module Scrivito
  module Migrations
    class CmsBackend
      def read
        if obj = find_migration_store_obj
          obj.data_from_cms.value_of('versions')
        else
          ''
        end
      end

      def save(value)
        CmsRestApi.put(endpoint("objs/#{migration_store_obj.id}"),
          obj: {versions: ['string', value]})

        Workspace.current.reload
      end

      private

      def create
        CmsRestApi.post(endpoint('objs'),
          obj: {_path: path, _obj_class: 'MigrationStore', versions: ['string', '']})

        Workspace.current.reload
      end

      def migration_store_obj
        create unless find_migration_store_obj
        find_migration_store_obj
      end

      def find_migration_store_obj
        Obj.find_by_path(path)
      end

      def path
        '/_internal/migration-store'
      end

      def endpoint(path)
        "workspaces/#{Workspace.current.id}/#{path}"
      end
    end
  end
end