/* C++ is picky about the linking of C
see 
https://stackoverflow.com/questions/38761620/undefined-reference-to-error-while-linking-object-files
*/
extern "C" {
#include <GL_STUFF/GLES_3_1_compatibility.h>
#include <glut.h>
}

#include <glm/gtc/type_ptr.hpp>
#include <glm/gtc/matrix_transform.hpp>
#include <cmath>
#include <ctime>
#include <iostream>
#include <string>

#include <GL_STUFF/HEADERS/CURVES/CurvesLoader.hpp>
#include <GL_STUFF/HEADERS/SCENE/InstancesLoader.h>
#include <GL_STUFF/HEADERS/CURVES/CurveIterator.hpp>
#include <GL_STUFF/HEADERS/SCENE/Camera.hpp>
#include <GL_STUFF/HEADERS/SCENE/Instance3D.h>
#include <GL_STUFF/HEADERS/SCENE/ShadingHelper.h>
#include <GL_STUFF/HEADERS/UTILS/ResourceCache.h>
#include <GL_STUFF/HEADERS/UTILS/ShaderMaker.h>
#include <GL_STUFF/HEADERS/UTILS/ClockIterator.hpp>
/* EXCLUDED BC NO COMPUTE SHADERS IN GLES2
#include <GL_STUFF/HEADERS/EFFECTS/CRT_shader.h>
*/
#include <GL_STUFF/HEADERS/EFFECTS/ReelManager.h>
#include <GL_STUFF/HEADERS/EFFECTS/TexMerger.h>
#include <GL_STUFF/HEADERS/EFFECTS/Scene.h>
#include <GL_STUFF/HEADERS/EFFECTS/Screen.h>

using namespace glm;
using namespace std;

const char *RES_FOLDER = "/CGI_DEMO/RESOURCES/";

const int TARGET_FPS = 15;
static int ONE_TICK_MS = 1000 / TARGET_FPS;

float viewSize = 2.0f;
float aspect_ratio;
int steps = 60;

GLuint linesShader;
GLuint curveVAO;
int nCurvePoints = 10000;
GLuint controlPointsVAO;
int nControlPoints;
GLuint curvePointsVBO;
GLuint controlPointsVBO;

mat4 projection;

int baseClock = 8000;

ClockIterator cubesClock = ClockIterator(baseClock);

vector<Instance3D*> columns = vector<Instance3D*>();
ShadingHelper* columnsShading;

Instance3D* cube;
ShadingHelper* cubeShading;
vector<TextureHelper> cubeTextures;
vector<Curve*> curves = vector<Curve*>();
vector<CurveIterator*> iterators = vector<CurveIterator*>();
CameraController *camera;

Scene* sceneBuffer;
ReelManager* reel;
TexMerger* merger;
Screen* canvas;

/*was false and triggerable via keypress but i have no input capturing*/
bool runIterator = true;








/* don't want to implement */
/* also removed 
	glEnable(GL_ALPHA_TEST);
	glDisable(GL_ALPHA_TEST);
*/
GLuint GLUT_COMPATIBILITY_PROFILE = 0 ;
GLuint GLUT_SINGLE = 0 ; 
GLuint GLUT_RGBA = 0 ;
const GLuint GLUT_SCREEN_WIDTH = 0;
const GLuint GLUT_SCREEN_HEIGHT = 1;

void glutInitContextVersion( int maj, int min){}
void glutInitContextProfile( GLuint profile){}
void glutInitDisplayMode( GLuint OR_ed_FLAGS){}

int glutGet(GLuint dimension){
	switch( dimension) {
		case GLUT_SCREEN_WIDTH :
			return 1920;
		break;
		case GLUT_SCREEN_HEIGHT :
			return 1156;
		break;
		default:
			exit(1);
	}
}




vector<GLuint> antiLogSelect(vector<GLuint> frames, float increment) {
	vector<int> indices = vector<int>();
	assert(increment > 1);
	float gap = 1;
	for (int index = 0; index < frames.size(); index += gap) {
		gap *= increment;
		indices.push_back(index);
	}
	vector<GLuint> selected = vector<GLuint>();
	for (int i = indices.size() - 1; i >= 0; i--) {
		selected.push_back(frames[frames.size() - 1 - indices[i]]);
	}
	return selected;
}


void drawAxis() {
	/*
	glUseProgram(linesShader);
	//AXIS
	glUniform3f(glGetUniformLocation(linesShader, "baseColor"), 1, 0, 0);
	glBegin(GL_LINES);
	glVertex3f(0, 0, 0);
	glVertex3f(5, 0, 0);
	glEnd();
	glUniform3f(glGetUniformLocation(linesShader, "baseColor"), 0, 0, 1);
	glBegin(GL_LINES);
	glVertex3f(0, 0, 0);
	glVertex3f(0, 5, 0);
	glEnd();
	glUniform3f(glGetUniformLocation(linesShader, "baseColor"), 0, 1, 0);
	glBegin(GL_LINES);
	glVertex3f(0, 0, 0);
	glVertex3f(0, 0, 5);
	glEnd();
	*/
}

void drawCurve() {
	glUseProgram(linesShader);
	//CURVE
	glUniform3f(glGetUniformLocation(linesShader, "baseColor"), 0, 1, 0);

	GLint localTransformUniform = glGetUniformLocation(linesShader, "Model");
	glUniformMatrix4fv(localTransformUniform, 1, GL_FALSE, value_ptr(glm::mat4(1.0)));

	GLint projectionUniform = glGetUniformLocation(linesShader, "Projection");
	glUniformMatrix4fv(projectionUniform, 1, GL_FALSE, value_ptr(projection));

	GLint viewUniform = glGetUniformLocation(linesShader, "View");
	glUniformMatrix4fv(viewUniform, 1, GL_FALSE, value_ptr(camera->getCamera()->getViewMat()));

	glBindVertexArray(curveVAO);
	glDrawArrays(GL_POINTS, 0, 2 * nCurvePoints);
	glBindVertexArray(0);

	/* DISABLED
	glUniform3f(glGetUniformLocation(linesShader, "baseColor"), 1, 0, 0);
	glPointSize(10.0);
	glBegin(GL_POINTS);
	vec3 p = iterators[0]->evaluation();
	glVertex3f(p.x, p.y, p.z);
	glEnd();
	glPointSize(1.0);
	glUniform3f(glGetUniformLocation(linesShader, "baseColor"), 0, 0, 1);
	glBegin(GL_LINES);
	vec3 d = p + iterators[0]->derivation();
	glVertex3f(p.x, p.y, p.z);
	glVertex3f(d.x, d.y, d.z);
	glEnd();
	*/
	glUniform3f(glGetUniformLocation(linesShader, "baseColor"), 1, 0, 0);
	glBindVertexArray(controlPointsVAO);
	glDrawArrays(GL_LINES, 0, 2 * nControlPoints);
	glBindVertexArray(0);
}




//funky stuff ahead
void renderLoop() {
	/* DISABLED
	reel->nextTexture();
	reel->clearTexture();
	vector<GLuint> frames = reel->getTextures();

	sceneBuffer->setOutTexture(frames.back());

	sceneBuffer->draw();
	*/
	glClearColor(0, 0, 0, 0);
	glClear(GL_COLOR_BUFFER_BIT | GL_DEPTH_BUFFER_BIT);

	glEnable(GL_CULL_FACE);
	glCullFace(GL_BACK);
	glDepthFunc(GL_LESS);
	//glEnable(GL_BLEND); //Attiva il blending
	//glBlendFunc(GL_SRC_ALPHA, GL_ONE_MINUS_SRC_ALPHA);

	cubeShading->useProgram();
	cubeShading->bindTexture2D(1, cubeTextures[0].texture, cubeTextures[0].uniformName);
	cubeShading->bindTexture2D(2, cubeTextures[1].texture, cubeTextures[1].uniformName);
	cubeShading->bindViewUniforms(projection, camera->getCamera()->getViewMat());
	cubeShading->bindLightUniforms(vec3(0, 100, 0), vec3(1.0f), camera->getCamera()->getPosition());
	cubeShading->bindModelUniforms(cube->getGlobalTransform(), cube->getLocalTransform());
	cube->getModel()->draw();

	glDisable(GL_CULL_FACE);
	glDisable(GL_DEPTH_TEST);


	glEnable(GL_DEPTH_TEST);
	glDepthFunc(GL_ALWAYS);
	/*
	glEnable(GL_ALPHA_TEST);
	*/
	glEnable(GL_BLEND); //Attiva il blending
	glBlendFunc(GL_SRC_ALPHA, GL_ONE_MINUS_SRC_ALPHA);
	glBlendEquation(GL_MAX);		//evita i brutti artefatti

	drawAxis();

	drawCurve();

	columnsShading->useProgram();
	glUniform1f(glGetUniformLocation(columnsShading->getProgram() , "time"), cubesClock.getPercentage() / 100.0f);
	columnsShading->bindViewUniforms(projection, camera->getCamera()->getViewMat());
	columnsShading->bindLightUniforms( vec3(0, 100, 0), vec3(1.0f), camera->getCamera()->getPosition());
	vec3 LBN = vec3(0,10000,0);
	vec3 RTF = vec3(0,-10000,0);
	for (Instance3D* inst : columns) {
		LBN = (LBN.y < inst->getModel()->getLBN().y) ? LBN : inst->getModel()->getLBN();
		RTF = (RTF.y > inst->getModel()->getRTF().y) ? RTF : inst->getModel()->getRTF();
	}
	for(Instance3D* inst : columns){
		glUniform3fv(glGetUniformLocation(columnsShading->getProgram(), "boundingBoxLBN"),1, &LBN[0]);
		glUniform3fv(glGetUniformLocation(columnsShading->getProgram(), "boundingBoxRTF"),1, &RTF[0]);
		columnsShading->bindModelUniforms(inst->getGlobalTransform(), inst->getLocalTransform());
		inst->getModel()->draw();
	}

	/*
	glDisable(GL_ALPHA_TEST);
	*/
	glDisable(GL_BLEND);

	/* DISABLED
	vector<GLuint> selectedFrames = antiLogSelect(frames, 1.01 + (1 - cubesClock.getPercentage() / 100.0f) * 5);
	GLuint merged = merger->merge(selectedFrames, 0, selectedFrames.size() - 1);
	*/
	//GLuint merged = selectedFrames.back();
	
	/*
	canvas->setInputTexture(merged);
	canvas->draw();
	*/
	
	/* DISABLED
	sceneBuffer->setOutTexture(merged);
	sceneBuffer->draw();


	CRT_Shader::get().loadColorFromFramebuffer(sceneBuffer->getFrameBuffer());
	glBindFramebuffer(GL_FRAMEBUFFER, 0);
	glClearColor(0, 0, 0, 0);
	glClear(GL_COLOR_BUFFER_BIT | GL_DEPTH_BUFFER_BIT);
	CRT_Shader::get().draw(ONE_TICK_MS, 0);
	*/
	
	glutSwapBuffers();
}

void timer(int value) {
	cubesClock.step(ONE_TICK_MS);
	cube->rotate(vec3(0, 1, 0), 1);
	if (runIterator) {
		//cube->setPosition(iterators[0]->evaluation());
		//cube->alignTo(iterators[0]->derivation());
		camera->getCamera()->setPosition(iterators[0]->evaluation());
		camera->getCamera()->alignTo(iterators[0]->derivation());
		for(int i = 0; i < 10; i++)
			iterators[0]->nextStep();
		/*
		std::cout << "eval at" << iterators[0]->getStep() << "\n";
		*/
	}
	glutTimerFunc(ONE_TICK_MS, timer, 0);
	glutPostRedisplay();
}

void keypressed(unsigned char key, int x, int y) {
	if (key >= '0' && key <= '9') {
		int prog = cubesClock.getPosition();
		cubesClock = ClockIterator(baseClock / pow( 3 , (key - '0') / 2.0f ));
		cubesClock.step(prog);
		//for (CurveIterator* it : iterators)
		//	it->setProgress((key - '0')/ 10.0f);
	}
	else if (key == 32) {

		runIterator = !runIterator;

	}else if (key == 27) {
		exit(0);
	}
	else {
		camera->keyPress(key);
	}

}

void mousemoved(int x, int y) {
	//camera.mouseMotion(x, y);
}

void emplaceModels() {

	char buf_1[256];
	char buf_2[256];

	snprintf(buf_1, sizeof(buf_1), "%s%s", RES_FOLDER, "SCENE/scene.txt");
	printf("would load %s\n", buf_1);

	loadInstances( buf_1, columns, false);

	snprintf(buf_1, sizeof(buf_1), "%s%s", RES_FOLDER, "vertexShader_pulse.glsl");
	snprintf(buf_2, sizeof(buf_2), "%s%s", RES_FOLDER, "fragmentShader_pulse.glsl");
	
	printf("would load %s | %s\n", buf_1, buf_2);

	columnsShading = new ShadingHelper(ResourceCache::get().getShader(&buf_1[0], &buf_2[0]));

	snprintf(buf_1, sizeof(buf_1), "%s%s", RES_FOLDER, "ico.obj");

	printf("would load %s\n", buf_1);
	Model3D* cubeModel = new Model3D(buf_1, true);

	snprintf(buf_1, sizeof(buf_1), "%s%s", RES_FOLDER, "vertexShader_gourard.glsl");
	snprintf(buf_2, sizeof(buf_2), "%s%s", RES_FOLDER, "fragmentShader_gourard.glsl");

	cubeShading = new ShadingHelper(ResourceCache::get().getShader(&buf_1[0], &buf_2[0]));

	cube = new Instance3D(cubeModel , vec3(10,0,0));
	TextureHelper col = TextureHelper();

	snprintf(buf_1, sizeof(buf_1), "%s%s", RES_FOLDER, "waito.png");
	printf("would load %s\n", buf_1);

	col.texture = ResourceCache::get().getImage( buf_1);
	col.uniformName = "colorMap";
	TextureHelper nor = TextureHelper();

	snprintf(buf_1, sizeof(buf_1), "%s%s", RES_FOLDER, "cube3.png");
	printf("would load %s\n", buf_1);
	
	nor.texture = ResourceCache::get().getImage( buf_1);
	nor.uniformName = "normalMap";
	cubeTextures.push_back(col);
	cubeTextures.push_back(nor);

}

void curveSetup() {

	char buf_1[256];
	char buf_2[256];

	snprintf(buf_1, sizeof( buf_1), "%s%s", RES_FOLDER, "curve5.txt");
	printf("would load %s\n", buf_1);
	CurvesLoader::loadCurves( buf_1, curves);

	//CurvesLoader::loadCurves("C:\\Users\\BoBoBoat\\Documents\\curve4cyclic.txt", curves);
	for (Curve* curve : curves)
		iterators.push_back( new CurveIterator(curve, nCurvePoints, CurveIterationMode::LENGTH));

	snprintf(buf_1, sizeof(buf_1), "%s%s", RES_FOLDER, "vertexShader_lines.glsl");
	snprintf(buf_2, sizeof(buf_2), "%s%s", RES_FOLDER, "fragmentShader_lines.glsl");

	printf("would load %s | %s\n", buf_1, buf_2);

	linesShader = ShaderMaker::createProgram( &buf_1[0], &buf_2[0]);
	
	glGenVertexArrays(1, &curveVAO);
	glBindVertexArray(curveVAO);
	vector<glm::vec3> curvePoints = vector<glm::vec3>();
	for (int i = 0; i < nCurvePoints; i++) {
		curvePoints.push_back(iterators[0]->evaluation());
		iterators[0]->nextStep();
		curvePoints.push_back(iterators[0]->evaluation());
	}
	glGenBuffers(1, &curvePointsVBO);
	glBindBuffer(GL_ARRAY_BUFFER, curvePointsVBO);
	glBufferData(GL_ARRAY_BUFFER, 2 * nCurvePoints * sizeof(vec3), &curvePoints[0], GL_STATIC_DRAW);
	glEnableVertexAttribArray(0);
	glVertexAttribPointer(0, 3, GL_FLOAT, GL_FALSE, 0, 0);
	glBindVertexArray(0);

	glGenVertexArrays(1, &controlPointsVAO);
	glBindVertexArray(controlPointsVAO);
	vector<vec3> controlPoints = vector<vec3>();
	vector<vec3> cp = *iterators[0]->getCurve()->getControlPoints();
	controlPoints.push_back(cp[0]);
	for (int i = 1; i < cp.size() - 1; i++) {
		controlPoints.push_back(cp[i]);
		controlPoints.push_back(cp[i]);
	}
	controlPoints.push_back(cp[cp.size() - 1]);
	nControlPoints = controlPoints.size();
	glGenBuffers(1, &controlPointsVBO);
	glBindBuffer(GL_ARRAY_BUFFER, controlPointsVBO);
	glBufferData(GL_ARRAY_BUFFER, nControlPoints * sizeof(vec3), &controlPoints[0], GL_STATIC_DRAW);
	glEnableVertexAttribArray(0);
	glVertexAttribPointer(0, 3, GL_FLOAT, GL_FALSE, 0, 0);
	glBindVertexArray(0);

}

int main(int argc, char* argv[])  {
	glutInit(&argc, argv);
	glutInitContextVersion(4, 0);
	glutInitContextProfile(GLUT_COMPATIBILITY_PROFILE);
	glutInitDisplayMode(GLUT_SINGLE | GLUT_RGBA);

	int scrWidth = glutGet(GLUT_SCREEN_WIDTH); //* 5 / 6;
	int scrHeight = glutGet(GLUT_SCREEN_HEIGHT); //* 5 / 6;
	//scrWidth = 640;
	//scrHeight = 480;
	aspect_ratio = ( (float) scrWidth) / scrHeight;
	glutInitWindowSize( scrWidth , scrHeight );
	glutInitWindowPosition( 0, 0);
	glutCreateWindow("TriDi");

	/*
	glewExperimental = GL_TRUE;
	GLenum err = glewInit();
	if (GLEW_OK != err)
		std::cout << "Error " << glewGetErrorString(err) << "\n";
	*/

	//glutSetCursor(GLUT_CURSOR_NONE);
	glutTimerFunc(ONE_TICK_MS, timer, 0);
	glutDisplayFunc(renderLoop);
	glutKeyboardFunc(keypressed);
	glutPassiveMotionFunc(mousemoved);

	/*get the pointers to the missing functions*/
	GLES_3_1_compatibility_init();
	

	printf(
		"GL info :\nversion : %s\nvendor: %s\nrenderer : %s\nshading language version: %s\n", 
		glGetString(GL_VERSION), 
		glGetString(GL_VENDOR), 
		glGetString(GL_RENDERER),
		glGetString(GL_SHADING_LANGUAGE_VERSION)
	);


	projection = glm::perspective( glm::radians(30.0f), aspect_ratio, 0.1f, 1000.0f);

	camera = new CameraController( new Camera(vec3( 0, 0, 2.0f),vec3(0,0,1.0f), vec3(0,1.0f,0)));
	camera->setWindowData( 0, scrWidth, 0, scrHeight);
	camera->getCamera()->setPosition(vec3(0, 0, 2));

	curveSetup();
	emplaceModels();

	/*
	printf("begin effects setup\n");
	sceneBuffer = new Scene( 0, 0, scrWidth, scrHeight);
	reel = new ReelManager(4 * TARGET_FPS, scrWidth, scrHeight);
	merger = new TexMerger(2 * TARGET_FPS, scrWidth, scrHeight);
	canvas = new Screen(0, 0, scrWidth, scrHeight);
	printf("end effects setup\n");
	*/

	/* DISABLED
	CRT_Shader::setup(scrWidth, scrHeight, TRUE, SIM_PRECISION::ROUGH);
	CRT_Shader::get();
	*/
	//glEnable(GL_CULL_FACE);
	//glCullFace(GL_BACK);

	glutMainLoop();
}