Message::removeReplyHead

protected function removeReplyHead(&$text)
{
	list($before, $after) = explode(static::QUOTE_PLACEHOLDER, $text, 2);

	if (!trim($before))
		return $text;

	$data = static::reduceTags($before);

	/**
	 * Outlook
	 *
	 * ________________________________________
	 * From: 
	 * Sent: 
	 * To: 
	 * Subject: 
	 */
	$fullHeadRegex = '/(?:^|nn)
		(?
_{20,}n(?:[tx20]*n)?)?
		(?(?:[^:n]{1,20}:[tx20]+.+(?:n|$)){2,6})s*$
	/x'.BX_UTF_PCRE_MODIFIER;
	if (preg_match($fullHeadRegex, $data, $matches))
	{
		$score  = (int) !empty($matches['hr']);
		$score += $this->scoreFullHead($matches['head']);

		if ($score > 1)
		{
			$pattern = preg_replace(array('/.+/', '/n/'), array('.+', 'n'), $matches[0]);
			$before  = preg_replace_callback(
				sprintf('/%s$/', $pattern),
				function($matches)
				{
					return Message::reduceHead($matches[0]);
				},
				$before
			);

			return sprintf('%s%s%s', $before, static::QUOTE_PLACEHOLDER, $after);
		}
	}

	/**
	 * Gmail, Yandex, Thunderbird
	 *
	 * , , :
	 */
	$shortHeadRegex = '/(?:^|n)
		(?.{5,50}d),?x20
		[^dn]{0,20}(?d{1,2}:d{2}(?::d{2})?x20?(?:am|pm)?),?x20
		(?.+):s*$
	/ix'.BX_UTF_PCRE_MODIFIER;
	if (preg_match($shortHeadRegex, $data, $matches))
	{
		$score = 0;
		$score += $this->scoreShortHead($matches[0]);

		if ($score > 0)
		{
			$pattern = preg_replace(array('/.+/', '/n/'), array('.+', 'n'), $matches[0]);
			$before  = preg_replace_callback(
				sprintf('/%s$/', $pattern),
				function($matches)
				{
					return Message::reduceHead($matches[0]);
				},
				$before
			);

			return sprintf('%s%s%s', $before, static::QUOTE_PLACEHOLDER, $after);
		}
	}

	return $text;
}