1 files changed, 128 insertions, 0 deletions
diff --git a/lib/gitlab/import_export/relation_factory.rb b/lib/gitlab/import_export/relation_factory.rb
new file mode 100644
index 00000000000..b872780f20a
--- /dev/null
+++ b/lib/gitlab/import_export/relation_factory.rb
@@ -0,0 +1,128 @@
+module Gitlab
+  module ImportExport
+    class RelationFactory
+
+      OVERRIDES = { snippets: :project_snippets,
+                    pipelines: 'Ci::Pipeline',
+                    statuses: 'commit_status',
+                    variables: 'Ci::Variable',
+                    triggers: 'Ci::Trigger',
+                    builds: 'Ci::Build',
+                    hooks: 'ProjectHook' }.freeze
+
+      USER_REFERENCES = %w[author_id assignee_id updated_by_id user_id].freeze
+
+      def self.create(*args)
+        new(*args).create
+      end
+
+      def initialize(relation_sym:, relation_hash:, members_mapper:, user:)
+        @relation_name = OVERRIDES[relation_sym] || relation_sym
+        @relation_hash = relation_hash.except('id', 'noteable_id')
+        @members_mapper = members_mapper
+        @user = user
+      end
+
+      # Creates an object from an actual model with name "relation_sym" with params from
+      # the relation_hash, updating references with new object IDs, mapping users using
+      # the "members_mapper" object, also updating notes if required.
+      def create
+        set_note_author if @relation_name == :notes
+        update_user_references
+        update_project_references
+        reset_ci_tokens if @relation_name == 'Ci::Trigger'
+
+        generate_imported_object
+      end
+
+      private
+
+      def update_user_references
+        USER_REFERENCES.each do |reference|
+          if @relation_hash[reference]
+            @relation_hash[reference] = @members_mapper.map[@relation_hash[reference]]
+          end
+        end
+      end
+
+      # Sets the author for a note. If the user importing the project
+      # has admin access, an actual mapping with new project members
+      # will be used. Otherwise, a note stating the original author name
+      # is left.
+      def set_note_author
+        old_author_id = @relation_hash['author_id']
+
+        # Users with admin access can map users
+        @relation_hash['author_id'] = admin_user? ? @members_mapper.map[old_author_id] : @members_mapper.default_user_id
+
+        author = @relation_hash.delete('author')
+
+        update_note_for_missing_author(author['name']) if missing_author?(old_author_id)
+      end
+
+      def missing_author?(old_author_id)
+        !admin_user? || @members_mapper.missing_author_ids.include?(old_author_id)
+      end
+
+      def missing_author_note(updated_at, author_name)
+        timestamp = updated_at.split('.').first
+        "\n\n *By #{author_name} on #{timestamp} (imported from GitLab project)*"
+      end
+
+      def generate_imported_object
+        if @relation_sym == 'commit_status' # call #trace= method after assigning the other attributes
+          trace = @relation_hash.delete('trace')
+          imported_object do |object|
+            object.trace = trace
+            object.commit_id = nil
+          end
+        else
+          imported_object
+        end
+      end
+
+      def update_project_references
+        project_id = @relation_hash.delete('project_id')
+
+        # project_id may not be part of the export, but we always need to populate it if required.
+        @relation_hash['project_id'] = project_id if relation_class.column_names.include?('project_id')
+        @relation_hash['gl_project_id'] = project_id if @relation_hash['gl_project_id']
+        @relation_hash['target_project_id'] = project_id if @relation_hash['target_project_id']
+        @relation_hash['source_project_id'] = -1 if @relation_hash['source_project_id']
+
+        # If source and target are the same, populate them with the new project ID.
+        if @relation_hash['source_project_id'] && @relation_hash['target_project_id'] &&
+          @relation_hash['target_project_id'] == @relation_hash['source_project_id']
+          @relation_hash['source_project_id'] = project_id
+        end
+      end
+
+      def reset_ci_tokens
+        return unless Gitlab::ImportExport.reset_tokens?
+
+        # If we import/export a project to the same instance, tokens will have to be reset.
+        @relation_hash['token'] = nil
+      end
+
+      def relation_class
+        @relation_class ||= @relation_name.to_s.classify.constantize
+      end
+
+      def imported_object
+        imported_object = relation_class.new(@relation_hash)
+        yield(imported_object) if block_given?
+        imported_object.importing = true if imported_object.respond_to?(:importing)
+        imported_object
+      end
+
+      def update_note_for_missing_author(author_name)
+        @relation_hash['note'] = '*Blank note*' if @relation_hash['note'].blank?
+        @relation_hash['note'] += missing_author_note(@relation_hash['updated_at'], author_name)
+      end
+
+      def admin_user?
+        @user.is_admin?
+      end
+    end
+  end
+end