1 files changed, 73 insertions, 0 deletions
diff --git a/lib/gitlab/metrics/dashboard/base_service.rb b/lib/gitlab/metrics/dashboard/base_service.rb
new file mode 100644
index 00000000000..94aabd0466c
--- /dev/null
+++ b/lib/gitlab/metrics/dashboard/base_service.rb
@@ -0,0 +1,73 @@
+# frozen_string_literal: true
+
+# Searches a projects repository for a metrics dashboard and formats the output.
+# Expects any custom dashboards will be located in `.gitlab/dashboards`
+module Gitlab
+  module Metrics
+    module Dashboard
+      class BaseService < ::BaseService
+        DASHBOARD_LAYOUT_ERROR = Gitlab::Metrics::Dashboard::Stages::BaseStage::DashboardLayoutError
+
+        def get_dashboard
+          return error("#{dashboard_path} could not be found.", :not_found) unless path_available?
+
+          success(dashboard: process_dashboard)
+        rescue DASHBOARD_LAYOUT_ERROR => e
+          error(e.message, :unprocessable_entity)
+        end
+
+        # Summary of all known dashboards for the service.
+        # @return [Array<Hash>] ex) [{ path: String, default: Boolean }]
+        def all_dashboard_paths(_project)
+          raise NotImplementedError
+        end
+
+        private
+
+        # Returns a new dashboard Hash, supplemented with DB info
+        def process_dashboard
+          Gitlab::Metrics::Dashboard::Processor
+            .new(project, params[:environment], raw_dashboard)
+            .process(insert_project_metrics: insert_project_metrics?)
+        end
+
+        # @return [String] Relative filepath of the dashboard yml
+        def dashboard_path
+          params[:dashboard_path]
+        end
+
+        # Returns an un-processed dashboard from the cache.
+        def raw_dashboard
+          Rails.cache.fetch(cache_key) { get_raw_dashboard }
+        end
+
+        # @return [Hash] an unmodified dashboard
+        def get_raw_dashboard
+          raise NotImplementedError
+        end
+
+        # @return [String]
+        def cache_key
+          raise NotImplementedError
+        end
+
+        # Determines whether custom metrics should be included
+        # in the processed output.
+        def insert_project_metrics?
+          false
+        end
+
+        # Checks if dashboard path exists or should be rejected
+        # as a result of file-changes to the project repository.
+        # @return [Boolean]
+        def path_available?
+          available_paths = Gitlab::Metrics::Dashboard::Finder.find_all_paths(project)
+
+          available_paths.any? do |path_params|
+            path_params[:path] == dashboard_path
+          end
+        end
+      end
+    end
+  end
+end