1 files changed, 132 insertions, 0 deletions
diff --git a/lib/gitlab/import_export/group/legacy_tree_restorer.rb b/lib/gitlab/import_export/group/legacy_tree_restorer.rb
new file mode 100644
index 00000000000..5d96a0f3c0a
--- /dev/null
+++ b/lib/gitlab/import_export/group/legacy_tree_restorer.rb
@@ -0,0 +1,132 @@
+# frozen_string_literal: true
+
+module Gitlab
+  module ImportExport
+    module Group
+      class LegacyTreeRestorer
+        include Gitlab::Utils::StrongMemoize
+
+        attr_reader :user
+        attr_reader :shared
+        attr_reader :group
+
+        def initialize(user:, shared:, group:, group_hash:)
+          @user = user
+          @shared = shared
+          @group = group
+          @group_hash = group_hash
+        end
+
+        def restore
+          @group_attributes = relation_reader.consume_attributes(nil)
+          @group_members = relation_reader.consume_relation(nil, 'members')
+            .map(&:first)
+
+          # We need to remove `name` and `path` as we did consume it in previous pass
+          @group_attributes.delete('name')
+          @group_attributes.delete('path')
+
+          @children = @group_attributes.delete('children')
+
+          if members_mapper.map && restorer.restore
+            @children&.each do |group_hash|
+              group = create_group(group_hash: group_hash, parent_group: @group)
+              shared = Gitlab::ImportExport::Shared.new(group)
+
+              self.class.new(
+                user: @user,
+                shared: shared,
+                group: group,
+                group_hash: group_hash
+              ).restore
+            end
+          end
+
+          return false if @shared.errors.any?
+
+          true
+        rescue => e
+          @shared.error(e)
+          false
+        end
+
+        private
+
+        def relation_reader
+          strong_memoize(:relation_reader) do
+            if @group_hash.present?
+              ImportExport::JSON::LegacyReader::Hash.new(
+                @group_hash,
+                relation_names: reader.group_relation_names)
+            else
+              ImportExport::JSON::LegacyReader::File.new(
+                File.join(shared.export_path, 'group.json'),
+                relation_names: reader.group_relation_names)
+            end
+          end
+        end
+
+        def restorer
+          @relation_tree_restorer ||= RelationTreeRestorer.new(
+            user:                  @user,
+            shared:                @shared,
+            relation_reader:       relation_reader,
+            members_mapper:        members_mapper,
+            object_builder:        object_builder,
+            relation_factory:      relation_factory,
+            reader:                reader,
+            importable:            @group,
+            importable_attributes: @group_attributes,
+            importable_path:       nil
+          )
+        end
+
+        def create_group(group_hash:, parent_group:)
+          group_params = {
+            name:      group_hash['name'],
+            path:      group_hash['path'],
+            parent_id: parent_group&.id,
+            visibility_level: sub_group_visibility_level(group_hash, parent_group)
+          }
+
+          ::Groups::CreateService.new(@user, group_params).execute
+        end
+
+        def sub_group_visibility_level(group_hash, parent_group)
+          original_visibility_level = group_hash['visibility_level'] || Gitlab::VisibilityLevel::PRIVATE
+
+          if parent_group && parent_group.visibility_level < original_visibility_level
+            Gitlab::VisibilityLevel.closest_allowed_level(parent_group.visibility_level)
+          else
+            original_visibility_level
+          end
+        end
+
+        def members_mapper
+          @members_mapper ||= Gitlab::ImportExport::MembersMapper.new(
+            exported_members: @group_members,
+            user: @user,
+            importable: @group
+          )
+        end
+
+        def relation_factory
+          Gitlab::ImportExport::Group::RelationFactory
+        end
+
+        def object_builder
+          Gitlab::ImportExport::Group::ObjectBuilder
+        end
+
+        def reader
+          @reader ||= Gitlab::ImportExport::Reader.new(
+            shared: @shared,
+            config: Gitlab::ImportExport::Config.new(
+              config: Gitlab::ImportExport.group_config_file
+            ).to_h
+          )
+        end
+      end
+    end
+  end
+end