#include "glew.h"
#include "freeglut.h"
#include "glm.hpp"
#include "ext.hpp"
#include <iostream>
#include <cmath>
#include <vector>

#include "Shader_Loader.h"
#include "Render_Utils.h"
#include "Camera.h"
#include "Texture.h"
#include "Physics.h"



GLuint programColor;
GLuint programTexture;

Core::Shader_Loader shaderLoader;

float appLoadingTime;

obj::Model planeModel;
obj::Model shipModel;
obj::Model sphereModel;

Core::RenderContext planeContext, shipContext, sphereContext;

float cameraAngle = glm::radians(0.0f);
glm::vec3 cameraPos = glm::vec3(0, 0 , 250);
glm::vec3 cameraDir;

glm::mat4 cameraMatrix, perspectiveMatrix;

glm::vec3 lightDir = glm::normalize(glm::vec3(1.0f, -1.0f, -1.0f));

GLuint textureTest;
GLuint textureEarth;
GLuint textureAsteroid;
GLuint textureShip;
GLuint textureSun;
GLuint textureEarthHighres;
GLuint textureMoon;

float frustumScale = 1.f;

float orbitSpeed = 0.005f;


void keyboard(unsigned char key, int x, int y)
{
	float angleSpeed = 0.5f;
	float moveSpeed = 0.5f;
	switch(key)
	{
	//case 'z': cameraAngle -= angleSpeed; break;
	//case 'x': cameraAngle += angleSpeed; break;
	//case 'd': cameraPos += glm::cross(cameraDir, glm::vec3(0, 1, 0)) * moveSpeed; break;
	//case 'a': cameraPos -= glm::cross(cameraDir, glm::vec3(0, 1, 0)) * moveSpeed; break;
	//case 'e': cameraPos += glm::vec3(0, 1, 0) * moveSpeed; break;
	//case 'q': cameraPos -= glm::vec3(0, 1, 0) * moveSpeed; break;

	case 'w': 
		if (orbitSpeed < 0.02f) {
			orbitSpeed += 0.001f;
		}
		break;
	case 's': 
		if (orbitSpeed > 0.001f) {
			orbitSpeed -= 0.001f;
		}
		break;
	}
}

glm::mat4 createCameraMatrix()
{
	float time = glutGet(GLUT_ELAPSED_TIME) / 1000.0f - appLoadingTime;

	// Obliczanie kierunku patrzenia kamery (w plaszczyznie x-z) przy uzyciu zmiennej cameraAngle kontrolowanej przez klawisze.
	cameraPos = glm::rotate(cameraPos, orbitSpeed, glm::vec3(0, 1, 0));
	//cameraDir = glm::vec3(cosf(cameraAngle), 0.0f, sinf(cameraAngle));
	cameraDir = glm::normalize(glm::vec3(0, 0, 0) - cameraPos);
	glm::vec3 up = glm::vec3(0, 1, 0);

	return Core::createViewMatrix(cameraPos, cameraDir, up);
}


void drawObjectColor(Core::RenderContext* context, glm::mat4 modelMatrix, glm::vec3 color)
{
	GLuint program = programColor;

	glUseProgram(program);

	glUniform3f(glGetUniformLocation(program, "objectColor"), color.x, color.y, color.z);
	glUniform3f(glGetUniformLocation(program, "lightDir"), lightDir.x, lightDir.y, lightDir.z);

	glm::mat4 transformation = perspectiveMatrix * cameraMatrix * modelMatrix;
	glUniformMatrix4fv(glGetUniformLocation(program, "modelViewProjectionMatrix"), 1, GL_FALSE, (float*)&transformation);
	glUniformMatrix4fv(glGetUniformLocation(program, "modelMatrix"), 1, GL_FALSE, (float*)&modelMatrix);

	Core::DrawContext(*context);

	glUseProgram(0);
}

void drawObjectTexture(Core::RenderContext* context, glm::mat4 modelMatrix, GLuint textureId)
{
	GLuint program = programTexture;

	glUseProgram(program);

	glUniform3f(glGetUniformLocation(program, "lightDir"), lightDir.x, lightDir.y, lightDir.z);
	Core::SetActiveTexture(textureId, "textureSampler", program, 0);

	glm::mat4 transformation = perspectiveMatrix * cameraMatrix * modelMatrix;
	glUniformMatrix4fv(glGetUniformLocation(program, "modelViewProjectionMatrix"), 1, GL_FALSE, (float*)&transformation);
	glUniformMatrix4fv(glGetUniformLocation(program, "modelMatrix"), 1, GL_FALSE, (float*)&modelMatrix);

	Core::DrawContext(*context);

	glUseProgram(0);
}

void renderScene()
{
	float time = glutGet(GLUT_ELAPSED_TIME) / 1000.0f - appLoadingTime;

	// opcjonalny ruch swiatla do testow
	bool animateLight = false;
	if (animateLight) {
		float lightAngle = (glutGet(GLUT_ELAPSED_TIME) / 1000.0f) * 3.14 / 8;
		lightDir = glm::normalize(glm::vec3(sin(lightAngle), -1.0f, cos(lightAngle)));
	}

	// Aktualizacja macierzy widoku i rzutowania.
	cameraMatrix = createCameraMatrix();
	perspectiveMatrix = Core::createPerspectiveMatrix(0.1f, 1000.f);

	glClear(GL_COLOR_BUFFER_BIT | GL_DEPTH_BUFFER_BIT);
	glClearColor(0.0f, 0.3f, 0.3f, 1.0f);

	//SHIP
	glm::mat4 shipModelMatrix = glm::translate(cameraPos + cameraDir * 0.6f + glm::vec3(0, -0.25f, 0)) * glm::rotate(-cameraAngle + glm::radians(90.0f), glm::vec3(0, 1, 0)); 
	drawObjectTexture(&shipContext, shipModelMatrix, textureShip);

	//SUN
	//drawObjectTexture(&sphereModel,  glm::translate(glm::vec3(0, 0, 0)) * glm::scale(glm::vec3(20.f)), textureSun);
	
	//EARTH nieruchoma - łatwiejsze dla naszej cutscenki
	drawObjectTexture(&sphereContext, glm::scale(glm::vec3(45)), textureEarthHighres);
	
	//MOON
	drawObjectTexture(&sphereContext, glm::rotate(time / 5.0f, glm::vec3(0, 1, 0)) * glm::translate(glm::vec3(0, 0, 300)) * glm::scale(glm::vec3(20)), textureMoon);


	glutSwapBuffers();
}

void init()
{
	glEnable(GL_DEPTH_TEST);

	programColor = shaderLoader.CreateProgram("shaders/shader_color.vert", "shaders/shader_color.frag");
	programTexture = shaderLoader.CreateProgram("shaders/shader_tex.vert", "shaders/shader_tex.frag");

	shipModel = obj::loadModelFromFile("models/ship.obj");
	shipContext.initFromOBJ(shipModel);

	sphereModel = obj::loadModelFromFile("models/sphere.obj");
	sphereContext.initFromOBJ(sphereModel);

	textureShip = Core::LoadTexture("textures/spaceship.png");
	textureEarthHighres = Core::LoadTexture("textures/4k_earth_daymap.png");
	textureAsteroid = Core::LoadTexture("textures/asteroid.png");
	textureSun = Core::LoadTexture("textures/2k_sun_texture.png");
	textureMoon = Core::LoadTexture("textures/2k_moon.png");

	appLoadingTime = glutGet(GLUT_ELAPSED_TIME) / 1000.0f;
}

void shutdown()
{
	shaderLoader.DeleteProgram(programColor);
	shaderLoader.DeleteProgram(programTexture);
}

void idle()
{
	glutPostRedisplay();
}

void onReshape(int width, int height)
{
	frustumScale = (float)width / height;

	glViewport(0, 0, width, height);
}

int main(int argc, char ** argv)
{
	glutInit(&argc, argv);
	glutInitDisplayMode(GLUT_DEPTH | GLUT_DOUBLE | GLUT_RGBA);
	glutInitWindowPosition(200, 200);
	glutInitWindowSize(600, 600);
	glutCreateWindow("OpenGL Pierwszy Program");
	glewInit();

	init();
	glutKeyboardFunc(keyboard);
	glutDisplayFunc(renderScene);
	glutIdleFunc(idle);
	glutReshapeFunc(onReshape);

	glutMainLoop();

	shutdown();

	return 0;
}