1 files changed, 81 insertions, 0 deletions
diff --git a/lib/gitlab/endpoint_attributes/config.rb b/lib/gitlab/endpoint_attributes/config.rb
new file mode 100644
index 00000000000..e31a3095736
--- /dev/null
+++ b/lib/gitlab/endpoint_attributes/config.rb
@@ -0,0 +1,81 @@
+# frozen_string_literal: true
+
+module Gitlab
+  module EndpointAttributes
+    class Config
+      RequestUrgency = Struct.new(:name, :duration)
+      REQUEST_URGENCIES = [
+        RequestUrgency.new(:high, 0.25),
+        RequestUrgency.new(:medium, 0.5),
+        RequestUrgency.new(:default, 1),
+        RequestUrgency.new(:low, 5)
+      ].index_by(&:name).freeze
+      SUPPORTED_ATTRIBUTES = %i[feature_category urgency].freeze
+
+      def initialize
+        @default_attributes = {}
+        @action_attributes = {}
+      end
+
+      def defined_actions
+        @action_attributes.keys
+      end
+
+      def set(actions, attributes)
+        sanitize_attributes!(attributes)
+
+        if actions.empty?
+          conflicted = conflicted_attributes(attributes, @default_attributes)
+          raise ArgumentError, "Attributes already defined: #{conflicted.join(", ")}" if conflicted.present?
+
+          @default_attributes.merge!(attributes)
+        else
+          set_attributes_for_actions(actions, attributes)
+        end
+
+        nil
+      end
+
+      def attribute_for_action(action, attribute_name)
+        value = @action_attributes.dig(action.to_s, attribute_name) || @default_attributes[attribute_name]
+        # Translate urgency to a representative struct
+        value = REQUEST_URGENCIES[value] if attribute_name == :urgency
+        value
+      end
+
+      private
+
+      def sanitize_attributes!(attributes)
+        unsupported_attributes = (attributes.keys - SUPPORTED_ATTRIBUTES).present?
+        raise ArgumentError, "Attributes not supported: #{unsupported_attributes.join(", ")}" if unsupported_attributes
+
+        if attributes[:urgency].present? && !REQUEST_URGENCIES.key?(attributes[:urgency])
+          raise ArgumentError, "Urgency not supported: #{attributes[:urgency]}"
+        end
+      end
+
+      def set_attributes_for_actions(actions, attributes)
+        conflicted = conflicted_attributes(attributes, @default_attributes)
+        if conflicted.present?
+          raise ArgumentError, "#{conflicted.join(", ")} are already defined for all actions, but re-defined for #{actions.join(", ")}"
+        end
+
+        actions.each do |action|
+          action = action.to_s
+          if @action_attributes[action].blank?
+            @action_attributes[action] = attributes.dup
+          else
+            conflicted = conflicted_attributes(attributes, @action_attributes[action])
+            raise ArgumentError, "Attributes re-defined for action #{action}: #{conflicted.join(", ")}" if conflicted.present?
+
+            @action_attributes[action].merge!(attributes)
+          end
+        end
+      end
+
+      def conflicted_attributes(attributes, existing_attributes)
+        attributes.keys.filter { |attr| existing_attributes[attr].present? && existing_attributes[attr] != attributes[attr] }
+      end
+    end
+  end
+end