feat: locking and retry in FB message parsing (#7701)

app/jobs/webhooks/facebook_events_job.rb

@@ -1,8 +1,28 @@
 class Webhooks::FacebookEventsJob < ApplicationJob
+  class LockAcquisitionError < StandardError; end
+
   queue_as :default
+  # https://edgeapi.rubyonrails.org/classes/ActiveJob/Exceptions/ClassMethods.html#method-i-retry_on
+  retry_on LockAcquisitionError, wait: 2.seconds, attempts: 5
 
   def perform(message)
     response = ::Integrations::Facebook::MessageParser.new(message)
-    ::Integrations::Facebook::MessageCreator.new(response).perform
+
+    lock_key = format(::Redis::Alfred::FACEBOOK_MESSAGE_MUTEX, sender_id: response.sender_id, recipient_id: response.recipient_id)
+    lock_manager = Redis::LockManager.new
+
+    if lock_manager.locked?(lock_key)
+      Rails.logger.error "[Facebook::MessageCreator] Failed to acquire lock on attempt #{executions + 1}: #{lock_key}"
+      raise LockAcquisitionError, "Failed to acquire lock for key: #{lock_key}"
+    end
+
+    begin
+      lock_manager.lock(lock_key)
+      Rails.logger.info "[Facebook::MessageCreator] Acquired lock for: #{lock_key}"
+      ::Integrations::Facebook::MessageCreator.new(response).perform
+    ensure
+      # Ensure that the lock is released even if there's an error in processing
+      lock_manager.unlock(lock_key)
+    end
   end
 end