start adding payment

functions/src/users.js

@@ -18,7 +18,9 @@ const WELCOME_EMAIL_SUBJECT = "Bienvenue sur MusicLand";
 exports.testWelcomMail = onRequest(async (req, res) => {
   if (req.method !== "GET") {
     res.set("Allow", "GET");
-    return res.status(405).json({ success: false, error: "Method not allowed" });
+    return res
+      .status(405)
+      .json({ success: false, error: "Method not allowed" });
   }
   try {
     const targetEmail = req.query.email || "tdtomthomas@gmail.com";
@@ -48,7 +50,27 @@ exports.testWelcomMail = onRequest(async (req, res) => {
 
 exports.onUserCreated = onDocumentCreated("users/{userID}", async (event) => {
   try {
-    const { email = "", firstName = "", lastName = "" } = event?.data?.data();
+    const {
+      email = "",
+      firstName = "",
+      lastName = "",
+    } = event?.data?.data() || {};
+
+    try {
+      await event.data.ref.set(
+        {
+          coins: admin.firestore.FieldValue.increment(10),
+          coinWelcomeGrantedAt: admin.firestore.FieldValue.serverTimestamp(),
+        },
+        { merge: true },
+      );
+    } catch (coinError) {
+      console.warn(
+        "[users-onUserCreated] Unable to grant welcome coins",
+        event?.params?.userID,
+        coinError?.message || coinError,
+      );
+    }
     if (email) {
       if (!resendClient) {
         console.warn("Resend API key not configured; skipping welcome email.");