(() => {
  if (!('serviceWorker' in navigator)) return;

  const toast = document.querySelector('[data-pwa-toast]');
  const title = toast?.querySelector('[data-pwa-title]');
  const message = toast?.querySelector('[data-pwa-message]');
  const primary = toast?.querySelector('[data-pwa-primary]');
  const close = toast?.querySelector('[data-pwa-close]');
  let installPrompt = null;
  let waitingWorker = null;
  let toastMode = '';
  let refreshing = false;

  const showToast = (mode, heading, detail, actionLabel) => {
    if (!toast || !title || !message || !primary) return;
    toastMode = mode;
    title.textContent = heading;
    message.textContent = detail;
    primary.textContent = actionLabel;
    primary.hidden = !actionLabel;
    toast.hidden = false;
  };

  const hideToast = () => {
    if (toast) toast.hidden = true;
  };

  const installDismissedRecently = () => {
    try {
      const dismissedAt = Number(localStorage.getItem('pwa-install-dismissed-at'));
      return dismissedAt > 0 && Date.now() - dismissedAt < 30 * 86400000;
    } catch {
      return false;
    }
  };

  window.addEventListener('beforeinstallprompt', (event) => {
    event.preventDefault();
    installPrompt = event;
    if (!installDismissedRecently()) {
      window.setTimeout(() => {
        if (installPrompt) showToast('install', '安装 Bi\'s Blog', '添加到桌面，像应用一样打开并阅读缓存过的文章。', '立即安装');
      }, 2500);
    }
  });

  window.addEventListener('appinstalled', () => {
    installPrompt = null;
    showToast('ready', '安装完成', '博客已经添加到你的设备。', '知道了');
  });

  primary?.addEventListener('click', async () => {
    if (toastMode === 'install' && installPrompt) {
      await installPrompt.prompt();
      await installPrompt.userChoice;
      installPrompt = null;
      hideToast();
      return;
    }

    if (toastMode === 'update' && waitingWorker) {
      refreshing = true;
      waitingWorker.postMessage({ type: 'SKIP_WAITING' });
      return;
    }

    hideToast();
  });

  close?.addEventListener('click', () => {
    if (toastMode === 'install') {
      try { localStorage.setItem('pwa-install-dismissed-at', String(Date.now())); } catch {}
    }
    hideToast();
  });

  navigator.serviceWorker.addEventListener('controllerchange', () => {
    if (refreshing) window.location.reload();
  });

  navigator.serviceWorker.register('/sw.js', { scope: '/' }).then((registration) => {
    if (registration.waiting && navigator.serviceWorker.controller) {
      waitingWorker = registration.waiting;
      showToast('update', '发现新版本', '刷新后即可使用博客的最新内容和功能。', '立即更新');
    }

    registration.addEventListener('updatefound', () => {
      const worker = registration.installing;
      worker?.addEventListener('statechange', () => {
        if (worker.state === 'installed' && navigator.serviceWorker.controller) {
          waitingWorker = worker;
          showToast('update', '发现新版本', '刷新后即可使用博客的最新内容和功能。', '立即更新');
        }
      });
    });
  }).catch((error) => {
    console.warn('PWA registration failed:', error);
  });

  const params = new URLSearchParams(window.location.search);
  if (params.get('action') === 'search') {
    window.setTimeout(() => document.querySelector('.search-typesense-trigger')?.click(), 350);
  }
})();