sanger/sequencescape

# frozen_string_literal: true

module Core::Io::Base::JsonFormattingBehaviour::Output
  def json_code_tree
    ::Core::Io::Json::Grammar::Root.new(self)
  end
  private :json_code_tree

  # rubocop:todo Metrics/MethodLength
  def generate_object_to_json_mapping(attribute_to_json) # rubocop:todo Metrics/AbcSize
    # Sort the attribute_to_json map such that the JSON elements are in order, thus ensuring that
    # we will only open and close blocks as we go.  Then build a tree that can be executed against
    # an object to generate the JSON appropriately.
    tree =
      attribute_to_json
        .sort_by(&:last)
        .map { |attribute, json| [json.split('.'), attribute.split('.').map(&:to_sym)] }
        .inject(json_code_tree.for(self)) do |tree, (json_path, attribute_path)|
          tree.tap do
            json_leaf = json_path.pop
            json_path.inject(tree) { |node, step| node[step] }.leaf(json_leaf, attribute_path)
          end
        end

    # Now we can generate a method that will use that tree to encode an object to JSON.
    singleton_class.send(:define_method, :json_code_tree) { tree }
    singleton_class.send(:define_method, :object_json, &tree.method(:encode))
  end
  # rubocop:enable Metrics/MethodLength
end