How to Create a User Reward System with Custom Rules in FlutterFlow

1// Cloud Functions: Reward System — Award + Redeem
2const functions = require('firebase-functions');
3const admin = require('firebase-admin');
4admin.initializeApp();
5
6// Generic point award helper
7async function awardPointsForAction(userId, action, reference) {
8  const db = admin.firestore();
9  const ruleSnap = await db.collection('reward_rules')
10    .where('action', '==', action)
11    .where('isActive', '==', true).limit(1).get();
12  if (ruleSnap.empty) return null;
13  const rule = ruleSnap.docs[0].data();
14
15  if (rule.maxPerDay > 0) {
16    const todayStart = new Date();
17    todayStart.setHours(0, 0, 0, 0);
18    const todayAwards = await db.collection('point_transactions')
19      .where('userId', '==', userId)
20      .where('action', '==', action)
21      .where('timestamp', '>=', admin.firestore.Timestamp.fromDate(todayStart))
22      .get();
23    if (todayAwards.size >= rule.maxPerDay) return null;
24  }
25
26  await db.collection('users').doc(userId).update({
27    rewardPoints: admin.firestore.FieldValue.increment(rule.pointsAwarded),
28  });
29  await db.collection('point_transactions').add({
30    userId, action, points: rule.pointsAwarded,
31    reference: reference || '',
32    timestamp: admin.firestore.FieldValue.serverTimestamp(),
33  });
34  return rule.pointsAwarded;
35}
36
37// Trigger: new order
38exports.awardPurchasePoints = functions.firestore
39  .document('orders/{orderId}')
40  .onCreate(async (snap, ctx) => {
41    await awardPointsForAction(snap.data().userId, 'purchase', ctx.params.orderId);
42  });
43
44// Trigger: new review
45exports.awardReviewPoints = functions.firestore
46  .document('reviews/{reviewId}')
47  .onCreate(async (snap, ctx) => {
48    await awardPointsForAction(snap.data().userId, 'review', ctx.params.reviewId);
49  });
50
51// Daily login (callable)
52exports.claimDailyLogin = functions.https.onCall(async (data, context) => {
53  if (!context.auth) throw new functions.https.HttpsError('unauthenticated', 'Login required');
54  const uid = context.auth.uid;
55  const result = await awardPointsForAction(uid, 'daily_login', 'daily');
56  if (result) {
57    await admin.firestore().collection('users').doc(uid).update({
58      lastLoginRewardDate: admin.firestore.FieldValue.serverTimestamp(),
59    });
60  }
61  return { awarded: result || 0 };
62});
63
64// Redeem reward
65exports.redeemReward = functions.https.onCall(async (data, context) => {
66  if (!context.auth) throw new functions.https.HttpsError('unauthenticated', 'Login required');
67  const { rewardId } = data;
68  const uid = context.auth.uid;
69  const db = admin.firestore();
70
71  return db.runTransaction(async (tx) => {
72    const userRef = db.collection('users').doc(uid);
73    const rewardRef = db.collection('rewards_catalog').doc(rewardId);
74    const [userDoc, rewardDoc] = await Promise.all([tx.get(userRef), tx.get(rewardRef)]);
75
76    if (!rewardDoc.exists) throw new functions.https.HttpsError('not-found', 'Reward not found');
77    const reward = rewardDoc.data();
78    if ((userDoc.data().rewardPoints || 0) < reward.pointsCost)
79      throw new functions.https.HttpsError('failed-precondition', 'Insufficient points');
80    if (reward.stock <= 0)
81      throw new functions.https.HttpsError('failed-precondition', 'Out of stock');
82
83    tx.update(userRef, { rewardPoints: admin.firestore.FieldValue.increment(-reward.pointsCost) });
84    tx.update(rewardRef, { stock: admin.firestore.FieldValue.increment(-1) });
85    tx.create(db.collection('redemptions').doc(), {
86      userId: uid, rewardId, rewardName: reward.name,
87      pointsSpent: reward.pointsCost,
88      redeemedAt: admin.firestore.FieldValue.serverTimestamp(),
89    });
90    return { success: true };
91  });
92});