1 files changed, 74 insertions, 0 deletions
diff --git a/app/finders/releases/group_releases_finder.rb b/app/finders/releases/group_releases_finder.rb
new file mode 100644
index 00000000000..d87ba8c0b03
--- /dev/null
+++ b/app/finders/releases/group_releases_finder.rb
@@ -0,0 +1,74 @@
+# frozen_string_literal: true
+module Releases
+  ##
+  # The GroupReleasesFinder does not support all the options of ReleasesFinder
+  # due to use of InOperatorOptimization for finding subprojects/subgroups
+  #
+  # order_by - only ordering by released_at is supported
+  # filter by tag - currently not supported
+  class GroupReleasesFinder
+    include Gitlab::Utils::StrongMemoize
+
+    attr_reader :parent, :current_user, :params
+
+    def initialize(parent, current_user = nil, params = {})
+      @parent = parent
+      @current_user = current_user
+      @params = params
+
+      params[:order_by] ||= 'released_at'
+      params[:sort] ||= 'desc'
+      params[:page] ||= 0
+      params[:per] ||= 30
+    end
+
+    def execute(preload: true)
+      return Release.none unless Ability.allowed?(current_user, :read_release, parent)
+
+      releases = get_releases(preload: preload)
+
+      paginate_releases(releases)
+    end
+
+    private
+
+    def include_subgroups?
+      params.fetch(:include_subgroups, false)
+    end
+
+    def accessible_projects_scope
+      if include_subgroups?
+        Project.for_group_and_its_subgroups(parent)
+      else
+        parent.projects
+      end
+    end
+
+    # rubocop: disable CodeReuse/ActiveRecord
+    def get_releases(preload: true)
+      Gitlab::Pagination::Keyset::InOperatorOptimization::QueryBuilder.new(
+        scope: releases_scope(preload: preload),
+        array_scope: accessible_projects_scope.select(:id),
+        array_mapping_scope: -> (project_id_expression) { Release.where(Release.arel_table[:project_id].eq(project_id_expression)) },
+        finder_query: -> (order_by, id_expression) { Release.where(Release.arel_table[:id].eq(id_expression)) }
+      )
+      .execute
+    end
+
+    def releases_scope(preload: true)
+      scope = Release.all
+      scope = order_releases(scope)
+      scope = scope.preloaded if preload
+      scope
+    end
+
+    def order_releases(scope)
+      scope.sort_by_attribute("released_at_#{params[:sort]}").order(id: params[:sort])
+    end
+
+    def paginate_releases(releases)
+      releases.page(params[:page].to_i).per(params[:per])
+    end
+    # rubocop: enable CodeReuse/ActiveRecord
+  end
+end