#include <app/application.h>
#include <platform/input.h>
#include <platform/window.h>
#include <utils/logger.h>
#include <utils/timer.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
}

Application &Application::instance() {
  static Application instance;
  return instance;
}

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

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

  config_ = config;

  PlatformType platform = config_.platform;
  if (platform == PlatformType::Auto) {
#ifdef __SWITCH__
    platform = PlatformType::Switch;
#else
    platform = PlatformType::PC;
#endif
  }

  if (platform == PlatformType::Switch) {
#ifdef __SWITCH__
    Result rc;
    rc = romfsInit();
    if (R_SUCCEEDED(rc)) {
      E2D_LOG_INFO("RomFS initialized successfully");
    } else {
      E2D_LOG_WARN("romfsInit failed: {:#08X}, will use regular filesystem",
                   rc);
    }

    rc = socketInitializeDefault();
    if (R_FAILED(rc)) {
      E2D_LOG_WARN(
          "socketInitializeDefault failed, nxlink will not be available");
    }
#endif
  }

  window_ = unique<Window>();
  WindowConfig winConfig;
  winConfig.title = config.title;
  winConfig.width = config.width;
  winConfig.height = config.height;
  if (platform == PlatformType::Switch) {
    winConfig.fullscreen = true;
    winConfig.fullscreenDesktop = false;
    winConfig.resizable = false;
    winConfig.enableCursors = false;
    winConfig.enableDpiScale = false;
  } else {
    winConfig.fullscreen = config.fullscreen;
    winConfig.resizable = config.resizable;
    winConfig.enableCursors = config.enableCursors;
    winConfig.enableDpiScale = config.enableDpiScale;
  }
  winConfig.vsync = config.vsync;
  winConfig.msaaSamples = config.msaaSamples;

  if (!window_->create(winConfig)) {
    E2D_LOG_ERROR("Failed to create window");
    return false;
  }

  timerManager_ = unique<TimerManager>();

  initialized_ = true;
  running_ = true;

  E2D_LOG_INFO("Application initialized successfully");
  return true;
}

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

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

  timerManager_.reset();

  if (window_) {
    window_->destroy();
    window_.reset();
  }

  PlatformType platform = config_.platform;
  if (platform == PlatformType::Auto) {
#ifdef __SWITCH__
    platform = PlatformType::Switch;
#else
    platform = PlatformType::PC;
#endif
  }
  if (platform == PlatformType::Switch) {
#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();

#ifdef __SWITCH__
  while (running_ && !window_->shouldClose()) {
    mainLoop();
  }
#else
  while (running_ && !window_->shouldClose()) {
    mainLoop();
  }
#endif
}

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

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

void Application::resume() {
  if (paused_) {
    paused_ = false;
    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;
  }

  window_->pollEvents();

  if (!paused_) {
    update();
  }

  window_->swapBuffers();

  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) {
      auto sleepSeconds = target - frameTime;
      std::this_thread::sleep_for(std::chrono::duration<double>(sleepSeconds));
    }
  }
}

void Application::update() {
  if (timerManager_) {
    timerManager_->update(deltaTime_);
  }
}

Input &Application::input() { return *window_->getInput(); }

TimerManager &Application::timers() { return *timerManager_; }

} // namespace extra2d