firebase functions verifyAndroid Android 購入を検証してFirestoreに保存する

purchase.js

exports.verifyAndroid = functions.https.onCall(async (data, context) => {
  if (context.auth === null) {
    return { result: NO_AUTH };
  }

  const uid = context.auth.uid;
  const verificationData = data["data"];

  const latestReceipt = await verifyReceiptAndroid(
    verificationData,
    context.auth
  );

  if (latestReceipt === null || latestReceipt === undefined) {
    return { result: INVALID_RECEIPT };
  }

  // 同じorderIdが存在しないか確認し、購入情報が既に登録済みでないか確認する
  const queryId = await admin.firestore().collectionGroup("receipts")
    .where("orderId", "==", latestReceipt["orderId"])
    .get();

  if (!queryId.empty) {
    return { result: ALREADY_EXIST };
  }

  // Firestoreに保存する
  const decodedReceipt = JSON.parse(verificationData);
  const purchaseDate = new Date(parseInt(latestReceipt["startTimeMillis"]));
  const expiresDate = new Date(parseInt(latestReceipt["expiryTimeMillis"]));
  const receiptRef = admin.firestore().collection('users').doc(uid).collection('receipts').doc();
  const result = await receiptRef.set({
    receipt_data : verificationData,
    product_id : decodedReceipt["productId"],
    orderId : latestReceipt["orderId"],
    purchase_date_ms : parseInt(latestReceipt["startTimeMillis"]),
    purchase_date : purchaseDate.toString(),
    expires_date_ms : parseInt(latestReceipt["expiryTimeMillis"]),
    expires_date : expiresDate.toString(),
    created_at: Firestore.FieldValue.serverTimestamp(),
  });

  // 期限内であることを確認する
  const now = Date.now();
  const expireDate = Number(latestReceipt["expiryTimeMillis"]);
  if (now < expireDate) {
    return { result: SUCCESS };
  } else {
    return { result: EXPIRED };
  }
});