/* ----------------------------------------------------------------------------
 * window.cpp
 *
 * Copyright (c) 2017 Yann Herklotz Grave <ymherklotz@gmail.com> -- MIT License
 * See file LICENSE for more details
 * ----------------------------------------------------------------------------
 */

#include "window.hpp"

#include <GL/glew.h>

#include <iostream>
#include <stdexcept>

namespace yage {

Window::Window() {}

Window::~Window() { SDL_DestroyWindow(window_); }

void Window::create(const std::string& window_name, int width, int height,
                    unsigned flags) {
    Uint32 gl_window_states = 0;

    // set the correct input flags
    if (flags & WindowFlags::SHOWN) gl_window_states |= SDL_WINDOW_OPENGL;
    if (flags & WindowFlags::HIDDEN) gl_window_states |= SDL_WINDOW_HIDDEN;
    if (flags & WindowFlags::FULLSCREEN)
        gl_window_states |= SDL_WINDOW_FULLSCREEN;
    if (flags & WindowFlags::BORDERLESS)
        gl_window_states |= SDL_WINDOW_BORDERLESS;

    // SDL_GL options

    // SDL_GL_SetAttribute (SDL_GL_CONTEXT_MAJOR_VERSION, 4);
    // SDL_GL_SetAttribute (SDL_GL_CONTEXT_MINOR_VERSION, 5);
    SDL_GL_SetAttribute(SDL_GL_DOUBLEBUFFER, 1);

    // create the SDL window
    window_ = SDL_CreateWindow(window_name.c_str(), SDL_WINDOWPOS_CENTERED,
                               SDL_WINDOWPOS_CENTERED, width, height,
                               gl_window_states);
    if (window_ == nullptr) throw std::runtime_error("SDL_CreateWindow failed");

    // initialize the GL context in the window
    SDL_GLContext gl_context = SDL_GL_CreateContext(window_);
    if (gl_context == nullptr)
        throw std::runtime_error("SDL_GL_CreateContext failed");

    // initialize glew
    GLenum error = glewInit();
    if (error != GLEW_OK) throw std::runtime_error("glewInit failed");

    // print out the current OpenGL version to debug
    std::cout << "***  OpenGL version: " << glGetString(GL_VERSION)
              << "  ***\n";

    // set vsync on instead of custom fps limiting
    SDL_GL_SetSwapInterval(1);
    // set the clear color to black
    glClearColor(0.f, 0.5f, 0.f, 1.f);
    // set alpha blending
    glEnable(GL_BLEND);
    glBlendFunc(GL_SRC_ALPHA, GL_ONE_MINUS_SRC_ALPHA);
}

void Window::swapBuffer() {
    // swap the window buffer
    SDL_GL_SwapWindow(window_);
}

void Window::clearBuffer() {
    // set the clear depth
    glClearDepth(1.f);
    // clears buffer with clear color
    glClear(GL_COLOR_BUFFER_BIT | GL_DEPTH_BUFFER_BIT);
}

}  // yage