# Heavily based on YARD::Handlers::Ruby::AttributeHandler
class DefinePropertyHandler < YARD::Handlers::Ruby::Base
  handles method_call(:define_property)
  namespace_only

  process do
    return if statement.type == :var_ref || statement.type == :vcall

    read = true
    write = true
    params = statement.parameters(false).dup

    # Add all attributes
    name = validated_attribute_names(params)

    namespace.attributes[scope][name] ||= SymbolHash[read: nil, write: nil]

    # Show their methods as well
    {read: name, write: "#{name}="}.each do |type, meth|
      if type == :read ? read : write
        o = MethodObject.new(namespace, meth, scope)
        if type == :write
          o.parameters = [['value', nil]]
          src = "def #{meth}(value)"
          full_src = "#{src}\n  @#{name} = value\nend"
          doc = "Sets the attribute #{name}\n@param value the value to set the attribute #{name} to."
        else
          src = "def #{meth}"
          full_src = "#{src}\n  @#{name}\nend"
          doc = "Returns the value of attribute #{name}"
        end
        o.source ||= full_src
        o.signature ||= src
        register(o)
        o.docstring = doc if o.docstring.blank?(false)

        # Register the object explicitly
        namespace.attributes[scope][name][type] = o
      else
        obj = namespace.children.find { |other| other.name == meth.to_sym && other.scope == scope }

        # register an existing method as attribute
        namespace.attributes[scope][name][type] = obj if obj
      end
    end
  end

  protected

  # Strips out any non-essential arguments from the attr statement.
  #
  # @param [Array<Parser::Ruby::AstNode>] params a list of the parameters
  #   in the attr call.
  # @return [Array<String>] the validated attribute names
  # @raise [Parser::UndocumentableError] if the arguments are not valid.
  def validated_attribute_names(params)
    obj = params.first

    case obj.type
    when :symbol_literal
      obj.jump(:ident, :op, :kw, :const).source
    when :string_literal
      obj.jump(:string_content).source
    else
      raise YARD::Parser::UndocumentableError, obj.source
    end
  end
end