// Copyright (c) 2025 Dominic Masters
// 
// This software is released under the MIT License.
// https://opensource.org/licenses/MIT

#include "Display.hpp"
#include "engine/Engine.hpp"

using namespace Dawn;

MeshVertex vertices[3] = {
  { {255, 0, 0, 255}, glm::vec2(0.5f, 1.0f), glm::vec3(0.0f, 0.5f, 0.0f) },
  { {0, 255, 0, 255}, glm::vec2(0.0f, 0.0f), glm::vec3(-0.5f, -0.5f, 0.0f) },
  { {0, 0, 255, 255}, glm::vec2(1.0f, 0.0f), glm::vec3(0.5f, -0.5f, 0.0f) }
};

Display::Display(Engine &engine) :
  #if DAWN_SDL2
    glContext(nullptr),
    window(nullptr),
  #endif
  engine(engine),
  mesh(3, PrimitiveType::TRIANGLES, vertices)
{

  #if DAWN_SDL2
    uint32_t flags = SDL_INIT_VIDEO;
    #if DAWN_SDL2_GAMEPAD
      flags |= SDL_INIT_GAMECONTROLLER | SDL_INIT_JOYSTICK;
    #endif

    if(SDL_Init(flags) != 0) {
      throw "Failed to initialize SDL2";
    }
    
    // Set OpenGL Attributes
    SDL_GL_SetAttribute(SDL_GL_DOUBLEBUFFER, 1);

    // Create window
    this->window = SDL_CreateWindow(
      "Dawn",
      SDL_WINDOWPOS_CENTERED,
      SDL_WINDOWPOS_CENTERED,
      DEFAULT_WIDTH,
      DEFAULT_HEIGHT,
      SDL_WINDOW_OPENGL | SDL_WINDOW_RESIZABLE | SDL_WINDOW_ALLOW_HIGHDPI | 
      SDL_WINDOW_SHOWN
    );
    if(!this->window) {
      throw "Failed to create SDL2 window";
    }

    // Create OpenGL context
    this->glContext = SDL_GL_CreateContext(this->window);
    if(!this->glContext) {
      throw "Failed to create OpenGL context";
    }

    // Setup GL
    SDL_GL_SetSwapInterval(1);// Enable vsync
    glDisable(GL_DEPTH_TEST);
    glDisable(GL_CULL_FACE);
    glDisable(GL_LIGHTING);// PSP defaults this on?
    glShadeModel(GL_SMOOTH);// Fixes color on PSP?
    glEnable(GL_BLEND);
    glBlendFunc(GL_SRC_ALPHA, GL_ONE_MINUS_SRC_ALPHA);
    glPixelStorei(GL_PACK_ALIGNMENT, 1);
    glPixelStorei(GL_UNPACK_ALIGNMENT, 1);

    glEnableClientState(GL_COLOR_ARRAY);// TODO: every frame on PSP?
    glEnableClientState(GL_TEXTURE_COORD_ARRAY);
    glEnableClientState(GL_VERTEX_ARRAY);
  #else
    #error "No display platform defined"
  #endif
}

void Display::update(void) {
  #if DAWN_SDL2
    SDL_Event event;
    while(SDL_PollEvent(&event)) {
      switch(event.type) {
        case SDL_QUIT: {
          engine.console.exec("exit");
          break;
        }

        case SDL_WINDOWEVENT: {
          switch(event.window.event) {
            case SDL_WINDOWEVENT_CLOSE: {
              engine.console.exec("exit");
              break;
            }

            default: {
              break;
            }
          }
          break;
        }

        default: {
          break;
        }
      }
    }

    // SDL_GL_MakeCurrent(this->window, this->glContext);

    glClear(GL_COLOR_BUFFER_BIT | GL_DEPTH_BUFFER_BIT);
    glClearColor(
      Color4F::CORNFLOWER_BLUE.r,
      Color4F::CORNFLOWER_BLUE.g,
      Color4F::CORNFLOWER_BLUE.b,
      Color4F::CORNFLOWER_BLUE.a
    );

    mesh.draw(0, -1);

    // glViewport(0, 0, DEFAULT_WIDTH, DEFAULT_HEIGHT);

    GLenum err = glGetError();
    if (err != GL_NO_ERROR) {
      printf("OpenGL error: %d\n", err);
    }

    SDL_GL_SwapWindow(this->window);
  #endif
}

Display::~Display(void) {
  #if DAWN_SDL2
    if(this->glContext) {
      SDL_GL_DeleteContext(this->glContext);
      this->glContext = nullptr;
    }

    if(this->window) {
      SDL_DestroyWindow(this->window);
      this->window = nullptr;
    }

    SDL_Quit();
  #endif
}