<?php

/**
 * Copyright (C) 2008-2012 FluxBB
 * based on code by Rickard Andersson copyright (C) 2002-2008 PunBB
 * License: http://www.gnu.org/licenses/gpl.html GPL version 2 or higher
 */

// Make sure no one attempts to run this script "directly"
if (!defined('PUN'))
	exit;

// Define line breaks in mail headers; possible values can be PHP_EOL, "\r\n", "\n" or "\r"
if (!defined('FORUM_EOL'))
	define('FORUM_EOL', PHP_EOL);

require PUN_ROOT.'include/utf8/utils/ascii.php';

//
// Validate an email address
//
function is_valid_email($email)
{
	if (strlen($email) > 80)
		return false;

	return preg_match('%^(([^<>()[\]\\.,;:\s@"]+(\.[^<>()[\]\\.,;:\s@"]+)*)|("[^"]+"))@((\[\d{1,3}\.\d{1,3}\.\d{1,3}\.\d{1,3}\])|(([a-zA-Z\d\-]+\.)+[a-zA-Z]{2,}))$%', $email);
}


//
// Check if $email is banned
//
function is_banned_email($email)
{
	global $pun_bans;

	foreach ($pun_bans as $cur_ban)
	{
		if ($cur_ban['email'] != '' &&
			($email == $cur_ban['email'] ||
			(strpos($cur_ban['email'], '@') === false && stristr($email, '@'.$cur_ban['email']))))
			return true;
	}

	return false;
}


//
// Only encode with base64, if there is at least one unicode character in the string
//
function encode_mail_text($str)
{
	if (utf8_is_ascii($str))
		return $str;

	return '=?UTF-8?B?'.base64_encode($str).'?=';
}


//
// Make a post email safe
//
function bbcode2email($text, $wrap_length = 72)
{
	static $base_url;

	if (!isset($base_url))
		$base_url = get_base_url();

	$text = pun_trim($text, "\t\n ");

	$shortcut_urls = array(
		'topic' => '/viewtopic.php?id=$1',
		'post' => '/viewtopic.php?pid=$1#p$1',
		'forum' => '/viewforum.php?id=$1',
		'user' => '/profile.php?id=$1',
	);

	// Split code blocks and text so BBcode in codeblocks won't be touched
	list($code, $text) = extract_blocks($text, '[code]', '[/code]');

	// Strip all bbcodes, except the quote, url, img, email, code and list items bbcodes
	$text = preg_replace(array(
		'%\[/?(?!(?:quote|url|topic|post|user|forum|img|email|code|list|\*))[a-z]+(?:=[^\]]+)?\]%i',
		'%\n\[/?list(?:=[^\]]+)?\]%i' // A separate regex for the list tags to get rid of some whitespace
	), '', $text);

	// Match the deepest nested bbcode
	// An adapted example from Mastering Regular Expressions
	$match_quote_regex = '%
		\[(quote|\*|url|img|email|topic|post|user|forum)(?:=([^\]]+))?\]
		(
			(?>[^\[]*)
			(?>
				(?!\[/?\1(?:=[^\]]+)?\])
				\[
				[^\[]*
			)*
		)
		\[/\1\]
	%ix';

	$url_index = 1;
	$url_stack = array();
	while (preg_match($match_quote_regex, $text, $matches))
	{
		// Quotes
		if ($matches[1] == 'quote')
		{
			// Put '>' or '> ' at the start of a line
			$replacement = preg_replace(
				array('%^(?=\>)%m', '%^(?!\>)%m'),
				array('>', '> '),
				$matches[2].":\n".$matches[3]);
		}

		// List items
		elseif ($matches[1] == '*')
		{
			$replacement = ' * '.$matches[3];
		}

		// URLs and emails
		elseif (in_array($matches[1], array('url', 'email')))
		{
			if (!empty($matches[2]))
			{
				$replacement = '['.$matches[3].']['.$url_index.']';
				$url_stack[$url_index] = $matches[2];
				$url_index++;
			}
			else
				$replacement = '['.$matches[3].']';
		}

		// Images
		elseif ($matches[1] == 'img')
		{
			if (!empty($matches[2]))
				$replacement = '['.$matches[2].']['.$url_index.']';
			else
				$replacement = '['.basename($matches[3]).']['.$url_index.']';

			$url_stack[$url_index] = $matches[3];
			$url_index++;
		}

		// Topic, post, forum and user URLs
		elseif (in_array($matches[1], array('topic', 'post', 'forum', 'user')))
		{
			$url = isset($shortcut_urls[$matches[1]]) ? $base_url.$shortcut_urls[$matches[1]] : '';

			if (!empty($matches[2]))
			{
				$replacement = '['.$matches[3].']['.$url_index.']';
				$url_stack[$url_index] = str_replace('$1', $matches[2], $url);
				$url_index++;
			}
			else
				$replacement = '['.str_replace('$1', $matches[3], $url).']';
		}

		// Update the main text if there is a replacement
		if (!is_null($replacement))
		{
			$text = str_replace($matches[0], $replacement, $text);
			$replacement = null;
		}
	}

	// Put code blocks and text together
	if (isset($code))
	{
		$parts = explode("\1", $text);
		$text = '';
		foreach ($parts as $i => $part)
		{
			$text .= $part;
			if (isset($code[$i]))
				$text .= trim($code[$i], "\n\r");
		}
	}

	// Put URLs at the bottom
	if ($url_stack)
	{
		$text .= "\n\n";
		foreach ($url_stack as $i => $url)
			$text .= "\n".' ['.$i.']: '.$url;
	}

	// Wrap lines if $wrap_length is higher than -1
	if ($wrap_length > -1)
	{
		// Split all lines and wrap them individually
		$parts = explode("\n", $text);
		foreach ($parts as $k => $part)
		{
			preg_match('%^(>+ )?(.*)%', $part, $matches);
			$parts[$k] = wordwrap($matches[1].$matches[2], $wrap_length -
				strlen($matches[1]), "\n".$matches[1]);
		}

		return implode("\n", $parts);
	}
	else
		return $text;
}


//
// Wrapper for PHP's mail()
//
function pun_mail($to, $subject, $message, $reply_to_email = '', $reply_to_name = '')
{
	global $pun_config, $lang_common;

	// Use \r\n for SMTP servers, the system's line ending for local mailers
	$smtp = $pun_config['o_smtp_host'] != '';
	$EOL = $smtp ? "\r\n" : FORUM_EOL;

	// Default sender/return address
	$from_name = sprintf($lang_common['Mailer'], $pun_config['o_board_title']);
	$from_email = $pun_config['o_webmaster_email'];

	// Do a little spring cleaning
	$to = pun_trim(preg_replace('%[\n\r]+%s', '', $to));
	$subject = pun_trim(preg_replace('%[\n\r]+%s', '', $subject));
	$from_email = pun_trim(preg_replace('%[\n\r:]+%s', '', $from_email));
	$from_name = pun_trim(preg_replace('%[\n\r:]+%s', '', str_replace('"', '', $from_name)));
	$reply_to_email = pun_trim(preg_replace('%[\n\r:]+%s', '', $reply_to_email));
	$reply_to_name = pun_trim(preg_replace('%[\n\r:]+%s', '', str_replace('"', '', $reply_to_name)));

	// Set up some headers to take advantage of UTF-8
	$from = '"'.encode_mail_text($from_name).'" <'.$from_email.'>';
	$subject = encode_mail_text($subject);

	$headers = 'From: '.$from.$EOL.'Date: '.gmdate('r').$EOL.'MIME-Version: 1.0'.$EOL.'Content-transfer-encoding: 8bit'.$EOL.'Content-type: text/plain; charset=utf-8'.$EOL.'X-Mailer: FluxBB Mailer';

	// If we specified a reply-to email, we deal with it here
	if (!empty($reply_to_email))
	{
		$reply_to = '"'.encode_mail_text($reply_to_name).'" <'.$reply_to_email.'>';

		$headers .= $EOL.'Reply-To: '.$reply_to;
	}

	// Make sure all linebreaks are LF in message (and strip out any NULL bytes)
	$message = str_replace("\0", '', pun_linebreaks($message));
	$message = str_replace("\n", $EOL, $message);
	
	$mailer = $smtp ? 'smtp_mail' : 'mail';
	$mailer($to, $subject, $message, $headers);
}


//
// This function was originally a part of the phpBB Group forum software phpBB2 (http://www.phpbb.com)
// They deserve all the credit for writing it. I made small modifications for it to suit PunBB and its coding standards
//
function server_parse($socket, $expected_response)
{
	$server_response = '';
	while (substr($server_response, 3, 1) != ' ')
	{
		if (!($server_response = fgets($socket, 256)))
			error('Couldn\'t get mail server response codes. Please contact the forum administrator.', __FILE__, __LINE__);
	}

	if (!(substr($server_response, 0, 3) == $expected_response))
		error('Unable to send email. Please contact the forum administrator with the following error message reported by the SMTP server: "'.$server_response.'"', __FILE__, __LINE__);
}


//
// This function was originally a part of the phpBB Group forum software phpBB2 (http://www.phpbb.com)
// They deserve all the credit for writing it. I made small modifications for it to suit PunBB and its coding standards.
//
function smtp_mail($to, $subject, $message, $headers = '')
{
	global $pun_config;
	static $local_host;

	$recipients = explode(',', $to);

	// Sanitize the message
	$message = str_replace("\r\n.", "\r\n..", $message);
	$message = (substr($message, 0, 1) == '.' ? '.'.$message : $message);

	// Are we using port 25 or a custom port?
	if (strpos($pun_config['o_smtp_host'], ':') !== false)
		list($smtp_host, $smtp_port) = explode(':', $pun_config['o_smtp_host']);
	else
	{
		$smtp_host = $pun_config['o_smtp_host'];
		$smtp_port = 25;
	}

	if ($pun_config['o_smtp_ssl'] == '1')
		$smtp_host = 'ssl://'.$smtp_host;

	if (!($socket = fsockopen($smtp_host, $smtp_port, $errno, $errstr, 15)))
		error('Could not connect to smtp host "'.$pun_config['o_smtp_host'].'" ('.$errno.') ('.$errstr.')', __FILE__, __LINE__);

	server_parse($socket, '220');

	if (!isset($local_host))
	{
		// Here we try to determine the *real* hostname (reverse DNS entry preferably)
		$local_host = php_uname('n');

		// Able to resolve name to IP
		if (($local_addr = @gethostbyname($local_host)) !== $local_host)
		{
			// Able to resolve IP back to name
			if (($local_name = @gethostbyaddr($local_addr)) !== $local_addr)
				$local_host = $local_name;
		}
	}

	if ($pun_config['o_smtp_user'] != '' && $pun_config['o_smtp_pass'] != '')
	{
		fwrite($socket, 'EHLO '.$local_host."\r\n");
		server_parse($socket, '250');

		fwrite($socket, 'AUTH LOGIN'."\r\n");
		server_parse($socket, '334');

		fwrite($socket, base64_encode($pun_config['o_smtp_user'])."\r\n");
		server_parse($socket, '334');

		fwrite($socket, base64_encode($pun_config['o_smtp_pass'])."\r\n");
		server_parse($socket, '235');
	}
	else
	{
		fwrite($socket, 'HELO '.$local_host."\r\n");
		server_parse($socket, '250');
	}

	fwrite($socket, 'MAIL FROM: <'.$pun_config['o_webmaster_email'].'>'."\r\n");
	server_parse($socket, '250');

	foreach ($recipients as $email)
	{
		fwrite($socket, 'RCPT TO: <'.$email.'>'."\r\n");
		server_parse($socket, '250');
	}

	fwrite($socket, 'DATA'."\r\n");
	server_parse($socket, '354');

	fwrite($socket, 'Subject: '.$subject."\r\n".'To: <'.implode('>, <', $recipients).'>'."\r\n".$headers."\r\n\r\n".$message."\r\n");

	fwrite($socket, '.'."\r\n");
	server_parse($socket, '250');

	fwrite($socket, 'QUIT'."\r\n");
	fclose($socket);

	return true;
}