replace)
 * @return string substituted string
 */
function replace_macros($s,$r) {
	$a = get_app();
	$t = $a->template_engine();
	$output = $t->replace_macros($s,$r);
	
	return $output;
}
// random string, there are 86 characters max in text mode, 128 for hex
// output is urlsafe
define('RANDOM_STRING_HEX',  0x00 );
define('RANDOM_STRING_TEXT', 0x01 );
function random_string($size = 64,$type = RANDOM_STRING_HEX) {
	// generate a bit of entropy and run it through the whirlpool
	$s = hash('whirlpool', (string) rand() . uniqid(rand(),true) . (string) rand(),(($type == RANDOM_STRING_TEXT) ? true : false));
	$s = (($type == RANDOM_STRING_TEXT) ? str_replace("\n","",base64url_encode($s,true)) : $s);
	return(substr($s,0,$size));
}
/**
 * This is our primary input filter. 
 *
 * The high bit hack only involved some old IE browser, forget which (IE5/Mac?)
 * that had an XSS attack vector due to stripping the high-bit on an 8-bit character
 * after cleansing, and angle chars with the high bit set could get through as markup.
 * 
 * This is now disabled because it was interfering with some legitimate unicode sequences 
 * and hopefully there aren't a lot of those browsers left. 
 *
 * Use this on any text input where angle chars are not valid or permitted
 * They will be replaced with safer brackets. This may be filtered further
 * if these are not allowed either.   
 *
 * @param string $string Input string
 * @return string Filtered string
 */
function notags($string) {
	return(str_replace(array("<",">"), array('[',']'), $string));
//  High-bit filter no longer used
//	return(str_replace(array("<",">","\xBA","\xBC","\xBE"), array('[',']','','',''), $string));
}
// use this on "body" or "content" input where angle chars shouldn't be removed,
// and allow them to be safely displayed.
/**
 * use this on "body" or "content" input where angle chars shouldn't be removed,
 * and allow them to be safely displayed.
 * @param string $string
 * @return string
 */
function escape_tags($string) {
	return(htmlspecialchars($string, ENT_COMPAT, 'UTF-8', false));
}
function z_input_filter($channel_id,$s,$type = 'text/bbcode') {
	if($type === 'text/bbcode')
		return escape_tags($s);
	if($type === 'text/markdown')
		return escape_tags($s);
	if($type == 'text/plain')
		return escape_tags($s);
	$r = q("select account_id, account_roles from account left join channel on channel_account_id = account_id where channel_id = %d limit 1",
		intval($channel_id)
	);
	if($r && ($r[0]['account_roles'] & ACCOUNT_ROLE_ALLOWCODE)) {
		if(local_user() && (get_account_id() == $r[0]['account_id'])) {
			return $s;
		}
	}
	if($type === 'text/html')
		return purify_html($s);
	return escape_tags($s);
	
}
function purify_html($s) {
	require_once('library/HTMLPurifier.auto.php');
	require_once('include/html2bbcode.php');
// FIXME this function has html output, not bbcode - so safely purify these
//	$s = html2bb_video($s);
//	$s = oembed_html2bbcode($s);
	$config = HTMLPurifier_Config::createDefault();
	$config->set('Cache.DefinitionImpl', null);
	$purifier = new HTMLPurifier($config);
	return $purifier->purify($s);
}
// generate a string that's random, but usually pronounceable. 
// used to generate initial passwords
/**
 * generate a string that's random, but usually pronounceable. 
 * used to generate initial passwords
 * @param int $len
 * @return string
 */
function autoname($len) {
	if($len <= 0)
		return '';
	$vowels = array('a','a','ai','au','e','e','e','ee','ea','i','ie','o','ou','u'); 
	if(mt_rand(0,5) == 4)
		$vowels[] = 'y';
	$cons = array(
			'b','bl','br',
			'c','ch','cl','cr',
			'd','dr',
			'f','fl','fr',
			'g','gh','gl','gr',
			'h',
			'j',
			'k','kh','kl','kr',
			'l',
			'm',
			'n',
			'p','ph','pl','pr',
			'qu',
			'r','rh',
			's','sc','sh','sm','sp','st',
			't','th','tr',
			'v',
			'w','wh',
			'x',
			'z','zh'
			);
	$midcons = array('ck','ct','gn','ld','lf','lm','lt','mb','mm', 'mn','mp',
				'nd','ng','nk','nt','rn','rp','rt');
	$noend = array('bl', 'br', 'cl','cr','dr','fl','fr','gl','gr',
				'kh', 'kl','kr','mn','pl','pr','rh','tr','qu','wh');
	$start = mt_rand(0,2);
  	if($start == 0)
    		$table = $vowels;
  	else
    		$table = $cons;
	$word = '';
	for ($x = 0; $x < $len; $x ++) {
  		$r = mt_rand(0,count($table) - 1);
  		$word .= $table[$r];
  
  		if($table == $vowels)
    			$table = array_merge($cons,$midcons);
  		else
    			$table = $vowels;
	}
	$word = substr($word,0,$len);
	foreach($noend as $noe) {
  		if((strlen($word) > 2) && (substr($word,-2) == $noe)) {
    			$word = substr($word,0,-1);
    			break;
  		}
	}
	if(substr($word,-1) == 'q')
		$word = substr($word,0,-1);    
	return $word;
}
// escape text ($str) for XML transport
// returns escaped text.
/**
 * escape text ($str) for XML transport
 * @param string $str
 * @return string Escaped text.
 */
function xmlify($str) {
	$buffer = '';
	
	$len = mb_strlen($str);
	for($x = 0; $x < $len; $x ++) {
		$char = mb_substr($str,$x,1);
        
		switch( $char ) {
			case "\r" :
				break;
			case "&" :
				$buffer .= '&';
				break;
			case "'" :
				$buffer .= ''';
				break;
			case "\"" :
				$buffer .= '"';
				break;
			case '<' :
				$buffer .= '<';
				break;
			case '>' :
				$buffer .= '>';
				break;
			case "\n" :
				$buffer .= "\n";
				break;
			default :
				$buffer .= $char;
				break;
		}	
	}
	$buffer = trim($buffer);
	return($buffer);
}
// undo an xmlify
// pass xml escaped text ($s), returns unescaped text
function unxmlify($s) {
	$ret = str_replace('&','&', $s);
	$ret = str_replace(array('<','>','"','''),array('<','>','"',"'"),$ret);
	return $ret;	
}
// convenience wrapper, reverse the operation "bin2hex"
// This is a built-in function in php >= 5.4
if(! function_exists('hex2bin')) {
function hex2bin($s) {
	if(! (is_string($s) && strlen($s)))
		return '';
	if(! ctype_xdigit($s)) {
		return($s);
	}
	return(pack("H*",$s));
}}
// Automatic pagination.
// To use, get the count of total items.
// Then call $a->set_pager_total($number_items);
// Optionally call $a->set_pager_itemspage($n) to the number of items to display on each page
// Then call paginate($a) after the end of the display loop to insert the pager block on the page
// (assuming there are enough items to paginate).
// When using with SQL, the setting LIMIT %d, %d => $a->pager['start'],$a->pager['itemspage']
// will limit the results to the correct items for the current page. 
// The actual page handling is then accomplished at the application layer. 
function paginate(&$a) {
	$o = '';
	$stripped = preg_replace('/(&page=[0-9]*)/','',$a->query_string);
//	$stripped = preg_replace('/&zid=(.*?)([\?&]|$)/ism','',$stripped);
	$stripped = str_replace('q=','',$stripped);
	$stripped = trim($stripped,'/');
	$pagenum = $a->pager['page'];
	$url = $a->get_baseurl() . '/' . $stripped;
	  if($a->pager['total'] > $a->pager['itemspage']) {
		$o .= '
'."\r\n";
	}
	return $o;
}
function alt_pager(&$a, $i, $more = '', $less = '') {
	$o = '';
	if(! $more)
		$more = t('older');
	if(! $less)
		$less = t('newer');
	$stripped = preg_replace('/(&page=[0-9]*)/','',$a->query_string);
	$stripped = str_replace('q=','',$stripped);
	$stripped = trim($stripped,'/');
	$pagenum = $a->pager['page'];
	$url = $a->get_baseurl() . '/' . $stripped;
	return replace_macros(get_markup_template('alt_pager.tpl'),array(
		'$has_less' => (($a->pager['page'] > 1) ? true : false),
		'$has_more' => (($i > 0 && $i >= $a->pager['itemspage']) ? true : false),
		'$less' => $less,
		'$more' => $more,
		'$url' => $url,
		'$prevpage' => $a->pager['page'] - 1,
		'$nextpage' => $a->pager['page'] + 1,
	));
}
// Turn user/group ACLs stored as angle bracketed text into arrays
function expand_acl($s) {
	// turn string array of angle-bracketed elements into string array
	// e.g. "<123xyz><246qyo>" => array(123xyz,246qyo,sxo33e);
	$ret = array();
	if(strlen($s)) {
		$t = str_replace('<','',$s);
		$a = explode('>',$t);
		foreach($a as $aa) {
			if($aa)
				$ret[] = $aa;
		}
	}
	return $ret;
}		
// Used to wrap ACL elements in angle brackets for storage 
function sanitise_acl(&$item) {
	if(strlen($item))
		$item = '<' . notags(trim($item)) . '>';
	else
		unset($item);
}
// Convert an ACL array to a storable string
function perms2str($p) {
	$ret = '';
	if(is_array($p))
		$tmp = $p;
	else
		$tmp = explode(',',$p);
	if(is_array($tmp)) {
		array_walk($tmp,'sanitise_acl');
		$ret = implode('',$tmp);
	}
	return $ret;
}
// generate a guaranteed unique (for this domain) item ID for ATOM
// safe from birthday paradox
function item_message_id() {
	do {
		$dups = false;
		$hash = random_string();
		$mid = $hash . '@' . get_app()->get_hostname();
		$r = q("SELECT `id` FROM `item` WHERE `mid` = '%s' LIMIT 1",
			dbesc($mid));
		if(count($r))
			$dups = true;
	} while($dups == true);
	return $mid;
}
// Generate a guaranteed unique photo ID.
// safe from birthday paradox
function photo_new_resource() {
	do {
		$found = false;
		$resource = hash('md5',uniqid(mt_rand(),true));
		$r = q("SELECT `id` FROM `photo` WHERE `resource_id` = '%s' LIMIT 1",
			dbesc($resource)
		);
		if(count($r))
			$found = true;
	} while($found == true);
	return $resource;
}
// for html,xml parsing - let's say you've got
// an attribute foobar="class1 class2 class3"
// and you want to find out if it contains 'class3'.
// you can't use a normal sub string search because you
// might match 'notclass3' and a regex to do the job is 
// possible but a bit complicated. 
// pass the attribute string as $attr and the attribute you 
// are looking for as $s - returns true if found, otherwise false
function attribute_contains($attr,$s) {
	$a = explode(' ', $attr);
	if(count($a) && in_array($s,$a))
		return true;
	return false;
}
function logger($msg,$level = 0) {
	// turn off logger in install mode
	global $a;
	global $db;
	if(($a->module == 'install') || (! ($db && $db->connected))) return;
	$debugging = get_config('system','debugging');
	$loglevel  = intval(get_config('system','loglevel'));
	$logfile   = get_config('system','logfile');
	if((! $debugging) || (! $logfile) || ($level > $loglevel))
		return;
	
	@file_put_contents($logfile, datetime_convert() . ':' . session_id() . ' ' . $msg . "\n", FILE_APPEND);
	return;
}
// This is a special logging facility for developers. It allows one to target specific things to trace/debug
// and is identical to logger() with the exception of the log filename. This allows one to isolate specific
// calls while allowing logger() to paint a bigger picture of overall activity and capture more detail.
// If you find dlogger() calls in checked in code, you are free to remove them - so as to provide a noise-free
// development environment which responds to events you are targetting personally. 
function dlogger($msg,$level = 0) {
	// turn off logger in install mode
	global $a;
	global $db;
	if(($a->module == 'install') || (! ($db && $db->connected))) return;
	$debugging = get_config('system','debugging');
	$loglevel  = intval(get_config('system','loglevel'));
	$logfile   = get_config('system','dlogfile');
	if((! $debugging) || (! $logfile) || ($level > $loglevel))
		return;
	
	@file_put_contents($logfile, datetime_convert() . ':' . session_id() . ' ' . $msg . "\n", FILE_APPEND);
	return;
}
function profiler($t1,$t2,$label) {
	if(file_exists('profiler.out') && $t1 && t2)
		@file_put_contents('profiler.out', sprintf('%01.4f %s',$t2 - $t1,$label) . "\n", FILE_APPEND);
}
function activity_match($haystack,$needle) {
	if(($haystack === $needle) || ((basename($needle) === $haystack) && strstr($needle,NAMESPACE_ACTIVITY_SCHEMA)))
		return true;
	return false;
}
// Pull out all #hashtags and @person tags from $s;
// We also get @person@domain.com - which would make 
// the regex quite complicated as tags can also
// end a sentence. So we'll run through our results
// and strip the period from any tags which end with one.
// Returns array of tags found, or empty array.
function get_tags($s) {
	$ret = array();
	// ignore anything in a code block
	$s = preg_replace('/\[code\](.*?)\[\/code\]/sm','',$s);
	// Match full names against @tags including the space between first and last
	// We will look these up afterward to see if they are full names or not recognisable.
	if(preg_match_all('/(@[^ \x0D\x0A,:?]+ [^ \x0D\x0A@,:?]+)([ \x0D\x0A@,:?]|$)/',$s,$match)) {
		foreach($match[1] as $mtch) {
			if(strstr($mtch,"]")) {
				// we might be inside a bbcode color tag - leave it alone
				continue;
			}
			if(substr($mtch,-1,1) === '.')
				$ret[] = substr($mtch,0,-1);
			else
				$ret[] = $mtch;
		}
	}
	// Otherwise pull out single word tags. These can be @nickname, @first_last
	// and #hash tags.
	if(preg_match_all('/([@#][^ \x0D\x0A,;:?]+)([ \x0D\x0A,;:?]|$)/',$s,$match)) {
		foreach($match[1] as $mtch) {
			if(strstr($mtch,"]")) {
				// we might be inside a bbcode color tag - leave it alone
				continue;
			}
			if(substr($mtch,-1,1) === '.')
				$mtch = substr($mtch,0,-1);
			// ignore strictly numeric tags like #1
			if((strpos($mtch,'#') === 0) && ctype_digit(substr($mtch,1)))
				continue;
			// try not to catch url fragments
			if(strpos($s,$mtch) && preg_match('/[a-zA-z0-9\/]/',substr($s,strpos($s,$mtch)-1,1)))
				continue;
			$ret[] = $mtch;
		}
	}
	return $ret;
}
// quick and dirty quoted_printable encoding
function qp($s) {
return str_replace ("%","=",rawurlencode($s));
} 
function get_mentions($item,$tags) {
	$o = '';
	if(! count($tags))
		return $o;
	foreach($tags as $x) {
		if($x['type'] == TERM_MENTION) {
			$o .= "\t\t" . '';
	$o .= '
';
	return $o;
}
function valid_email($x){
	if(get_config('system','disable_email_validation'))
		return true;
	if(preg_match('/^[_a-zA-Z0-9\-\+]+(\.[_a-zA-Z0-9\-\+]+)*@[a-zA-Z0-9-]+(\.[a-zA-Z0-9-]+)+$/',$x))
		return true;
	return false;
}
/**
 *
 * Function: linkify
 *
 * Replace naked text hyperlink with HTML formatted hyperlink
 *
 */
function linkify($s) {
	$s = preg_replace("/(https?\:\/\/[a-zA-Z0-9\:\/\-\?\&\;\.\=\_\@\~\#\'\%\$\!\+]*)/", ' $1 ', $s);
	$s = preg_replace("/\<(.*?)(src|href)=(.*?)\&\;(.*?)\>/ism",'<$1$2=$3&$4>',$s);
	return($s);
}
function get_poke_verbs() {
	
	// index is present tense verb
	// value is array containing past tense verb, translation of present, translation of past
	$arr = array(
		'poke' => array( 'poked', t('poke'), t('poked')),
		'ping' => array( 'pinged', t('ping'), t('pinged')),
		'prod' => array( 'prodded', t('prod'), t('prodded')),
		'slap' => array( 'slapped', t('slap'), t('slapped')),
		'finger' => array( 'fingered', t('finger'), t('fingered')),
		'rebuff' => array( 'rebuffed', t('rebuff'), t('rebuffed')),
	);
	call_hooks('poke_verbs', $arr);
	return $arr;
}
function get_mood_verbs() {
	
	// index is present tense verb
	// value is array containing past tense verb, translation of present, translation of past
	$arr = array(
		'happy'      => t('happy'),
		'sad'        => t('sad'),
		'mellow'     => t('mellow'),
		'tired'      => t('tired'),
		'perky'      => t('perky'),
		'angry'      => t('angry'),
		'stupefied'  => t('stupified'),
		'puzzled'    => t('puzzled'),
		'interested' => t('interested'),
		'bitter'     => t('bitter'),
		'cheerful'   => t('cheerful'),
		'alive'      => t('alive'),
		'annoyed'    => t('annoyed'),
		'anxious'    => t('anxious'),
		'cranky'     => t('cranky'),
		'disturbed'  => t('disturbed'),
		'frustrated' => t('frustrated'),
		'motivated'  => t('motivated'),
		'relaxed'    => t('relaxed'),
		'surprised'  => t('surprised'),
	);
	call_hooks('mood_verbs', $arr);
	return $arr;
}
/**
 * 
 * Function: smilies
 *
 * Description:
 * Replaces text emoticons with graphical images
 *
 * @Parameter: string $s
 *
 * Returns string
 *
 * It is expected that this function will be called using HTML text.
 * We will escape text between HTML pre and code blocks from being 
 * processed. 
 * 
 * At a higher level, the bbcode [nosmile] tag can be used to prevent this 
 * function from being executed by the prepare_text() routine when preparing
 * bbcode source for HTML display
 *
 */
function smilies($s, $sample = false) {
	$a = get_app();
	if(intval(get_config('system','no_smilies')) 
		|| (local_user() && intval(get_pconfig(local_user(),'system','no_smilies'))))
		return $s;
	$s = preg_replace_callback('/(.*?)<\/pre>/ism','smile_encode',$s);
	$s = preg_replace_callback('/(.*?)<\/code>/ism','smile_encode',$s);
	$texts =  array( 
		'<3', 
		'</3', 
		'<\\3', 
		':-)', 
		';-)', 
		':-(', 
		':-P', 
		':-p', 
		':-"', 
		':-"', 
		':-x', 
		':-X', 
		':-D', 
		'8-|', 
		'8-O', 
		':-O', 
		'\\o/', 
		'o.O', 
		'O.o', 
		'o_O', 
		'O_o', 
		":'(", 
		":-!", 
		":-/", 
		":-[", 
		"8-)",
		':beer', 
		':homebrew', 
		':coffee', 
		':facepalm',
		':like',
		':dislike',
		'red#',
		'r#',
		'~friendica'
	);
	$icons = array(
		'red red ~friendica  '
	);
	$params = array('texts' => $texts, 'icons' => $icons, 'string' => $s);
	call_hooks('smilie', $params);
	if($sample) {
		$s = '';
		for($x = 0; $x < count($params['texts']); $x ++) {
			$s .= '
' . $params['texts'][$x] . ' ' . $params['icons'][$x] . ' ';
		}
	}
	else {
		$params['string'] = preg_replace_callback('/<(3+)/','preg_heart',$params['string']);
		$s = str_replace($params['texts'],$params['icons'],$params['string']);
	}
	$s = preg_replace_callback('/
(.*?)<\/pre>/ism','smile_decode',$s);
	$s = preg_replace_callback('/(.*?)<\/code>/ism','smile_decode',$s);
	return $s;
}
function smile_encode($m) {
	return(str_replace($m[1],base64url_encode($m[1]),$m[0]));
}
function smile_decode($m) {
	return(str_replace($m[1],base64url_decode($m[1]),$m[0]));
}
// expand <3333 to the correct number of hearts
function preg_heart($x) {
	$a = get_app();
	if(strlen($x[1]) == 1)
		return $x[0];
	$t = '';
	for($cnt = 0; $cnt < strlen($x[1]); $cnt ++)
		$t .= '' . $icon . ' ';
			$attaches[] = array('title' => $title, 'url' => $url, 'icon' => $icon );
		}
	}
	$s = replace_macros(get_markup_template('item_attach.tpl'), array(
		'$attaches' => $attaches
	));
	return $s;
}
function format_categories(&$item,$writeable) {
	$s = '';
	$terms = get_terms_oftype($item['term'],TERM_CATEGORY);
	if($terms) {
		$categories = array();
		foreach($terms as $t) {
			$term = htmlspecialchars($t['term'],ENT_COMPAT,'UTF-8') ;
			if(! trim($term))
				continue;
			$removelink = (($writeable) ?  z_root() . '/filerm/' . $item['id'] . '?f=&cat=' . urlencode($t['term']) : '');
			$categories[] = array('term' => $term, 'writeable' => $writeable, 'removelink' => $removelink, 'url' => $t['url']);
		}
	}
	$s = replace_macros(get_markup_template('item_categories.tpl'),array(
		'$remove' => t('remove category'),
		'$categories' => $categories
	));
	return $s;
}
function format_filer(&$item) {
	$s = '';
	$terms = get_terms_oftype($item['term'],TERM_FILE);
	if($terms) {
		$categories = array();
		foreach($terms as $t) {
			$term = htmlspecialchars($t['term'],ENT_COMPAT,'UTF-8') ;
			if(! trim($term))
				continue;
			$removelink = z_root() . '/filerm/' . $item['id'] . '?f=&term=' . urlencode($t['term']);
			$categories[] = array('term' => $term, 'removelink' => $removelink);
		}
	}
	$s = replace_macros(get_markup_template('item_filer.tpl'),array(
		'$remove' => t('remove from file'),
		'$categories' => $categories
	));
	return $s;
}
function prepare_body(&$item,$attach = false) {
	$a = get_app();
	call_hooks('prepare_body_init', $item); 
	unobscure($item);
	$s = prepare_text($item['body'],$item['mimetype']);
	$prep_arr = array('item' => $item, 'html' => $s);
	call_hooks('prepare_body', $prep_arr);
	$s = $prep_arr['html'];
	if(! $attach) {
		return $s;
	}
	$s .= theme_attachments($item);
	$writeable = ((get_observer_hash() == $item['owner_xchan']) ? true : false); 
	$s .= format_categories($item,$writeable);
	if(local_user() == $item['uid'])
		$s .= format_filer($item);
	// Look for spoiler
	$spoilersearch = '';
	// Remove line breaks before the spoiler
	while ((strpos($s, "\n".$spoilersearch) !== false))
		$s = str_replace("\n".$spoilersearch, $spoilersearch, $s);
	while ((strpos($s, "'.sprintf(t('Click to open/close')).' '.
	                                '';
		$s = substr($s, 0, $pos).$spoilerreplace.substr($s, $pos+strlen($spoilersearch));
	}
	// Look for quote with author
	$authorsearch = '';
	while ((strpos($s, $authorsearch) !== false)) {
		$pos = strpos($s, $authorsearch);
		$rnd = random_string(8);
		$authorreplace = ''.sprintf(t('Click to open/close')).' '.
	                                '';
		$s = substr($s, 0, $pos).$authorreplace.substr($s, $pos+strlen($authorsearch));
	}
	$prep_arr = array('item' => $item, 'html' => $s);
	call_hooks('prepare_body_final', $prep_arr);
	return $prep_arr['html'];
}
// Given a text string, convert from bbcode to html and add smilie icons.
function prepare_text($text,$content_type = 'text/bbcode') {
	switch($content_type) {
		case 'text/plain':
			$s = escape_tags($text);
			break;
		case 'text/html':
			$s = $text;
			break;
		case 'text/markdown':
			require_once('library/markdown.php');
			$s = Markdown($text);
			break;
		// No security checking is done here at display time - so we need to verify 
		// that the author is allowed to use PHP before storing. We also cannot allow 
		// importation of PHP text bodies from other sites. Therefore this content 
		// type is only valid for web pages (and profile details).
		// It may be possible to provide a PHP message body which is evaluated on the 
		// sender's site before sending it elsewhere. In that case we will have a 
		// different content-type here.  
		case 'application/x-php':
			ob_start();
			eval($text);
			$s = ob_get_contents();
			ob_end_clean();
			break;
		case 'text/bbcode':
		case '':
		default:
			require_once('include/bbcode.php');
			if(stristr($text,'[nosmile]'))
				$s = bbcode($text);
			else
				$s = smilies(bbcode($text));
			$s = zidify_links($s);
			break;
	}
//logger('prepare_text: ' . $s);
	return $s;
}
/**
 * zidify_callback() and zidify_links() work together to turn any HTML a tags with class="zrl" into zid links
 * These will typically be generated by a bbcode '[zrl]' tag. This is done inside prepare_text() rather than bbcode() 
 * because the latter is used for general purpose conversions and the former is used only when preparing text for
 * immediate display.
 * 
 * Issues: Currently the order of HTML parameters in the text is somewhat rigid and inflexible.
 *    We assume it looks like  and will not work if zrl and href appear in a different order. 
 */
function zidify_callback($match) {
	if (feature_enabled(local_user(),'sendzid')) {
		$replace = ' ';
		$empty_selected = (($current === '') ? ' selected="selected" ' : '');
		$o .= '' . t('default') . ' ';
		foreach($r as $rr) {
			$selected = (($rr['mid'] == $current) ? ' selected="selected" ' : '');
			$o .= '' . $rr['sid'] . ' ';
		}
		$o .= ' ';
	}
	return $o;
}
function mimetype_select($channel_id, $current = 'text/bbcode') {
	$x = array(
		'text/bbcode',
		'text/html',
		'text/markdown',
		'text/plain'
	);
	$r = q("select account_id, account_roles from account left join channel on account_id = channel_account_id where
		channel_id = %d limit 1",
		intval($channel_id)
	);
	if($r) {
		if($r[0]['account_roles'] & ACCOUNT_ROLE_ALLOWCODE) {
			if(local_user() && get_account_id() == $r[0]['account_id'])
				$x[] = 'application/x-php';
		}
	}
	$o = t('Page content type: ');
	$o .= '';
	foreach($x as $y) {
		$select = (($y == $current)	? ' selected="selected" ' : '');
		$o .= '' . $y . ' ';
	}
	$o .= ' ';
	return $o;
}
function lang_selector() {
	global $a;
	
	$langs = glob('view/*/strings.php');
	
	$lang_options = array();
	$selected = "";
	
	if(is_array($langs) && count($langs)) {
		$langs[] = '';
		if(! in_array('view/en/strings.php',$langs))
			$langs[] = 'view/en/';
		asort($langs);
		foreach($langs as $l) {
			if($l == '') {
				$lang_options[""] = t('default');
				continue;
			}
			$ll = substr($l,5);
			$ll = substr($ll,0,strrpos($ll,'/'));
			$selected = (($ll === $a->language && (x($_SESSION, 'language'))) ? $ll : $selected);
			$lang_options[$ll]=$ll;
		}
	}
	$tpl = get_markup_template("lang_selector.tpl");	
	$o = replace_macros($tpl, array(
		'$title' => t('Select an alternate language'),
		'$langs' => array($lang_options, $selected),
		
	));
	return $o;
}
function return_bytes ($size_str) {
    switch (substr ($size_str, -1))
    {
        case 'M': case 'm': return (int)$size_str * 1048576;
        case 'K': case 'k': return (int)$size_str * 1024;
        case 'G': case 'g': return (int)$size_str * 1073741824;
        default: return $size_str;
    }
}
function generate_user_guid() {
	$found = true;
	do {
		$guid = random_string(16);
		$x = q("SELECT `uid` FROM `user` WHERE `guid` = '%s' LIMIT 1",
			dbesc($guid)
		);
		if(! count($x))
			$found = false;
	} while ($found == true );
	return $guid;
}
function base64url_encode($s, $strip_padding = true) {
	$s = strtr(base64_encode($s),'+/','-_');
	if($strip_padding)
		$s = str_replace('=','',$s);
	return $s;
}
function base64url_decode($s) {
	if(is_array($s)) {
		logger('base64url_decode: illegal input: ' . print_r(debug_backtrace(), true));
		return $s;
	}
/*
 *  // Placeholder for new rev of salmon which strips base64 padding.
 *  // PHP base64_decode handles the un-padded input without requiring this step
 *  // Uncomment if you find you need it.
 *
 *	$l = strlen($s);
 *	if(! strpos($s,'=')) {
 *		$m = $l % 4;
 *		if($m == 2)
 *			$s .= '==';
 *		if($m == 3)
 *			$s .= '=';
 *	}
 *
 */
	return base64_decode(strtr($s,'-_','+/'));
}
function cleardiv() {
	return '
';
}
function bb_translate_video($s) {
	$matches = null;
	$r = preg_match_all("/\[video\](.*?)\[\/video\]/ism",$s,$matches,PREG_SET_ORDER);
	if($r) {
		foreach($matches as $mtch) {
			if((stristr($mtch[1],'youtube')) || (stristr($mtch[1],'youtu.be')))
				$s = str_replace($mtch[0],'[youtube]' . $mtch[1] . '[/youtube]',$s);
			elseif(stristr($mtch[1],'vimeo'))
				$s = str_replace($mtch[0],'[vimeo]' . $mtch[1] . '[/vimeo]',$s);
		}
	}
	return $s;	
}
function html2bb_video($s) {
	$s = preg_replace('#]+>(.*?)https?://www.youtube.com/((?:v|cp)/[A-Za-z0-9\-_=]+)(.*?) #ism',
			'[youtube]$2[/youtube]', $s);
	$s = preg_replace('##ism',
			'[youtube]$2[/youtube]', $s);
	$s = preg_replace('##ism',
			'[vimeo]$2[/vimeo]', $s);
	return $s;
}
/**
 * apply xmlify() to all values of array $val, recursively
 */
function array_xmlify($val){
	if (is_bool($val)) return $val?"true":"false";
	if (is_array($val)) return array_map('array_xmlify', $val);
	return xmlify((string) $val);
}
function reltoabs($text, $base)
{
  if (empty($base))
	return $text;
  $base = rtrim($base,'/');
  $base2 = $base . "/";
 	
  // Replace links
  $pattern = "/]*) href=\"(?!http|https|\/)([^\"]*)\"/";
  $replace = " ]*) href=\"(?!http|https)([^\"]*)\"/";
  $replace = " ]*) src=\"(?!http|https|\/)([^\"]*)\"/";
  $replace = "