/*****************************************************************************************
 *                                                                                       *
 * OpenSpace                                                                             *
 *                                                                                       *
 * Copyright (c) 2014                                                                    *
 *                                                                                       *
 * Permission is hereby granted, free of charge, to any person obtaining a copy of this  *
 * software and associated documentation files (the "Software"), to deal in the Software *
 * without restriction, including without limitation the rights to use, copy, modify,    *
 * merge, publish, distribute, sublicense, and/or sell copies of the Software, and to    *
 * permit persons to whom the Software is furnished to do so, subject to the following   *
 * conditions:                                                                           *
 *                                                                                       *
 * The above copyright notice and this permission notice shall be included in all copies *
 * or substantial portions of the Software.                                              *
 *                                                                                       *
 * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR IMPLIED,   *
 * INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, FITNESS FOR A         *
 * PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT    *
 * HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF  *
 * CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE  *
 * OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.                                         *
 ****************************************************************************************/

#include <openspace/rendering/volumeraycasterbox.h>

#include <openspace/engine/openspaceengine.h>
#include <sgct.h>

#include <ghoul/opengl/programobject.h>
#include <ghoul/opengl/framebufferobject.h>
#include <ghoul/logging/logmanager.h>
#include <ghoul/filesystem/filesystem.h>


namespace {
    std::string _loggerCat = "VolumeRaycasterBox";
}

using namespace ghoul::opengl;

namespace openspace {

VolumeRaycasterBox::VolumeRaycasterBox(): _fbo(nullptr), _backTexture(nullptr),
    _frontTexture(nullptr), _boxProgram(nullptr), _boundingBox(nullptr) {

}

VolumeRaycasterBox::~VolumeRaycasterBox() {
    if(_boundingBox)
        delete _boundingBox;
    
    if(_fbo) {
        _fbo->detachAll();  // maybe not needed
        delete _fbo;
    }
}

bool VolumeRaycasterBox::initialize() {
    _boundingBox = new sgct_utils::SGCTBox(1.0f, sgct_utils::SGCTBox::Regular);
    
    //	------ SETUP SHADER -----------------
    OsEng.configurationManager().getValue("RaycastProgram", _boxProgram);
	_MVPLocation = _boxProgram->uniformLocation("modelViewProjection");
    
	//	------ SETUP FBO ---------------------
	_fbo = new FramebufferObject();
	_fbo->activate();
    
    // changed from getActiveXResolution to getCurrentViewportPixelCoords because
    // if there are more viewports in the same screen.
	//size_t x = sgct::Engine::instance()->getActiveXResolution();
	//size_t y = sgct::Engine::instance()->getActiveYResolution();
    int x1, xSize, y1, ySize;
    sgct::Engine::instance()->getActiveWindowPtr()->getCurrentViewportPixelCoords(x1, y1, xSize, ySize);
    size_t x = xSize;
    size_t y = ySize;
    
    _dimensions = glm::size2_t(x, y);
    
	_backTexture = new Texture(glm::size3_t(x,y,1));
	_frontTexture = new Texture(glm::size3_t(x,y,1));
    _backTexture->uploadTexture();
    _frontTexture->uploadTexture();
	_fbo->attachTexture(_backTexture, GL_COLOR_ATTACHMENT0);
	_fbo->attachTexture(_frontTexture, GL_COLOR_ATTACHMENT1);
	_fbo->deactivate();
    
    return true;
}

void VolumeRaycasterBox::render(const glm::mat4& MVP) {
    GLuint activeFBO = FramebufferObject::getActiveObject(); // Save SGCTs main FBO
	_fbo->activate();
	_boxProgram->activate();
	_boxProgram->setUniform(_MVPLocation, MVP);
    
    sgct_core::Frustum::FrustumMode mode =  sgct::Engine::instance()->
                                            getActiveWindowPtr()->
                                            getCurrentViewport()->
                                            getEye();
    
    // oh god why..?
    if(mode == sgct_core::Frustum::FrustumMode::Mono ||
       mode == sgct_core::Frustum::FrustumMode::StereoLeftEye) {
        glDrawBuffer(GL_COLOR_ATTACHMENT0);
        glClearColor(0.0, 0.0, 0.0, 0.0);
        glClear(GL_COLOR_BUFFER_BIT);
        glDrawBuffer(GL_COLOR_ATTACHMENT1);
        glClearColor(0.0, 0.0, 0.0, 0.0);
        glClear(GL_COLOR_BUFFER_BIT);
    
    }

    // make sure GL_CULL_FACE is enabled (it should be)
    glEnable(GL_CULL_FACE);
    
	//	Draw backface
	glDrawBuffer(GL_COLOR_ATTACHMENT0);
	glCullFace(GL_FRONT);
	_boundingBox->draw();

	//	Draw frontface (now the normal cull face is is set)
	glDrawBuffer(GL_COLOR_ATTACHMENT1);
	glCullFace(GL_BACK);
	_boundingBox->draw();

	_boxProgram->deactivate();
	_fbo->deactivate();
    
    // rebind the previous FBO
    glBindFramebuffer(GL_FRAMEBUFFER, activeFBO);
}

Texture* VolumeRaycasterBox::backFace() {
	return _backTexture;
}

Texture* VolumeRaycasterBox::frontFace() {
	return _frontTexture;
}

glm::size2_t VolumeRaycasterBox::dimensions() {
    return _dimensions;
}

} /* namespace openspace */