1 files changed, 74 insertions, 0 deletions
diff --git a/lib/gitlab/gl_repository/identifier.rb b/lib/gitlab/gl_repository/identifier.rb
new file mode 100644
index 00000000000..dc3e7931696
--- /dev/null
+++ b/lib/gitlab/gl_repository/identifier.rb
@@ -0,0 +1,74 @@
+# frozen_string_literal: true
+
+module Gitlab
+  class GlRepository
+    class Identifier
+      attr_reader :gl_repository, :repo_type
+
+      def initialize(gl_repository)
+        @gl_repository = gl_repository
+        @segments = gl_repository.split('-')
+
+        raise_error if segments.size > 3
+
+        @repo_type = find_repo_type
+        @container_id = find_container_id
+        @container_class = find_container_class
+      end
+
+      def fetch_container!
+        container_class.find_by_id(container_id)
+      end
+
+      private
+
+      attr_reader :segments, :container_class, :container_id
+
+      def find_repo_type
+        type_name = three_segments_format? ? segments.last : segments.first
+        type = Gitlab::GlRepository.types[type_name]
+
+        raise_error unless type
+
+        type
+      end
+
+      def find_container_class
+        if three_segments_format?
+          case segments[0]
+          when 'project'
+            Project
+          when 'group'
+            Group
+          else
+            raise_error
+          end
+        else
+          repo_type.container_class
+        end
+      end
+
+      def find_container_id
+        id = Integer(segments[1], 10, exception: false)
+
+        raise_error unless id
+
+        id
+      end
+
+      # gl_repository can either have 2 or 3 segments:
+      # "wiki-1" is the older 2-segment format, where container is implied.
+      # "group-1-wiki" is the newer 3-segment format, including container information.
+      #
+      # TODO: convert all 2-segment format to 3-segment:
+      # https://gitlab.com/gitlab-org/gitlab/-/issues/219192
+      def three_segments_format?
+        segments.size == 3
+      end
+
+      def raise_error
+        raise ArgumentError, "Invalid GL Repository \"#{gl_repository}\""
+      end
+    end
+  end
+end