Move ci_environments_status to a model

GET :namespace/merge_requests/:id/ci_environments_status complexity
already reached a limit for a direct serialization from an hash
computed at within the controller function.

Here we introduce a virtual model EnvironmentStatus and its serializer.

4 files changed, 96 insertions, 36 deletions

diff --git a/app/controllers/projects/merge_requests_controller.rb b/app/controllers/projects/merge_requests_controller.rb
index 8bc3a81d771..f87337b67aa 100644
--- a/app/controllers/projects/merge_requests_controller.rb
+++ b/app/controllers/projects/merge_requests_controller.rb
@@ -198,43 +198,11 @@ class Projects::MergeRequestsController < Projects::MergeRequests::ApplicationCo
   end
 
   def ci_environments_status
-    environments =
-      begin
-        @merge_request.environments_for(current_user).map do |environment|
-          project    = environment.project
-          deployment = environment.first_deployment_for(@merge_request.diff_head_sha)
-
-          stop_url =
-            if can?(current_user, :stop_environment, environment)
-              stop_project_environment_path(project, environment)
-            end
-
-          metrics_url =
-            if can?(current_user, :read_environment, environment) && environment.has_metrics?
-              metrics_project_environment_deployment_path(project, environment, deployment)
-            end
-
-          metrics_monitoring_url =
-            if can?(current_user, :read_environment, environment)
-              environment_metrics_path(environment)
-            end
-
-          {
-            id: environment.id,
-            name: environment.name,
-            url: project_environment_path(project, environment),
-            metrics_url: metrics_url,
-            metrics_monitoring_url: metrics_monitoring_url,
-            stop_url: stop_url,
-            external_url: environment.external_url,
-            external_url_formatted: environment.formatted_external_url,
-            deployed_at: deployment.try(:created_at),
-            deployed_at_formatted: deployment.try(:formatted_deployment_time)
-          }
-        end.compact
-      end
+    environments = @merge_request.environments_for(current_user).map do |environment|
+      EnvironmentStatus.new(environment, @merge_request)
+    end
 
-    render json: environments
+    render json: EnvironmentStatusSerializer.new(current_user: current_user).represent(environments)
   end
 
   def rebase
diff --git a/app/models/environment_status.rb b/app/models/environment_status.rb
new file mode 100644
index 00000000000..cae0d396089
--- /dev/null
+++ b/app/models/environment_status.rb
@@ -0,0 +1,27 @@
+# frozen_string_literal: true
+
+class EnvironmentStatus
+  include Gitlab::Utils::StrongMemoize
+
+  attr_reader :environment, :merge_request
+
+  delegate :id, to: :environment
+  delegate :name, to: :environment
+  delegate :project, to: :environment
+  delegate :deployed_at, to: :deployment, allow_nil: true
+
+  def initialize(environment, merge_request)
+    @environment = environment
+    @merge_request = merge_request
+  end
+
+  def deployment
+    strong_memoize(:deployment) do
+      environment.first_deployment_for(merge_request.diff_head_sha)
+    end
+  end
+
+  def deployed_at
+    deployment&.created_at
+  end
+end
diff --git a/app/serializers/environment_status_entity.rb b/app/serializers/environment_status_entity.rb
new file mode 100644
index 00000000000..62152dd1d40
--- /dev/null
+++ b/app/serializers/environment_status_entity.rb
@@ -0,0 +1,60 @@
+# frozen_string_literal: true
+
+class EnvironmentStatusEntity < Grape::Entity
+  include RequestAwareEntity
+
+  expose :id
+  expose :name
+
+  expose :url do |es|
+    project_environment_path(es.project, es.environment)
+  end
+
+  expose :metrics_url, if: ->(*) { can_read_environment? && environment.has_metrics? } do |es|
+    metrics_project_environment_deployment_path(es.project, es.environment, es.deployment)
+  end
+
+  expose :metrics_monitoring_url, if: ->(*) { can_read_environment? } do |es|
+    environment_metrics_path(es.environment)
+  end
+
+  expose :stop_url, if: ->(*) { can_stop_environment? } do |es|
+    stop_project_environment_path(es.project, es.environment)
+  end
+
+  expose :external_url do |es|
+    es.environment.external_url
+  end
+
+  expose :external_url_formatted do |es|
+    es.environment.formatted_external_url
+  end
+
+  expose :deployed_at
+
+  expose :deployed_at_formatted do |es|
+    es.deployment.try(:formatted_deployment_time)
+  end
+
+  private
+
+  def environment
+    object.environment
+  end
+
+  def project
+    object.environment.project
+  end
+
+  def current_user
+    request.current_user
+  end
+
+  def can_read_environment?
+    can?(current_user, :read_environment, environment)
+  end
+
+  def can_stop_environment?
+    can?(current_user, :stop_environment, environment)
+  end
+end
diff --git a/app/serializers/environment_status_serializer.rb b/app/serializers/environment_status_serializer.rb
new file mode 100644
index 00000000000..f8d37934763
--- /dev/null
+++ b/app/serializers/environment_status_serializer.rb
@@ -0,0 +1,5 @@
+# frozen_string_literal: true
+
+class EnvironmentStatusSerializer < BaseSerializer
+  entity EnvironmentStatusEntity
+end