module RuboCop::Cop::MultilineExpressionIndentation

def argument_in_method_call(node, kind)
  node.each_ancestor(:send, :block).find do |a|
    # If the node is inside a block, it makes no difference if that block
    # is an argument in a method call. It doesn't count.
    break false if a.block_type?
    next if a.setter_method?
    a.arguments.any? do |arg|
      within_node?(node, arg) && (kind == :with_or_without_parentheses ||
                                  kind == :with_parentheses &&
                                  parentheses?(node.parent))
    end
  end
end

def assignment_rhs(node)
  case node.type
  when :casgn   then _scope, _lhs, rhs = *node
  when :op_asgn then _lhs, _op, rhs = *node
  when :send    then rhs = node.last_argument
  else               _lhs, rhs = *node
  end
  rhs
end

def check(range, node, lhs, rhs)
  if range
    incorrect_style_detected(range, node, lhs, rhs)
  else
    correct_style_detected
  end
end

def correct_indentation(node)
  if kw_node_with_special_indentation(node)
    # This cop could have its own IndentationWidth configuration
    configured_indentation_width +
      @config.for_cop('Layout/IndentationWidth')['Width']
  else
    configured_indentation_width
  end
end

def disqualified_rhs?(candidate, ancestor)
  UNALIGNED_RHS_TYPES.include?(ancestor.type) ||
    ancestor.block_type? && part_of_block_body?(candidate, ancestor)
end

def grouped_expression?(node)
  node.begin_type? && node.loc.respond_to?(:begin) && node.loc.begin
end

def incorrect_style_detected(range, node, lhs, rhs)
  add_offense(range, location: range, message: message(node, lhs, rhs)) do
    if supported_styles.size > 2 ||
       offending_range(node, lhs, rhs, alternative_style)
      unrecognized_style_detected
    else
      opposite_style_detected
    end
  end
end

def indentation(node)
  node.source_range.source_line =~ /\S/
end

def indented_keyword_expression(node)
  if node.for_type?
    expression = node.collection
  else
    expression, = *node
  end
  expression
end

def inside_arg_list_parentheses?(node, ancestor)
  return false unless ancestor.send_type? && ancestor.parenthesized?
  node.source_range.begin_pos > ancestor.loc.begin.begin_pos &&
    node.source_range.end_pos < ancestor.loc.end.end_pos
end

def keyword_message_tail(node)
  keyword = node.loc.keyword.source
  kind    = keyword == 'for' ? 'collection' : 'condition'
  article = keyword =~ /^[iu]/ ? 'an' : 'a'
  format(KEYWORD_MESSAGE_TAIL, kind: kind,
                               article: article,
                               keyword: keyword)
end

def kw_node_with_special_indentation(node)
  keyword_node =
    node.each_ancestor(*KEYWORD_ANCESTOR_TYPES).find do |ancestor|
      next if ancestor.if_type? && ancestor.ternary?
      within_node?(node, indented_keyword_expression(ancestor))
    end
  if keyword_node && block_given?
    yield keyword_node
  else
    keyword_node
  end
end

def left_hand_side(lhs)
  lhs = lhs.parent while lhs.parent && lhs.parent.send_type?
  lhs
end

def not_for_this_cop?(node)
  node.ancestors.any? do |ancestor|
    grouped_expression?(ancestor) ||
      inside_arg_list_parentheses?(node, ancestor)
  end
end

def on_send(node)
  return if !node.receiver || node.method?(:[])
  return unless relevant_node?(node)
  lhs = left_hand_side(node.receiver)
  rhs = right_hand_side(node)
  range = offending_range(node, lhs, rhs, style)
  check(range, node, lhs, rhs)
end

def operation_description(node, rhs)
  kw_node_with_special_indentation(node) do |ancestor|
    return keyword_message_tail(ancestor)
  end
  part_of_assignment_rhs(node, rhs) do |_node|
    return ASSIGNMENT_MESSAGE_TAIL
  end
  DEFAULT_MESSAGE_TAIL
end

def part_of_assignment_rhs(node, candidate)
  rhs_node = node.each_ancestor.find do |ancestor|
    break if disqualified_rhs?(candidate, ancestor)
    valid_rhs?(candidate, ancestor)
  end
  if rhs_node && block_given?
    yield rhs_node
  else
    rhs_node
  end
end

def part_of_block_body?(candidate, block_node)
  block_node.body && within_node?(candidate, block_node.body)
end

def regular_method_right_hand_side(send_node)
  dot = send_node.loc.dot
  selector = send_node.loc.selector
  if send_node.dot? && selector && dot.line == selector.line
    dot.join(selector)
  elsif selector
    selector
  elsif send_node.implicit_call?
    dot.join(send_node.loc.begin)
  end
end

def right_hand_side(send_node)
  if send_node.operator_method? && send_node.arguments?
    send_node.first_argument.source_range # not used for method calls
  else
    regular_method_right_hand_side(send_node)
  end
end

def valid_method_rhs_candidate?(candidate, node)
  node.setter_method? &&
    valid_rhs_candidate?(candidate, node.last_argument)
end

def valid_rhs?(candidate, ancestor)
  if ancestor.send_type?
    valid_method_rhs_candidate?(candidate, ancestor)
  elsif Util::ASGN_NODES.include?(ancestor.type)
    valid_rhs_candidate?(candidate, assignment_rhs(ancestor))
  else
    false
  end
end

def valid_rhs_candidate?(candidate, node)
  !candidate || within_node?(candidate, node)
end

def within_node?(inner, outer)
  o = outer.is_a?(AST::Node) ? outer.source_range : outer
  i = inner.is_a?(AST::Node) ? inner.source_range : inner
  i.begin_pos >= o.begin_pos && i.end_pos <= o.end_pos
end