// Service Worker registration with automatic update detection for Next.js
// This ensures users always get the latest version after deployment

type Config = {
  onUpdate?: (registration: ServiceWorkerRegistration) => void;
  onSuccess?: (registration: ServiceWorkerRegistration) => void;
};

export function register(config?: Config) {
  if (typeof window !== 'undefined' && 'serviceWorker' in navigator) {
    // Wait for page load to avoid impacting initial page load performance
    window.addEventListener('load', () => {
      const swUrl = `/sw.js`;

      registerValidSW(swUrl, config);

      // Check for updates every hour
      setInterval(() => {
        checkForUpdates(swUrl);
      }, 60 * 60 * 1000); // 1 hour
    });
  }
}

function registerValidSW(swUrl: string, config?: Config) {
  navigator.serviceWorker
    .register(swUrl)
    .then((registration) => {
      // Check for updates on initial registration
      registration.update();

      registration.onupdatefound = () => {
        const installingWorker = registration.installing;
        if (installingWorker == null) {
          return;
        }

        installingWorker.onstatechange = () => {
          if (installingWorker.state === 'installed') {
            if (navigator.serviceWorker.controller) {
              // New content is available; please refresh
              console.log('New content available! Please refresh.');

              // Execute onUpdate callback
              if (config && config.onUpdate) {
                config.onUpdate(registration);
              }
            } else {
              // Content is cached for offline use
              console.log('Content cached for offline use.');

              // Execute onSuccess callback
              if (config && config.onSuccess) {
                config.onSuccess(registration);
              }
            }
          }
        };
      };
    })
    .catch((error) => {
      console.error('Error during service worker registration:', error);
    });
}

function checkForUpdates(swUrl: string) {
  navigator.serviceWorker
    .getRegistration(swUrl)
    .then((registration) => {
      if (registration) {
        registration.update();
      }
    })
    .catch((error) => {
      console.error('Error checking for service worker updates:', error);
    });
}

export function unregister() {
  if (typeof window !== 'undefined' && 'serviceWorker' in navigator) {
    navigator.serviceWorker.ready
      .then((registration) => {
        registration.unregister();
      })
      .catch((error) => {
        console.error(error.message);
      });
  }
}

// Force refresh when a new service worker is waiting
export function skipWaitingAndReload() {
  if (typeof window !== 'undefined') {
    navigator.serviceWorker.ready.then((registration) => {
      if (registration.waiting) {
        // Tell the waiting service worker to skip waiting and become active
        registration.waiting.postMessage({ type: 'SKIP_WAITING' });
      }
    });

    // Listen for the controller change and reload
    navigator.serviceWorker.addEventListener('controllerchange', () => {
      window.location.reload();
    });
  }
}