Observe issue, merge request, note creation - create event

app/models/event.rb

@@ -1,17 +1,36 @@
 class Event < ActiveRecord::Base
+  Created   = 1
+  Updated   = 2
+  Closed    = 3
+  Reopened  = 4
+  Pushed    = 5
+  Commented = 6
+
   belongs_to :project
+  belongs_to :target, :polymorphic => true
+
   serialize :data
+
+  def self.determine_action(record)
+    if [Issue, MergeRequest].include? record.class
+      Event::Created
+    elsif record.kind_of? Note
+      Event::Commented
+    end
+  end
 end
 # == Schema Information
 #
 # Table name: events
 #
-#  id         :integer         not null, primary key
-#  data_type  :string(255)
-#  data_id    :string(255)
-#  title      :string(255)
-#  data       :text
-#  project_id :integer
-#  created_at :datetime        not null
-#  updated_at :datetime        not null
+#  id          :integer         not null, primary key
+#  target_type :string(255)
+#  target_id   :integer
+#  title       :string(255)
+#  data        :text
+#  project_id  :integer
+#  created_at  :datetime        not null
+#  updated_at  :datetime        not null
+#  action      :integer
 #
+