<?php
namespace RequestResponse;

class Request{

    const PARAM_ALPHA = 'alpha';
    const PARAM_ALPHANUM = 'alphanum';
    const PARAM_ALPHAEXT = 'alphaext';
    const PARAM_ALPHANUMEXT = 'alphanumext';
    const PARAM_INT = 'int';
    const PARAM_FLOAT = 'float';
    const PARAM_BOOL = 'bool';
    const PARAM_RAW = 'raw';
    const PARAM_TEXT = 'text';

    const PARAM_AUTH = 'auth';
    const PARAM_BASE64 = 'base64';
    const PARAM_CAPABILITY = 'capability';
    const PARAM_CLEANHTML = 'cleanhtml';
    const PARAM_EMAIL = 'email';
    const PARAM_FILE = 'file';
    const PARAM_HOST = 'host';
    const PARAM_LANG = 'lang';
    const PARAM_LOCALURL = 'localurl';
    const PARAM_NOTAGS = 'notags';
    const PARAM_PATH = 'path';
    const PARAM_PEM = 'pem';
    const PARAM_PERMISSION = 'permission';
    const PARAM_RAW_TRIMMED = 'raw_trimmed';
    const PARAM_SAFEDIR = 'safedir';
    const PARAM_SAFEPATH = 'safepath';
    const PARAM_SEQUENCE = 'sequence';
    const PARAM_TAG = 'tag';
    const PARAM_TAGLIST = 'taglist';
    const PARAM_THEME = 'theme';
    const PARAM_URL = 'url';
    const PARAM_USERNAME = 'username';
    const PARAM_STRINGID = 'stringid';


    public static function required_param($parname, $type) {
        if (func_num_args() != 2 or empty($parname) or empty($type)) {
            throw new \Exception('required_param() requires $parname and $type to be specified (parameter: '.$parname.')');
        }
        // POST has precedence.
        if (isset($_POST[$parname])) {
            $param = $_POST[$parname];
        } else if (isset($_GET[$parname])) {
            $param = $_GET[$parname];
        } else {
            throw new \Exception('');
        }

        if (is_array($param)) {
            return required_param_array($parname, $type);
        }

        return self::clean_param($param, $type);
    }

    public static function required_param_array($parname, $type) {
        if (func_num_args() != 2 or empty($parname) or empty($type)) {
            throw new \Exception('required_param_array() requires $parname and $type to be specified (parameter: '.$parname.')');
        }
        // POST has precedence.
        if (isset($_POST[$parname])) {
            $param = $_POST[$parname];
        } else if (isset($_GET[$parname])) {
            $param = $_GET[$parname];
        } else {
            throw new \Exception('');
        }
        if (!is_array($param)) {
            throw new \Exception('');
        }

        $result = array();
        foreach ($param as $key => $value) {
            if (!preg_match('/^[a-z0-9_-]+$/i', $key)) {
                continue;
            }
            $result[$key] = clean_param($value, $type);
        }
        return $result;
    }


    public static function optional_param($parname, $default = '', $type){
        if (func_num_args() != 3 or empty($parname) or empty($type)) {
            throw new \Exception('optional_param requires $parname, $default + $type to be specified (parameter: '.$parname.')');
        }

        if (isset($_POST[$parname])) {
            $param = $_POST[$parname];
        } else if (isset($_GET[$parname])) {
            $param = $_GET[$parname];
        } else {
            return $default;
        }

        if (is_array($param)) {
            return optional_param_array($parname, $default, $type);
        }

        return self::clean_param($param, $type);
    }

    public static function optional_param_array($parname, $default = Array(), $type) {
        if (func_num_args() != 3 or empty($parname) or empty($type)) {
            throw new \Exception('optional_param_array requires $parname, $default + $type to be specified (parameter: '.$parname.')');
        }

        // POST has precedence.
        if (isset($_POST[$parname])) {
            $param = $_POST[$parname];
        } else if (isset($_GET[$parname])) {
            $param = $_GET[$parname];
        } else {
            return $default;
        }
        if (!is_array($param)) {
            return $default;
        }

        $result = array();
        foreach ($param as $key => $value) {
            if (!preg_match('/^[a-z0-9_-]+$/i', $key)) {
                continue;
            }
        }

        return $result;
    }

    public static function clean_param($param, $type) {
        global $CFG;

        if (is_array($param)) {
            throw new coding_exception('clean_param() can not process arrays, please use clean_param_array() instead.');
        } else if (is_object($param)) {
            if (method_exists($param, '__toString')) {
                $param = $param->__toString();
            } else {
                throw new coding_exception('clean_param() can not process objects, please use clean_param_array() instead.');
            }
        }

        switch ($type) {
            case self::PARAM_RAW:
                // No cleaning at all.
                $param = fix_utf8($param);
                return $param;

            case self::PARAM_RAW_TRIMMED:
                // No cleaning, but strip leading and trailing whitespace.
                $param = fix_utf8($param);
                return trim($param);

            case self::PARAM_INT:
                // Convert to integer.
                return (int)$param;

            case self::PARAM_FLOAT:
                // Convert to float.
                return (float)$param;

            case self::PARAM_ALPHA:
                // Remove everything not `a-z`.
                return preg_replace('/[^a-zA-Z]/i', '', $param);

            case self::PARAM_ALPHAEXT:
                // Remove everything not `a-zA-Z_-` (originally allowed "/" too).
                return preg_replace('/[^a-zA-Z_-]/i', '', $param);

            case self::PARAM_ALPHANUM:
                // Remove everything not `a-zA-Z0-9`.
                return preg_replace('/[^A-Za-z0-9]/i', '', $param);

            case self::PARAM_ALPHANUMEXT:
                // Remove everything not `a-zA-Z0-9_-`.
                return preg_replace('/[^A-Za-z0-9_-]/i', '', $param);

            case self::PARAM_SEQUENCE:
                // Remove everything not `0-9,`.
                return preg_replace('/[^0-9,]/i', '', $param);

            case self::PARAM_BOOL:
                // Convert to 1 or 0.
                $tempstr = strtolower($param);
                if ($tempstr === 'on' or $tempstr === 'yes' or $tempstr === 'true') {
                    $param = 1;
                } else if ($tempstr === 'off' or $tempstr === 'no'  or $tempstr === 'false') {
                    $param = 0;
                } else {
                    $param = empty($param) ? 0 : 1;
                }
                return $param;

            case self::PARAM_NOTAGS:
                // Strip all tags.
                $param = fix_utf8($param);
                return strip_tags($param);

            case self::PARAM_TEXT:
                // Leave only tags needed for multilang.
                $param = fix_utf8($param);
                // If the multilang syntax is not correct we strip all tags because it would break xhtml strict which is required
                // for accessibility standards please note this cleaning does not strip unbalanced '>' for BC compatibility reasons.
                do {
                    if (strpos($param, '</lang>') !== false) {
                        // Old and future mutilang syntax.
                        $param = strip_tags($param, '<lang>');
                        if (!preg_match_all('/<.*>/suU', $param, $matches)) {
                            break;
                        }
                        $open = false;
                        foreach ($matches[0] as $match) {
                            if ($match === '</lang>') {
                                if ($open) {
                                    $open = false;
                                    continue;
                                } else {
                                    break 2;
                                }
                            }
                            if (!preg_match('/^<lang lang="[a-zA-Z0-9_-]+"\s*>$/u', $match)) {
                                break 2;
                            } else {
                                $open = true;
                            }
                        }
                        if ($open) {
                            break;
                        }
                        return $param;

                    } else if (strpos($param, '</span>') !== false) {
                        // Current problematic multilang syntax.
                        $param = strip_tags($param, '<span>');
                        if (!preg_match_all('/<.*>/suU', $param, $matches)) {
                            break;
                        }
                        $open = false;
                        foreach ($matches[0] as $match) {
                            if ($match === '</span>') {
                                if ($open) {
                                    $open = false;
                                    continue;
                                } else {
                                    break 2;
                                }
                            }
                            if (!preg_match('/^<span(\s+lang="[a-zA-Z0-9_-]+"|\s+class="multilang"){2}\s*>$/u', $match)) {
                                break 2;
                            } else {
                                $open = true;
                            }
                        }
                        if ($open) {
                            break;
                        }
                        return $param;
                    }
                } while (false);
                // Easy, just strip all tags, if we ever want to fix orphaned '&' we have to do that in format_string().
                return strip_tags($param);

            case self::PARAM_COMPONENT:
                // We do not want any guessing here, either the name is correct or not
                // please note only normalised component names are accepted.
                if (!preg_match('/^[a-z]+(_[a-z][a-z0-9_]*)?[a-z0-9]+$/', $param)) {
                    return '';
                }
                if (strpos($param, '__') !== false) {
                    return '';
                }
                if (strpos($param, 'mod_') === 0) {
                    // Module names must not contain underscores because we need to differentiate them from invalid plugin types.
                    if (substr_count($param, '_') != 1) {
                        return '';
                    }
                }
                return $param;


            case self::PARAM_SAFEDIR:
                // Remove everything not a-zA-Z0-9_- .
                return preg_replace('/[^a-zA-Z0-9_-]/i', '', $param);

            case self::PARAM_SAFEPATH:
                // Remove everything not a-zA-Z0-9/_- .
                return preg_replace('/[^a-zA-Z0-9\/_-]/i', '', $param);

            case self::PARAM_FILE:
                // Strip all suspicious characters from filename.
                $param = fix_utf8($param);
                $param = preg_replace('~[[:cntrl:]]|[&<>"`\|\':\\\\/]~u', '', $param);
                if ($param === '.' || $param === '..') {
                    $param = '';
                }
                return $param;

            case self::PARAM_PATH:
                // Strip all suspicious characters from file path.
                $param = fix_utf8($param);
                $param = str_replace('\\', '/', $param);

                // Explode the path and clean each element using the PARAM_FILE rules.
                $breadcrumb = explode('/', $param);
                foreach ($breadcrumb as $key => $crumb) {
                    if ($crumb === '.' && $key === 0) {
                        // Special condition to allow for relative current path such as ./currentdirfile.txt.
                    } else {
                        $crumb = clean_param($crumb, PARAM_FILE);
                    }
                    $breadcrumb[$key] = $crumb;
                }
                $param = implode('/', $breadcrumb);

                // Remove multiple current path (./././) and multiple slashes (///).
                $param = preg_replace('~//+~', '/', $param);
                $param = preg_replace('~/(\./)+~', '/', $param);
                return $param;

            case self::PARAM_HOST:
                // Allow FQDN or IPv4 dotted quad.
                $param = preg_replace('/[^\.\d\w-]/', '', $param );
                // Match ipv4 dotted quad.
                if (preg_match('/(\d{1,3})\.(\d{1,3})\.(\d{1,3})\.(\d{1,3})/', $param, $match)) {
                    // Confirm values are ok.
                    if ( $match[0] > 255
                        || $match[1] > 255
                        || $match[3] > 255
                        || $match[4] > 255 ) {
                        // Hmmm, what kind of dotted quad is this?
                        $param = '';
                    }
                } else if ( preg_match('/^[\w\d\.-]+$/', $param) // Dots, hyphens, numbers.
                    && !preg_match('/^[\.-]/',$param) // No leading dots/hyphens.
                    && !preg_match('/[\.-]$/',$param) // No trailing dots/hyphens.
                ) {
                    // All is ok - $param is respected.
                } else {
                    // All is not ok...
                    $param='';
                }
                return $param;

            case self::PARAM_URL:          // Allow safe ftp, http, mailto urls.
                $param = fix_utf8($param);
                if (!empty($param) && self::validateUrlSyntax($param, 's?H?S?F?E?u-P-a?I?p?f?q?r?')) {
                    // All is ok, param is respected.
                } else {
                    // Not really ok.
                    $param ='';
                }
                return $param;


            case self::PARAM_PEM:
                $param = trim($param);
                // PEM formatted strings may contain letters/numbers and the symbols:
                //   forward slash: /
                //   plus sign:     +
                //   equal sign:    =
                //   , surrounded by BEGIN and END CERTIFICATE prefix and suffixes.
                if (preg_match('/^-----BEGIN CERTIFICATE-----([\s\w\/\+=]+)-----END CERTIFICATE-----$/', trim($param), $matches)) {
                    list($wholething, $body) = $matches;
                    unset($wholething, $matches);
                    $b64 = clean_param($body, PARAM_BASE64);
                    if (!empty($b64)) {
                        return "-----BEGIN CERTIFICATE-----\n$b64\n-----END CERTIFICATE-----\n";
                    } else {
                        return '';
                    }
                }
                return '';

            case self::PARAM_BASE64:
                if (!empty($param)) {
                    // PEM formatted strings may contain letters/numbers and the symbols
                    //   forward slash: /
                    //   plus sign:     +
                    //   equal sign:    =.
                    if (0 >= preg_match('/^([\s\w\/\+=]+)$/', trim($param))) {
                        return '';
                    }
                    $lines = preg_split('/[\s]+/', $param, -1, PREG_SPLIT_NO_EMPTY);
                    // Each line of base64 encoded data must be 64 characters in length, except for the last line which may be less
                    // than (or equal to) 64 characters long.
                    for ($i=0, $j=count($lines); $i < $j; $i++) {
                        if ($i + 1 == $j) {
                            if (64 < strlen($lines[$i])) {
                                return '';
                            }
                            continue;
                        }

                        if (64 != strlen($lines[$i])) {
                            return '';
                        }
                    }
                    return implode("\n", $lines);
                } else {
                    return '';
                }

            case self::PARAM_TAGLIST:
                $param = fix_utf8($param);
                $tags = explode(',', $param);
                $result = array();
                foreach ($tags as $tag) {
                    $res = clean_param($tag, PARAM_TAG);
                    if ($res !== '') {
                        $result[] = $res;
                    }
                }
                if ($result) {
                    return implode(',', $result);
                } else {
                    return '';
                }

            case self::PARAM_USERNAME:
                $param = fix_utf8($param);
                $param = trim($param);
                // Convert uppercase to lowercase MDL-16919.
                $param = core_text::strtolower($param);
                if (empty($CFG->extendedusernamechars)) {
                    $param = str_replace(" " , "", $param);
                    // Regular expression, eliminate all chars EXCEPT:
                    // alphanum, dash (-), underscore (_), at sign (@) and period (.) characters.
                    $param = preg_replace('/[^-\.@_a-z0-9]/', '', $param);
                }
                return $param;

            case self::PARAM_EMAIL:
                $param = fix_utf8($param);
                if (validate_email($param)) {
                    return $param;
                } else {
                    return '';
                }

            case self::PARAM_STRINGID:
                if (preg_match('|^[a-zA-Z][a-zA-Z0-9\.:/_-]*$|', $param)) {
                    return $param;
                } else {
                    return '';
                }

            case self::PARAM_TIMEZONE:
                // Can be int, float(with .5 or .0) or string seperated by '/' and can have '-_'.
                $param = fix_utf8($param);
                $timezonepattern = '/^(([+-]?(0?[0-9](\.[5|0])?|1[0-3](\.0)?|1[0-2]\.5))|(99)|[[:alnum:]]+(\/?[[:alpha:]_-])+)$/';
                if (preg_match($timezonepattern, $param)) {
                    return $param;
                } else {
                    return '';
                }

            default:
                // Doh! throw error, switched parameters in optional_param or another serious problem.
                print_error("unknownparamtype", '', '', $type);
        }
    }

    function fix_utf8($value) {
        if (is_null($value) or $value === '') {
            return $value;

        } else if (is_string($value)) {
            if ((string)(int)$value === $value) {
                // Shortcut.
                return $value;
            }
            // No null bytes expected in our data, so let's remove it.
            $value = str_replace("\0", '', $value);

            // Note: this duplicates min_fix_utf8() intentionally.
            static $buggyiconv = null;
            if ($buggyiconv === null) {
                $buggyiconv = (!function_exists('iconv') or @iconv('UTF-8', 'UTF-8//IGNORE', '100'.chr(130).'€') !== '100€');
            }

            if ($buggyiconv) {
                if (function_exists('mb_convert_encoding')) {
                    $subst = mb_substitute_character();
                    mb_substitute_character('');
                    $result = mb_convert_encoding($value, 'utf-8', 'utf-8');
                    mb_substitute_character($subst);

                } else {
                    // Warn admins on admin/index.php page.
                    $result = $value;
                }

            } else {
                $result = @iconv('UTF-8', 'UTF-8//IGNORE', $value);
            }

            return $result;

        } else if (is_array($value)) {
            foreach ($value as $k => $v) {
                $value[$k] = fix_utf8($v);
            }
            return $value;

        } else if (is_object($value)) {
            // Do not modify original.
            $value = clone($value);
            foreach ($value as $k => $v) {
                $value->$k = fix_utf8($v);
            }
            return $value;

        } else {
            // This is some other type, no utf-8 here.
            return $value;
        }
    }

    function validateUrlSyntax( $urladdr, $options="" ){

        // Force Options parameter to be lower case
        // DISABLED PERMAMENTLY - OK to remove from code
        //    $options = strtolower($options);

        // Check Options Parameter
        if (!preg_match( '/^([sHSEFuPaIpfqr][+?-])*$/', $options ))
        {
            trigger_error("Options attribute malformed", E_USER_ERROR);
        }

        // Set Options Array, set defaults if options are not specified
        // Scheme
        if (strpos( $options, 's') === false) $aOptions['s'] = '?';
        else $aOptions['s'] = substr( $options, strpos( $options, 's') + 1, 1);
        // http://
        if (strpos( $options, 'H') === false) $aOptions['H'] = '?';
        else $aOptions['H'] = substr( $options, strpos( $options, 'H') + 1, 1);
        // https:// (SSL)
        if (strpos( $options, 'S') === false) $aOptions['S'] = '?';
        else $aOptions['S'] = substr( $options, strpos( $options, 'S') + 1, 1);
        // mailto: (email)
        if (strpos( $options, 'E') === false) $aOptions['E'] = '-';
        else $aOptions['E'] = substr( $options, strpos( $options, 'E') + 1, 1);
        // ftp://
        if (strpos( $options, 'F') === false) $aOptions['F'] = '-';
        else $aOptions['F'] = substr( $options, strpos( $options, 'F') + 1, 1);
        // User section
        if (strpos( $options, 'u') === false) $aOptions['u'] = '?';
        else $aOptions['u'] = substr( $options, strpos( $options, 'u') + 1, 1);
        // Password in user section
        if (strpos( $options, 'P') === false) $aOptions['P'] = '?';
        else $aOptions['P'] = substr( $options, strpos( $options, 'P') + 1, 1);
        // Address Section
        if (strpos( $options, 'a') === false) $aOptions['a'] = '+';
        else $aOptions['a'] = substr( $options, strpos( $options, 'a') + 1, 1);
        // IP Address in address section
        if (strpos( $options, 'I') === false) $aOptions['I'] = '?';
        else $aOptions['I'] = substr( $options, strpos( $options, 'I') + 1, 1);
        // Port number
        if (strpos( $options, 'p') === false) $aOptions['p'] = '?';
        else $aOptions['p'] = substr( $options, strpos( $options, 'p') + 1, 1);
        // File Path
        if (strpos( $options, 'f') === false) $aOptions['f'] = '?';
        else $aOptions['f'] = substr( $options, strpos( $options, 'f') + 1, 1);
        // Query Section
        if (strpos( $options, 'q') === false) $aOptions['q'] = '?';
        else $aOptions['q'] = substr( $options, strpos( $options, 'q') + 1, 1);
        // Fragment (Anchor)
        if (strpos( $options, 'r') === false) $aOptions['r'] = '?';
        else $aOptions['r'] = substr( $options, strpos( $options, 'r') + 1, 1);


        // Loop through options array, to search for and replace "-" to "{0}" and "+" to ""
        foreach($aOptions as $key => $value)
        {
            if ($value == '-')
            {
                $aOptions[$key] = '{0}';
            }
            if ($value == '+')
            {
                $aOptions[$key] = '';
            }
        }

        // DEBUGGING - Unescape following line to display to screen current option values
        // echo '<pre>'; print_r($aOptions); echo '</pre>';


        // Preset Allowed Characters
        $alphanum    = '[a-zA-Z0-9]';  // Alpha Numeric
        $unreserved  = '[a-zA-Z0-9_.!~*' . '\'' . '()-]';
        $escaped     = '(%[0-9a-fA-F]{2})'; // Escape sequence - In Hex - %6d would be a 'm'
        $reserved    = '[;/?:@&=+$,]'; // Special characters in the URI

        // Beginning Regular Expression
        // Scheme - Allows for 'http://', 'https://', 'mailto:', or 'ftp://'
        $scheme            = '(';
        if     ($aOptions['H'] === '') { $scheme .= 'http://'; }
        elseif ($aOptions['S'] === '') { $scheme .= 'https://'; }
        elseif ($aOptions['E'] === '') { $scheme .= 'mailto:'; }
        elseif ($aOptions['F'] === '') { $scheme .= 'ftp://'; }
        else
        {
            if ($aOptions['H'] === '?') { $scheme .= '|(http://)'; }
            if ($aOptions['S'] === '?') { $scheme .= '|(https://)'; }
            if ($aOptions['E'] === '?') { $scheme .= '|(mailto:)'; }
            if ($aOptions['F'] === '?') { $scheme .= '|(ftp://)'; }
            $scheme = str_replace('(|', '(', $scheme); // fix first pipe
        }
        $scheme            .= ')' . $aOptions['s'];
        // End setting scheme

        // User Info - Allows for 'username@' or 'username:password@'. Note: contrary to rfc, I removed ':' from username section, allowing it only in password.
        //   /---------------- Username -----------------------\  /-------------------------------- Password ------------------------------\
        $userinfo          = '((' . $unreserved . '|' . $escaped . '|[;&=+$,]' . ')+(:(' . $unreserved . '|' . $escaped . '|[;:&=+$,]' . ')+)' . $aOptions['P'] . '@)' . $aOptions['u'];

        // IP ADDRESS - Allows 0.0.0.0 to 255.255.255.255
        $ipaddress         = '((((2(([0-4][0-9])|(5[0-5])))|([01]?[0-9]?[0-9]))\.){3}((2(([0-4][0-9])|(5[0-5])))|([01]?[0-9]?[0-9])))';

        // Tertiary Domain(s) - Optional - Multi - Although some sites may use other characters, the RFC says tertiary domains have the same naming restrictions as second level domains
        $domain_tertiary   = '(' . $alphanum . '(([a-zA-Z0-9-]{0,62})' . $alphanum . ')?\.)*';

        /* MDL-9295 - take out domain_secondary here and below, so that URLs like http://localhost/ and lan addresses like http://host/ are accepted.
                               // Second Level Domain - Required - First and last characters must be Alpha-numeric. Hyphens are allowed inside.
            $domain_secondary  = '(' . $alphanum . '(([a-zA-Z0-9-]{0,62})' . $alphanum . ')?\.)';
        */

// we want more relaxed URLs in Moodle: MDL-11462
        // Top Level Domain - First character must be Alpha. Last character must be AlphaNumeric. Hyphens are allowed inside.
        $domain_toplevel   = '([a-zA-Z](([a-zA-Z0-9-]*)[a-zA-Z0-9])?)';
        /*                       // Top Level Domain - Required - Domain List Current As Of December 2004. Use above escaped line to be forgiving of possible future TLD's
            $domain_toplevel   = '(aero|biz|com|coop|edu|gov|info|int|jobs|mil|mobi|museum|name|net|org|post|pro|travel|ac|ad|ae|af|ag|ai|al|am|an|ao|aq|ar|as|at|au|aw|az|ax|ba|bb|bd|be|bf|bg|bh|bi|bj|bm|bn|bo|br|bs|bt|bv|bw|by|bz|ca|cc|cd|cf|cg|ch|ci|ck|cl|cm|cn|co|cr|cs|cu|cv|cx|cy|cz|de|dj|dk|dm|do|dz|ec|ee|eg|eh|er|es|et|eu|fi|fj|fk|fm|fo|fr|ga|gb|gd|ge|gf|gg|gh|gi|gl|gm|gn|gp|gq|gr|gs|gt|gu|gw|gy|hk|hm|hn|hr|ht|hu|id|ie|il|im|in|io|iq|ir|is|it|je|jm|jo|jp|ke|kg|kh|ki|km|kn|kp|kr|kw|ky|kz|la|lb|lc|li|lk|lr|ls|lt|lu|lv|ly|ma|mc|md|mg|mh|mk|ml|mm|mn|mo|mp|mq|mr|ms|mt|mu|mv|mw|mx|my|mz|na|nc|ne|nf|ng|ni|nl|no|np|nr|nu|nz|om|pa|pe|pf|pg|ph|pk|pl|pm|pn|pr|ps|pt|pw|py|qa|re|ro|ru|rw|sa|sb|sc|sd|se|sg|sh|si|sj|sk|sl|sm|sn|so|sr|st|sv|sy|sz|tc|td|tf|tg|th|tj|tk|tl|tm|tn|to|tp|tr|tt|tv|tw|tz|ua|ug|uk|um|us|uy|uz|va|vc|ve|vg|vi|vn|vu|wf|ws|ye|yt|yu|za|zm|zw)';
        */

        // Address can be IP address or Domain
        if ($aOptions['I'] === '{0}') {       // IP Address Not Allowed
            $address       = '(' . $domain_tertiary . /* MDL-9295 $domain_secondary . */ $domain_toplevel . ')';
        } elseif ($aOptions['I'] === '') {  // IP Address Required
            $address       = '(' . $ipaddress . ')';
        } else {                            // IP Address Optional
            $address       = '((' . $ipaddress . ')|(' . $domain_tertiary . /* MDL-9295 $domain_secondary . */ $domain_toplevel . '))';
        }
        $address = $address . $aOptions['a'];

        // Port Number - :80 or :8080 or :65534 Allows range of :0 to :65535
        //    (0-59999)         |(60000-64999)   |(65000-65499)    |(65500-65529)  |(65530-65535)
        $port_number       = '(:(([0-5]?[0-9]{1,4})|(6[0-4][0-9]{3})|(65[0-4][0-9]{2})|(655[0-2][0-9])|(6553[0-5])))' . $aOptions['p'];

        // Path - Can be as simple as '/' or have multiple folders and filenames
        $path              = '(/((;)?(' . $unreserved . '|' . $escaped . '|' . '[:@&=+$,]' . ')+(/)?)*)' . $aOptions['f'];

        // Query Section - Accepts ?var1=value1&var2=value2 or ?2393,1221 and much more
        $querystring       = '(\?(' . $reserved . '|' . $unreserved . '|' . $escaped . ')*)' . $aOptions['q'];

        // Fragment Section - Accepts anchors such as #top
        $fragment          = '(\#(' . $reserved . '|' . $unreserved . '|' . $escaped . ')*)' . $aOptions['r'];


        // Building Regular Expression
        $regexp = '#^' . $scheme . $userinfo . $address . $port_number . $path . $querystring . $fragment . '$#i';

        // DEBUGGING - Uncomment Line Below To Display The Regular Expression Built
        // echo '<pre>' . htmlentities(wordwrap($regexp,70,"\n",1)) . '</pre>';

        // Running the regular expression
        if (preg_match( $regexp, $urladdr ))
        {
            return true; // The domain passed
        }
        else
        {
            return false; // The domain didn't pass the expression
        }

    }

    function validateEmailSyntax( $emailaddr, $options="" ){

        // Check Options Parameter
        if (!preg_match( '/^([sHSEFuPaIpfqr][+?-])*$/', $options ))
        {
            trigger_error("Options attribute malformed", E_USER_ERROR);
        }

        // Set Options Array, set defaults if options are not specified
        // Scheme
        if (strpos( $options, 's') === false) $aOptions['s'] = '-';
        else $aOptions['s'] = substr( $options, strpos( $options, 's') + 1, 1);
        // http://
        if (strpos( $options, 'H') === false) $aOptions['H'] = '-';
        else $aOptions['H'] = substr( $options, strpos( $options, 'H') + 1, 1);
        // https:// (SSL)
        if (strpos( $options, 'S') === false) $aOptions['S'] = '-';
        else $aOptions['S'] = substr( $options, strpos( $options, 'S') + 1, 1);
        // mailto: (email)
        if (strpos( $options, 'E') === false) $aOptions['E'] = '?';
        else $aOptions['E'] = substr( $options, strpos( $options, 'E') + 1, 1);
        // ftp://
        if (strpos( $options, 'F') === false) $aOptions['F'] = '-';
        else $aOptions['F'] = substr( $options, strpos( $options, 'F') + 1, 1);
        // User section
        if (strpos( $options, 'u') === false) $aOptions['u'] = '+';
        else $aOptions['u'] = substr( $options, strpos( $options, 'u') + 1, 1);
        // Password in user section
        if (strpos( $options, 'P') === false) $aOptions['P'] = '-';
        else $aOptions['P'] = substr( $options, strpos( $options, 'P') + 1, 1);
        // Address Section
        if (strpos( $options, 'a') === false) $aOptions['a'] = '+';
        else $aOptions['a'] = substr( $options, strpos( $options, 'a') + 1, 1);
        // IP Address in address section
        if (strpos( $options, 'I') === false) $aOptions['I'] = '-';
        else $aOptions['I'] = substr( $options, strpos( $options, 'I') + 1, 1);
        // Port number
        if (strpos( $options, 'p') === false) $aOptions['p'] = '-';
        else $aOptions['p'] = substr( $options, strpos( $options, 'p') + 1, 1);
        // File Path
        if (strpos( $options, 'f') === false) $aOptions['f'] = '-';
        else $aOptions['f'] = substr( $options, strpos( $options, 'f') + 1, 1);
        // Query Section
        if (strpos( $options, 'q') === false) $aOptions['q'] = '-';
        else $aOptions['q'] = substr( $options, strpos( $options, 'q') + 1, 1);
        // Fragment (Anchor)
        if (strpos( $options, 'r') === false) $aOptions['r'] = '-';
        else $aOptions['r'] = substr( $options, strpos( $options, 'r') + 1, 1);

        // Generate options
        $newoptions = '';
        foreach($aOptions as $key => $value)
        {
            $newoptions .= $key . $value;
        }

        // DEBUGGING - Uncomment line below to display generated options
        // echo '<pre>' . $newoptions . '</pre>';

        // Send to validateUrlSyntax() and return result
        return validateUrlSyntax( $emailaddr, $newoptions);

    }

    function validateFtpSyntax( $ftpaddr, $options="" ){

        // Check Options Parameter
        if (!preg_match( '/^([sHSEFuPaIpfqr][+?-])*$/', $options ))
        {
            trigger_error("Options attribute malformed", E_USER_ERROR);
        }

        // Set Options Array, set defaults if options are not specified
        // Scheme
        if (strpos( $options, 's') === false) $aOptions['s'] = '?';
        else $aOptions['s'] = substr( $options, strpos( $options, 's') + 1, 1);
        // http://
        if (strpos( $options, 'H') === false) $aOptions['H'] = '-';
        else $aOptions['H'] = substr( $options, strpos( $options, 'H') + 1, 1);
        // https:// (SSL)
        if (strpos( $options, 'S') === false) $aOptions['S'] = '-';
        else $aOptions['S'] = substr( $options, strpos( $options, 'S') + 1, 1);
        // mailto: (email)
        if (strpos( $options, 'E') === false) $aOptions['E'] = '-';
        else $aOptions['E'] = substr( $options, strpos( $options, 'E') + 1, 1);
        // ftp://
        if (strpos( $options, 'F') === false) $aOptions['F'] = '+';
        else $aOptions['F'] = substr( $options, strpos( $options, 'F') + 1, 1);
        // User section
        if (strpos( $options, 'u') === false) $aOptions['u'] = '?';
        else $aOptions['u'] = substr( $options, strpos( $options, 'u') + 1, 1);
        // Password in user section
        if (strpos( $options, 'P') === false) $aOptions['P'] = '?';
        else $aOptions['P'] = substr( $options, strpos( $options, 'P') + 1, 1);
        // Address Section
        if (strpos( $options, 'a') === false) $aOptions['a'] = '+';
        else $aOptions['a'] = substr( $options, strpos( $options, 'a') + 1, 1);
        // IP Address in address section
        if (strpos( $options, 'I') === false) $aOptions['I'] = '?';
        else $aOptions['I'] = substr( $options, strpos( $options, 'I') + 1, 1);
        // Port number
        if (strpos( $options, 'p') === false) $aOptions['p'] = '?';
        else $aOptions['p'] = substr( $options, strpos( $options, 'p') + 1, 1);
        // File Path
        if (strpos( $options, 'f') === false) $aOptions['f'] = '?';
        else $aOptions['f'] = substr( $options, strpos( $options, 'f') + 1, 1);
        // Query Section
        if (strpos( $options, 'q') === false) $aOptions['q'] = '-';
        else $aOptions['q'] = substr( $options, strpos( $options, 'q') + 1, 1);
        // Fragment (Anchor)
        if (strpos( $options, 'r') === false) $aOptions['r'] = '-';
        else $aOptions['r'] = substr( $options, strpos( $options, 'r') + 1, 1);

        // Generate options
        $newoptions = '';
        foreach($aOptions as $key => $value)
        {
            $newoptions .= $key . $value;
        }

        // DEBUGGING - Uncomment line below to display generated options
        // echo '<pre>' . $newoptions . '</pre>';

        // Send to validateUrlSyntax() and return result
        return validateUrlSyntax( $ftpaddr, $newoptions);

    }


}