#include "SlideShowConstructor.h"

#include <osg/Geometry>
#include <osg/PolygonOffset>
#include <osg/Geode>
#include <osg/Texture2D>
#include <osg/MatrixTransform>

#include <osgDB/ReadFile>

#include <osgText/Text>


SlideShowConstructor::SlideShowConstructor()
{
    _slideOrigin.set(0.0f,0.0f,0.0f);
    _slideWidth = 1280.0f;
    _slideHeight = 1024.0f;

    _backgroundColor.set(0.0f,0.0f,0.0f,1.0f);
    _textColor.set(1.0f,1.0f,1.0f,1.0f);
    _textFont = "fonts/arial.ttf";

}

void SlideShowConstructor::createPresentation()
{
    _titleHeight = _slideHeight*0.08f;
    _titleWidth = _slideWidth*0.8f;
    _titleOrigin = _slideOrigin + osg::Vec3(_slideWidth*0.5f,0.0f,_slideHeight*0.98f-_titleHeight);

    _textHeight = _slideHeight*0.05f;
    _textWidth = _slideWidth*0.8f;
    
    _textOrigin = _slideOrigin + osg::Vec3(_slideWidth*0.1f,0.0f,_titleOrigin.z()-2*_textHeight);
    _imageOrigin = _slideOrigin + osg::Vec3(_slideWidth*0.7f,0.0f,_titleOrigin.z()*0.5f);
    _modelLeft = _slideOrigin + osg::Vec3(_slideWidth*0.0f,0.0f,_titleOrigin.z()*0.5f);
    _modelRight = _slideOrigin + osg::Vec3(_slideWidth*1.0f,0.0f,_titleOrigin.z()*0.5f);
    
    _root = new osg::ClearNode;
    _root->setClearColor(_backgroundColor);
    
    _presentationSwitch = new osg::Switch;
    _presentationSwitch->setName(std::string("Presentation_")+_presentationName);
    
    _root->addChild(_presentationSwitch.get());
    
}

void SlideShowConstructor::setBackgroundColor(const osg::Vec4& color)
{
    _backgroundColor = color;
    if (_root.valid()) _root->setClearColor(_backgroundColor);
}

void SlideShowConstructor::setTextColor(const osg::Vec4& color)
{
    _textColor = color;
}

void SlideShowConstructor::setPresentationName(const std::string& name)
{
    _presentationName = name;
    if (_presentationSwitch.valid()) _presentationSwitch->setName(std::string("Presentation_")+_presentationName);
}


void SlideShowConstructor::addSlide()
{
    if (!_presentationSwitch) createPresentation();

    // reset cursors
    _textCursor = _textOrigin;
    _imageCursor = _imageOrigin;
    _modelCursor = _modelLeft*0.5f + _modelRight*0.5f;
    
    _slide = new osg::Switch;
    _slide->setName(std::string("Slide_")+_slideTitle);
    
    _presentationSwitch->addChild(_slide.get());

    _previousLayer = 0;
    _currentLayer = 0;    
}

void SlideShowConstructor::addLayer()
{
    if (!_slide) addSlide();

    _previousLayer = _currentLayer;
    
    _currentLayer = new osg::Group;
    
    _slide->addChild(_currentLayer.get());
    
    if (!_previousLayer)
    {
        // create the background and title..
        if (!_slideBackgroundImageFileName.empty())
        {
            osg::Geometry* backgroundQuad = osg::createTexturedQuadGeometry(_slideOrigin,
                                                            osg::Vec3(_slideWidth,0.0f,0.0f),
                                                            osg::Vec3(0.0f,0.0f,_slideHeight));

            osg::Geode* background = new osg::Geode;

            osg::StateSet* backgroundStateSet = background->getOrCreateStateSet();
            backgroundStateSet->setAttributeAndModes(
                        new osg::PolygonOffset(1.0f,1.0f),
                        osg::StateAttribute::ON);

            backgroundStateSet->setTextureAttributeAndModes(0,
                        new osg::Texture2D(osgDB::readImageFile(_slideBackgroundImageFileName)),
                        osg::StateAttribute::ON);

            background->addDrawable(backgroundQuad);

            _currentLayer->addChild(background);
        }
        
        if (!_slideTitle.empty())
        {
            osg::Geode* geode = new osg::Geode;

            osgText::Text* text = new osgText::Text;
            text->setFont(_textFont);
            text->setColor(_textColor);
            text->setCharacterSize(_titleHeight);
            text->setMaximumWidth(_titleWidth);
            text->setAxisAlignment(osgText::Text::XZ_PLANE);
            text->setAlignment(osgText::Text::CENTER_BASE_LINE);
            text->setPosition(_titleOrigin);

            text->setText(_slideTitle);

            geode->addDrawable(text);

            _currentLayer->addChild(geode);
        }
        
    }
    else
    {
        // copy previous layer's children across into new layer.
        for(unsigned int i=0;i<_previousLayer->getNumChildren();++i)
        {
            _currentLayer->addChild(_previousLayer->getChild(i));
        }
    }

}

void SlideShowConstructor::addBullet(const std::string& bullet)
{
    if (!_currentLayer) addLayer();

    osg::Geode* geode = new osg::Geode;

    osgText::Text* text = new osgText::Text;

    text->setFont(_textFont);
    text->setColor(_textColor);
    text->setCharacterSize(_textHeight);
    text->setMaximumWidth(_textWidth);
    text->setAxisAlignment(osgText::Text::XZ_PLANE);
    text->setAlignment(osgText::Text::BASE_LINE);
    text->setPosition(_textCursor);
    
    text->setText(bullet);

    osg::BoundingBox bb = text->getBound();
    _textCursor.z() = bb.zMin()-_textHeight*1.5;

    geode->addDrawable(text);
    
    _currentLayer->addChild(geode);
    
}

void SlideShowConstructor::addParagraph(const std::string& paragraph)
{
    if (!_currentLayer) addLayer();

    osg::Geode* geode = new osg::Geode;

    osgText::Text* text = new osgText::Text;

    text->setFont(_textFont);
    text->setColor(_textColor);
    text->setCharacterSize(_textHeight);
    text->setMaximumWidth(_textWidth);
    text->setAxisAlignment(osgText::Text::XZ_PLANE);
    text->setAlignment(osgText::Text::BASE_LINE);
    text->setPosition(_textCursor);
    
    text->setText(paragraph);

    osg::BoundingBox bb = text->getBound();
    _textCursor.z() = bb.zMin()-_textHeight*1.5;

    geode->addDrawable(text);
    
    _currentLayer->addChild(geode);
}

void SlideShowConstructor::addImage(const std::string& filename,float height)
{
    if (!_currentLayer) addLayer();

    osg::Image* image = osgDB::readImageFile(filename);
    
    if (!image) return;
    
    float s = image->s();
    float t = image->t();
    
    float image_height = _slideHeight*0.6f;
    float image_width =  image_height*s/t;
    float offset = height*image_height*0.1f;
    
    osg::Vec3 pos = _imageCursor + osg::Vec3(-image_width*0.5f+offset,-offset,-image_height*0.5f-offset);

    osg::Geometry* backgroundQuad = osg::createTexturedQuadGeometry(pos,
                                                    osg::Vec3(image_width,0.0f,0.0f),
                                                    osg::Vec3(0.0f,0.0f,image_height));

    osg::Geode* background = new osg::Geode;

    osg::StateSet* backgroundStateSet = background->getOrCreateStateSet();

    backgroundStateSet->setTextureAttributeAndModes(0,
                new osg::Texture2D(image),
                osg::StateAttribute::ON);

    background->addDrawable(backgroundQuad);

    _currentLayer->addChild(background);
}

void SlideShowConstructor::addModel(const std::string& filename,float scale,float rotation,float position)
{
    if (!_currentLayer) addLayer();

    osg::Node* model = osgDB::readNodeFile(filename);

    if (!model) return;

    osg::Vec3 pos = _modelLeft*(1.0f-position) + _modelRight*position;
    float radius = scale*_slideHeight*0.7f;
    osg::Quat quat;
    quat.makeRotate(osg::DegreesToRadians(rotation),0.0f,0.0f,1.0f);

    osg::MatrixTransform* transform = new osg::MatrixTransform;
    
    const osg::BoundingSphere& bs = model->getBound();
    
    transform->setDataVariance(osg::Object::STATIC);
    transform->setMatrix(osg::Matrix::translate(-bs.center())*
                         osg::Matrix::scale(radius/bs.radius(),radius/bs.radius(),radius/bs.radius())*
                         osg::Matrix::rotate(quat)*
                         osg::Matrix::translate(pos));
                         
    transform->addChild(model);
    
    _currentLayer->addChild(transform);

}