chore: Logger for non-existent WhatsApp channels (#11064)

- Add a warning logger for cases where we are getting webhook events for
inactive numbers.
- Add config to discard events for inactive numbers so that the meta
will stop sending events

---------

Co-authored-by: Pranav <pranav@chatwoot.com>

spec/controllers/webhooks/whatsapp_controller_spec.rb

@@ -29,5 +29,34 @@ RSpec.describe 'Webhooks::WhatsappController', type: :request do
       post '/webhooks/whatsapp/123221321', params: { content: 'hello' }
       expect(response).to have_http_status(:success)
     end
+
+    context 'when phone number is in inactive list' do
+      before do
+        allow(GlobalConfig).to receive(:get_value).with('INACTIVE_WHATSAPP_NUMBERS').and_return('+1234567890,+9876543210')
+      end
+
+      it 'returns service unavailable for inactive phone number in URL params' do
+        allow(Rails.logger).to receive(:warn)
+        expect(Rails.logger).to receive(:warn).with('Rejected webhook for inactive WhatsApp number: +1234567890')
+
+        post '/webhooks/whatsapp/+1234567890', params: { content: 'hello' }
+        expect(response).to have_http_status(:unprocessable_entity)
+        expect(response.parsed_body['error']).to eq('Inactive WhatsApp number')
+      end
+    end
+
+    context 'when INACTIVE_WHATSAPP_NUMBERS config is not set' do
+      before do
+        allow(GlobalConfig).to receive(:get_value).with('INACTIVE_WHATSAPP_NUMBERS').and_return(nil)
+      end
+
+      it 'processes the webhook normally' do
+        allow(Webhooks::WhatsappEventsJob).to receive(:perform_later)
+        expect(Webhooks::WhatsappEventsJob).to receive(:perform_later)
+
+        post '/webhooks/whatsapp/+1234567890', params: { content: 'hello' }
+        expect(response).to have_http_status(:success)
+      end
+    end
   end
 end

spec/jobs/webhooks/whatsapp_events_job_spec.rb

@@ -81,6 +81,22 @@ RSpec.describe Webhooks::WhatsappEventsJob do
       expect(Whatsapp::IncomingMessageService).not_to receive(:new)
       job.perform_now(params)
     end
+
+    it 'logs a warning when channel is inactive' do
+      channel.prompt_reauthorization!
+      allow(Rails.logger).to receive(:warn)
+
+      expect(Rails.logger).to receive(:warn).with("Inactive WhatsApp channel: #{channel.phone_number}")
+      job.perform_now(params)
+    end
+
+    it 'logs a warning with unknown phone number when channel does not exist' do
+      unknown_phone = '+1234567890'
+      allow(Rails.logger).to receive(:warn)
+
+      expect(Rails.logger).to receive(:warn).with("Inactive WhatsApp channel: unknown - #{unknown_phone}")
+      job.perform_now(phone_number: unknown_phone)
+    end
   end
 
   context 'when default provider' do