class RuboCop::Cop::Style::MethodCallWithoutArgsParentheses

def any_assignment?(node)
  node.each_ancestor(*AST::Node::ASSIGNMENTS).any? do |asgn_node|
    # `obj.method = value` parses as (send ... :method= ...), and will
    # not be returned as an `asgn_node` here, however,
    # `obj.method ||= value` parses as (or-asgn (send ...) ...)
    # which IS an `asgn_node`. Similarly, `obj.method += value` parses
    # as (op-asgn (send ...) ...), which is also an `asgn_node`.
    if asgn_node.shorthand_asgn?
      asgn_node, _value = *asgn_node
      next if asgn_node.send_type?
    end
    yield asgn_node
  end
end

def default_argument?(node)
  node.parent&.optarg_type?
end

def ineligible_node?(node)
  node.camel_case_method? || node.implicit_call? || node.prefix_not?
end

def offense_range(node)
  node.loc.begin.join(node.loc.end)
end

def on_send(node)
  return unless !node.arguments? && node.parenthesized?
  return if ineligible_node?(node)
  return if default_argument?(node)
  return if ignored_method?(node.method_name)
  return if same_name_assignment?(node)
  register_offense(node)
end

def register_offense(node)
  add_offense(offense_range(node)) do |corrector|
    corrector.remove(node.loc.begin)
    corrector.remove(node.loc.end)
  end
end

def same_name_assignment?(node)
  any_assignment?(node) do |asgn_node|
    next variable_in_mass_assignment?(node.method_name, asgn_node) if asgn_node.masgn_type?
    asgn_node.loc.name.source == node.method_name.to_s
  end
end

def variable_in_mass_assignment?(variable_name, node)
  mlhs_node, _mrhs_node = *node
  var_nodes = *mlhs_node
  var_nodes.any? { |n| n.to_a.first == variable_name }
end