feat: Add filter APIs for Contacts and Conversations (#3264)

app/services/contacts/filter_service.rb

@@ -0,0 +1,44 @@
+class Contacts::FilterService < FilterService
+  def perform
+    @contacts = contact_query_builder
+
+    {
+      contacts: @contacts,
+      count: {
+        all_count: @contacts.count
+      }
+    }
+  end
+
+  def contact_query_builder
+    contact_filters = @filters['contacts']
+
+    @params[:payload].each_with_index do |query_hash, current_index|
+      current_filter = contact_filters[query_hash['attribute_key']]
+      @query_string += contact_query_string(current_filter, query_hash, current_index)
+    end
+
+    base_relation.where(@query_string, @filter_values.with_indifferent_access)
+  end
+
+  def contact_query_string(current_filter, query_hash, current_index)
+    attribute_key = query_hash[:attribute_key]
+    query_operator = query_hash[:query_operator]
+    filter_operator_value = filter_operation(query_hash, current_index)
+
+    case current_filter['attribute_type']
+    when 'additional_attributes'
+      " contacts.additional_attributes ->> '#{attribute_key}' #{filter_operator_value} #{query_operator} "
+    when 'standard'
+      if attribute_key == 'labels'
+        " tags.id #{filter_operator_value} #{query_operator} "
+      else
+        " contacts.#{attribute_key} #{filter_operator_value} #{query_operator} "
+      end
+    end
+  end
+
+  def base_relation
+    Current.account.contacts.left_outer_joins(:labels)
+  end
+end