#include <glad/glad.h>
#include <GLFW/glfw3.h>
#include <cmath>
#include <string>
#include <fstream>
#include <iostream>

double round_to_presicion( double value, int precision ) {
    const int adjustment = pow(10,precision);
    return floor( value*(adjustment) + 0.5 )/adjustment;
}

std::string readFile(std::string path) {
	std::ifstream file(path);
	if (!file.is_open())
		std::cerr << "File " << path << " was not found." << std::endl;

	std::string content = "";
	std::string buffer = "";

	while(getline(file, buffer)) {
		content += buffer + "\n";
	}

	content += '\0';
	file.close();
	return content;
}

void gracefulExit(int code) {
	glfwTerminate();
	exit(code);
}

unsigned int prepareShaders() {
	unsigned int vertexShader = glCreateShader(GL_VERTEX_SHADER);
	unsigned int fragmentShader = glCreateShader(GL_FRAGMENT_SHADER);

	std::string vertexShaderSourceString = readFile("../shaders/shader.vert");
	std::string fragmentShaderSourceString = readFile("../shaders/shader.frag");

	const char *vertexShaderSource = vertexShaderSourceString.c_str();
	const char *fragmentShaderSource = fragmentShaderSourceString.c_str();

	glShaderSource(vertexShader, 1, &vertexShaderSource, NULL);
	glCompileShader(vertexShader);

	int success;
	char log[512];
	glGetShaderiv(vertexShader, GL_COMPILE_STATUS, &success);
	if (!success) {
		glGetShaderInfoLog(vertexShader, 512, NULL, log);
		std::cerr << "Could not compile vertex shader: " << log << std::endl;
		gracefulExit(-1);
	}
	glShaderSource(fragmentShader, 1, &fragmentShaderSource, NULL);
	glCompileShader(fragmentShader);

	glGetShaderiv(fragmentShader, GL_COMPILE_STATUS, &success);
	if (!success) {
		glGetShaderInfoLog(fragmentShader, 512, NULL, log);
		std::cerr << "Could not compile fragment shader: " << log << std::endl;
		gracefulExit(-1);
	}

	unsigned int shaderProgram;
	shaderProgram = glCreateProgram();
	glAttachShader(shaderProgram, vertexShader);
	glAttachShader(shaderProgram, fragmentShader);
	glLinkProgram(shaderProgram);

	glGetProgramiv(shaderProgram, GL_LINK_STATUS, &success);
	if(!success) {
    	glGetProgramInfoLog(shaderProgram, 512, NULL, log);
		std::cerr << "Could not link program: " << log << std::endl;
		gracefulExit(-1);
	}

	glDeleteShader(vertexShader);
	glDeleteShader(fragmentShader);
	return shaderProgram;
}