Cloud functions for referral rewards and notifications

index.js

exports.referralUpdate = functions.database.ref('/rewards/{uid}/referredBy').onCreate((data, context) => {
  const snapshot = data;
  const uid = context.params.uid;
  const referredByUid = snapshot.val().uid;
  const referredByClientIdKey = snapshot.val().clientIdKey;
  return admin.database().ref(`/users/${referredByUid}/clients`).once('value').then(dataSnapshot => {
    var validReferral = true;
    var value = dataSnapshot.val();
    if (value) {
      dataSnapshot.forEach(function(snapshot) {
          if (referredByClientIdKey == snapshot.key) {
            validReferral = false;
          }
      });
    }

    if(!validReferral) {
      return utils.logInfo("Invalid referral", {user: uid, from : referredByUid});
    }
    //Compare client ids
    return admin.database().ref(`/rewards/${referredByUid}/referrals/${uid}`).set(true).then(result => {
      return utils.logInfo("Added referral", {user: uid, from : referredByUid});
    }).catch(error => {
      return utils.reportError(error, { type: 'database_write', context: 'referral update2'});
    });
  }).catch(error => {
    return utils.reportError(error, { type: 'database_write', context: 'referral update1'});
  });
});

exports.referralReward = functions.database.ref('/rewards/{uid}/referrals').onUpdate((data, context) => {
  const uid = context.params.uid;
  const snapshot = data;
  return admin.database().ref(`/users/${uid}`).once('value').then(dataSnapshot => {
    const referralCount = snapshot.numChildren();
    const purchaseToken = dataSnapshot.val().subscriptionToken;
    const subscriptionId = dataSnapshot.val().subscriptionId;
    const orderId = dataSnapshot.val().orderId;
    const subscriptionStatus = dataSnapshot.val().subscriptionStatus;
    const instanceId = dataSnapshot.val().instanceId;
    const notificationKey = dataSnapshot.val().notificationKey;

    // if referrals are more than 52/2*7 then stop
    if(referralCount > 182){
      return utils.logInfo("Referral limit reached", {user: uid});
    }

    if(subscriptionStatus == 0){
      //TODO: Remove previous referrals if subscription is cancelled
      return utils.logInfo("Not subscribed", {user: uid});
    }

    // send notification for every 7 referrals
    const giveReward = referralCount % 7 == 0;
    if (!giveReward) {
      const message = `One of your referrals has just signed up. Your total referral count is ${referralCount}`;
      return sendReferralNotifications(message, uid, instanceId, notificationKey);
    }

    if (orderId.startsWith('GPA')){
      if (!purchaseToken) {
        return utils.reportError("No purchaseToken", {user: uid, context: 'referral reward'});
      }

      return utils.extendSubscription(uid, purchaseToken, subscriptionId).then(result => {
        utils.logInfo("Reward referral", {user: uid});
        const message = "You have been rewarded a week subcription FREE";
        return sendReferralNotifications(message, uid, instanceId, notificationKey);
      }).catch(error => {
        return utils.reportError(error, {user: uid, context: 'referral reward'});
      });
    } else{
      //TODO: figure out something for iOS users
      return utils.logInfo("Not reward for iOS users", {user: uid});
    }
  }).catch(error => {
    return utils.reportError(error, {type: 'database_query', context: 'referral reward'});
  });
});

function sendReferralNotifications(message, userId, instanceId, notificationKey) {
  const ttl = 60 * 60 * 24;
  const payload = {
    notification: {
      title: "Reward",
      body: message,
      sound: 'default',
      icon: 'ic_reward',
      android_channel_id: "info_channel",
      tag: "Reward"
    },
    data: {
      title: "Reward",
      body: message,
      sound: 'default',
      icon: 'ic_reward',
      type: "reward",
      android_channel_id: "info_channel",
      tag: "Reward"
    }
  };

  var options = {
    priority: "normal",
    timeToLive: ttl,
    mutableContent: true,
  };

  return utils.sendNotification(userId, instanceId, notificationKey,  payload, options);
}