#include "MyGlWindow.h"
//Getting the projection matrix
glm::mat4x4 perspective(float fovy, float aspect, float near, float far)
{
	float fovy2 = glm::tan(fovy / 2);

	glm::mat4x4 pmat{ { 1 / (aspect * fovy2), 0, 0, 0},
					  { 0, 1 / fovy2, 0, 0},
					  { 0, 0, -((far + near) / (far - near)), -1},
					  { 0, 0, -((2 * far * near) / (far - near)), 0} };


	return pmat;
}

// Getting the view matrix
glm::mat4x4 lookAt(glm::vec3 campos, glm::vec3 look, glm::vec3 up)
{
	glm::vec3 ZCam(glm::normalize(campos - look));
	glm::vec3 XCam(glm::normalize(glm::cross(up, ZCam)));
	glm::vec3 YCam(glm::normalize(glm::cross(ZCam, XCam)));

	glm::mat4x4 cam_mat{ {XCam.x, YCam.x, ZCam.x, 0},
						 {XCam.y, YCam.y, ZCam.y, 0},
						 {XCam.z, YCam.z, ZCam.z, 0},
						 {0, 0, 0 ,1} };

	glm::mat4x4 norm_mat{ {1, 0, 0, 0},
						  {0, 1, 0, 0},
						  {0, 0, 1, 0},
						  {-campos.x, -campos.y, -campos.z, 1} };

	return cam_mat * norm_mat;
}


MyGlWindow::MyGlWindow(int w, int h) : 
	viewer(glm::vec3(5, 5, 5), glm::vec3(0, 0, 0), glm::vec3(0, 1, 0), 45.0f, (w / (float)h))
{
	m_width = w;
	m_height = h;

	_scnctx.height = m_height;
	_scnctx.width = m_width;

	setup();
}

MyGlWindow::~MyGlWindow()
{	
	shaders.clear();	
}

void MyGlWindow::setBgColor(float bgColor[3])
{
	_scnctx.bg = glm::vec4(bgColor[0], bgColor[1], bgColor[2], 1);
}

void MyGlWindow::textureSetup()
{
	glTexParameterf(GL_TEXTURE_2D, GL_TEXTURE_MAG_FILTER, GL_LINEAR);
	glTexParameterf(GL_TEXTURE_2D, GL_TEXTURE_MIN_FILTER, GL_LINEAR);
	glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_WRAP_S, GL_MIRRORED_REPEAT);
	glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_WRAP_T, GL_MIRRORED_REPEAT);

	_scnctx.textures.emplace("BrickTex", Texture("brick1.jpg"));
	_scnctx.textures.emplace("MossTex", Texture("moss.png"));
	_scnctx.textures.emplace("EarthTex", Texture("earth.jpg"));	
	_scnctx.textures.emplace("OgreTex", Texture("Models/ogre/ogre_diffuse.png"));
	_scnctx.textures["OgreTex"].mat.shininess = 3.0f;
	_scnctx.textures["OgreTex"].mat.ks = glm::vec3(0.1f, 0.1f, 0.1f);
	_scnctx.textures["OgreTex"].mat.ka = glm::vec3(0.3f, 0.3f, 0.3f);
	_scnctx.textures["OgreTex"].mat.enabled = true;
	_scnctx.textures.emplace("OgreNmap", Texture("Models/ogre/ogre_normalmap.png"));
	_scnctx.textures["OgreNmap"].isNmap = true;
	_scnctx.textures.emplace("CubeTex", Texture("Models/cube/color_map.jpg"));
	_scnctx.textures["CubeTex"].mat.shininess = 3.0f;
	_scnctx.textures["CubeTex"].mat.ks = glm::vec3(0.1f, 0.1f, 0.1f);
	_scnctx.textures["CubeTex"].mat.ka = glm::vec3(0.3f, 0.3f, 0.3f);
	_scnctx.textures["CubeTex"].mat.enabled = true;
	_scnctx.textures.emplace("CubeNmap", Texture("Models/cube/normal_map.jpg"));
	_scnctx.textures["CubeNmap"].isNmap = true;
}

void MyGlWindow::shaderSetup()
{
	shaders["Simple"] = new Shader("simple.vert", "simple.frag");
	shaders["Simple"]->uniformFlags = ShaderFlags::MVP_FLAG;

	shaders["BaseLight"] = new Shader("base_light.vert", "base_light.frag");
	shaders["ShadowLight"] = new Shader("shadow_light.vert", "shadow_light.frag");
	shaders["LightPOV"] = new Shader("light_pov.vert", "light_pov.frag");
	shaders["LightPOV"]->uniformFlags = 0;
	shaders["Fog"] = new Shader("fog.vert", "fog.frag");

	shaders["TexBaseLight"] = new Shader("tex_base_light.vert", "tex_base_light.frag");
	shaders["TexNmapLight"] = new Shader("nmap.vert", "nmap.frag");
	shaders["TexNmapLight"]->uniformFlags &= ~ShaderFlags::KD_FLAG;

	shaders["SpotLight"] = new Shader("spotlight.vert", "spotlight.frag");
	shaders["SpotLight"]->light_type = Light::LightType::SPOT;
	shaders["TexSpotLight"] = new Shader("tex_spotlight.vert", "tex_spotlight.frag");
	shaders["TexSpotLight"]->light_type = Light::LightType::SPOT;

	shaders["Silhouette"] = new Shader("silhouette.vert", "silhouette.frag");
	shaders["Silhouette"]->uniformFlags = ShaderFlags::MVP_FLAG;
	shaders["Silhouette"]->addUniform("fColor", glm::vec3(237 / 255, 229 / 255, 194 / 255));
	shaders["Silhouette"]->addUniform("sil_offset", 0.1f);
	
	shaders["Toon"] = new Shader("base_light.vert", "toon.frag");
	//Removing useless specular component
	shaders["Toon"]->uniformFlags &= ~ShaderFlags::KS_FLAG;
	shaders["Toon"]->uniformFlags &= ~ShaderFlags::SHINE_FLAG;

	shaders["Skybox"] = new Shader("skybox.vert", "skybox.frag");
	shaders["Skybox"]->uniformFlags = MVP_FLAG | MODEL_MATRIX_FLAG | SKYBOX_TEX_FLAG;
	shaders["Skybox"]->addUniform("RefractionIndex", glm::vec3(0.65, 0.67, 0.69));

	shaders["DSGeometryPass"] = new Shader("DSGeometryPass.vert", "DSGeometryPass.frag");
	shaders["DSGeometryPass"]->uniformFlags = MVP_FLAG | KA_FLAG | KD_FLAG | KS_FLAG | SHINE_FLAG;

	shaders["DSLightPass"] = new Shader("DSLightPass.vert", "DSLightPass.frag");
	shaders["DSLightPass"]->uniformFlags = LIGHTS_FLAG;
}

void MyGlWindow::lightSetup()
{
	//Showcase lights
	//_scnctx.lights.emplace("Spotlight1", Light(glm::vec3(0.8f), glm::vec4(10, 10, 10, 1)));
	//	24, 12, 2, glm::vec4(0, 1, 0, 1)));

	//Party lights
	//_scnctx.lights.emplace("Light1", Light(glm::vec3(0.0f, 0.5f, 0.5f), glm::vec4(10, 10, 0, 1)));
	//_scnctx.lights.emplace("Light2", Light(glm::vec3(0.0f, 0.0f, 0.5f), glm::vec4(3.09, 10, 9.51, 1)));
	//_scnctx.lights.emplace("Light3", Light(glm::vec3(0.5f, 0.0f, 0.0f), glm::vec4(-8.09, 10, 5.87, 1)));
	//_scnctx.lights.emplace("Light4", Light(glm::vec3(0.0f, 0.5f, 0.0f), glm::vec4(-8.09, 10, -5.87, 1)));
	//_scnctx.lights.emplace("Light5", Light(glm::vec3(0.5f, 0.5f, 0.5f), glm::vec4(3.09, 10, -9.51, 1)));
}

void MyGlWindow::multipassSetup()
{	
	//_multipassManager.shader = shaders["ShadowLight"];
	_multipassManager.addTexture("position_buffer", GL_NEAREST, GL_RGB, GL_FLOAT, false, _scnctx);
	_multipassManager.addTexture("normal_buffer", GL_NEAREST, GL_RGB, GL_RGB, false, _scnctx);
	_multipassManager.addTexture("color_buffer", GL_NEAREST, GL_RGB, GL_RGB, false, _scnctx);	
	_multipassManager.bindToFrameBuffer(GL_COLOR_ATTACHMENT0, GL_TEXTURE_2D, "position_buffer");
	_multipassManager.bindToFrameBuffer(GL_COLOR_ATTACHMENT1, GL_TEXTURE_2D, "normal_buffer");
	_multipassManager.bindToFrameBuffer(GL_COLOR_ATTACHMENT2, GL_TEXTURE_2D, "color_buffer");

	//_multipassManager.setDrawBuffers();

	_multipassManager.shader->addSubroutine(GL_FRAGMENT_SHADER, "depthing");
	_multipassManager.shader->addSubroutine(GL_FRAGMENT_SHADER, "blurring");
	_multipassManager.shader->addSubroutine(GL_FRAGMENT_SHADER, "sharpening");
	_multipassManager.shader->addSubroutine(GL_FRAGMENT_SHADER, "sepia");
	_multipassManager.shader->addSubroutine(GL_FRAGMENT_SHADER, "grayscale");
	_multipassManager.shader->addSubroutine(GL_FRAGMENT_SHADER, "sobel_filter");
	_multipassManager.shader->addSubroutine(GL_FRAGMENT_SHADER, "absolutely_no_postprocess");
}

void MyGlWindow::setup()
{	
	glEnable(GL_DEPTH_TEST);
	glEnable(GL_DEPTH_BUFFER);
	glEnable(GL_TEXTURE_2D);
	
	textureSetup();
	shaderSetup();
	skybox.initialize("Models/Skybox/", shaders["Skybox"]);
	skybox.scale = 10;
	_scnctx.skybox_tex = skybox.getTexID();
	lightSetup();
	multipassSetup();
	
	Dataset moddata;	
	moddata.checkeredFloor(100, 100, glm::vec3(0.1, 0.1, 0.1), glm::vec3(0.7, 0.7, 0.7));	
	meshes.emplace("Floor", new Mesh(moddata, shaders["BaseLight"]));	

	moddata.simpleCube();

	//Hardcoded seed for easy scene replication
	std::srand(18);

	int zob = std::rand();
	for (int i = 0; i < 30; i++)
	{		
		std::string cube_name = "Cube" + std::to_string(i);
		meshes.emplace(cube_name, new Mesh(moddata, shaders["BaseLight"]));	

		float pos_x = std::rand() % 100 - 50;
		float pos_z = std::rand() % 100 - 50;

		meshes[cube_name]->addStartTranslation(glm::vec4(0, 1, 0, 0));
		meshes[cube_name]->addStartTranslation(glm::vec4(pos_x, 0, 0, 0));
		meshes[cube_name]->addStartTranslation(glm::vec4(0, 0, pos_z, 0));
		meshes[cube_name]->addStartRotation(glm::vec4(1, 0, 0, std::rand() % 360));
		meshes[cube_name]->addStartRotation(glm::vec4(0, 1, 0, std::rand() % 360));
		meshes[cube_name]->addStartRotation(glm::vec4(0, 0, 1, std::rand() % 360));
				
		float light_r = (40 + std::rand() % 60) / 100.f;
		float light_g = (40 + std::rand() % 60) / 100.f;
		float light_b = (40 + std::rand() % 60) / 100.f;

		_scnctx.lights.emplace("RandLight" + i,
			Light(glm::vec3(light_r, light_g, light_b), glm::vec4(pos_x, 2, pos_z, 1)));
	}
}

void MyGlWindow::draw()
{	
	_scnctx.height = m_height;
	_scnctx.width = m_width;	

	glm::vec3 eye(viewer.getViewPoint().x, viewer.getViewPoint().y, viewer.getViewPoint().z);
	glm::vec3 look(viewer.getViewCenter().x, viewer.getViewCenter().y, viewer.getViewCenter().z);
	glm::vec3 up(viewer.getUpVector().x, viewer.getUpVector().y, viewer.getUpVector().z);
	glm::mat4 view = lookAt(eye, look, up);   //Calculate view matrix from parameters of m_viewer
	glm::mat4 projection = perspective(45.0f, (float)_scnctx.width / (float)_scnctx.height, 0.1f, 1000.0f);

	_scnctx.viewMatrix = view;
	_scnctx.projectionMatrix = projection;
	
	glClearColor(_scnctx.bg.r, _scnctx.bg.g, _scnctx.bg.b, _scnctx.bg.a);
	glViewport(0, 0, _scnctx.width, _scnctx.height);
	glClear(GL_COLOR_BUFFER_BIT | GL_DEPTH_BUFFER_BIT);
				

	for (auto it = meshes.begin(); it != meshes.end(); it++)
		(*it).second->draw(_scnctx);
		
	//_multipassManager.drawResultToScreen(_scnctx);	
}



void MyGlWindow::resize(int w, int h)
{
	m_width = w;
	m_height = h;
	viewer.setAspectRatio(w / float(h));
}