IMAGESCROLLAREAGL_H