//##################################################################################################
//
//   Custom Visualization Core library
//   Copyright (C) 2018- Ceetron Solutions AS
//
//   This library may be used under the terms of either the GNU General Public License or
//   the GNU Lesser General Public License as follows:
//
//   GNU General Public License Usage
//   This library is free software: you can redistribute it and/or modify
//   it under the terms of the GNU General Public License as published by
//   the Free Software Foundation, either version 3 of the License, or
//   (at your option) any later version.
//
//   This library is distributed in the hope that it will be useful, but WITHOUT ANY
//   WARRANTY; without even the implied warranty of MERCHANTABILITY or
//   FITNESS FOR A PARTICULAR PURPOSE.
//
//   See the GNU General Public License at <<http://www.gnu.org/licenses/gpl.html>>
//   for more details.
//
//   GNU Lesser General Public License Usage
//   This library is free software; you can redistribute it and/or modify
//   it under the terms of the GNU Lesser General Public License as published by
//   the Free Software Foundation; either version 2.1 of the License, or
//   (at your option) any later version.
//
//   This library is distributed in the hope that it will be useful, but WITHOUT ANY
//   WARRANTY; without even the implied warranty of MERCHANTABILITY or
//   FITNESS FOR A PARTICULAR PURPOSE.
//
//   See the GNU Lesser General Public License at <<http://www.gnu.org/licenses/lgpl-2.1.html>>
//   for more details.
//
//##################################################################################################


#pragma once

#include "cafDisplayCoordTransform.h"
#include "cafTitledOverlayFrame.h"
#include "cvfOverlayItem.h"
#include "cvfArray.h"
#include "cvfCamera.h"
#include "cvfString.h"
#include "cvfRect.h"

#include <array>

namespace cvf {
class Font;
class ShaderProgram;
class MatrixState;
class TextDrawer;
class ScalarMapper;
}

namespace caf {


//==================================================================================================
//
// Overlay color legend
//
//==================================================================================================
class OverlayScaleLegend : public caf::TitledOverlayFrame
{
    using Font = cvf::Font;
    using OpenGLContext = cvf::OpenGLContext;
    using Vec2i = cvf::Vec2i;
    using Vec2ui = cvf::Vec2ui;
    using String = cvf::String;
    using MatrixState = cvf::MatrixState;
    using Vec2f = cvf::Vec2f;
    using TextDrawer = cvf::TextDrawer;
    using Camera = cvf::Camera;

public:
    enum Orientation {HORIZONTAL, VERTICAL};

public:
    OverlayScaleLegend(Font* font);
    ~OverlayScaleLegend() override;

    void            setTickPrecision(int precision);
    enum            NumberFormat { AUTO, SCIENTIFIC, FIXED};
    void            setTickFormat(NumberFormat format);
    void            setOrientation(Orientation orientation);
    Orientation     orientation() const;

    cvf::Vec2ui preferredSize() override;
    
    void setDisplayCoordTransform(const caf::DisplayCoordTransform* displayCoordTransform);
    void updateFromCamera(const Camera* camera);

protected:
    void            render(OpenGLContext* oglContext, const Vec2i& position, const Vec2ui& size) override;
    void            renderSoftware(OpenGLContext* oglContext, const Vec2i& position, const Vec2ui& size) override;

    struct LayoutInfo
    {
        struct Tick
        {
            Tick(double displayValue, double domainValue, bool isMajor)
                : displayValue(displayValue)
                , domainValue(domainValue)
                , isMajor(isMajor) {}
            double displayValue;
            double domainValue;
            bool isMajor;
        };

        LayoutInfo(const Vec2ui& setSize)
        {
            charWidth = 0.0f;
            charHeight = 0.0f;
            lineSpacing = 0.0f;
            margins = cvf::Vec2f::ZERO;
            tickTextLeadSpace = 0.0f;
            
            axisStartPt = cvf::Vec2f::ZERO;
            axisLength = 0.0f;
            majorTickSize = 0.0f;
            minorTickSize = 0.0f;

            overallLegendSize = setSize;
        }

        float charWidth;
        float charHeight;
        float lineSpacing;
        Vec2f margins;
        float tickTextLeadSpace;

        //Rectf colorBarRect;
        Vec2f axisStartPt;
        float axisLength;
        float majorTickSize;
        float minorTickSize;

        std::vector<Tick> ticks;

        Vec2ui overallLegendSize;
    };

    void         layoutInfo(LayoutInfo* layout);

    void         renderGeneric(OpenGLContext* oglContext,
                               const Vec2i& position,
                               const Vec2ui& size,
                               bool software);
    void         renderLegendUsingShaders(OpenGLContext* oglContext,
                                          LayoutInfo* layout,
                                          const MatrixState& matrixState);
    void         renderLegendImmediateMode(OpenGLContext* oglContext,
                                           LayoutInfo* layout);
    void         setupHorizontalTextDrawer(TextDrawer* textDrawer, const LayoutInfo* layout);
    void         setupVerticalTextDrawer(TextDrawer* textDrawer, const LayoutInfo* layout);

protected:
    std::vector<bool>   m_visibleTickLabels;    // Skip tick labels ending up on top of previous visible label
    int                 m_tickNumberPrecision;
    NumberFormat        m_numberFormat;

    Orientation                 m_orientation;
    LayoutInfo                  m_Layout;
    cvf::ref<TextDrawer>        m_textDrawer;

    cvf::ref<Font>              m_font;

    cvf::cref<caf::DisplayCoordTransform>   m_dispalyCoordsTransform;
    double                                  m_currentScale;    // [pixels/length]
    std::vector<double>                     m_ticksInDomain;
};

}