module RuboCop::Cop::Util

def begins_its_line?(range)
  (range.source_line =~ /\S/) == range.column
end

def comment_line?(line_source)
  line_source =~ /^\s*#/
end

def compatible_external_encoding_for?(src)
  src = src.dup if RUBY_ENGINE == 'jruby'
  src.force_encoding(Encoding.default_external).valid_encoding?
end

def double_quotes_required?(string)
  # Double quotes are required for strings which either:
  # - Contain single quotes
  # - Contain non-printable characters, which must use an escape
  # Regex matches IF there is a ' or there is a \\ in the string that is
  # not preceded/followed by another \\ (e.g. "\\x34") but not "\\\\".
  string =~ /'|(?<! \\) \\{2}* \\ (?![\\"])/x
end

def escape_string(string)
  string.inspect[1..-2].tap { |s| s.gsub!(/\\"/, '"') }
end

def first_part_of_call_chain(node)
  while node
    case node.type
    when :send
      node = node.receiver
    when :block
      node = node.send_node
    else
      break
    end
  end
  node
end

def interpret_string_escapes(string)
  StringInterpreter.interpret(string)
end

def line_range(node)
  node.first_line..node.last_line
end

def needs_escaping?(string)
  double_quotes_required?(escape_string(string))
end

def on_node(syms, sexp, excludes = [], &block)
  return to_enum(:on_node, syms, sexp, excludes) unless block_given?
  yield sexp if Array(syms).include?(sexp.type)
  return if Array(excludes).include?(sexp.type)
  sexp.each_child_node { |elem| on_node(syms, elem, excludes, &block) }
end

def parentheses?(node)
  node.loc.respond_to?(:end) && node.loc.end &&
    node.loc.end.is?(')')
end

def same_line?(node1, node2)
  node1.respond_to?(:loc) &&
    node2.respond_to?(:loc) &&
    node1.loc.line == node2.loc.line
end

def to_string_literal(string)
  if needs_escaping?(string) && compatible_external_encoding_for?(string)
    string.inspect
  else
    "'#{string.gsub('\\') { '\\\\' }}'"
  end
end

def to_supported_styles(enforced_style)
  enforced_style
    .sub(/^Enforced/, 'Supported')
    .sub('Style', 'Styles')
end

def tokens(node)
  @tokens ||= {}
  return @tokens[node.object_id] if @tokens[node.object_id]
  source_range = node.source_range
  begin_pos = source_range.begin_pos
  end_pos = source_range.end_pos
  @tokens[node.object_id] = processed_source.tokens.select do |token|
    token.end_pos <= end_pos && token.begin_pos >= begin_pos
  end
end

def trim_string_interporation_escape_character(str)
  str.gsub(/\\\#{(.*?)\}/) { "\#{#{Regexp.last_match(1)}}" }
end