/*****************************************************************************************
*                                                                                       *
* OpenSpace                                                                             *
*                                                                                       *
* Copyright (c) 2014-2016                                                               *
*                                                                                       *
* 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 <modules/base/rendering/screenspaceframebuffer.h>
#include <openspace/engine/openspaceengine.h>
#include <openspace/rendering/renderengine.h>
#include <modules/onscreengui/include/gui.h>
#include <openspace/util/camera.h>

#include <openspace/rendering/renderer.h>
#include <openspace/rendering/abufferrenderer.h>
#include <openspace/rendering/framebufferrenderer.h>

namespace openspace {
ScreenSpaceFramebuffer::ScreenSpaceFramebuffer() 
	:ScreenSpaceRenderable()
	,_framebuffer(nullptr)
{
	_id = id();
	setName("ScreenSpaceFramebuffer" + std::to_string(_id));
	registerProperties();
}

ScreenSpaceFramebuffer::~ScreenSpaceFramebuffer(){}

bool ScreenSpaceFramebuffer::initialize(){
	_originalViewportSize = OsEng.windowWrapper().currentWindowResolution();

	createPlane();
	createShaders();

	createFragmentbuffer();

	// Setting spherical/euclidean onchange handler
	_useFlatScreen.onChange([this](){
		useEuclideanCoordinates(_useFlatScreen.value());
	});

	return isReady();
}

bool ScreenSpaceFramebuffer::deinitialize(){
	glDeleteVertexArrays(1, &_quad);
	_quad = 0;

	glDeleteBuffers(1, &_vertexPositionBuffer);
	_vertexPositionBuffer = 0;

	_texture = nullptr;

	 RenderEngine& renderEngine = OsEng.renderEngine();
    if (_shader) {
        renderEngine.removeRenderProgram(_shader);
        _shader = nullptr;
    }

    _framebuffer->detachAll();

	return true;
}

void ScreenSpaceFramebuffer::render(){
	if(!_renderFunctions.empty()){
		glViewport (0, 0, _originalViewportSize.x, _originalViewportSize.y);
		GLint defaultFBO = _framebuffer->getActiveObject();
		_framebuffer->activate();
		
		glClearColor (0.0f, 0.0f, 0.0f, 0.0f);
		glClear (GL_COLOR_BUFFER_BIT | GL_DEPTH_BUFFER_BIT);

		for(auto renderFunction : _renderFunctions){

			(*renderFunction)();

		}
		_framebuffer->deactivate();

		glBindFramebuffer(GL_FRAMEBUFFER, defaultFBO);
		glm::vec2 resolution = OsEng.windowWrapper().currentWindowResolution();
		glViewport (0, 0, resolution.x, resolution.y);
		
		glm::mat4 rotation = rotationMatrix();
		glm::mat4 translation = translationMatrix();
		glm::mat4 scale = scaleMatrix();
		scale = glm::scale(scale, glm::vec3(1.0f, -1.0f, 1.0f));
		glm::mat4 modelTransform = rotation*translation*scale;
		draw(modelTransform);
	}
}

void ScreenSpaceFramebuffer::update(){}

bool ScreenSpaceFramebuffer::isReady() const{
	bool ready = true;
	if (!_shader)
		ready &= false;
	if(!_texture)
		ready &= false;
	return ready;
}

int ScreenSpaceFramebuffer::id(){
		static int id = 0;
		return id++;
}

void ScreenSpaceFramebuffer::createFragmentbuffer(){
	_framebuffer = std::make_unique<ghoul::opengl::FramebufferObject>();
	_framebuffer->activate();
	_texture = std::make_unique<ghoul::opengl::Texture>(glm::uvec3(_originalViewportSize.x, _originalViewportSize.y, 1));
	_texture->uploadTexture();
	_texture->setFilter(ghoul::opengl::Texture::FilterMode::Linear);
	_framebuffer->attachTexture(_texture.get(), GL_COLOR_ATTACHMENT0);
	_framebuffer->deactivate();

	// GLuint depthrenderbuffer;
	// glGenRenderbuffers(1, &depthrenderbuffer);
	// glBindRenderbuffer(GL_RENDERBUFFER, depthrenderbuffer);
	// glRenderbufferStorage(GL_RENDERBUFFER, GL_DEPTH_COMPONENT, _originalViewportSize.x, _originalViewportSize.y);
	// glFramebufferRenderbuffer(GL_FRAMEBUFFER, GL_DEPTH_ATTACHMENT, GL_RENDERBUFFER, depthrenderbuffer);

	// GLenum DrawBuffers[1] = {GL_COLOR_ATTACHMENT0};
	// glDrawBuffers(1, DrawBuffers);
}

void ScreenSpaceFramebuffer::addRenderFunction(std::shared_ptr<std::function<void()>> renderFunction){
	_renderFunctions.push_back(renderFunction);
}
} //namespace openspace