Introduce an Events API

* Meld the following disparate endpoints:
 * `/projects/:id/events`
 * `/events`
 * `/users/:id/events`
+ Add result filtering to the above endpoints:
 * action
 * target_type
 * before and after dates

1 files changed, 86 insertions, 0 deletions

diff --git a/lib/api/events.rb b/lib/api/events.rb
new file mode 100644
index 00000000000..ed5df268ae3
--- /dev/null
+++ b/lib/api/events.rb
@@ -0,0 +1,86 @@
+module API
+  class Events < Grape::API
+    include PaginationParams
+
+    helpers do
+      params :event_filter_params do
+        optional :action, type: String, values: Event.actions, desc: 'Event action to filter on'
+        optional :target_type, type: String, values: Event.target_types, desc: 'Event target type to filter on'
+        optional :before, type: Date, desc: 'Include only events created before this date'
+        optional :after, type: Date, desc: 'Include only events created after this date'
+      end
+
+      params :sort_params do
+        optional :sort, type: String, values: %w[asc desc], default: 'desc',
+                        desc: 'Return events sorted in ascending and descending order'
+      end
+
+      def present_events(events)
+        events = events.reorder(created_at: params[:sort])
+
+        present paginate(events), with: Entities::Event
+      end
+    end
+
+    resource :events do
+      desc "List currently authenticated user's events" do
+        detail 'This feature was introduced in GitLab 9.3.'
+        success Entities::Event
+      end
+      params do
+        use :pagination
+        use :event_filter_params
+        use :sort_params
+      end
+      get do
+        authenticate!
+
+        events = EventsFinder.new(params.merge(source: current_user, current_user: current_user)).execute.preload(:author, :target)
+
+        present_events(events)
+      end
+    end
+
+    params do
+      requires :id, type: Integer, desc: 'The ID of the user'
+    end
+    resource :users do
+      desc 'Get the contribution events of a specified user' do
+        detail 'This feature was introduced in GitLab 8.13.'
+        success Entities::Event
+      end
+      params do
+        use :pagination
+        use :event_filter_params
+        use :sort_params
+      end
+      get ':id/events' do
+        user = User.find_by(id: params[:id])
+        not_found!('User') unless user
+
+        events = EventsFinder.new(params.merge(source: user, current_user: current_user)).execute.preload(:author, :target)
+
+        present_events(events)
+      end
+    end
+
+    params do
+      requires :id, type: String, desc: 'The ID of a project'
+    end
+    resource :projects, requirements: { id: %r{[^/]+} } do
+      desc "List a Project's visible events" do
+        success Entities::Event
+      end
+      params do
+        use :pagination
+        use :event_filter_params
+        use :sort_params
+      end
+      get ":id/events" do
+        events = EventsFinder.new(params.merge(source: user_project, current_user: current_user)).execute.preload(:author, :target)
+
+        present_events(events)
+      end
+    end
+  end
+end