1 files changed, 105 insertions, 0 deletions
diff --git a/lib/gitlab/import_export/project_tree_restorer.rb b/lib/gitlab/import_export/project_tree_restorer.rb
new file mode 100644
index 00000000000..dd71b92c522
--- /dev/null
+++ b/lib/gitlab/import_export/project_tree_restorer.rb
@@ -0,0 +1,105 @@
+module Gitlab
+  module ImportExport
+    class ProjectTreeRestorer
+
+      def initialize(user:, shared:, project:)
+        @path = File.join(shared.export_path, 'project.json')
+        @user = user
+        @shared = shared
+        @project = project
+      end
+
+      def restore
+        json = IO.read(@path)
+        @tree_hash = ActiveSupport::JSON.decode(json)
+        @project_members = @tree_hash.delete('project_members')
+        create_relations
+      rescue => e
+        @shared.error(e)
+        false
+      end
+
+      def restored_project
+        @restored_project ||= restore_project
+      end
+
+      private
+
+      def members_mapper
+        @members_mapper ||= Gitlab::ImportExport::MembersMapper.new(exported_members: @project_members,
+                                                                    user: @user,
+                                                                    project: restored_project)
+      end
+
+      # Loops through the tree of models defined in import_export.yml and
+      # finds them in the imported JSON so they can be instantiated and saved
+      # in the DB. The structure and relationships between models are guessed from
+      # the configuration yaml file too.
+      # Finally, it updates each attribute in the newly imported project.
+      def create_relations
+        saved = []
+        default_relation_list.each do |relation|
+          next unless relation.is_a?(Hash) || @tree_hash[relation.to_s].present?
+
+          create_sub_relations(relation, @tree_hash) if relation.is_a?(Hash)
+
+          relation_key = relation.is_a?(Hash) ? relation.keys.first : relation
+          relation_hash = create_relation(relation_key, @tree_hash[relation_key.to_s])
+          saved << restored_project.update_attribute(relation_key, relation_hash)
+        end
+        saved.all?
+      end
+
+      def default_relation_list
+        Gitlab::ImportExport::Reader.new(shared: @shared).tree.reject do |model|
+          model.is_a?(Hash) && model[:project_members]
+        end
+      end
+
+      def restore_project
+        return @project unless @tree_hash
+
+        project_params = @tree_hash.reject { |_key, value| value.is_a?(Array) }
+        @project.update(project_params)
+        @project
+      end
+
+      # Given a relation hash containing one or more models and its relationships,
+      # loops through each model and each object from a model type and
+      # and assigns its correspondent attributes hash from +tree_hash+
+      # Example:
+      # +relation_key+ issues, loops through the list of *issues* and for each individual
+      # issue, finds any subrelations such as notes, creates them and assign them back to the hash
+      def create_sub_relations(relation, tree_hash)
+        relation_key = relation.keys.first.to_s
+        tree_hash[relation_key].each do |relation_item|
+          relation.values.flatten.each do |sub_relation|
+            relation_hash, sub_relation = assign_relation_hash(relation_item, sub_relation)
+            relation_item[sub_relation.to_s] = create_relation(sub_relation, relation_hash) unless relation_hash.blank?
+          end
+        end
+      end
+
+      def assign_relation_hash(relation_item, sub_relation)
+        if sub_relation.is_a?(Hash)
+          relation_hash = relation_item[sub_relation.keys.first.to_s]
+          sub_relation = sub_relation.keys.first
+        else
+          relation_hash = relation_item[sub_relation.to_s]
+        end
+        [relation_hash, sub_relation]
+      end
+
+      def create_relation(relation, relation_hash_list)
+        relation_array = [relation_hash_list].flatten.map do |relation_hash|
+          Gitlab::ImportExport::RelationFactory.create(relation_sym: relation.to_sym,
+                                                       relation_hash: relation_hash.merge('project_id' => restored_project.id),
+                                                       members_mapper: members_mapper,
+                                                       user: @user)
+        end
+
+        relation_hash_list.is_a?(Array) ? relation_array : relation_array.first
+      end
+    end
+  end
+end