feat(notification-ms): add template mapping resolution for multi-channel dispatch

- Strip "Bearer " prefix from WhatsApp access tokens to handle pre-formatted tokens
- Add token normalization in both WhatsApp send and validate methods
- Refactor _get_merchant_notification_config to use new _get_merchant_settings helper
- Fetch both notification_channels and notification_templates in single query
- Implement template name resolution per channel using merchant notification_templates mapping
- Add WhatsApp template name mapping with fallback to doc template_name
- Add SMS template ID resolution from merchant settings with fallback
- Add email template ID resolution from merchant settings with fallback
- Add logging for WhatsApp and SMS template resolution for debugging
- Enables merchants to map generic template names to channel-specific template identifiers

app/channels/whatsapp.py

@@ -45,8 +45,12 @@ class WhatsAppChannel:
             return False, "WhatsApp channel not configured for this merchant", None
 
         whatsapp_number = WhatsAppChannel._normalize_number(recipient)
+        # Strip existing "Bearer " prefix if already included in stored token
+        token = access_token.strip()
+        if token.lower().startswith("bearer "):
+            token = token[7:]
         headers = {
-            "Authorization": f"Bearer {access_token.strip()}",
+            "Authorization": f"Bearer {token}",
             "Content-Type": "application/json",
         }
 
@@ -112,8 +116,11 @@ class WhatsAppChannel:
             return False, False, None
 
         number = WhatsAppChannel._normalize_number(mobile)
+        token = access_token.strip()
+        if token.lower().startswith("bearer "):
+            token = token[7:]
         headers = {
-            "Authorization": f"Bearer {access_token.strip()}",
+            "Authorization": f"Bearer {token}",
             "Content-Type": "application/json",
         }
         try:

app/services/dispatcher.py

@@ -31,18 +31,31 @@ class NotificationDispatcher:
     """Dispatches a notification doc through its requested channels."""
 
     @staticmethod
-    async def _get_merchant_notification_config(
+    async def _get_merchant_settings(
         merchant_id: str,
     ) -> Optional[Dict[str, Any]]:
         """
-        Fetch notification_channels from scm_merchant_settings for a merchant.
-        Returns the notification_channels dict or None.
+        Fetch notification_channels and notification_templates from scm_merchant_settings.
+        Returns dict with both keys, or None if not found.
         """
         db = get_database()
         doc = await db[settings.MERCHANT_SETTINGS_COLLECTION].find_one(
             {"merchant_id": merchant_id},
-            {"_id": 0, "notification_channels": 1},
+            {"_id": 0, "notification_channels": 1, "notification_templates": 1},
         )
+        if not doc:
+            return None
+        return doc
+
+    @staticmethod
+    async def _get_merchant_notification_config(
+        merchant_id: str,
+    ) -> Optional[Dict[str, Any]]:
+        """
+        Fetch notification_channels from scm_merchant_settings for a merchant.
+        Returns the notification_channels dict or None.
+        """
+        doc = await NotificationDispatcher._get_merchant_settings(merchant_id)
         if not doc:
             return None
         return doc.get("notification_channels")
@@ -108,9 +121,9 @@ class NotificationDispatcher:
             doc["status"] = NotificationStatus.FAILED.value
             return doc
 
-        # Fetch merchant notification config
-        notification_config = await NotificationDispatcher._get_merchant_notification_config(merchant_id)
-        if not notification_config:
+        # Fetch merchant notification config + template mappings
+        merchant_settings = await NotificationDispatcher._get_merchant_settings(merchant_id)
+        if not merchant_settings:
             await collection.update_one(
                 {"notification_id": nid},
                 {
@@ -127,6 +140,10 @@ class NotificationDispatcher:
             doc["status"] = NotificationStatus.FAILED.value
             return doc
 
+        notification_config = merchant_settings.get("notification_channels", {})
+        # notification_templates maps template_name → {whatsapp_template_name, sms_template_id, email_template_id}
+        notification_templates = merchant_settings.get("notification_templates", {})
+
         # Mark as sending
         await collection.update_one(
             {"notification_id": nid},
@@ -174,7 +191,9 @@ class NotificationDispatcher:
                 }
                 continue
 
-            # Dispatch to channel — resolve templates for SMS and email
+            # Resolve channel-specific template name from merchant notification_templates mapping
+            # e.g. notification_templates["password_reset"] = {whatsapp_template_name: "...", sms_template_id: "..."}
+            tpl_mapping = notification_templates.get(doc["template_name"], {})
 
             if channel_enum == NotificationChannel.PUSH:
                 success, message, provider_id = await PushChannel.send(
@@ -185,29 +204,36 @@ class NotificationDispatcher:
                     merchant_id=merchant_id,
                 )
             elif channel_enum == NotificationChannel.WHATSAPP:
+                # Use merchant-mapped WATI template name if available, else fall back to doc template_name
+                wa_template_name = tpl_mapping.get("whatsapp_template_name") or doc["template_name"]
+                logger.info(f"WhatsApp template resolved: {doc['template_name']} → {wa_template_name}")
                 success, message, provider_id = await WhatsAppChannel.send(
                     recipient=doc["recipient"],
-                    template_name=doc["template_name"],
+                    template_name=wa_template_name,
                     template_data=raw_data,
                     channel_config=ch_config,
                 )
             elif channel_enum == NotificationChannel.EMAIL:
+                email_tpl_id = tpl_mapping.get("email_template_id") or doc["template_name"]
                 resolved_data = await NotificationDispatcher._resolve_template(
-                    doc["template_name"], "email", raw_data
+                    email_tpl_id, "email", raw_data
                 )
                 success, message, provider_id = await EmailChannel.send(
                     recipient=doc["recipient"],
-                    template_name=doc["template_name"],
+                    template_name=email_tpl_id,
                     template_data=resolved_data,
                     channel_config=ch_config,
                 )
             elif channel_enum == NotificationChannel.SMS:
+                # sms_template_id is the name of the template in notification_templates collection
+                sms_tpl_name = tpl_mapping.get("sms_template_id") or doc["template_name"]
+                logger.info(f"SMS template resolved: {doc['template_name']} → {sms_tpl_name}")
                 resolved_data = await NotificationDispatcher._resolve_template(
-                    doc["template_name"], "sms", raw_data
+                    sms_tpl_name, "sms", raw_data
                 )
                 success, message, provider_id = await SMSChannel.send(
                     recipient=doc["recipient"],
-                    template_name=doc["template_name"],
+                    template_name=sms_tpl_name,
                     template_data=resolved_data,
                     channel_config=ch_config,
                 )