class RuboCop::Cop::Style::HashAsLastArrayItem

def braces_style?
  style == :braces
end

def check_braces(node)
  return if node.braces?
  add_offense(node, message: 'Wrap hash in `{` and `}`.') do |corrector|
    corrector.wrap(node, '{', '}')
  end
end

def check_no_braces(node)
  return unless node.braces?
  return if node.children.empty? # Empty hash cannot be "unbraced"
  add_offense(node, message: 'Omit the braces around the hash.') do |corrector|
    remove_last_element_trailing_comma(corrector, node.parent)
    corrector.remove(node.loc.begin)
    corrector.remove(node.loc.end)
  end
end

def containing_array(hash_node)
  parent = hash_node.parent
  parent if parent&.array_type?
end

def explicit_array?(array)
  # an implicit array cannot have an "unbraced" hash
  array.square_brackets?
end

def last_array_item?(array, node)
  return false if array.child_nodes.all?(&:hash_type?)
  array.children.last.equal?(node)
end

def on_hash(node)
  return unless (array = containing_array(node))
  return unless last_array_item?(array, node) && explicit_array?(array)
  if braces_style?
    check_braces(node)
  else
    check_no_braces(node)
  end
end

def remove_last_element_trailing_comma(corrector, node)
  range = range_with_surrounding_space(
    range: node.children.last.source_range,
    side: :right
  ).end.resize(1)
  corrector.remove(range) if range.source == ','
end