/app/common/utils.php

<?php

/**
 * Converts current time for given timezone (considering DST) to 14-digit UTC timestamp (YYYYMMDDHHMMSS)
 *
 * DateTime requires PHP >= 5.2
 *
 * @param $str_user_timezone
 * @param string $str_server_timezone
 * @param string $str_server_dateformat
 * @return string
 */
function now($str_user_timezone,
			 $str_server_timezone = CONST_SERVER_TIMEZONE,
			 $str_server_dateformat = CONST_SERVER_DATEFORMAT) {

	// set timezone to user timezone
	date_default_timezone_set($str_user_timezone);

	$date = new DateTime('now');
	$date->setTimezone(new DateTimeZone($str_server_timezone));
	$str_server_now = $date->format($str_server_dateformat);

	// return timezone to server default
	date_default_timezone_set($str_server_timezone);

	return $str_server_now;
}


/**
 * Converts a UTC timestamp to date string of given timezone (considering DST) and given dateformat
 *
 * DateTime requires PHP >= 5.2
 *
 * @param $str_server_datetime
 *
 * <li>Normally is a 14-digit UTC timestamp (YYYYMMDDHHMMSS). It can also be 8-digit (date), 12-digit (datetime without seconds).
 * If given dateformat (<var>$str_user_dateformat</var>) is longer than <var>$str_server_datetime</var>,
 * the missing digits of input value are filled with zero,
 * so (YYYYMMDD is equivalent to YYYYMMDD000000 and YYYYMMDDHHMM is equivalent to YYYYMMDDHHMM00).
 *
 * <li>It can also be 'now', null or empty string. In this case returns the current time.
 *
 * <li>Other values (invalid datetime strings) throw an error. Milliseconds are not supported.
 *
 * @param string $str_user_timezone
 * @param $str_user_dateformat
 * @return string
 */
function date_decode($str_server_datetime,
					 $str_user_timezone,
					 $str_user_dateformat) {

	// create date object
	try {
		$date = new DateTime($str_server_datetime);
	} catch(Exception $e) {
		trigger_error('date_decode: Invalid datetime: ' . $e->getMessage(), E_USER_ERROR);
	}

	// convert to user timezone
	$userTimeZone = new DateTimeZone($str_user_timezone);
	$date->setTimeZone($userTimeZone);

	// convert to user dateformat
	$str_user_datetime = $date->format($str_user_dateformat);

	return $str_user_datetime;
}

/**
 * Converts a date string of given timezone (considering DST) and format to 14-digit UTC timestamp (YYYYMMDDHHMMSS)
 *
 * DateTime::createFromFormat requires PHP >= 5.3
 *
 * <li><b>Note about strtotime</b>: Dates in the m/d/y or d-m-y formats are disambiguated by looking at the separator between the various components:
 * if the separator is a slash (/), then the American m/d/y is assumed;
 * whereas if the separator is a dash (-) or a dot (.), then the European d-m-y format is assumed.
 *
 * To avoid potential ambiguity, it's best to use ISO 8601 (YYYY-MM-DD) dates or DateTime::createFromFormat() when possible.
 *
 * @param $str_user_datetime
 *
 * <li><var>$str_user_timezone</var> and <var>$str_user_dateformat</var> must match. Otherwise error occurs.
 *
 * <li>If <var>$str_server_dateformat</var> is longer than <var>$str_user_dateformat</var>,
 * the missing time digits filled with zero, but if all times digits are missing current time is returned.
 *
 * <li>Other values (invalid datetime strings) throw an error. Milliseconds are not supported.
 *
 * @param $str_user_timezone
 * @param $str_user_dateformat
 * @param string $str_server_timezone
 * @param string $str_server_dateformat
 * @param string $str_safe_dateformat_strtotime
 * @return string
 *
 * @link http://www.php.net/manual/en/function.strtotime.php
 * @link http://stackoverflow.com/questions/4163641/php-using-strtotime-with-a-uk-date-format-dd-mm-yy
 * @link http://derickrethans.nl/british-date-format-parsing.html
 */
function date_encode($str_user_datetime,
					 $str_user_timezone,
					 $str_user_dateformat,
					 $str_server_timezone = CONST_SERVER_TIMEZONE,
					 $str_server_dateformat = CONST_SERVER_DATEFORMAT,
					 $str_safe_dateformat_strtotime = CONST_SAFE_DATEFORMAT_STRTOTIME) {

	// set timezone to user timezone
	date_default_timezone_set($str_user_timezone);

	// create date object using any given format
	if($str_user_datetime == 'now' || !$str_user_datetime) {
		$date = new DateTime('', new DateTimeZone($str_user_timezone));
	} else {
		$date = DateTime::createFromFormat($str_user_dateformat, $str_user_datetime, new DateTimeZone($str_user_timezone));
		if($date === false) {
			trigger_error('date_encode: Invalid date', E_USER_ERROR);
		}
	}

	// convert given datetime to safe format for strtotime
	$str_user_datetime = $date->format($str_safe_dateformat_strtotime);

	// convert to UTC
	$str_server_datetime = gmdate($str_server_dateformat, strtotime($str_user_datetime));

	// return timezone to server default
	date_default_timezone_set($str_server_timezone);

	return $str_server_datetime;
}

/**
 * Return the offset (in seconds) from UTC of a given timezone timestring (considering DST)
 *
 * @param $str_datetime
 * @param $str_timezone
 * @return int
 */
function get_time_offset($str_datetime, $str_timezone) {
	$timezone = new DateTimeZone($str_timezone);
	$offset = $timezone->getOffset(new DateTime($str_datetime));
	return $offset;
}

/**
 * * Multi-byte CASE INSENSITIVE str_replace
 *
 * @param $co
 * @param $naCo
 * @param $wCzym
 * @return string
 * @link http://www.php.net/manual/en/function.mb-ereg-replace.php#55659
 */
function mb_str_ireplace($co, $naCo, $wCzym) {
	$wCzymM = mb_strtolower($wCzym);
	$coM = mb_strtolower($co);
	$offset = 0;

	while(!is_bool($poz = mb_strpos($wCzymM, $coM, $offset))) {
		$offset = $poz + mb_strlen($naCo);
		$wCzym = mb_substr($wCzym, 0, $poz) . $naCo . mb_substr($wCzym, $poz + mb_strlen($co));
		$wCzymM = mb_strtolower($wCzym);
	}

	return $wCzym;
}

/**
 * Timezones list with GMT offset
 *
 * @return array
 * @link http://stackoverflow.com/a/9328760
 */
function tz_list() {
	$zones_array = array();
	$timestamp = time();
	foreach(timezone_identifiers_list() as $key => $zone) {
		date_default_timezone_set($zone);
		$zones_array[$key]['zone'] = $zone;
		$zones_array[$key]['diff_from_GMT'] = 'UTC/GMT ' . date('P', $timestamp);
	}
	return $zones_array;
}

/**
 * Create dateformat array
 *
 * @param $a_df
 * @param $tz
 * @return array
 */
function df_list($a_df, $tz = CONST_SERVER_TIMEZONE) {
	$df_array = array();
	$tz = new DateTimeZone($tz);
	$date = new DateTime('');
	$date->setTimeZone($tz);
	foreach($a_df as $df_key => $df_val) {
		$df = $df_val['php_datetime'];
		$df_example = $date->format($df);
		$df_array[$df_key] = array('dateformat' => $df, 'example' => $df_example);
	}
	return $df_array;
}

/**
 * Get either a Gravatar URL or complete image tag for a specified email address.
 *
 * @param string $email The email address
 * @param int|string $s Size in pixels, defaults to 80px [ 1 - 2048 ]
 * @param string $d Default imageset to use [ 404 | mm | identicon | monsterid | wavatar ]
 * @param string $r Maximum rating (inclusive) [ g | pg | r | x ]
 * @param bool|\boole $img True to return a complete IMG tag False for just the URL
 * @param array $atts Optional, additional key/value attributes to include in the IMG tag
 * @return String containing either just a URL or a complete image tag
 * @link http://gravatar.com/site/implement/images/php/
 */
function get_gravatar($email, $s = 80, $d = 'mm', $r = 'g', $img = false, $atts = array()) {
	$url = 'http://www.gravatar.com/avatar/';
	$url .= md5(strtolower(trim($email)));
	$url .= "?s=$s&d=$d&r=$r";
	if($img) {
		$url = '<img src="' . $url . '"';
		foreach($atts as $key => $val)
			$url .= ' ' . $key . '="' . $val . '"';
		$url .= ' />';
	}
	return $url;
}

/**
 * Get Gravatar profile url
 *
 * @param $email
 * @param bool $decode_url
 * @return string
 * @link https://en.gravatar.com/site/implement/profiles/php/
 */
function get_gravatar_profile($email, $decode_url = false) {
	$url_encoded = 'http://www.gravatar.com/' . md5(strtolower(trim($email)));
	if(!$decode_url) {
		return $url_encoded;
	} else {
		$url = $url_encoded . '.php';
		$str = file_get_contents($url);
		if($str === false) {
			return $url_encoded;
		} else {
			$profile = unserialize($str);
			if(is_array($profile) && isset($profile['entry'])) {
				return $profile['entry'][0]['profileUrl'];
			} else {
				return $url_encoded;
			}
		}
	}

}

/**
 * @param $str
 * @return mixed
 * @link http://myshadowself.com/coding/php-function-to-convert-accented-characters-to-their-non-accented-equivalant/
 */
function removeAccents($str) {
	$a = array('À', 'Á', 'Â', 'Ã', 'Ä', 'Å', 'Æ', 'Ç', 'È', 'É', 'Ê', 'Ë', 'Ì', 'Í', 'Î', 'Ï', 'Ð', 'Ñ', 'Ò', 'Ó', 'Ô', 'Õ', 'Ö', 'Ø', 'Ù', 'Ú', 'Û', 'Ü', 'Ý', 'ß', 'à', 'á', 'â', 'ã', 'ä', 'å', 'æ', 'ç', 'è', 'é', 'ê', 'ë', 'ì', 'í', 'î', 'ï', 'ñ', 'ò', 'ó', 'ô', 'õ', 'ö', 'ø', 'ù', 'ú', 'û', 'ü', 'ý', 'ÿ', 'Ā', 'ā', 'Ă', 'ă', 'Ą', 'ą', 'Ć', 'ć', 'Ĉ', 'ĉ', 'Ċ', 'ċ', 'Č', 'č', 'Ď', 'ď', 'Đ', 'đ', 'Ē', 'ē', 'Ĕ', 'ĕ', 'Ė', 'ė', 'Ę', 'ę', 'Ě', 'ě', 'Ĝ', 'ĝ', 'Ğ', 'ğ', 'Ġ', 'ġ', 'Ģ', 'ģ', 'Ĥ', 'ĥ', 'Ħ', 'ħ', 'Ĩ', 'ĩ', 'Ī', 'ī', 'Ĭ', 'ĭ', 'Į', 'į', 'İ', 'ı', 'IJ', 'ij', 'Ĵ', 'ĵ', 'Ķ', 'ķ', 'Ĺ', 'ĺ', 'Ļ', 'ļ', 'Ľ', 'ľ', 'Ŀ', 'ŀ', 'Ł', 'ł', 'Ń', 'ń', 'Ņ', 'ņ', 'Ň', 'ň', 'ʼn', 'Ō', 'ō', 'Ŏ', 'ŏ', 'Ő', 'ő', 'Œ', 'œ', 'Ŕ', 'ŕ', 'Ŗ', 'ŗ', 'Ř', 'ř', 'Ś', 'ś', 'Ŝ', 'ŝ', 'Ş', 'ş', 'Š', 'š', 'Ţ', 'ţ', 'Ť', 'ť', 'Ŧ', 'ŧ', 'Ũ', 'ũ', 'Ū', 'ū', 'Ŭ', 'ŭ', 'Ů', 'ů', 'Ű', 'ű', 'Ų', 'ų', 'Ŵ', 'ŵ', 'Ŷ', 'ŷ', 'Ÿ', 'Ź', 'ź', 'Ż', 'ż', 'Ž', 'ž', 'ſ', 'ƒ', 'Ơ', 'ơ', 'Ư', 'ư', 'Ǎ', 'ǎ', 'Ǐ', 'ǐ', 'Ǒ', 'ǒ', 'Ǔ', 'ǔ', 'Ǖ', 'ǖ', 'Ǘ', 'ǘ', 'Ǚ', 'ǚ', 'Ǜ', 'ǜ', 'Ǻ', 'ǻ', 'Ǽ', 'ǽ', 'Ǿ', 'ǿ', 'Ά', 'ά', 'Έ', 'έ', 'Ό', 'ό', 'Ώ', 'ώ', 'Ί', 'ί', 'ϊ', 'ΐ', 'Ύ', 'ύ', 'ϋ', 'ΰ', 'Ή', 'ή');
	$b = array('A', 'A', 'A', 'A', 'A', 'A', 'AE', 'C', 'E', 'E', 'E', 'E', 'I', 'I', 'I', 'I', 'D', 'N', 'O', 'O', 'O', 'O', 'O', 'O', 'U', 'U', 'U', 'U', 'Y', 's', 'a', 'a', 'a', 'a', 'a', 'a', 'ae', 'c', 'e', 'e', 'e', 'e', 'i', 'i', 'i', 'i', 'n', 'o', 'o', 'o', 'o', 'o', 'o', 'u', 'u', 'u', 'u', 'y', 'y', 'A', 'a', 'A', 'a', 'A', 'a', 'C', 'c', 'C', 'c', 'C', 'c', 'C', 'c', 'D', 'd', 'D', 'd', 'E', 'e', 'E', 'e', 'E', 'e', 'E', 'e', 'E', 'e', 'G', 'g', 'G', 'g', 'G', 'g', 'G', 'g', 'H', 'h', 'H', 'h', 'I', 'i', 'I', 'i', 'I', 'i', 'I', 'i', 'I', 'i', 'IJ', 'ij', 'J', 'j', 'K', 'k', 'L', 'l', 'L', 'l', 'L', 'l', 'L', 'l', 'l', 'l', 'N', 'n', 'N', 'n', 'N', 'n', 'n', 'O', 'o', 'O', 'o', 'O', 'o', 'OE', 'oe', 'R', 'r', 'R', 'r', 'R', 'r', 'S', 's', 'S', 's', 'S', 's', 'S', 's', 'T', 't', 'T', 't', 'T', 't', 'U', 'u', 'U', 'u', 'U', 'u', 'U', 'u', 'U', 'u', 'U', 'u', 'W', 'w', 'Y', 'y', 'Y', 'Z', 'z', 'Z', 'z', 'Z', 'z', 's', 'f', 'O', 'o', 'U', 'u', 'A', 'a', 'I', 'i', 'O', 'o', 'U', 'u', 'U', 'u', 'U', 'u', 'U', 'u', 'U', 'u', 'A', 'a', 'AE', 'ae', 'O', 'o', 'Α', 'α', 'Ε', 'ε', 'Ο', 'ο', 'Ω', 'ω', 'Ι', 'ι', 'ι', 'ι', 'Υ', 'υ', 'υ', 'υ', 'Η', 'η');
	return str_replace($a, $b, $str);
}

/**
 * @param $url
 * @param $url_length
 * @param bool $remove_accents
 * @param bool $convert_to_lower_case
 * @param bool $replace_space_between_words_with_dash
 * @return mixed|string
 */
function sanitize_url($url,
					  $url_length,
					  $remove_accents = true,
					  $convert_to_lower_case = true,
					  $replace_space_between_words_with_dash = true) {
	$url = trim($url);
	$url = preg_replace('/\-+/', '-', $url); //replace multiple dashes with one
	$url = preg_replace('/\s+/', ' ', $url); //replace multiple spaces with one
	$url = preg_replace('/_+/', '.', $url); //replace multiple underscore with one
	$url = preg_replace('/\/+/', '/', $url); //replace multiple slashes with one
	$url = preg_replace('/\:+/', ':', $url); //replace multiple colon with one
	$url = preg_replace('/\.+/', '.', $url); //replace multiple dots with one

	$url = $remove_accents ? removeAccents($url) : $url; // remove accented characters

	$url = $convert_to_lower_case ? mb_strtolower($url) : $url; // convert to lower case

	$url = $replace_space_between_words_with_dash ? preg_replace('/ /', '-', $url) : $url; //replace space between words with dash

	$url = mb_substr($url, 0, $url_length); // truncate to max length

	return $url;
}

/**
 * Check for valid URL
 *
 * preg_match \w (unicode word characters) does not work with php < 5.3.10
 *
 * @param $url
 * @param $str_regex
 * @param $str_regex_php_legacy
 * @return bool
 *
 * @link http://stackoverflow.com/questions/8915713/php5-3-preg-match-with-umlaute-utf-8-modifier
 */
function valid_url($url, $str_regex, $str_regex_php_legacy) {
	$res = true;
	if(version_compare(phpversion(), '5.3.10', 'ge')) {
		$res = preg_match($str_regex, $url) ? false : true;
	} else {
		$res = preg_match($str_regex_php_legacy, $url) ? false : true;
	}
	return $res;
}

/**
 * Check if a string is a valid date(time)
 *
 * @param $str_dt
 * @param $str_dateformat
 * @param $str_timezone
 * @return bool
 */
function isValidDateTimeString($str_dt, $str_dateformat, $str_timezone) {
	$date = DateTime::createFromFormat($str_dateformat, $str_dt, new DateTimeZone($str_timezone));
	return ($date === false ? false : true);
}

?>