#ifndef VIEWPORTWIDGET_H
#define VIEWPORTWIDGET_H

#include <QOpenGLWidget>
#include <QOpenGLFunctions>
#include <QMatrix4x4>
#include <QPoint>
#include <QVector3D>
#include <QRect>
#include <gp_Pnt.hxx>
#include <QMap>
#include <QOpenGLShaderProgram>
#include <QOpenGLVertexArrayObject>
#include <QOpenGLBuffer>

class QSvgRenderer;
class ViewCube;
class SketchGrid;
class Document;
class FeatureBrowser;
class SketchFeature;
class Camera;
class SketchTool;
class Snapping;

class ViewportWidget : public QOpenGLWidget, protected QOpenGLFunctions
{
    Q_OBJECT

public:
    enum class SketchPlane {
        NONE,
        XY,
        XZ,
        YZ
    };

    explicit ViewportWidget(QWidget *parent = nullptr);
    ~ViewportWidget();

    void setDocument(Document* document);

    QVector3D project(const QVector3D& worldCoord, const QMatrix4x4& modelView, const QMatrix4x4& projection, const QRect& viewport);
    QVector3D unproject(const QPoint& screenPos, SketchPlane plane);
    QOpenGLShaderProgram* shaderProgram() { return m_shaderProgram; }
    QOpenGLBuffer& vbo() { return m_vbo; }
    int colorLoc() const { return m_colorLoc; }
    Camera* camera() const { return m_camera; }
    Document* document() const { return m_document; }
    SketchPlane currentPlane() const { return m_currentPlane; }
    const QPoint& currentMousePos() const { return m_currentMousePos; }
    bool isSnappingOrigin() const;
    bool isSnappingVertex() const;
    const gp_Pnt& snapVertex() const;
    int activeTool() const { return m_activeTool; }
    bool isSnappingHorizontal() const { return m_isSnappingHorizontal; }
    bool isSnappingVertical() const { return m_isSnappingVertical; }
    void setSnappingHorizontal(bool snapping);
    void setSnappingVertical(bool snapping);

    void addLine(const gp_Pnt& start, const gp_Pnt& end);
    void deactivateActiveTool();

public slots:
    void onSketchModeStarted(SketchPlane plane);
    void onSketchModeEnded();
    void onPlaneSelectionModeStarted();
    void onActiveToolChanged(int tool);

signals:
    void lineAdded(const gp_Pnt& start, const gp_Pnt& end);
    void rectangleAdded(const gp_Pnt& corner1, const gp_Pnt& corner2);
    void circleAdded(const gp_Pnt& center, double radius);
    void planeSelected(SketchPlane plane);
    void toolDeactivated();

private slots:
    void onRestoreStateAnimationFinished();

protected:
    void initializeGL() override;
    void paintGL() override;
    void resizeGL(int w, int h) override;

    void mousePressEvent(QMouseEvent *event) override;
    void mouseReleaseEvent(QMouseEvent *event) override;
    void mouseMoveEvent(QMouseEvent *event) override;
    void wheelEvent(QWheelEvent *event) override;
    void keyPressEvent(QKeyEvent *event) override;
    bool focusNextPrevChild(bool next) override;

private:
    void initShaders();
    void drawSketch(const SketchFeature* sketch);
    void drawSelectionPlanes();
    ViewportWidget::SketchPlane checkPlaneSelection(const QPoint& screenPos);

    QMatrix4x4 projection;
    QOpenGLShaderProgram* m_shaderProgram = nullptr;
    QOpenGLShaderProgram* m_litShaderProgram = nullptr;
    QOpenGLVertexArrayObject m_vao;
    QOpenGLBuffer m_vbo;

    // Shader uniform locations
    int m_projMatrixLoc = -1;
    int m_mvMatrixLoc = -1;
    int m_colorLoc = -1;

    // Lit shader uniform locations
    int m_litProjMatrixLoc = -1;
    int m_litMvMatrixLoc = -1;
    int m_litNormalMatrixLoc = -1;
    Camera* m_camera = nullptr;
    ViewCube* m_viewCube;
    SketchGrid* m_sketchGrid = nullptr;
    FeatureBrowser* m_featureBrowser = nullptr;
    Document* m_document = nullptr;
    SketchPlane m_currentPlane = SketchPlane::NONE;

    bool m_isSelectingPlane = false;
    SketchPlane m_highlightedPlane = SketchPlane::NONE;

    int m_activeTool = 0;
    SketchTool* m_activeSketchTool = nullptr;
    QMap<int, SketchTool*> m_sketchTools;
    QPoint m_currentMousePos;
    Snapping* m_snapping = nullptr;
    bool m_isSnappingHorizontal = false;
    bool m_isSnappingVertical = false;

    QMap<int, QSvgRenderer*> m_toolIcons;
    QSvgRenderer* m_cursorRenderer = nullptr;
};

#endif // VIEWPORTWIDGET_H