// Service Worker for Zellyy Finance PWA
const CACHE_NAME = "zellyy-finance-v1";
const STATIC_CACHE_NAME = `${CACHE_NAME}-static`;
const DYNAMIC_CACHE_NAME = `${CACHE_NAME}-dynamic`;
const API_CACHE_NAME = `${CACHE_NAME}-api`;

// Static files to cache
const STATIC_FILES = [
  "/",
  "/manifest.json",
  "/favicon.ico",
  "/zellyy.png",
  "/og-image.png",
  "/placeholder.svg",
];

// API endpoints to cache
const API_ENDPOINTS = ["/api/transactions", "/api/budgets", "/api/analytics"];

// Install event - cache static files
self.addEventListener("install", (event) => {
  console.log("Service Worker: Installing...");

  event.waitUntil(
    caches
      .open(STATIC_CACHE_NAME)
      .then((cache) => {
        console.log("Service Worker: Caching static files");
        return cache.addAll(STATIC_FILES);
      })
      .then(() => {
        console.log("Service Worker: Installation complete");
        return self.skipWaiting();
      })
      .catch((error) => {
        console.error("Service Worker: Installation failed:", error);
      })
  );
});

// Activate event - clean up old caches
self.addEventListener("activate", (event) => {
  console.log("Service Worker: Activating...");

  event.waitUntil(
    caches
      .keys()
      .then((cacheNames) => {
        return Promise.all(
          cacheNames.map((cacheName) => {
            if (
              cacheName !== STATIC_CACHE_NAME &&
              cacheName !== DYNAMIC_CACHE_NAME &&
              cacheName !== API_CACHE_NAME
            ) {
              console.log("Service Worker: Deleting old cache:", cacheName);
              return caches.delete(cacheName);
            }
          })
        );
      })
      .then(() => {
        console.log("Service Worker: Activation complete");
        return self.clients.claim();
      })
      .catch((error) => {
        console.error("Service Worker: Activation failed:", error);
      })
  );
});

// Fetch event - handle network requests
self.addEventListener("fetch", (event) => {
  const { request } = event;
  const url = new URL(request.url);

  // Handle different types of requests
  if (request.method !== "GET") {
    // Don't cache non-GET requests
    return;
  }

  // Handle API requests
  if (isApiRequest(url)) {
    event.respondWith(handleApiRequest(request));
    return;
  }

  // Handle static assets
  if (isStaticAsset(url)) {
    event.respondWith(handleStaticAsset(request));
    return;
  }

  // Handle navigation requests (HTML pages)
  if (isNavigationRequest(request)) {
    event.respondWith(handleNavigationRequest(request));
    return;
  }

  // Default: network first, cache fallback
  event.respondWith(
    fetch(request)
      .then((response) => {
        // Cache successful responses
        if (response.status === 200) {
          const responseClone = response.clone();
          caches
            .open(DYNAMIC_CACHE_NAME)
            .then((cache) => cache.put(request, responseClone));
        }
        return response;
      })
      .catch(() => {
        // Fallback to cache
        return caches.match(request);
      })
  );
});

// Handle API requests with network-first strategy
async function handleApiRequest(request) {
  try {
    const networkResponse = await fetch(request);

    if (networkResponse.ok) {
      // Cache successful API responses
      const responseClone = networkResponse.clone();
      const cache = await caches.open(API_CACHE_NAME);
      await cache.put(request, responseClone);
      return networkResponse;
    }

    throw new Error(`API request failed: ${networkResponse.status}`);
  } catch (error) {
    console.log("Service Worker: Network failed, trying cache:", error);

    // Fallback to cache
    const cachedResponse = await caches.match(request);
    if (cachedResponse) {
      return cachedResponse;
    }

    // Return offline page for failed API requests
    return new Response(
      JSON.stringify({
        error: "Offline - data not available",
        offline: true,
        timestamp: Date.now(),
      }),
      {
        status: 503,
        statusText: "Service Unavailable",
        headers: {
          "Content-Type": "application/json",
        },
      }
    );
  }
}

// Handle static assets with cache-first strategy
async function handleStaticAsset(request) {
  const cachedResponse = await caches.match(request);

  if (cachedResponse) {
    return cachedResponse;
  }

  try {
    const networkResponse = await fetch(request);

    if (networkResponse.ok) {
      const responseClone = networkResponse.clone();
      const cache = await caches.open(DYNAMIC_CACHE_NAME);
      await cache.put(request, responseClone);
    }

    return networkResponse;
  } catch (error) {
    console.error("Service Worker: Failed to fetch static asset:", error);

    // Return placeholder for failed static assets
    if (
      request.url.includes(".png") ||
      request.url.includes(".jpg") ||
      request.url.includes(".svg")
    ) {
      return caches.match("/placeholder.svg");
    }

    throw error;
  }
}

// Handle navigation requests with network-first strategy
async function handleNavigationRequest(request) {
  try {
    const networkResponse = await fetch(request);

    if (networkResponse.ok) {
      const responseClone = networkResponse.clone();
      const cache = await caches.open(DYNAMIC_CACHE_NAME);
      await cache.put(request, responseClone);
    }

    return networkResponse;
  } catch (error) {
    console.log("Service Worker: Navigation network failed, trying cache");

    // Fallback to cached version
    const cachedResponse = await caches.match(request);
    if (cachedResponse) {
      return cachedResponse;
    }

    // Fallback to cached index.html for SPA routing
    return caches.match("/");
  }
}

// Helper functions
function isApiRequest(url) {
  return (
    url.pathname.startsWith("/api/") ||
    url.hostname !== self.location.hostname ||
    API_ENDPOINTS.some((endpoint) => url.pathname.includes(endpoint))
  );
}

function isStaticAsset(url) {
  const pathname = url.pathname;
  return (
    pathname.includes(".") &&
    (pathname.endsWith(".js") ||
      pathname.endsWith(".css") ||
      pathname.endsWith(".png") ||
      pathname.endsWith(".jpg") ||
      pathname.endsWith(".jpeg") ||
      pathname.endsWith(".svg") ||
      pathname.endsWith(".webp") ||
      pathname.endsWith(".ico") ||
      pathname.endsWith(".woff") ||
      pathname.endsWith(".woff2") ||
      pathname.endsWith(".ttf") ||
      pathname.endsWith(".eot"))
  );
}

function isNavigationRequest(request) {
  return (
    request.mode === "navigate" ||
    (request.method === "GET" &&
      request.headers.get("accept").includes("text/html"))
  );
}

// Push notification event
self.addEventListener("push", (event) => {
  console.log("Service Worker: Push notification received");

  let data = {};

  if (event.data) {
    try {
      data = event.data.json();
    } catch (error) {
      data = { title: event.data.text() || "Zellyy Finance" };
    }
  }

  const options = {
    title: data.title || "Zellyy Finance",
    body: data.body || "새로운 알림이 있습니다.",
    icon: "/zellyy.png",
    badge: "/zellyy.png",
    data: data.url || "/",
    actions: [
      {
        action: "open",
        title: "열기",
      },
      {
        action: "close",
        title: "닫기",
      },
    ],
    vibrate: [100, 50, 100],
    tag: "zellyy-notification",
  };

  event.waitUntil(self.registration.showNotification(options.title, options));
});

// Notification click event
self.addEventListener("notificationclick", (event) => {
  console.log("Service Worker: Notification clicked");

  event.notification.close();

  if (event.action === "close") {
    return;
  }

  const urlToOpen = event.notification.data || "/";

  event.waitUntil(
    clients
      .matchAll({ type: "window", includeUncontrolled: true })
      .then((clientList) => {
        // Check if app is already open
        for (const client of clientList) {
          if (client.url === urlToOpen && "focus" in client) {
            return client.focus();
          }
        }

        // Open new window
        if (clients.openWindow) {
          return clients.openWindow(urlToOpen);
        }
      })
  );
});

// Background sync event (for future use)
self.addEventListener("sync", (event) => {
  console.log("Service Worker: Background sync triggered");

  if (event.tag === "background-sync") {
    event.waitUntil(
      // Handle background sync tasks
      handleBackgroundSync()
    );
  }
});

async function handleBackgroundSync() {
  try {
    // Sync pending transactions or other offline data
    console.log("Service Worker: Performing background sync");

    // This would sync any pending data when network is available
    // Implementation depends on app's offline storage strategy
  } catch (error) {
    console.error("Service Worker: Background sync failed:", error);
  }
}

// Message event for communication with main thread
self.addEventListener("message", (event) => {
  console.log("Service Worker: Message received:", event.data);

  switch (event.data.type) {
    case "SKIP_WAITING":
      self.skipWaiting();
      break;

    case "GET_CACHE_SIZE":
      getCacheSize().then((size) => {
        event.ports[0].postMessage({ cacheSize: size });
      });
      break;

    case "CLEAR_CACHE":
      clearAllCaches().then(() => {
        event.ports[0].postMessage({ cleared: true });
      });
      break;

    default:
      console.log("Service Worker: Unknown message type:", event.data.type);
  }
});

async function getCacheSize() {
  const cacheNames = await caches.keys();
  let totalSize = 0;

  for (const cacheName of cacheNames) {
    const cache = await caches.open(cacheName);
    const requests = await cache.keys();
    totalSize += requests.length;
  }

  return totalSize;
}

async function clearAllCaches() {
  const cacheNames = await caches.keys();

  return Promise.all(cacheNames.map((cacheName) => caches.delete(cacheName)));
}