#include <stdio.h>
#include <stdlib.h>
#include <stdbool.h>
#include <glad/glad.h>
#include <GLFW/glfw3.h>
#include "main.h"
#include <acl/file.h>

int main() {
	if(!glfwInit()) {
		printf("Faild to initalize GLFW\n");
		return -1;
	}
	glfwSetErrorCallback(&glfwError);
	glfwWindowHint(GLFW_SAMPLES, 4);
	glfwWindowHint(GLFW_CONTEXT_VERSION_MAJOR, 3);
	glfwWindowHint(GLFW_CONTEXT_VERSION_MINOR, 3);
	glfwWindowHint(GLFW_OPENGL_FORWARD_COMPAT, GL_TRUE);
	glfwWindowHint(GLFW_OPENGL_PROFILE, GLFW_OPENGL_CORE_PROFILE);
	GLFWwindow *window;
	window = glfwCreateWindow(1920, 1080, "Minecraft-Clone", NULL, NULL);
	if(window == NULL) {
		printf("Failed to open GLFW window.\n");
		glfwTerminate();
		return -1;
	}
	glfwMakeContextCurrent(window);
	if(!gladLoadGLLoader((GLADloadproc)glfwGetProcAddress)) {
		printf("Failed to initialize GLAD\n");
    		return -1;
	}
	glViewport(0, 0, 1920, 1080);
	glfwSetFramebufferSizeCallback(window, framebuffer_size_callback);
	glfwSetInputMode(window, GLFW_STICKY_KEYS, GL_TRUE);
	float vertices[] = {
		-0.5f, -0.5f, 0.0f,
		0.5f, -0.5f, 0.0f,
		0.0f,  0.5f, 0.0f
	};
	// parse shader
	unsigned int vertexShader = parseShader("shader/test.vert", GL_VERTEX_SHADER);
	unsigned int fragmentShader = parseShader("shader/test.frag", GL_FRAGMENT_SHADER);
	unsigned int shaderProgram = linkShader(vertexShader, fragmentShader);
	glUseProgram(shaderProgram);
	unsigned int VBO;
	glGenBuffers(1, &VBO);  
	glBindBuffer(GL_ARRAY_BUFFER, VBO);
	glBufferData(GL_ARRAY_BUFFER, sizeof(vertices), vertices, GL_STATIC_DRAW);
	unsigned int VAO;
	glGenVertexArrays(1, &VAO);
	glBindVertexArray(VAO);
	glBindBuffer(GL_ARRAY_BUFFER, VBO);
	glBindBuffer(GL_ARRAY_BUFFER, VBO);
	glBufferData(GL_ARRAY_BUFFER, sizeof(vertices), vertices, GL_STATIC_DRAW);
	glVertexAttribPointer(0, 3, GL_FLOAT, GL_FALSE, 3 * sizeof(float), (void*)0);
	glEnableVertexAttribArray(0);
	while(!glfwWindowShouldClose(window)) {
		glUseProgram(shaderProgram);
		glBindVertexArray(VAO);
		glDrawArrays(GL_TRIANGLES, 0, 3);
		glfwSwapBuffers(window);
		glfwPollEvents();    
	}
	glfwTerminate();
	return 0;
}
void glfwError(int id, const char* description) {
	printf("Glfw Error: %s\n", description);
}

void framebuffer_size_callback(GLFWwindow* window, int width, int height) {
	glViewport(0, 0, width, height);
}
unsigned int parseShader(const char *filePath, const GLenum shaderType) {
	bool success;
	unsigned int ShaderId;
	char *ShaderSrc = acl_ReadTextFile(filePath, &success);
	if(!success) {
		printf("Failed to read Shader: %s", filePath);
		glfwTerminate();
		exit(-1);
	}
	ShaderId = glCreateShader(shaderType);
	const char *tmpShaderSrc = ShaderSrc;
	glShaderSource(ShaderId, 1, &tmpShaderSrc, NULL);
	glCompileShader(ShaderId);
	free(ShaderSrc);
	int compileSuccess;
	glGetShaderiv(ShaderId, GL_COMPILE_STATUS, &compileSuccess);
	if(!compileSuccess) {
		char infoLog[512];
		glGetShaderInfoLog(ShaderId, 512, NULL, infoLog);
		printf("Failed to compile Shader: %s Error: %s", filePath, infoLog);
	}
	return ShaderId;
}
unsigned int linkShader(unsigned int vertexShader, unsigned int fragmentShader) {
	unsigned int shaderProgram = glCreateProgram();
	glAttachShader(shaderProgram, vertexShader);
	glAttachShader(shaderProgram, fragmentShader);
	glLinkProgram(shaderProgram);
	int success;
	glGetProgramiv(shaderProgram, GL_LINK_STATUS, &success);
	if(!success) {
		char infoLog[512];
		glGetProgramInfoLog(shaderProgram, 512, NULL, infoLog);
		printf("Failed to link Shader. Error: %s", infoLog);
		glfwTerminate();
		exit(-1);
	}
	glDeleteShader(vertexShader);
	glDeleteShader(fragmentShader);
	return shaderProgram;
}