import { FCM, FcmOptions, FcmMessage } from "fcm-cloudflare-workers";

// Init FCM with options (minimal example)
const fcmOptions = new FcmOptions(
    // Pass in your service account JSON private key file (https://console.firebase.google.com/u/0/project/_/settings/serviceaccounts/adminsdk)
    serviceAccount: JSON.parse(env.FIREBASE_SERVICE_ACCOUNT_JSON),
);

// Or, init FCM with access token caching using KV (optional but recommended for performance)
const fcmOptions = new FcmOptions(
    serviceAccount: JSON.parse(env.FIREBASE_SERVICE_ACCOUNT_JSON),
    // Specify a KV namespace
    kvStore: env.MY_KV_NAMESPACE,
    // Specify a key to use for caching the access token
    kvCacheKey: 'fcm_access_token',
);

const fcmClient = new FCM(fcmOptions);

// Recipient device tokens
const tokens = ["TOKEN_1", "TOKEN_N"];

// Message to send
const message = {
  notification: {
    title: "Test",
    body: "Hello from Cloudflare Workers",
  },
  data: {
    notification: "true",
  },
} satisfies FcmMessage;

try {
  const unregisteredTokens = await fcmClient.sendMulticast(message, tokens);

  // Sending successful
  console.log("Message sent successfully");

  // Remove unregistered tokens from your database
  if (unregisteredTokens.length > 0) {
    console.log(
      "Unregistered device token(s): ",
      unregisteredTokens.join(", ")
    );
  }
} catch (error) {
  console.log("Sending failed", error.message);
}