#ifndef CONSTANTS_HPP
#include <GLFW/glfw3.h>
#include <iostream>
#include <string_view>

namespace constants 
{
    // best practice is to use inline constexpr std::string_view but glfwCreateWindow takes only char* as input
    inline const char* MAIN_WINDOW_NAME { "Match" }; 
    inline constexpr int MAIN_WINDOW_WIDTH { 800 };
    inline constexpr int MAIN_WINDOW_HEIGHT { 600 };
    inline constexpr struct  { 
        GLfloat red = 1.0f;
        GLfloat green = 0.0f;
        GLfloat blue = 0.0f;
        GLfloat alpha = 1.0f;
    } RED;

        inline constexpr struct  { 
        GLfloat red = 1.0f;
        GLfloat green = 1.0f;
        GLfloat blue = 1.0f;
        GLfloat alpha = 1.0f;
    } WHITE;

    inline constexpr struct  { 
        GLfloat red = 0.2f;
        GLfloat green = 0.3f;
        GLfloat blue = 0.3f;
        GLfloat alpha = 1.0f;
    } LEARN_OPEN_GL_COLOR;

    // we write vertex shader 
    // version of glsl (since ogl 3.3 same as ogl so we pick 330)
    // in this shader we just forward input data to shader output
    inline const char *vertexShaderSource { "#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" } ;

    // write fragment shader
    // we set the color of each pixel to be orange
    inline const char *fragmentShaderSource {
        "#version 330 core\n"
        "out vec4 FragColor;\n"
        "void main()\n"
        "{\n"
            "FragColor = vec4(1.0f, 0.5f, 0.2f, 1.0f);\n"
        "}\0"
    };

    // we specify three vertices
    // each of them with position in 3d space
    // x y z
    inline constexpr float TRIANGLE_VERTICES[] {
        -0.5f, -0.5f, 0.0f,
        0.5f, -0.5f, 0.0f,
        0.0f,  0.5f, 0.0f
    };

    inline constexpr size_t TRIANGLE_VERTICES_SIZE = { sizeof(TRIANGLE_VERTICES) };

    // compare with square done with only vertices:
    /*
    float vertices[] = {
    // first triangle
     0.5f,  0.5f, 0.0f,  // top right
     0.5f, -0.5f, 0.0f,  // bottom right
    -0.5f,  0.5f, 0.0f,  // top left 
    // second triangle
     0.5f, -0.5f, 0.0f,  // bottom right
    -0.5f, -0.5f, 0.0f,  // bottom left
    -0.5f,  0.5f, 0.0f   // top left
    };
    bottom right and top left is specified twice ! 
    */
    inline constexpr float SQUARE_VERTICES[] {
        0.5f,  0.5f, 0.0f,  // top right
        0.5f, -0.5f, 0.0f,  // bottom right
        -0.5f, -0.5f, 0.0f,  // bottom left
        -0.5f,  0.5f, 0.0f   // top left 
    };

    inline constexpr unsigned int SQUARE_INDICES[] {
        0, 1, 3,   // first triangle
        1, 2, 3    // second triangle
    };

    inline constexpr size_t SQUARE_INDICES_SIZE = { sizeof(SQUARE_INDICES) };

    inline constexpr size_t SQUARE_VERTICES_SIZE = { sizeof(SQUARE_VERTICES) };

}

#endif