feat: Add APIs for Dialogflow integration V1 (#2155)

Co-authored-by: Muhsin Keloth <muhsinkeramam@gmail.com>
Co-authored-by: Pranav Raj S <pranav@chatwoot.com>

lib/integrations/dialogflow/processor_service.rb

@@ -0,0 +1,69 @@
+class Integrations::Dialogflow::ProcessorService
+  pattr_initialize [:event_name!, :hook!, :event_data!]
+
+  def perform
+    message = event_data[:message]
+    return if message.private?
+    return unless processable_message?(message)
+    return unless message.conversation.bot?
+
+    response = get_dialogflow_response(message.conversation.contact_inbox.source_id, message_content(message))
+    process_response(message, response)
+  end
+
+  private
+
+  def message_content(message)
+    return message.content_attributes['submitted_values'].first['value'] if event_name == 'message.updated'
+
+    message.content
+  end
+
+  def processable_message?(message)
+    return unless message.reportable?
+    return if message.outgoing? && !processable_outgoing_message?(message)
+
+    true
+  end
+
+  def processable_outgoing_message?(message)
+    event_name == 'message.updated' && ['input_select'].include?(message.content_type)
+  end
+
+  def get_dialogflow_response(session_id, message)
+    Google::Cloud::Dialogflow.configure { |config| config.credentials = hook.settings['credentials'] }
+    session_client = Google::Cloud::Dialogflow.sessions
+    session = session_client.session_path project: hook.settings['project_id'], session: session_id
+    query_input = { text: { text: message, language_code: 'en-US' } }
+    session_client.detect_intent session: session, query_input: query_input
+  end
+
+  def process_response(message, response)
+    text_response = response.query_result['fulfillment_text']
+
+    content_params = { content: text_response } if text_response.present?
+    content_params ||= response.query_result['fulfillment_messages'].first['payload'].to_h
+
+    process_action(message, content_params['action']) and return if content_params['action'].present?
+
+    create_conversation(message, content_params)
+  end
+
+  def create_conversation(message, content_params)
+    return if content_params.blank?
+
+    conversation = message.conversation
+    conversation.messages.create(content_params.merge({
+                                                        message_type: :outgoing,
+                                                        account_id: conversation.account_id,
+                                                        inbox_id: conversation.inbox_id
+                                                      }))
+  end
+
+  def process_action(message, action)
+    case action
+    when 'handoff'
+      message.conversation.open!
+    end
+  end
+end