#include<cmath>
#include<iostream>
#include<GL/glew.h>
#include<GLFW/glfw3.h>

#include<SOIL.h>

#include<glm/glm.hpp>
#include<glm/gtc/type_ptr.hpp>
#include<glm/gtc/matrix_transform.hpp>
#include "shader.h"

typedef GLint Int;
typedef GLuint Uint;
typedef GLchar Char;
typedef GLfloat Float;

Uint WIDTH = 500, HEIGHT = 450;

glm::vec3 cameraPos = glm::vec3(0.0f, 0.0f, 3.0f);
glm::vec3 cameraFront = glm::vec3(0.0f, 0.0f, -1.0f);
glm::vec3 cameraUp = glm::vec3(0.0f, 1.0f, 0.0f);

bool keys[1025];
Float deltaTime = 0.0f;
Float lastFrame = 0.0f;

void keyboard(GLFWwindow* window, int key, int scancode, int action, int mode)
{
	if (key == GLFW_KEY_ESCAPE && action == GLFW_PRESS)
		glfwSetWindowShouldClose(window, GL_TRUE);

	if (action == GLFW_PRESS)
		keys[key] = true;
	else if (action == GLFW_RELEASE)
		keys[key] = false;

	/*
	Float cameraSpeed = 0.05f;
 if(key == GLFW_KEY_W)
 cameraPos += cameraSpeed * cameraFront;

 if(key == GLFW_KEY_S)
 cameraPos -= cameraSpeed * cameraFront;

 if(key == GLFW_KEY_A)
 cameraPos -= glm::normalize(glm::cross(cameraFront, cameraUp)) * cameraSpeed;

 if(key == GLFW_KEY_D)
 cameraPos += glm::normalize(glm::cross(cameraFront, cameraUp)) * cameraSpeed;
	*/
}

void do_movent()
{
	Float currentFrame = glfwGetTime();
	deltaTime = currentFrame - lastFrame;
	lastFrame = currentFrame;

	Float cameraSpeed = 5.0f * deltaTime;
	if (keys[GLFW_KEY_W])
		cameraPos += cameraSpeed*cameraFront;
	if (keys[GLFW_KEY_S])
		cameraPos -= cameraSpeed*cameraFront;
	if (keys[GLFW_KEY_A])
		cameraPos += glm::normalize(glm::cross(cameraFront, cameraUp))*cameraSpeed;
	if (keys[GLFW_KEY_D])
		cameraPos -= glm::normalize(glm::cross(cameraFront, cameraUp))*cameraSpeed;
}
GLFWwindow* InitWindow()
{
	glfwInit();
	glfwWindowHint(GLFW_RESIZABLE, GL_FALSE);
	glfwWindowHint(GLFW_CONTEXT_VERSION_MINOR, 3);
	glfwWindowHint(GLFW_CONTEXT_VERSION_MAJOR, 3);
	glfwWindowHint(GLFW_OPENGL_PROFILE, GLFW_OPENGL_CORE_PROFILE);

	GLFWwindow* window = glfwCreateWindow(WIDTH, HEIGHT, "transform", nullptr, nullptr);
	glfwMakeContextCurrent(window);

	glfwSetKeyCallback(window, keyboard);

	glewExperimental = GL_TRUE;
	glewInit();
	return window;
}


int main()
{
	GLFWwindow* window = InitWindow();

	const Char* vertexPath = "E:\\OpenGL\\OpenGL_test1\\Shader\\vertexShader.glsl";
	const Char* fragmentPath = "E:\\OpenGL\\OpenGL_test1\\Shader\\fragmentShader.glsl";

	Shader ourShader(vertexPath, fragmentPath);

	GLfloat vertices[] = {
 -0.5f, -0.5f, -0.5f, 0.0f, 0.0f,
 0.5f, -0.5f, -0.5f, 1.0f, 0.0f,
 0.5f, 0.5f, -0.5f, 1.0f, 1.0f,
 0.5f, 0.5f, -0.5f, 1.0f, 1.0f,
 -0.5f, 0.5f, -0.5f, 0.0f, 1.0f,
 -0.5f, -0.5f, -0.5f, 0.0f, 0.0f,

 -0.5f, -0.5f, 0.5f, 0.0f, 0.0f,
 0.5f, -0.5f, 0.5f, 1.0f, 0.0f,
 0.5f, 0.5f, 0.5f, 1.0f, 1.0f,
 0.5f, 0.5f, 0.5f, 1.0f, 1.0f,
 -0.5f, 0.5f, 0.5f, 0.0f, 1.0f,
 -0.5f, -0.5f, 0.5f, 0.0f, 0.0f,

 -0.5f, 0.5f, 0.5f, 1.0f, 0.0f,
 -0.5f, 0.5f, -0.5f, 1.0f, 1.0f,
 -0.5f, -0.5f, -0.5f, 0.0f, 1.0f,
 -0.5f, -0.5f, -0.5f, 0.0f, 1.0f,
 -0.5f, -0.5f, 0.5f, 0.0f, 0.0f,
 -0.5f, 0.5f, 0.5f, 1.0f, 0.0f,

 0.5f, 0.5f, 0.5f, 1.0f, 0.0f,
 0.5f, 0.5f, -0.5f, 1.0f, 1.0f,
 0.5f, -0.5f, -0.5f, 0.0f, 1.0f,
 0.5f, -0.5f, -0.5f, 0.0f, 1.0f,
 0.5f, -0.5f, 0.5f, 0.0f, 0.0f,
 0.5f, 0.5f, 0.5f, 1.0f, 0.0f,

 -0.5f, -0.5f, -0.5f, 0.0f, 1.0f,
 0.5f, -0.5f, -0.5f, 1.0f, 1.0f,
 0.5f, -0.5f, 0.5f, 1.0f, 0.0f,
 0.5f, -0.5f, 0.5f, 1.0f, 0.0f,
 -0.5f, -0.5f, 0.5f, 0.0f, 0.0f,
 -0.5f, -0.5f, -0.5f, 0.0f, 1.0f,

 -0.5f, 0.5f, -0.5f, 0.0f, 1.0f,
 0.5f, 0.5f, -0.5f, 1.0f, 1.0f,
 0.5f, 0.5f, 0.5f, 1.0f, 0.0f,
 0.5f, 0.5f, 0.5f, 1.0f, 0.0f,
 -0.5f, 0.5f, 0.5f, 0.0f, 0.0f,
 -0.5f, 0.5f, -0.5f, 0.0f, 1.0f
};

	Uint indices[] = {
		0,1,2,
		0,2,3
	};
	
	Uint VAO, VBO, EBO;
	glGenVertexArrays(1,&VAO);
	glGenBuffers(1, &VBO);
	glGenBuffers(1, &EBO);

	glBindVertexArray(VAO);
	
	glBindBuffer(GL_ARRAY_BUFFER, VBO);
	glBufferData(GL_ARRAY_BUFFER, sizeof(vertices), vertices, GL_STATIC_DRAW);

	glBindBuffer(GL_ELEMENT_ARRAY_BUFFER, EBO);
	glBufferData(GL_ELEMENT_ARRAY_BUFFER, sizeof(indices), indices, GL_STATIC_DRAW);

	glVertexAttribPointer(0, 3, GL_FLOAT, GL_FALSE, 5 * sizeof(GLfloat), (GLvoid*)0);
	glEnableVertexAttribArray(0);

	glVertexAttribPointer(1, 2, GL_FLOAT, GL_FALSE, 5 * sizeof(GLfloat), (GLvoid*)(3*sizeof(GLfloat)));
	glEnableVertexAttribArray(1);

	glBindVertexArray(0);

	//************ TEXTURE **************//

	Uint texture1, texture2;

	// texture 1
	glGenTextures(1, &texture1);
	glBindTexture(GL_TEXTURE_2D, texture1);

	glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_WRAP_S, GL_NEAREST);
	glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_WRAP_T, GL_NEAREST);
	glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MIN_FILTER, GL_LINEAR);
	glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MAG_FILTER, GL_LINEAR);

	int width=0, height=0;
	const Char* imagePath = "E:\\OpenGL\\OpenGL_test1\\Images\\wall.jpg";
	unsigned char* image = SOIL_load_image(imagePath, &width, &height, 0, SOIL_LOAD_RGB);
	glTexImage2D(GL_TEXTURE_2D, 0, GL_RGB, width, height, 0, GL_RGB, GL_UNSIGNED_BYTE, image);
	glGenerateMipmap(GL_TEXTURE_2D);
	SOIL_free_image_data(image);
	glBindTexture(GL_TEXTURE_2D, 0);

	// texture 2
	glGenTextures(1, &texture2);
	glBindTexture(GL_TEXTURE_2D, texture2);

	glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_WRAP_S, GL_NEAREST);
	glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_WRAP_T, GL_NEAREST);
	glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MIN_FILTER, GL_LINEAR);
	glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MAG_FILTER, GL_LINEAR);

	imagePath = "E:\\OpenGL\\OpenGL_test1\\Images\\awesomeface.png";
	image = SOIL_load_image(imagePath, &width, &height, 0, SOIL_LOAD_RGB);
	glTexImage2D(GL_TEXTURE_2D, 0, GL_RGB, width, height, 0, GL_RGB, GL_UNSIGNED_BYTE, image);
	SOIL_free_image_data(image);
	glBindTexture(GL_TEXTURE_2D, 0);

	// 十个立方体
	glm::vec3 cubePositions[] = {
 glm::vec3( 0.0f, 0.0f, 0.0f),
 glm::vec3( 2.0f, 5.0f, -15.0f),
 glm::vec3(-1.5f, -2.2f, -2.5f),
 glm::vec3(-3.8f, -2.0f, -12.3f),
 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)
	};

	//glPolygonMode(GL_FRONT_AND_BACK, GL_LINE);
	glEnable(GL_DEPTH_TEST);
	while (!glfwWindowShouldClose(window))
	{
		glfwPollEvents();
		do_movent();

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

		ourShader.Use();

		glm::mat4 views;
		glm::mat4 projection;

		/*
		Float radius = 10.f;
		Float camX = sin(glfwGetTime())*radius;
		Float camZ = cos(glfwGetTime())*radius;

		views = glm::lookAt(glm::vec3(camX, 0.0f, camZ), glm::vec3(0.0, 0.0, 0.0), glm::vec3(0.0, 1.0, 0.0));
		*/

		views = glm::lookAt(cameraPos, cameraPos + cameraFront, cameraUp);

		projection = glm::perspective(glm::radians(45.0f), (GLfloat)WIDTH / (GLfloat)HEIGHT, 0.1f, 100.0f);

		Uint views_Location = glGetUniformLocation(ourShader.Program, "views");
		Uint projection_Location = glGetUniformLocation(ourShader.Program, "projection");

		glUniformMatrix4fv(views_Location, 1, GL_FALSE, glm::value_ptr(views));
		glUniformMatrix4fv(projection_Location, 1, GL_FALSE, glm::value_ptr(projection));

		glActiveTexture(GL_TEXTURE0);
		glBindTexture(GL_TEXTURE_2D, texture1);
		glUniform1i(glGetUniformLocation(ourShader.Program, "ourTexture1"),0);

		glActiveTexture(GL_TEXTURE1);
		glBindTexture(GL_TEXTURE_2D, texture2);
		glUniform1i(glGetUniformLocation(ourShader.Program, "ourTexture2"),1);

		glBindVertexArray(VAO);

		for (int i = 0; i < 10; ++i)
		{
			glm::mat4 model;
			model = glm::translate(model, cubePositions[i]);
			model = glm::rotate(model, 1*(GLfloat)glfwGetTime(), glm::vec3(1.0f, 0.3f, 0.5f));
			Uint model_Location = glGetUniformLocation(ourShader.Program, "model");
			glUniformMatrix4fv(model_Location, 1, GL_FALSE, glm::value_ptr(model));
			glDrawArrays(GL_TRIANGLES, 0, 36);
		}
		glBindVertexArray(0);

		glfwSwapBuffers(window);
	}
	glfwTerminate();
	return 0;
}