module TarvitHelpers
  module HashPresenter

    class Custom < WithRules

      def _custom_hash
        _rules_holder.rules.each_with_object(_hash.clone) do |rule, res|
          _apply_rule(res, rule, rule.path.clone, [])
        end
      end

      protected

      def _apply_rule(node, rule, rule_path, current_path)
        current_level = rule_path.shift

        if rule_path.empty?
          _assign_value(node, rule, current_path, current_level) && return
        end

        current_node = node[current_level]
        current_path << current_level

        if current_node.is_a?(Array)
          current_node.each_with_index do |node_element, index|
            _apply_rule(node_element, rule, rule_path.clone, (current_path + [ index ]))
          end
        else
          _apply_rule(current_node, rule, rule_path.clone, current_path.clone)
        end
      end

      def _assign_value(node, rule, current_path, current_level)
        presenter = _path_presenter(current_path)
        node[ current_level ] = rule.value_transformer.call(node[current_level], presenter)
      end

      def _path_presenter(path)
        path.inject(self) do |res, level|
          res.is_a?(Array) ? res[level] : res.send(level)
        end
      end

    end
  end
end