#include <app/application.h>
#include <context/context.h>
#include <event/events.h>
#include <platform/sdl2.h>
#include <utils/logger.h>

#include <chrono>
#include <thread>

#ifdef __SWITCH__
#include <switch.h>
#endif

namespace extra2d {

/**
 * @brief 获取当前时间（秒）
 */
static double getTimeSeconds() {
#ifdef __SWITCH__
  struct timespec ts;
  clock_gettime(CLOCK_MONOTONIC, &ts);
  return static_cast<double>(ts.tv_sec) +
         static_cast<double>(ts.tv_nsec) / 1000000000.0;
#else
  using namespace std::chrono;
  auto now = steady_clock::now();
  auto duration = now.time_since_epoch();
  return duration_cast<std::chrono::duration<double>>(duration).count();
#endif
}

std::unique_ptr<Application> Application::create() {
  return std::unique_ptr<Application>(new Application());
}

Application::Application() = default;

Application::~Application() {
  shutdown();
}

Application::Application(Application&&) noexcept = default;
Application& Application::operator=(Application&&) noexcept = default;

bool Application::init(const AppConfig &config) {
  if (initialized_) {
    E2D_LOG_WARN("Application already initialized");
    return true;
  }

  config_ = config;

#ifdef __SWITCH__
  Result rc;
  rc = romfsInit();
  if (R_SUCCEEDED(rc)) {
    E2D_LOG_INFO("RomFS initialized successfully");
  } else {
    E2D_LOG_WARN("romfsInit failed: {:#08X}", rc);
  }

  rc = socketInitializeDefault();
  if (R_FAILED(rc)) {
    E2D_LOG_WARN("socketInitializeDefault failed");
  }
#endif

  if (!Sdl2::initAll()) {
    E2D_LOG_ERROR("Failed to initialize SDL2");
    return false;
  }

  // 创建引擎上下文
  context_ = Context::create();
  if (!context_) {
    E2D_LOG_ERROR("Failed to create context");
    return false;
  }

  // 初始化引擎
  if (!context_->init()) {
    E2D_LOG_ERROR("Failed to initialize context");
    return false;
  }

  initialized_ = true;
  running_ = true;

  events::OnInit::emit();

  E2D_LOG_INFO("Application initialized successfully");
  E2D_LOG_INFO("Window: {}x{}, Fullscreen: {}, VSync: {}", config_.width,
               config_.height, config_.fullscreen, config_.vsync);
  return true;
}

void Application::shutdown() {
  if (!initialized_)
    return;

  events::OnShutdown::emit();

  E2D_LOG_INFO("Shutting down application...");

  // 关闭上下文（会自动关闭模块和插件）
  context_.reset();

  Sdl2::shutdown();

#ifdef __SWITCH__
  romfsExit();
  socketExit();
#endif

  initialized_ = false;
  running_ = false;

  E2D_LOG_INFO("Application shutdown complete");
}

void Application::run() {
  if (!initialized_) {
    E2D_LOG_ERROR("Application not initialized");
    return;
  }

  lastFrameTime_ = getTimeSeconds();

  while (running_) {
    mainLoop();
  }
}

void Application::quit() {
  shouldQuit_ = true;
  running_ = false;
}

void Application::pause() {
  if (!paused_) {
    paused_ = true;
    events::OnPause::emit();
    E2D_LOG_INFO("Application paused");
  }
}

void Application::resume() {
  if (paused_) {
    paused_ = false;
    events::OnResume::emit();
    lastFrameTime_ = getTimeSeconds();
    E2D_LOG_INFO("Application resumed");
  }
}

void Application::mainLoop() {
  double currentTime = getTimeSeconds();
  deltaTime_ = static_cast<float>(currentTime - lastFrameTime_);
  lastFrameTime_ = currentTime;

  totalTime_ += deltaTime_;

  frameCount_++;
  fpsTimer_ += deltaTime_;
  if (fpsTimer_ >= 1.0f) {
    currentFps_ = frameCount_;
    frameCount_ = 0;
    fpsTimer_ -= 1.0f;
  }

  if (!paused_) {
    update();
  }

  // 帧率限制
  if (!config_.vsync && config_.fpsLimit > 0) {
    double frameEndTime = getTimeSeconds();
    double frameTime = frameEndTime - currentTime;
    double target = 1.0 / static_cast<double>(config_.fpsLimit);
    if (frameTime < target) {
      std::this_thread::sleep_for(
          std::chrono::duration<double>(target - frameTime));
    }
  }
}

void Application::update() {
  // 通过上下文更新引擎
  if (context_) {
    context_->tick(deltaTime_);
  }
}

} // namespace extra2d