// Service Worker version
const CACHE_VERSION = 'v1.0.0';
const CACHE_NAME = `game-timer-${CACHE_VERSION}`;

// Files to cache
const CACHE_FILES = [
  './',
  './index.html',
  '../src/js/app.js',
  '../src/js/ui/audio.js',
  './css/styles.css',
  './manifest.json',
  './icons/android-chrome-192x192.png',
  './icons/android-chrome-512x512.png',
  './icons/apple-touch-icon.png',
  './icons/favicon-32x32.png',
  './icons/favicon-16x16.png'
];

// Install event - Cache files
self.addEventListener('install', event => {
  console.log('[ServiceWorker] Install');
  event.waitUntil(
    caches.open(CACHE_NAME)
      .then(cache => {
        console.log('[ServiceWorker] Caching app shell');
        return cache.addAll(CACHE_FILES);
      })
      .then(() => {
        console.log('[ServiceWorker] Skip waiting on install');
        return self.skipWaiting();
      })
  );
});

// Activate event - Clean old caches
self.addEventListener('activate', event => {
  console.log('[ServiceWorker] Activate');
  event.waitUntil(
    caches.keys().then(keyList => {
      return Promise.all(keyList.map(key => {
        if (key !== CACHE_NAME) {
          console.log('[ServiceWorker] Removing old cache', key);
          return caches.delete(key);
        }
      }));
    })
    .then(() => {
      console.log('[ServiceWorker] Claiming clients');
      return self.clients.claim();
    })
  );
});

// Helper function to determine if a response should be cached
function shouldCacheResponse(request, response) {
  // Only cache GET requests
  if (request.method !== 'GET') return false;
  
  // Don't cache errors
  if (!response || response.status !== 200) return false;
  
  // Check if URL should be cached
  const url = new URL(request.url);
  
  // Don't cache query parameters (except common ones for content)
  if (url.search && !url.search.match(/\?(v|version|cache)=/)) return false;
  
  return true;
}

self.addEventListener('push', event => {
  console.log('[ServiceWorker] Push received');
  
  let pushData = {
    title: 'Flic Action',
    body: 'Button pressed!',
    data: { 
      action: 'Unknown', 
      button: 'Unknown',
      batteryLevel: undefined
    }
  };

  // --- Attempt to parse data payload ---
  if (event.data) {
    try {
      const parsedData = event.data.json();
      console.log('[ServiceWorker] Push data:', parsedData);

      // Use parsed data for notification and message
      pushData = {
        title: parsedData.title || pushData.title,
        body: parsedData.body || pushData.body,
        data: parsedData.data || pushData.data // Expecting { action: 'SingleClick', button: 'game-button', batteryLevel: 75 }
      };
      
    } catch (e) {
      console.error('[ServiceWorker] Error parsing push data:', e);
      // Use default notification if parsing fails
      pushData.body = event.data.text() || pushData.body; // Fallback to text
    }
  } else {
    console.log('[ServiceWorker] Push event but no data');
  }

  // --- Send message to client(s) ---
  const messagePayload = {
    type: 'flic-action', // Custom message type
    action: pushData.data.action, // e.g., 'SingleClick', 'DoubleClick', 'Hold'
    button: pushData.data.button,  // e.g., the button name
    timestamp: pushData.data.timestamp, // e.g., the timestamp of the action
    batteryLevel: pushData.data.batteryLevel // e.g., the battery level percentage
  };

  // Send message to all open PWA windows controlled by this SW
  event.waitUntil(
    self.clients.matchAll({
      type: 'window', // Only target window clients
      includeUncontrolled: true // Include clients that might not be fully controlled yet
    }).then(clientList => {
      if (!clientList || clientList.length === 0) {
        console.log('[ServiceWorker] No client windows found to send message to.');
        // If no window is open, we MUST show a notification
        return self.registration.showNotification(pushData.title, {
          body: pushData.body,
          icon: './icons/android-chrome-192x192.png', // Optional: path to an icon
          data: pushData.data // Pass data if needed when notification is clicked
        });
      }

      // Post message to each client
      let messageSent = false;
      clientList.forEach(client => {
        console.log(`[ServiceWorker] Posting message to client: ${client.id}`, messagePayload);
        client.postMessage(messagePayload);
        messageSent = true; // Mark that we at least tried to send a message
      });

      // Decide whether to still show a notification even if a window is open.
      // Generally good practice unless you are SURE the app will handle it visibly.
      // You might choose *not* to show a notification if a client was found and focused.
      // For simplicity here, we'll still show one. Adjust as needed.
      if (!messageSent) { // Only show notification if no message was sent? Or always show?
        return self.registration.showNotification(pushData.title, {
          body: pushData.body,
          icon: './icons/android-chrome-192x192.png',
          data: pushData.data
        });
      }
    })
  );

  // --- Show a notification (Important!) ---
  // Push notifications generally REQUIRE showing a notification to the user
  // unless the PWA is already in the foreground AND handles the event visually.
  // It's safer to always show one unless you have complex foreground detection.
  /* This part is now handled inside the clients.matchAll promise */
  /*
  const notificationOptions = {
      body: pushData.body,
      icon: './icons/android-chrome-192x192.png', // Optional: path to an icon
      data: pushData.data // Attach data if needed when notification is clicked
  };
  event.waitUntil(
      self.registration.showNotification(pushData.title, notificationOptions)
  );
  */
});

// This helps with navigation after app is installed
self.addEventListener('notificationclick', event => {
  console.log('[ServiceWorker] Notification click received');
  
  event.notification.close();
  
  // Handle the notification click
  event.waitUntil(
    self.clients.matchAll({ type: 'window' })
      .then(clientList => {
        for (const client of clientList) {
          if (client.url.startsWith(self.location.origin) && 'focus' in client) {
            return client.focus();
          }
        }
        
        if (self.clients.openWindow) {
          return self.clients.openWindow('./');
        }
      })
  );
});