feat: implement event dispatching for incoming WhatsApp messages (#230)

* feat: implement event dispatching for incoming WhatsApp messages

* refactor: remove unused dispatcher instance variable in event dispatching context

app/services/whatsapp/incoming_message_whatsapp_cloud_service.rb

@@ -2,8 +2,23 @@
 # https://developers.facebook.com/docs/whatsapp/api/media/
 
 class Whatsapp::IncomingMessageWhatsappCloudService < Whatsapp::IncomingMessageBaseService
+  include Events::Types
+
+  def perform
+    return if processed_params.blank?
+
+    Rails.configuration.dispatcher.dispatch(PROVIDER_EVENT_RECEIVED, Time.zone.now, inbox: inbox, event: whatsapp_cloud_event_type,
+                                                                                    payload: processed_params)
+
+    super
+  end
+
   private
 
+  def whatsapp_cloud_event_type
+    params.dig(:entry, 0, :changes, 0, :field) || 'unknown'
+  end
+
   def processed_params
     @processed_params ||= params[:entry].try(:first).try(:[], 'changes').try(:first).try(:[], 'value')
   end

spec/services/whatsapp/incoming_message_whatsapp_cloud_service_spec.rb

@@ -107,6 +107,53 @@ describe Whatsapp::IncomingMessageWhatsappCloudService do
       end
     end
 
+    context 'when dispatching provider events' do
+      let(:message_params) do
+        {
+          phone_number: whatsapp_channel.phone_number,
+          object: 'whatsapp_business_account',
+          entry: [{
+            changes: [{
+              field: 'messages',
+              value: {
+                contacts: [{ profile: { name: 'Sojan Jose' }, wa_id: '2423423243' }],
+                messages: [{
+                  from: '2423423243',
+                  text: { body: 'Hello' },
+                  timestamp: '1664799904', type: 'text'
+                }]
+              }
+            }]
+          }]
+        }.with_indifferent_access
+      end
+
+      before do
+        allow(Rails.configuration.dispatcher).to receive(:dispatch)
+      end
+
+      it 'dispatches provider_event_received with the webhook field as event type' do
+        described_class.new(inbox: whatsapp_channel.inbox, params: message_params).perform
+
+        expect(Rails.configuration.dispatcher).to have_received(:dispatch).with(
+          'provider.event_received',
+          anything,
+          hash_including(
+            inbox: whatsapp_channel.inbox,
+            event: 'messages',
+            payload: message_params[:entry][0][:changes][0][:value]
+          )
+        )
+      end
+
+      it 'does not dispatch when processed_params is blank' do
+        empty_params = { phone_number: whatsapp_channel.phone_number, object: 'whatsapp_business_account', entry: {} }.with_indifferent_access
+        described_class.new(inbox: whatsapp_channel.inbox, params: empty_params).perform
+
+        expect(Rails.configuration.dispatcher).not_to have_received(:dispatch).with('provider.event_received', anything, anything)
+      end
+    end
+
     context 'when message is a reply (has context)' do
       let(:reply_params) do
         {