/*
 * Copyright 2022 Frederico de Oliveira Linhares
 *
 * Licensed under the Apache License, Version 2.0 (the "License");
 * you may not use this file except in compliance with the License.
 * You may obtain a copy of the License at
 *
 *     http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 */

#include <chrono>
#include <thread>

#include "candy_gear.hpp"
#include "core.hpp"
#include "key.hpp"
#include "model.hpp"
#include "rotation3d.hpp"
#include "sound.hpp"
#include "sprite.hpp"
#include "texture.hpp"
#include "vector3d.hpp"

cg_sCore cg_core;

static void handle_error(mrb_state *mrb)
{
    mrb_print_error(mrb);
    cg_core.quit_game = true;
}

int main(int argc, char *argv[])
{
  using namespace std::chrono;
  using namespace std::this_thread;

  SDL_Event event;

  // Random numbers
  random_number_generator.seed(random_seed());

  mrb_value main_obj;
  mrb_sym sym_init, sym_key_down, sym_key_up, sym_quit, sym_tick;
  FILE *fp;

  cg_core.config_file = argv[1];

  try{ cg_sCore::loader.execute(nullptr); }
  catch(const CommandError &error)
  {
    cg_core.log.message(Log::Level::Fatal, error.what());
    return 1;
  }

  mrb_define_module(cg_core.mrb, "CandyGear");
  cg_candy_gear_init(cg_core.mrb);
  cg_key_init(cg_core.mrb);
  cg_model_init(cg_core.mrb);
  cg_rotation3d_init(cg_core.mrb);
  cg_sound_init(cg_core.mrb);
  cg_sprite_init(cg_core.mrb);
  cg_texture_init(cg_core.mrb);
  cg_vector3d_init(cg_core.mrb);

  main_obj = mrb_obj_iv_inspect(cg_core.mrb, cg_core.mrb->top_self);
  sym_init = mrb_intern_cstr(cg_core.mrb, "init");
  sym_key_down = mrb_intern_cstr(cg_core.mrb, "key_down");
  sym_key_up = mrb_intern_cstr(cg_core.mrb, "key_up");
  sym_quit = mrb_intern_cstr(cg_core.mrb, "quit");
  sym_tick = mrb_intern_cstr(cg_core.mrb, "tick");

  fp = fopen(argv[2], "r");
  mrb_load_irep_file(cg_core.mrb, fp);
  fclose(fp);
  if (cg_core.mrb->exc)
    handle_error(cg_core.mrb);
  else
  {
    mrb_funcall_id(cg_core.mrb, main_obj, sym_init, 0);
    if (cg_core.mrb->exc) handle_error(cg_core.mrb);
  }

  auto frame_start = steady_clock::now();

  // Game main loop.
  while(!cg_core.quit_game)
  {
    // Get input.
    while(SDL_PollEvent(&event) != 0)
    {
      switch(event.type)
      {
      case SDL_KEYDOWN:
	mrb_funcall_id(
	  cg_core.mrb, main_obj, sym_key_down, 1,
	  mrb_int_value(cg_core.mrb, event.key.keysym.sym));
	break;
      case SDL_KEYUP:
	mrb_funcall_id(
	  cg_core.mrb, main_obj, sym_key_up, 1,
	  mrb_int_value(cg_core.mrb, event.key.keysym.sym));
	break;
      case SDL_MOUSEMOTION:
	break;
      case SDL_MOUSEBUTTONDOWN:
	break;
      case SDL_MOUSEBUTTONUP:
	break;
      case SDL_QUIT:
	mrb_funcall_id(cg_core.mrb, main_obj, sym_quit, 0);
	break;
      }
    }

    mrb_funcall_id(cg_core.mrb, main_obj, sym_tick, 0);
    if (cg_core.mrb->exc) handle_error(cg_core.mrb);

    cg_core.vk_renderer->draw();

    // Timer
    {
      auto frame_stop = steady_clock::now();
      auto frame_duration = frame_stop - frame_start;

      // If frame take less time than maximum allowed.
      if(cg_core.max_frame_duration > frame_duration)
	sleep_for(cg_core.max_frame_duration - frame_duration);

      frame_start = frame_stop;
    }
  }

  cg_sCore::loader.revert(nullptr);

  return 0;
}