1 files changed, 64 insertions, 0 deletions
diff --git a/app/models/design_management/design_action.rb b/app/models/design_management/design_action.rb
new file mode 100644
index 00000000000..22baa916296
--- /dev/null
+++ b/app/models/design_management/design_action.rb
@@ -0,0 +1,64 @@
+# frozen_string_literal: true
+
+module DesignManagement
+  # Parameter object which is a tuple of the database record and the
+  # last gitaly call made to change it. This serves to perform the
+  # logical mapping from git action to database representation.
+  class DesignAction
+    include ActiveModel::Validations
+
+    EVENT_FOR_GITALY_ACTION = {
+      create: DesignManagement::Action.events[:creation],
+      update: DesignManagement::Action.events[:modification],
+      delete: DesignManagement::Action.events[:deletion]
+    }.freeze
+
+    attr_reader :design, :action, :content
+
+    delegate :issue_id, to: :design
+
+    validates :design, presence: true
+    validates :action, presence: true, inclusion: { in: EVENT_FOR_GITALY_ACTION.keys }
+    validates :content,
+      absence: { if: :forbids_content?,
+                  message: 'this action forbids content' },
+      presence: { if: :needs_content?,
+                  message: 'this action needs content' }
+
+    # Parameters:
+    # - design [DesignManagement::Design]: the design that was changed
+    # - action [Symbol]: the action that gitaly performed
+    def initialize(design, action, content = nil)
+      @design, @action, @content = design, action, content
+      validate!
+    end
+
+    def row_attrs(version)
+      { design_id: design.id, version_id: version.id, event: event }
+    end
+
+    def gitaly_action
+      { action: action, file_path: design.full_path, content: content }.compact
+    end
+
+    # This action has been performed - do any post-creation actions
+    # such as clearing method caches.
+    def performed
+      design.clear_version_cache
+    end
+
+    private
+
+    def needs_content?
+      action != :delete
+    end
+
+    def forbids_content?
+      action == :delete
+    end
+
+    def event
+      EVENT_FOR_GITALY_ACTION[action]
+    end
+  end
+end