class RuboCop::Cop::Style::UnneededPercentQ

def acceptable_capital_q?(node)
  src = node.source
  src.include?(QUOTE) &&
    (src =~ STRING_INTERPOLATION_REGEXP ||
    (node.str_type? && double_quotes_acceptable?(node.str_content)))
end

def autocorrect(node)
  delimiter =
    node.source =~ /^%Q[^"]+$|'/ ? QUOTE : SINGLE_QUOTE
  lambda do |corrector|
    corrector.replace(node.loc.begin, delimiter)
    corrector.replace(node.loc.end, delimiter)
  end
end

def check(node)
  src = node.source
  return unless start_with_percent_q_variant?(src)
  return if src.include?(SINGLE_QUOTE) && src.include?(QUOTE)
  if src.start_with?(PERCENT_Q) && src =~ STRING_INTERPOLATION_REGEXP
    return
  end
  if src.start_with?(PERCENT_CAPITAL_Q) && acceptable_capital_q?(node)
    return
  end
  add_offense(node, :expression)
end

def message(node)
  src = node.source
  extra = if src.start_with?(PERCENT_CAPITAL_Q)
            DYNAMIC_MSG
          else
            EMPTY
          end
  format(MSG, src[0, 2], extra)
end

def on_dstr(node)
  check(node)
end

def on_str(node)
  # Interpolated strings that contain more than just interpolation
  # will call `on_dstr` for the entire string and `on_str` for the
  # non interpolated portion of the string
  return unless string_literal?(node)
  check(node)
end

def start_with_percent_q_variant?(string)
  string.start_with?(PERCENT_Q, PERCENT_CAPITAL_Q)
end

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