#include <GL/glew.h>
#include "shader.h"
#include <string>
#include <fstream>
#include <sstream>
#include <iostream>
#include <filesystem>
Shader::Shader(const char* vertexPath, const char* fragmentPath)
{
    std::string vertexCode;
    std::string fragmentCode;
    std::ifstream vShaderFile;
    std::ifstream fShaderFile;
    // ensure ifstream objects can throw exceptions:
    vShaderFile.exceptions (std::ifstream::failbit | std::ifstream::badbit);
    fShaderFile.exceptions (std::ifstream::failbit | std::ifstream::badbit);

    try
    {
        // open files
        vShaderFile.open(vertexPath);
        fShaderFile.open(fragmentPath);
        std::stringstream vShaderStream, fShaderStream;
        // read file's buffer contents into streams
        vShaderStream << vShaderFile.rdbuf();
        fShaderStream << fShaderFile.rdbuf();
        // close file handlers
        vShaderFile.close();
        fShaderFile.close();
        // convert stream into string
        vertexCode = vShaderStream.str();
        fragmentCode = fShaderStream.str();

    }
    catch (std::ifstream::failure& e)
    {
        std::__fs::filesystem::path currentPath = std::__fs::filesystem::current_path();
        std::cout << "Current path: " << currentPath << std::endl;
        std::cout << "ERROR::SHADER::FILE_NOT_SUCCESFULLY_READ" << std::endl;
    }
    const char* vShaderCode = vertexCode.c_str();
    const char* fShaderCode = fragmentCode.c_str();

    //compiling shaders
    unsigned int vertex, fragment;
    vertex = glCreateShader(GL_VERTEX_SHADER);
    glShaderSource(vertex, 1, &vShaderCode, NULL);
    glCompileShader(vertex);

    fragment = glCreateShader(GL_FRAGMENT_SHADER);
    glShaderSource(fragment, 1, &fShaderCode, NULL);
    glCompileShader(fragment);

    //shader program
    ID = glCreateProgram();
    glAttachShader(ID, vertex);
    glAttachShader(ID, fragment);
    glLinkProgram(ID);
    glDeleteShader(vertex);
    glDeleteShader(fragment);

}

unsigned int Shader::programID(){
    return ID;
}