// like prev color picker hotkeys are same,
#include <iostream>
#include <glad\glad.h>
#include <GLFW\glfw3.h>
const char *vertexShader_source =
"#version 330 core\n"
"layout(location = 0) in vec3 aPos;\n"
"void main()\n"
"{\n"
"	gl_Position = vec4(aPos.x, aPos.y, aPos.z, 1.0);\n"
"}\0";
const char *fragmentShader_source =
"#version 330 core\n"
"out vec4 FragColor;\n"
"uniform vec4 ourColor; "
"void main()\n"
"{\n"
"	FragColor = ourColor;\n"
"}\0";
/*		 -- [ Varribles ] --		*/

float red = 0.0f, green = 0.0f, blue = 0.0f;
bool pressedOnce = false;

void Resizer(GLFWwindow* window, int width, int height)
{
	glViewport(0, 0, width, height);
}
void GLAD_Check()
{
	if (!gladLoadGLLoader((GLADloadproc)glfwGetProcAddress))
		std::cout << "Failed to initialize GLAD" << std::endl;
}
void key_callback(GLFWwindow* window, int key, int scancode, int action, int mods)
{
	if (glfwGetKey(window, GLFW_KEY_ENTER) == GLFW_PRESS)
		pressedOnce = true;
	if (pressedOnce == true && glfwGetKey(window, GLFW_KEY_ENTER) == GLFW_RELEASE)
		glfwSetWindowShouldClose(window, true);

	if (glfwGetKey(window, GLFW_KEY_Q) == GLFW_PRESS && red < 255)
		red++;
	if (glfwGetKey(window, GLFW_KEY_A) == GLFW_PRESS && red > 0)
		red--;
	if (glfwGetKey(window, GLFW_KEY_W) == GLFW_PRESS && green < 255)
		green++;
	if (glfwGetKey(window, GLFW_KEY_S) == GLFW_PRESS && green > 0)
		green--;
	if (glfwGetKey(window, GLFW_KEY_E) == GLFW_PRESS && blue < 255)
		blue++;
	if (glfwGetKey(window, GLFW_KEY_D) == GLFW_PRESS && blue > 0)
		blue--;

	std::cout << "rgb(" << red << ',' << green << ',' << blue << ")\n";
}

int main()
{
	/*			--- [ SETUP ] ---				*/
	glfwInit();
	glfwWindowHint(GLFW_CONTEXT_VERSION_MAJOR, 3);
	glfwWindowHint(GLFW_CONTEXT_VERSION_MINOR, 3);
	glfwWindowHint(GLFW_OPENGL_PROFILE, GLFW_OPENGL_CORE_PROFILE);
	GLFWwindow *myWindow = glfwCreateWindow(800, 600, "I'm learning OpenGL", NULL, NULL); // creating a window
	glfwMakeContextCurrent(myWindow);
	GLAD_Check();
	glViewport(0, 0, 800, 600);
	glfwSetFramebufferSizeCallback(myWindow, Resizer);
	/*			--- [ SETUP ] ---				*/
	float vertcies[] = // vertcies
	{
		0.0f, 0.2f, 1.0f,   //bottom
		-0.2f, 0.8, 1.0f,   //top left
		0.2f, 0.8f, 1.0f,   //top right

		-0.3f, 0.2f, 1.0f,  //bottom
		-0.8f, 0.6, 1.0f,   //top left
		-0.4f, 0.8f, 1.0f,  //top right


		0.3f, 0.2f, 1.0f,   //bottom
		0.8f, 0.6, 1.0f,    //top left
		0.4f, 0.8f, 1.0f,   //top right

		0.0f, -0.1, 1.0f,   //top
		-0.4f, -0.8, 1.0f,  //bottom left
		0.4f, -0.8, 1.0f    //bottom right
	};
	/*			=== [ VBO & VAO ] ===			*/
	unsigned int VBO;
	glGenBuffers(1, &VBO);
	glBindBuffer(GL_ARRAY_BUFFER, VBO);
	glBufferData(GL_ARRAY_BUFFER, sizeof(vertcies), vertcies, GL_STATIC_DRAW);
	glCompileShader(VBO);
	unsigned int VAO;
	glGenVertexArrays(1, &VAO);
	glBindVertexArray(VBO);
	glVertexAttribPointer(0, 3, GL_FLOAT, GL_FALSE, 3 * sizeof(float), (void*)0);
	glEnableVertexAttribArray(0);
	/*			=== [ VBO & VAO ] ===			*/

	/*			 ===== [ vertex_shader & fragment_shader ]			 ===== */
	unsigned int vertexShader = glCreateShader(GL_VERTEX_SHADER);
	glShaderSource(vertexShader, 1, &vertexShader_source, NULL);
	glCompileShader(vertexShader);

	unsigned int fragmentShader = glCreateShader(GL_FRAGMENT_SHADER);
	glShaderSource(fragmentShader, 1, &fragmentShader_source, NULL);
	glCompileShader(fragmentShader);
	/*			 ===== [ vertex_shader & fragment_shader ]			 ===== */

	/*		 -- [ shader_program ] --		*/
	unsigned int shaderProgram = glCreateProgram();
	glAttachShader(shaderProgram, vertexShader);
	glAttachShader(shaderProgram, fragmentShader);
	glLinkProgram(shaderProgram);
	glUseProgram(shaderProgram);
	int vertexColorLocation = glGetUniformLocation(shaderProgram, "ourColor");

	while (!glfwWindowShouldClose(myWindow))
	{
		/*	  --[ INPUT ]--		*/
		glfwSetKeyCallback(myWindow, key_callback);

		glClearColor(0.2, 0.3, 0.4, 1.0f);
		glClear(GL_COLOR_BUFFER_BIT);

		glUniform4f(vertexColorLocation, 0, green / 255, 0, 1.0f);
		glDrawArrays(GL_TRIANGLES, 0, 3);
		glUniform4f(vertexColorLocation, red / 255, 0, 0, 1.0f);
		glDrawArrays(GL_TRIANGLES, 3, 3);
		glUniform4f(vertexColorLocation, 0, 0, blue / 255, 1.0f);
		glDrawArrays(GL_TRIANGLES, 6, 3);
		glUniform4f(vertexColorLocation, red / 255, green / 255, blue / 255, 1.0f);
		glDrawArrays(GL_TRIANGLES, 9, 3);

		glfwPollEvents();
		glfwSwapBuffers(myWindow);
	}
	glfwTerminate();
	return 0;
}