#define GLFW_DLL

#include <GL/glew.h>
#include <GLFW/glfw3.h>
#include <glm\mat4x4.hpp>
#include <glm/gtc/type_ptr.hpp>
#include <glm\gtc\quaternion.hpp>
#include <glm\gtc\matrix_transform.hpp>
#include <SOIL.h>

#include <string>

#include "Shader.hpp"
#include "Cube.hpp"
#include "lighting.hpp"
#include "camera.hpp"
#include "material.hpp"
#include "utility.hpp"
#include "model.hpp"

#pragma region "Constants"
const char* TITLE = "Predator-Prey Simulation";

const float WIDTH = 1920.f;
const float HEIGHT = 1080.f;
const float FIELD_OF_VIEW = 90.f;
const float NEAR_PLANE = 0.1f;
const float FAR_PLANE = 100.f;

const glm::vec3 START_CAMERA_POSITION = glm::vec3(0.f, 2.f, 4.f);
const glm::vec3 START_CAMERA_FRONT = glm::vec3(0.f, 0.f, -1.f);
const glm::vec3 START_CAMERA_UP = glm::vec3(0.f, 1.f, 0.f);

const char* DEFAULT_VERTEX_SHADER_FILE = "vert.glsl";
const char* DEFAULT_FRAGMENT_SHADER_FILE = "frag.glsl";
const char* LIGHT_OBJECT_FRAGMENT_SHADER_FILE = "light.glsl";

const bool USE_POINT_LIGHTING = true;
const bool USE_DIRECTIONAL_LIGHTING = true;
const bool USE_SPOT_LIGHTING = true;
const int NUM_POINT_LIGHTS = 3;
#pragma endregion

Model model;

Material material;

PointLight pointLight[NUM_POINT_LIGHTS];
DirectionalLight directionalLight;
SpotLight spotLight;

Camera camera;
Orientation orientation;

FrameTiming frameTiming;
Input input;

Shader shader;
Shader lightShader;

Cube cube;
Cube cubeLamp;

GLFWwindow* window;
glm::mat4 projectionMatrix;

glm::vec3 cubePositions[] = {
	glm::vec3(0.0f, 0.0f, 0.0f),
	glm::vec3(2.0f, 5.0f, -4.0f),
	glm::vec3(-1.5f, -2.2f, -2.5f),
	glm::vec3(-3.8f, -2.0f, -6.3f),
	glm::vec3(2.4f, -0.4f, -3.5f),
	glm::vec3(-1.7f, 3.0f, -7.5f),
	glm::vec3(1.3f, -2.0f, -2.5f),
	glm::vec3(1.5f, 2.0f, -2.5f),
	glm::vec3(1.5f, 0.2f, -1.5f),
	glm::vec3(-1.3f, 1.0f, -1.5f)
};

GLuint amount = 104907;
glm::mat4* modelMatrices;
float* instanceColours;


void instancedRender() {
	lightShader.use();

	glUniformMatrix4fv(glGetUniformLocation(lightShader.program, "projection"), 1, GL_FALSE, value_ptr(projectionMatrix));
	glUniformMatrix4fv(glGetUniformLocation(lightShader.program, "view"), 1, GL_FALSE, value_ptr(camera.viewMatrix));
	glUniform3fv(glGetUniformLocation(lightShader.program, "pointLight.ambient"), 1, value_ptr(glm::vec3(1.f)));
	glUniform3fv(glGetUniformLocation(lightShader.program, "pointLight.diffuse"), 1, value_ptr(glm::vec3(1.f)));
	glUniform3fv(glGetUniformLocation(lightShader.program, "pointLight.specular"), 1, value_ptr(glm::vec3(1.f)));
	glBindVertexArray(cube.vao);
	glDrawArraysInstanced(GL_TRIANGLES, 0, 36, amount);
	glBindVertexArray(0);

}

void initInstancedRender() {
	lightShader = Shader(DEFAULT_VERTEX_SHADER_FILE, LIGHT_OBJECT_FRAGMENT_SHADER_FILE);

	camera.position = START_CAMERA_POSITION;
	camera.front = START_CAMERA_FRONT;
	camera.up = START_CAMERA_UP;
	camera.speed = 50.f;
	camera.viewMatrix = lookAt(camera.position, camera.position + camera.front, camera.up);

	projectionMatrix = glm::infinitePerspective(glm::radians(FIELD_OF_VIEW), WIDTH / HEIGHT, 0.1f);

	modelMatrices = new glm::mat4[amount];
	int index = 0;
	for (GLint x = 0; x < 187; x++) {
		for (GLint z = 0; z < 561; z++) {
			glm::mat4 model;
			model = glm::scale(model, glm::vec3(3.F, 1.F, 1.F));
			model = glm::translate(model, glm::vec3(-x * 1.9F, 0.f, -z * 1.9F));
			modelMatrices[index++] = model;
		}
	}

	instanceColours = new float[amount];

	std::fstream in;
	in.open("data5.txt", std::fstream::in);
	std::string line;
	std::vector<float> v;
	std::getline(in, line);
	float value;
	std::istringstream iss(line);
	std::copy(std::istream_iterator<float>(iss),
			  std::istream_iterator<float>(),
			  std::back_inserter(v));

	in.close();

	int i1 = 0;
	for (float f : v) {
		instanceColours[i1] = v.at(i1);
		i1++;
	}

	cube.init();

	orientation.pitch = -25.f;
	orientation.yaw = -90.f;
	orientation.roll = 0.f;

	input.previousMousePosX = WIDTH / 2.f;
	input.previousMousePosY = HEIGHT / 2.f;
	input.mouseInitiallyMoved = true;
	input.mouseSensitivity = 0.2f;

	GLuint buffer;
	GLuint buffer2;
	glBindVertexArray(cube.vao);
	glGenBuffers(1, &buffer);
	glBindBuffer(GL_ARRAY_BUFFER, buffer);
	glBufferData(GL_ARRAY_BUFFER, amount * sizeof(glm::mat4), &modelMatrices[0], GL_STATIC_DRAW);
	// Set attribute pointers for matrix (4 times vec4)
	glEnableVertexAttribArray(3);
	glVertexAttribPointer(3, 4, GL_FLOAT, GL_FALSE, sizeof(glm::mat4), (GLvoid*)0);
	glEnableVertexAttribArray(4);
	glVertexAttribPointer(4, 4, GL_FLOAT, GL_FALSE, sizeof(glm::mat4), (GLvoid*)(sizeof(glm::vec4)));
	glEnableVertexAttribArray(5);
	glVertexAttribPointer(5, 4, GL_FLOAT, GL_FALSE, sizeof(glm::mat4), (GLvoid*)(2 * sizeof(glm::vec4)));
	glEnableVertexAttribArray(6);
	glVertexAttribPointer(6, 4, GL_FLOAT, GL_FALSE, sizeof(glm::mat4), (GLvoid*)(3 * sizeof(glm::vec4)));

	glVertexAttribDivisor(3, 1);
	glVertexAttribDivisor(4, 1);
	glVertexAttribDivisor(5, 1);
	glVertexAttribDivisor(6, 1);

	glGenBuffers(1, &buffer2);
	glBindBuffer(GL_ARRAY_BUFFER, buffer2);
	glBufferData(GL_ARRAY_BUFFER, amount * sizeof(float), &instanceColours[0], GL_STATIC_DRAW);
	glEnableVertexAttribArray(7);
	glVertexAttribPointer(7, 1, GL_FLOAT, GL_FALSE, sizeof(float), (GLvoid*)0);

	glVertexAttribDivisor(7, 1);

	glBindVertexArray(0);
}








void initSimulation()
{




	shader = Shader(DEFAULT_VERTEX_SHADER_FILE, DEFAULT_FRAGMENT_SHADER_FILE);
	lightShader = Shader(DEFAULT_VERTEX_SHADER_FILE, LIGHT_OBJECT_FRAGMENT_SHADER_FILE);

	camera.position = START_CAMERA_POSITION;
	camera.front = START_CAMERA_FRONT;
	camera.up = START_CAMERA_UP;
	camera.speed = 5.f;
	camera.viewMatrix = lookAt(camera.position, camera.position + camera.front, camera.up);

	projectionMatrix = glm::perspective(glm::radians(FIELD_OF_VIEW), WIDTH / HEIGHT, NEAR_PLANE, FAR_PLANE);


	//RED
	pointLight[0].ambient = glm::vec3(0.05f, 0.f, 0.0f);
	pointLight[0].diffuse = glm::vec3(0.7f, 0.f, 0.0f);
	pointLight[0].specular = glm::vec3(1.f, 0.f, 0.f);
	pointLight[0].attenuation.constant = 1.f;
	pointLight[0].attenuation.linear = 0.14f;
	pointLight[0].attenuation.quadratic = 0.07f;
	pointLight[0].position = glm::vec3(0.f);

	//GREEN
	pointLight[1].ambient = glm::vec3(0.0f, 0.05f, 0.0f);
	pointLight[1].diffuse = glm::vec3(0.0f, 0.7f, 0.0f);
	pointLight[1].specular = glm::vec3(0.f, 1.f, 0.f);
	pointLight[1].attenuation.constant = 1.f;
	pointLight[1].attenuation.linear = 0.14f;
	pointLight[1].attenuation.quadratic = 0.07f;
	pointLight[1].position = glm::vec3(1.f, 0.f, 0.f);

	//BLUE
	pointLight[2].ambient = glm::vec3(0.0f, 0.f, 0.05f);
	pointLight[2].diffuse = glm::vec3(0.0f, 0.f, 0.9f);
	pointLight[2].specular = glm::vec3(0.f, 0.f, 1.f);
	pointLight[2].attenuation.constant = 1.f;
	pointLight[2].attenuation.linear = 0.14f;
	pointLight[2].attenuation.quadratic = 0.07f;
	pointLight[2].position = glm::vec3(2.f, 0.f, 0.f);

	directionalLight.ambient = glm::vec3(0.1f, 0.1f, 0.1f);
	directionalLight.diffuse = glm::vec3(0.3f, 0.3f, 0.3f);
	directionalLight.specular = glm::vec3(1.f, 1.f, 1.f);
	directionalLight.direction = glm::vec3(0.f, 1.f, 0.f);

	spotLight.ambient = glm::vec3(0.0f, 0.f, 1.f);
	spotLight.diffuse = glm::vec3(0.0f, 0.f, 1.f);
	spotLight.specular = glm::vec3(0.f, 0.f, 1.f);
	spotLight.attenuation.constant = 1.f;
	spotLight.attenuation.linear = 0.045f;
	spotLight.attenuation.quadratic = 0.0075f;
	spotLight.position = camera.position;
	spotLight.direction = camera.front;
	spotLight.innerCutoffAngle = 6.f;
	spotLight.outerCutoffAngle = 20.f;

	material.shininess = 32.f;
	glGenTextures(1, &material.diffuseMap);
	int width;
	int height;
	unsigned char* img;
	img = SOIL_load_image("box_diffuse.png", &width, &height, nullptr, SOIL_LOAD_RGB);
	glBindTexture(GL_TEXTURE_2D, material.diffuseMap);
	glTexImage2D(GL_TEXTURE_2D, 0, GL_SRGB, width, height, 0, GL_RGB, GL_UNSIGNED_BYTE, img);
	glGenerateMipmap(GL_TEXTURE_2D);
	SOIL_free_image_data(img);
	glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_WRAP_S, GL_REPEAT);
	glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_WRAP_T, GL_REPEAT);
	glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MIN_FILTER, GL_LINEAR_MIPMAP_LINEAR);
	glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MAG_FILTER, GL_NEAREST_MIPMAP_NEAREST);

	glGenTextures(1, &material.specularMap);
	img = SOIL_load_image("box_specular.png", &width, &height, nullptr, SOIL_LOAD_RGB);
	glBindTexture(GL_TEXTURE_2D, material.specularMap);
	glTexImage2D(GL_TEXTURE_2D, 0, GL_SRGB, width, height, 0, GL_RGB, GL_UNSIGNED_BYTE, img);
	glGenerateMipmap(GL_TEXTURE_2D);
	SOIL_free_image_data(img);
	glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_WRAP_S, GL_REPEAT);
	glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_WRAP_T, GL_REPEAT);
	glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MIN_FILTER, GL_LINEAR_MIPMAP_LINEAR);
	glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MAG_FILTER, GL_NEAREST_MIPMAP_NEAREST);

	cubeLamp = Cube();
	cubeLamp.init();

	cube = Cube();
	cube.init();

	model = Model("Metroid/metroid.DAE");

	orientation.pitch = -25.f;
	orientation.yaw = -90.f;
	orientation.roll = 0.f;

	input.previousMousePosX = WIDTH / 2.f;
	input.previousMousePosY = HEIGHT / 2.f;
	input.mouseInitiallyMoved = true;
	input.mouseSensitivity = 0.2f;
}


void key_callback(GLFWwindow* window, int key, int scancode, int action, int mode);
void mouse_callback(GLFWwindow* window, double xpos, double ypos);

void moveCamera() {
	auto movementFactor = camera.speed * frameTiming.deltaTime;

	if (input.keyPressedStates[GLFW_KEY_W])
		camera.position += camera.front * movementFactor;
	if (input.keyPressedStates[GLFW_KEY_S])
		camera.position -= camera.front * movementFactor;
	if (input.keyPressedStates[GLFW_KEY_A])
		camera.position -= normalize(cross(camera.front, camera.up)) * movementFactor;
	if (input.keyPressedStates[GLFW_KEY_D])
		camera.position += normalize(cross(camera.front, camera.up)) * movementFactor;
}







void renderObject()
{
	shader.use();

	glUniform3fv(glGetUniformLocation(shader.program, "cameraPosition"), 1, value_ptr(camera.position));

	glUniform1i(glGetUniformLocation(shader.program, "material.diffuse"), 0);
	glUniform1i(glGetUniformLocation(shader.program, "material.specular"), 1);
	glUniform1f(glGetUniformLocation(shader.program, "material.shininess"), material.shininess);

	for (auto i = 0; i < NUM_POINT_LIGHTS; i++)
	{
		auto index = std::to_string(i);
		//pointLight[i].position.x = sin(glfwGetTime() + i * 300);
		//pointLight[i].position.z = -2.f + cos(glfwGetTime() + i * 300);
		//pointLight[i].position.y = 1.f;
		glUniform3fv(glGetUniformLocation(shader.program, ("pointLight[" + index + "].ambient").c_str()), 1, value_ptr(pointLight[i].ambient));
		glUniform3fv(glGetUniformLocation(shader.program, ("pointLight[" + index + "].diffuse").c_str()), 1, value_ptr(pointLight[i].diffuse));
		glUniform3fv(glGetUniformLocation(shader.program, ("pointLight[" + index + "].specular").c_str()), 1, value_ptr(pointLight[i].specular));
		glUniform3fv(glGetUniformLocation(shader.program, ("pointLight[" + index + "].position").c_str()), 1, value_ptr(pointLight[i].position));
		glUniform1f(glGetUniformLocation(shader.program, ("pointLight[" + index + "].attenuation.constant").c_str()), pointLight[i].attenuation.constant);
		glUniform1f(glGetUniformLocation(shader.program, ("pointLight[" + index + "].attenuation.linear").c_str()), pointLight[i].attenuation.linear);
		glUniform1f(glGetUniformLocation(shader.program, ("pointLight[" + index + "].attenuation.quadratic").c_str()), pointLight[i].attenuation.quadratic);
	}

	glUniform3fv(glGetUniformLocation(shader.program, "directionalLight.ambient"), 1, value_ptr(directionalLight.ambient));
	glUniform3fv(glGetUniformLocation(shader.program, "directionalLight.diffuse"), 1, value_ptr(directionalLight.diffuse));
	glUniform3fv(glGetUniformLocation(shader.program, "directionalLight.specular"), 1, value_ptr(directionalLight.specular));
	glUniform3fv(glGetUniformLocation(shader.program, "directionalLight.direction"), 1, value_ptr(directionalLight.direction));

	spotLight.position = camera.position;
	spotLight.direction = camera.front;
	glUniform3fv(glGetUniformLocation(shader.program, "spotLight.ambient"), 1, value_ptr(spotLight.ambient));
	glUniform3fv(glGetUniformLocation(shader.program, "spotLight.diffuse"), 1, value_ptr(spotLight.diffuse));
	glUniform3fv(glGetUniformLocation(shader.program, "spotLight.specular"), 1, value_ptr(spotLight.specular));
	glUniform3fv(glGetUniformLocation(shader.program, "spotLight.position"), 1, value_ptr(spotLight.position));
	glUniform1f(glGetUniformLocation(shader.program, "spotLight.attenuation.constant"), spotLight.attenuation.constant);
	glUniform1f(glGetUniformLocation(shader.program, "spotLight.attenuation.linear"), spotLight.attenuation.linear);
	glUniform1f(glGetUniformLocation(shader.program, "spotLight.attenuation.quadratic"), spotLight.attenuation.quadratic);
	glUniform3fv(glGetUniformLocation(shader.program, "spotLight.position"), 1, value_ptr(spotLight.position));
	glUniform3fv(glGetUniformLocation(shader.program, "spotLight.direction"), 1, value_ptr(spotLight.direction));
	glUniform1f(glGetUniformLocation(shader.program, "spotLight.innerCutoffAngle"), glm::cos(glm::radians(spotLight.innerCutoffAngle)));
	glUniform1f(glGetUniformLocation(shader.program, "spotLight.outerCutoffAngle"), glm::cos(glm::radians(spotLight.outerCutoffAngle)));

	glActiveTexture(GL_TEXTURE0);
	glBindTexture(GL_TEXTURE_2D, material.diffuseMap);
	glActiveTexture(GL_TEXTURE1);
	glBindTexture(GL_TEXTURE_2D, material.specularMap);


	for (auto i = 0; i < 10; i++)
	{
		glm::mat4 model;
		model = translate(model, cubePositions[i]);
		model = rotate(model, 0.f, glm::vec3(1.0f, 0.3f, 0.5f));
		auto MVP = projectionMatrix * camera.viewMatrix * model;
		glUniformMatrix4fv(glGetUniformLocation(shader.program, "MVP"), 1, GL_FALSE, value_ptr(MVP));
		glUniformMatrix4fv(glGetUniformLocation(shader.program, "modelMatrix"), 1, GL_FALSE, value_ptr(model));

		cube.render();
	}

	glm::mat4 m;
	m = translate(m, glm::vec3(0.0f, -1.75f, -2.0f));
	m = scale(m, glm::vec3(0.05f, 0.05f, 0.05f));
	auto MVP = projectionMatrix * camera.viewMatrix * m;
	glUniformMatrix4fv(glGetUniformLocation(shader.program, "MVP"), 1, GL_FALSE, value_ptr(MVP));
	glUniformMatrix4fv(glGetUniformLocation(shader.program, "modelMatrix"), 1, GL_FALSE, value_ptr(m));
	model.draw(shader);

}

void renderPointLight()
{
	lightShader.use();

	for (auto i = 0; i < 3; i++) {
		glm::mat4 model;
		model = translate(model, pointLight[i].position);
		auto MVP = projectionMatrix * camera.viewMatrix * model;
		glUniformMatrix4fv(glGetUniformLocation(lightShader.program, "MVP"), 1, GL_FALSE, value_ptr(MVP));
		glUniform3fv(glGetUniformLocation(lightShader.program, "pointLight.ambient"), 1, value_ptr(pointLight[i].ambient));
		glUniform3fv(glGetUniformLocation(lightShader.program, "pointLight.diffuse"), 1, value_ptr(pointLight[i].diffuse));
		glUniform3fv(glGetUniformLocation(lightShader.program, "pointLight.specular"), 1, value_ptr(pointLight[i].specular));
		cubeLamp.render();
	}
}

void updateSimulation()
{
	frameTiming.updateDeltaTime();
	camera.viewMatrix = lookAt(camera.position, camera.position + camera.front, camera.up);
	moveCamera();
}

void renderSimulation()
{
	instancedRender();
	//renderObject();
	//renderPointLight();
}

int main()
{
	glfwInit();
	//glfwWindowHint(GLFW_SAMPLES, 4);
	glfwWindowHint(GLFW_SRGB_CAPABLE, true);
	window = glfwCreateWindow(static_cast<int>(WIDTH), static_cast<int>(HEIGHT), TITLE, nullptr, nullptr);
	glfwMakeContextCurrent(window);
	glfwSetKeyCallback(window, key_callback);
	glfwSetCursorPos(window, WIDTH / 2, HEIGHT / 2);
	glfwSetCursorPosCallback(window, mouse_callback);

	glewExperimental = GL_TRUE;
	glewInit();
	glEnable(GL_FRAMEBUFFER_SRGB);
	//glEnable(GL_MULTISAMPLE);
	glEnable(GL_DEPTH_TEST);
	glDepthFunc(GL_LESS);

	//initSimulation();

	glClearColor(0.f, 0.f, 0.f, 1.f);

	initInstancedRender();

	while (!glfwWindowShouldClose(window))
	{
		glClear(GL_COLOR_BUFFER_BIT | GL_DEPTH_BUFFER_BIT);
		updateSimulation();
		renderSimulation();
		glfwSwapBuffers(window);
		glfwPollEvents();
	}

	glfwTerminate();
	return 0;
}

void key_callback(GLFWwindow* window, int key, int /*scancode*/, int action, int /*mode*/)
{
	if (action == GLFW_PRESS)
	{
		input.keyPressedStates[key] = true;
	}
	else if (action == GLFW_RELEASE)
	{
		input.keyPressedStates[key] = false;
	}

	if (key == GLFW_KEY_ESCAPE && action == GLFW_PRESS)
		glfwSetWindowShouldClose(window, GL_TRUE);
}

void mouse_callback(GLFWwindow* /*window*/, double xpos, double ypos)
{
	if (input.mouseInitiallyMoved)
	{
		input.previousMousePosX = xpos;
		input.previousMousePosY = ypos;
		input.mouseInitiallyMoved = false;
	}

	float xOffset = (xpos - input.previousMousePosX) * input.mouseSensitivity;
	float yOffset = (input.previousMousePosY - ypos) * input.mouseSensitivity;
	input.previousMousePosX = xpos;
	input.previousMousePosY = ypos;

	orientation.yaw += xOffset;
	orientation.pitch += yOffset;
	if (orientation.pitch > 89.f)
		orientation.pitch = 89.f;
	else if (orientation.pitch < -89.f)
	{
		orientation.pitch = -89.f;
	}

	glm::vec3 front;
	front.x = cos(glm::radians(orientation.yaw)) * cos(glm::radians(orientation.pitch));
	front.y = sin(glm::radians(orientation.pitch));
	front.z = sin(glm::radians(orientation.yaw)) * cos(glm::radians(orientation.pitch));
	camera.front = normalize(front);
}