source: trunk/lib/Utilities.inc.php @ 763

<?php
/**
 * The Strangecode Codebase - a general application development framework for PHP
 * For details visit the project site: <http://trac.strangecode.com/codebase/>
 * Copyright 2001-2012 Strangecode, LLC
 *
 * This file is part of The Strangecode Codebase.
 *
 * The Strangecode Codebase is free software: you can redistribute it and/or
 * modify it under the terms of the GNU General Public License as published by the
 * Free Software Foundation, either version 3 of the License, or (at your option)
 * any later version.
 *
 * The Strangecode Codebase is distributed in the hope that it will be useful, but
 * WITHOUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
 * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License for more
 * details.
 *
 * You should have received a copy of the GNU General Public License along with
 * The Strangecode Codebase. If not, see <http://www.gnu.org/licenses/>.
 */

/**
 * Utilities.inc.php
 */


/**
 * Print variable dump.
 *
 * @param  mixed    $var        The variable to dump.
 * @param  bool     $display    Print the dump in <pre> tags or hide it in html comments (non-CLI only).
 * @param  bool     $dump_method   Dump method. See SC_DUMP_* constants.
 * @param  string   $file       Value of __FILE__.
 * @param  string   $line       Value of __LINE__
 */
define('SC_DUMP_PRINT_R', 0);
define('SC_DUMP_VAR_DUMP', 1);
define('SC_DUMP_VAR_EXPORT', 2);
define('SC_DUMP_JSON', 3);
function dump($var, $display=false, $dump_method=SC_DUMP_PRINT_R, $file='', $line='')
{
    $app =& App::getInstance();

    if ($app->isCLI()) {
        echo ('' != $file . $line) ? "DUMP FROM: $file $line\n" : "DUMP:\n";
    } else {
        echo $display ? "\n<br />DUMP <strong>$file $line</strong><br /><pre>\n" : "\n<!-- DUMP $file $line\n";
    }

    switch ($dump_method) {
    case SC_DUMP_PRINT_R:
    default:
        // Print human-readable descriptions of invisible types.
        if (null === $var) {
            echo '(null)';
        } else if (true === $var) {
            echo '(bool: true)';
        } else if (false === $var) {
            echo '(bool: false)';
        } else if (is_scalar($var) && '' === $var) {
            echo '(empty string)';
        } else if (is_scalar($var) && preg_match('/^\s+$/', $var)) {
            echo '(only white space)';
        } else {
            print_r($var);
        }
        break;

    case SC_DUMP_VAR_DUMP:
        var_dump($var);
        break;

    case SC_DUMP_VAR_EXPORT:
        var_export($var);
        break;

    case SC_DUMP_JSON:
        echo json_encode($var, JSON_PRETTY_PRINT);
        break;
    }

    if ($app->isCLI()) {
        echo "\n";
    } else {
        echo $display ? "\n</pre><br />\n" : "\n-->\n";
    }
}

/*
* Log a PHP variable to javascript console. Relies on getDump(), below.
*
* @access   public
* @param    mixed   $var      The variable to dump.
* @param    string  $prefix   A short note to print before the output to make identifying output easier.
* @param    string  $file     The value of __FILE__.
* @param    string  $line     The value of __LINE__.
* @return   null
* @author   Quinn Comendant <quinn@strangecode.com>
*/
function jsDump($var, $prefix='jsDump', $file='-', $line='-')
{
    if (!empty($var)) {
        ?>
        <script type="text/javascript">
        /* <![CDATA[ */
        console.log('<?php printf('%s: %s (on line %s of %s)', $prefix, str_replace("'", "\\'", getDump($var, true)), $line, $file); ?>');
        /* ]]> */
        </script>
        <?php
    }
}

/*
* Return a string version of any variable, optionally serialized on one line.
*
* @access   public
* @param    mixed   $var        The variable to dump.
* @param    bool    $serialize  If true, remove line-endings. Useful for logging variables.
* @return   string              The dumped variable.
* @author   Quinn Comendant <quinn@strangecode.com>
*/
function getDump($var, $serialize=false)
{
    $app =& App::getInstance();

    ob_start();
    print_r($var);
    $d = ob_get_contents();
    ob_end_clean();
    return $serialize ? preg_replace('/\s+/m' . $app->getParam('preg_u'), ' ', $d) : $d;
}

/*
* Return dump as cleaned text. Useful for dumping data into emails or output from CLI scripts.
* To output tab-style lists set $indent to "\t" and $depth to 0;
* To output markdown-style lists set $indent to '- ' and $depth to 1;
* Also see yaml_emit() https://secure.php.net/manual/en/function.yaml-emit.php
*
* @param  array    $var        Variable to dump.
* @param  string   $indent     A string to prepend indented lines.
* @param  string   $depth      Starting depth of this iteration of recursion (set to 0 to have no initial indentation).
* @return string               Pretty dump of $var.
* @author   Quinn Comendant <quinn@strangecode.com>
* @version 2.0
*/
function fancyDump($var, $indent='- ', $depth=1)
{
    $app =& App::getInstance();

    $indent_str = str_repeat($indent, $depth);
    $output = '';
    if (is_array($var)) {
        foreach ($var as $k=>$v) {
            $k = ucfirst(mb_strtolower(str_replace(array('_', '  '), ' ', $k)));
            if (is_array($v)) {
                $output .= sprintf("\n%s%s:\n%s\n", $indent_str, $k, fancyDump($v, $indent, $depth+1));
            } else {
                $output .= sprintf("%s%s: %s\n", $indent_str, $k, $v);
            }
        }
    } else {
        $output .= sprintf("%s%s\n", $indent_str, $var);
    }
    return preg_replace(['/^[ \t]+$/' . $app->getParam('preg_u'), '/\n\n+/' . $app->getParam('preg_u'), '/^(?:\S( ))?(?:\S( ))?(?:\S( ))?(?:\S( ))?(?:\S( ))?(?:\S( ))?(?:\S( ))?(?:\S( ))?(\S )/m' . $app->getParam('preg_u')], ['', "\n", '$1$1$2$2$3$3$4$4$5$5$6$6$7$7$8$8$9'], $output);
}

/**
 * @param string|mixed $value A string to UTF8-encode.
 *
 * @returns string|mixed The UTF8-encoded string, or the object passed in if
 *    it wasn't a string.
 */
function conditionalUTF8Encode($value)
{
  if (is_string($value) && mb_detect_encoding($value, 'UTF-8', true) != 'UTF-8') {
    return utf8_encode($value);
  } else {
    return $value;
  }
}


/**
 * Returns text with appropriate html translations (a smart wrapper for htmlspecialchars()).
 *
 * @param  string $text             Text to clean.
 * @param  bool   $preserve_html    If set to true, oTxt will not translate <, >, ", or '
 *                                  characters into HTML entities. This allows HTML to pass through undisturbed.
 * @return string                   HTML-safe text.
 */
function oTxt($text, $preserve_html=false)
{
    $app =& App::getInstance();

    $search = array();
    $replace = array();

    // Make converted ampersand entities into normal ampersands (they will be done manually later) to retain HTML entities.
    $search['retain_ampersand']     = '/&amp;/';
    $replace['retain_ampersand']    = '&';

    if ($preserve_html) {
        // Convert characters that must remain non-entities for displaying HTML.
        $search['retain_left_angle']       = '/&lt;/';
        $replace['retain_left_angle']      = '<';

        $search['retain_right_angle']      = '/&gt;/';
        $replace['retain_right_angle']     = '>';

        $search['retain_single_quote']     = '/&#039;/';
        $replace['retain_single_quote']    = "'";

        $search['retain_double_quote']     = '/&quot;/';
        $replace['retain_double_quote']    = '"';
    }

    // & becomes &amp;. Exclude any occurrence where the & is followed by a alphanum or unicode character.
    $search['ampersand']        = '/&(?![\w\d#]{1,10};)/';
    $replace['ampersand']       = '&amp;';

    return preg_replace($search, $replace, htmlspecialchars($text, ENT_QUOTES, $app->getParam('character_set')));
}

/**
 * Returns text with stylistic modifications. Warning: this will break some HTML attributes!
 * TODO: Allow a string such as this to be passed: <a href="javascript:openPopup('/foo/bar.php')">Click here</a>
 *
 * @param  string   $text Text to clean.
 * @return string         Cleaned text.
 */
function fancyTxt($text, $extra_search=null, $extra_replace=null)
{
    $search = array();
    $replace = array();

    // "double quoted text"  →  “double quoted text”
    $search['_double_quotes']    = '/(?<=^|[^\w=(])(?:"|&quot;|&#0?34;|&#x22;|&ldquo;)([\w\'.
(—–-][^"]*?)(?:"|&quot;|&#0?34;|&#x22;|&rdquo;)(?=[^)\w]|$)/imsu'; // " is the same as &quot; and &#34; and &#034; and &#x22;
    $replace['_double_quotes']   = '“$1”';

    // text's apostrophes  →  text’s apostrophes (except foot marks: 6'3")
    $search['_apostrophe']       = '/(?<=[a-z])(?:\'|&#0?39;)(?=\w)/imsu';
    $replace['_apostrophe']      = '’';

    // 'single quoted text'  →  ‘single quoted text’
    $search['_single_quotes']    = '/(?<=^|[^\w=(])(?:\'|&#0?39;|&lsquo;)([\w"][^\']+?)(?:\'|&#0?39;|&rsquo;)(?=[^)\w]|$)/imsu';
    $replace['_single_quotes']   = '‘$1’';

    // plural posessives' apostrophes  →  posessives’  (except foot marks: 6')
    $search['_apostrophes']      = '/(?<=s)(?:\'|&#0?39;|&rsquo;)(?=\s)/imsu';
    $replace['_apostrophes']     = '’';

    // double--hyphens  →  en — dashes
    $search['_em_dash']          = '/(?<=[\w\s"\'”’)])--(?=[\w\s“”‘"\'(?])/imsu';
    $replace['_em_dash']         = ' – ';

    // ...  →  

    $search['_elipsis']          = '/(?<=^|[^.])\.\.\.(?=[^.]|$)/imsu';
    $replace['_elipsis']         = '
';

    if (is_array($extra_search) && is_array($extra_replace) && sizeof($extra_search) == sizeof($extra_replace)) {
        // Append additional search replacements.
        $search = array_merge($search, $extra_search);
        $replace = array_merge($replace, $extra_replace);
    }

    return trim(preg_replace($search, $replace, $text));
}

/*
* Finds all URLs in text and hyperlinks them.
*
* @access   public
* @param    string  $text   Text to search for URLs.
* @param    bool    $strict True to only include URLs starting with a scheme (http:// ftp:// im://), or false to include URLs starting with 'www.'.
* @param    mixed   $length Number of characters to truncate URL, or NULL to disable truncating.
* @param    string  $delim  Delimiter to append, indicate truncation.
* @return   string          Same input text, but URLs hyperlinked.
* @author   Quinn Comendant <quinn@strangecode.com>
* @version  2.2
* @since    22 Mar 2015 23:29:04
*/
function hyperlinkTxt($text, $strict=false, $length=null, $delim='
')
{
    // A list of schemes we allow at the beginning of a URL.
    $schemes = 'mailto:|tel:|skype:|callto:|facetime:|bitcoin:|geo:|magnet:\?|sip:|sms:|xmpp:|view-source:(?:https?://)?|[\w-]{2,}://';

    // Capture the full URL into the first match and only the first X characters into the second match.
    // This will match URLs not preceded by " ' or = (URLs inside an attribute) or ` (Markdown quoted) or double-scheme (http://http://www.asdf.com)
    // https://stackoverflow.com/questions/1547899/which-characters-make-a-url-invalid/1547940#1547940
    $regex = '@
        \b                                 # Start with a word-boundary.
        (?<!"|\'|=|>|`|\]\(|\[\d\] |[:/]/) # Negative look-behind to exclude URLs already in <a> tag, <tags>beween</tags>, `Markdown quoted`, [Markdown](link), [1] www.markdown.footnotes, and avoid broken:/ and doubled://schemes://
        (                                  # Begin match 1
            (                              # Begin match 2
                (?:%s)                     # URL starts with known scheme or www. if strict = false
                [^\s/$.?#]+                # Any domain-valid characters
                [^\s"`<>]{1,%s}            # Match 2 is limited to a maximum of LENGTH valid URL characters
            )
            [^\s"`<>]*                     # Match 1 continues with any further valid URL characters
            ([^\P{Any}\s
<>«»"—–%s])       # Final character not a space or common end-of-sentence punctuation (.,:;?!, etc). Using double negation set, see http://stackoverflow.com/a/4786560/277303
        )
        @Suxi
    ';
    $regex = sprintf($regex,
        ($strict ? $schemes : $schemes . '|www\.'), // Strict=false adds "www." to the list of allowed start-of-URL.
        ($length ? $length : ''),
        ($strict ? '' : '?!.,:;)\'-') // Strict=false excludes some "URL-valid" characters from the last character of URL. (Hyphen must remain last character in this class.)
    );

    // Use a callback function to decide when to append the delim.
    // Also encode special chars with oTxt().
    return preg_replace_callback($regex, function ($m) use ($length, $delim) {
        $url = $m[1];
        $truncated_url = $m[2] . $m[3];
        $absolute_url = preg_replace('!^www\.!', 'http://www.', $url);
        if (is_null($length) || $url == $truncated_url) {
            // If not truncating, or URL was not truncated.
            // Remove http schemas, and any single trailing / to make the display URL.
            $display_url = preg_replace(['!^https?://!u', '!^([^/]+)/$!u'], ['', '$1'], $url);
            return sprintf('<a href="%s">%s</a>', oTxt($absolute_url), oTxt($display_url));
        } else {
            // Truncated URL.
            // Remove http schemas, and any single trailing / to make the display URL.
            $display_url = preg_replace(['!^https?://!u', '!^([^/]+)/$!u'], ['', '$1'], trim($truncated_url));
            return sprintf('<a href="%s">%s%s</a>', oTxt($absolute_url), oTxt($display_url), $delim);
        }
    }, $text);
}

/**
 * Applies a class to search terms to highlight them ala google results.
 *
 * @param  string   $text   Input text to search.
 * @param  string   $search String of word(s) that will be highlighted.
 * @param  string   $class  CSS class to apply.
 * @return string           Text with searched words wrapped in <span>.
 */
function highlightWords($text, $search, $class='sc-highlightwords')
{
    $app =& App::getInstance();

    $words = preg_split('/[^\w]/', $search, -1, PREG_SPLIT_NO_EMPTY);

    $search = array();
    $replace = array();

    foreach ($words as $w) {
        if ('' != trim($w)) {
            $search[] = '/\b(' . preg_quote($w) . ')\b/i' . $app->getParam('preg_u');
            $replace[] = '<span class="' . oTxt($class) . '">$1</span>';
        }
    }

    return empty($replace) ? $text : preg_replace($search, $replace, $text);
}

/**
 * Generates a hexadecimal html color based on provided word.
 *
 * @access public
 * @param  string $text  A string for which to convert to color.
 * @param  float  $n     Brightness value between 0-1.
 * @return string        A hexadecimal html color.
 */
function getTextColor($text, $method=1, $n=0.87)
{
    $hash = md5($text);
    $rgb = array(
        mb_substr($hash, 0, 1),
        mb_substr($hash, 1, 1),
        mb_substr($hash, 2, 1),
        mb_substr($hash, 3, 1),
        mb_substr($hash, 4, 1),
        mb_substr($hash, 5, 1),
    );

    switch ($method) {
    case 1 :
    default :
        // Reduce all hex values slightly to avoid all white.
        array_walk($rgb, function (&$v) use ($n) {
            $v = dechex(round(hexdec($v) * $n));
        });
        break;

    case 2 :
        foreach ($rgb as $i => $v) {
            if (hexdec($v) > hexdec('c')) {
                $rgb[$i] = dechex(hexdec('f') - hexdec($v));
            }
        }
        break;
    }

    return join('', $rgb);
}

/**
 * Encodes a string into unicode values 128-255.
 * Useful for hiding an email address from spambots.
 *
 * @access  public
 * @param   string   $text   A line of text to encode.
 * @return  string   Encoded text.
 */
function encodeAscii($text)
{
    $output = '';
    $num = mb_strlen($text);
    for ($i=0; $i<$num; $i++) {
        $output .= sprintf('&#%03s', ord($text[$i]));
    }
    return $output;
}

/**
 * Encodes an email into a "user at domain dot com" format.
 *
 * @access  public
 * @param   string   $email   An email to encode.
 * @param   string   $at      Replaces the @.
 * @param   string   $dot     Replaces the ..
 * @return  string   Encoded email.
 */
function encodeEmail($email, $at=' at ', $dot=' dot ')
{
    $app =& App::getInstance();

    $search = array('/@/' . $app->getParam('preg_u'), '/\./' . $app->getParam('preg_u'));
    $replace = array($at, $dot);
    return preg_replace($search, $replace, $email);
}

/**
 * Truncates "a really long string" into a string of specified length
 * at the beginning: "
long string"
 * at the middle: "a rea
string"
 * or at the end: "a really
".
 *
 * The regular expressions below first match and replace the string to the specified length and position,
 * and secondly they remove any whitespace from around the delimiter (to avoid "this 
 " from happening).
 *
 * @access  public
 * @param   string  $str    Input string
 * @param   int     $len    Maximum string length.
 * @param   string  $where  Where to cut the string. One of: 'start', 'middle', or 'end'.
 * @return  string          Truncated output string.
 * @author  Quinn Comendant <quinn@strangecode.com>
 * @since   29 Mar 2006 13:48:49
 */
function truncate($str, $len=50, $where='end', $delim='
')
{
    $app =& App::getInstance();

    $dlen = mb_strlen($delim);
    if ($len <= $dlen || mb_strlen($str) <= $dlen) {
        return substr($str, 0, $len);
    }
    $part1 = floor(($len - $dlen) / 2);
    $part2 = ceil(($len - $dlen) / 2);

    if ($len > ini_get('pcre.backtrack_limit')) {
        $app =& App::getInstance();
        $app->logMsg(sprintf('Asked to truncate string len of %s > pcre.backtrack_limit of %s', $len, ini_get('pcre.backtrack_limit')), LOG_DEBUG, __FILE__, __LINE__);
        ini_set('pcre.backtrack_limit', $len);
    }

    switch ($where) {
    case 'start' :
        return preg_replace(array(sprintf('/^.{%s,}(.{%s})$/s' . $app->getParam('preg_u'), $dlen + 1, $part1 + $part2), sprintf('/\s*%s{%s,}\s*/s' . $app->getParam('preg_u'), preg_quote($delim), $dlen)), array($delim . '$1', $delim), $str);

    case 'middle' :
        return preg_replace(array(sprintf('/^(.{%s}).{%s,}(.{%s})$/s' . $app->getParam('preg_u'), $part1, $dlen + 1, $part2), sprintf('/\s*%s{%s,}\s*/s' . $app->getParam('preg_u'), preg_quote($delim), $dlen)), array('$1' . $delim . '$2', $delim), $str);

    case 'end' :
    default :
        return preg_replace(array(sprintf('/^(.{%s}).{%s,}$/s' . $app->getParam('preg_u'), $part1 + $part2, $dlen + 1), sprintf('/\s*%s{%s,}\s*/s' . $app->getParam('preg_u'), preg_quote($delim), $dlen)), array('$1' . $delim, $delim), $str);
    }
}

/*
* A substitution for the missing mb_ucfirst function.
*
* @access   public
* @param    string  $string The string
* @return   string          String with upper-cased first character.
* @author   Quinn Comendant <quinn@strangecode.com>
* @version  1.0
* @since    06 Dec 2008 17:04:01
*/
if (!function_exists('mb_ucfirst')) {
    function mb_ucfirst($string)
    {
        return mb_strtoupper(mb_substr($string, 0, 1)) . mb_substr($string, 1, mb_strlen($string));
    }
}

/*
* A substitution for the missing mb_strtr function.
*
* @access   public
* @param    string  $string The string
* @param    string  $from   String of characters to translate from
* @param    string  $to     String of characters to translate to
* @return   string          String with translated characters.
* @author   Quinn Comendant <quinn@strangecode.com>
* @version  1.0
* @since    20 Jan 2013 12:33:26
*/
if (!function_exists('mb_strtr')) {
    function mb_strtr($string, $from, $to)
    {
        return str_replace(mb_split('.', $from), mb_split('.', $to), $string);
    }
}

/*
* A substitution for the missing mb_str_pad function.
*
* @access   public
* @param    string  $input      The string that receives padding.
* @param    string  $pad_length Total length of resultant string.
* @param    string  $pad_string The string to use for padding
* @param    string  $pad_type   Flags STR_PAD_RIGHT or STR_PAD_LEFT or STR_PAD_BOTH
* @return   string          String with translated characters.
* @author   Quinn Comendant <quinn@strangecode.com>
* @version  1.0
* @since    20 Jan 2013 12:33:26
*/
if (!function_exists('mb_str_pad')) {
    function mb_str_pad($input, $pad_length, $pad_string=' ', $pad_type=STR_PAD_RIGHT) {
        $diff = strlen($input) - mb_strlen($input);
        return str_pad($input, $pad_length + $diff, $pad_string, $pad_type);
    }
}

/**
 * Return a human readable disk space measurement. Input value measured in bytes.
 *
 * @param       int    $size        Size in bytes.
 * @param       int    $unit        The maximum unit
 * @param       int    $format      The return string format
 * @author      Aidan Lister <aidan@php.net>
 * @author      Quinn Comendant <quinn@strangecode.com>
 * @version     1.2.0
 */
function humanFileSize($size, $format='%01.2f %s', $max_unit=null, $multiplier=1024)
{
    // Units
    $units = array('B', 'KB', 'MB', 'GB', 'TB');
    $ii = count($units) - 1;

    // Max unit
    $max_unit = array_search((string) $max_unit, $units);
    if ($max_unit === null || $max_unit === false) {
        $max_unit = $ii;
    }

    // Loop
    $i = 0;
    while ($max_unit != $i && $size >= $multiplier && $i < $ii) {
        $size /= $multiplier;
        $i++;
    }

    return sprintf($format, $size, $units[$i]);
}

/*
* Returns a human readable amount of time for the given amount of seconds.
*
* 45 seconds
* 12 minutes
* 3.5 hours
* 2 days
* 1 week
* 4 months
*
* Months are calculated using the real number of days in a year: 365.2422 / 12.
*
* @access   public
* @param    int $seconds Seconds of time.
* @param    string $max_unit Key value from the $units array.
* @param    string $format Sprintf formatting string.
* @return   string Value of units elapsed.
* @author   Quinn Comendant <quinn@strangecode.com>
* @version  1.0
* @since    23 Jun 2006 12:15:19
*/
function humanTime($seconds, $max_unit=null, $format='%01.1f')
{
    // Units: array of seconds in the unit, singular and plural unit names.
    $units = array(
        'second' => array(1, _("second"), _("seconds")),
        'minute' => array(60, _("minute"), _("minutes")),
        'hour' => array(3600, _("hour"), _("hours")),
        'day' => array(86400, _("day"), _("days")),
        'week' => array(604800, _("week"), _("weeks")),
        'month' => array(2629743.84, _("month"), _("months")),
        'year' => array(31556926.08, _("year"), _("years")),
        'decade' => array(315569260.8, _("decade"), _("decades")),
        'century' => array(3155692608, _("century"), _("centuries")),
    );

    // Max unit to calculate.
    $max_unit = isset($units[$max_unit]) ? $max_unit : 'year';

    $final_time = $seconds;
    $final_unit = 'second';
    foreach ($units as $k => $v) {
        if ($seconds >= $v[0]) {
            $final_time = $seconds / $v[0];
            $final_unit = $k;
        }
        if ($max_unit == $final_unit) {
            break;
        }
    }
    $final_time = sprintf($format, $final_time);
    return sprintf('%s %s', $final_time, (1 == $final_time ? $units[$final_unit][1] : $units[$final_unit][2]));
}

/*
* Calculate a prorated amount for the duration between two dates.
*
* @access   public
* @param    float   $amount     Original price per duration.
* @param    string  $duration   Unit of time for the original price (`year`, `quarter`, `month`, or `day`).
* @param    string  $start_date Start date of prorated period (strtotime-compatible date).
* @param    string  $end_date   End date of prorated period (strtotime-compatible date).
* @return   float               The prorated amount.
* @author   Quinn Comendant <quinn@strangecode.com>
* @since    03 Nov 2021 22:44:30
*/
function prorate($amount, $duration, $start_date, $end_date)
{
    $app =& App::getInstance();

    switch ($duration) {
    case 'yr':
    case 'year':
        $amount_per_day = $amount / 365;
        break;

    case 'quarter':
        $amount_per_day = $amount / 91.25;
        break;

    case 'mo':
    case 'month':
        $amount_per_day = $amount / 30.4167;
        break;

    case 'week':
        $amount_per_day = $amount / 7;
        break;

    case 'day':
        $amount_per_day = $amount;
        break;

    default:
        $app->logMsg(sprintf('Unknown prorate duration “%s”. Please use one of: year, yr, quarter, month, mo, week, day.', $duration), LOG_ERR, __FILE__, __LINE__);
        return false;
    }

    $diff_time = strtotime($end_date) - strtotime($start_date);
    $days = $diff_time / (60 * 60 * 24);
    return $amount_per_day * $days;
}

/*
* Converts strange characters into ASCII using a htmlentities hack. If a character does not have a specific rule, it will remain as its entity name, e.g., `5¢` becomes `5&cent;` which becomes `5cent`.
*
* @access   public
* @param    string  $str    Input string of text containing accents.
* @return   string          String with accented characters converted to ASCII equivalents.
* @author   Quinn Comendant <quinn@strangecode.com>
* @since    30 Apr 2020 21:29:16
*/
function simplifyAccents($str)
{
    $app =& App::getInstance();

    return preg_replace([
        '/&amp;(?=[\w\d#]{1,10};)/i' . $app->getParam('preg_u'),
        '/&([a-z]{1,2})(?:acute|cedil|circ|grave|lig|orn|ring|slash|th|tilde|uml|caron);/i' . $app->getParam('preg_u'),
        '/&(?:ndash|mdash|horbar);/i' . $app->getParam('preg_u'),
        '/&(?:nbsp);/i' . $app->getParam('preg_u'),
        '/&(?:bdquo|ldquo|ldquor|lsquo|lsquor|rdquo|rdquor|rsquo|rsquor|sbquo|lsaquo|rsaquo);/i' . $app->getParam('preg_u'),
        '/&(?:amp);/i' . $app->getParam('preg_u'), // This replacement must come after matching all other entities.
        '/[&;]+/' . $app->getParam('preg_u'),
    ], [
        '&',
        '$1',
        '-',
        ' ',
        '',
        'and',
        '',
    ], htmlentities($str, ENT_NOQUOTES | ENT_IGNORE, $app->getParam('character_set')));
}

/*
* Converts a string into a URL-safe slug, removing spaces and non word characters.
*
* @access   public
* @param    string  $str    String to convert.
* @return   string          URL-safe slug.
* @author   Quinn Comendant <quinn@strangecode.com>
* @version  1.0
* @since    18 Aug 2014 12:54:29
*/
function URLSlug($str)
{
    $app =& App::getInstance();

    return strtolower(urlencode(preg_replace(['/[-\s–—.:;?!@#=+_\/\\\]+|(?:&nbsp;|&#160;|&ndash;|&#8211;|&mdash;|&#8212;|%c2%a0|%e2%80%93|%e2%80%9)+/' . $app->getParam('preg_u'), '/-+/' . $app->getParam('preg_u'), '/[^\w-]+/' . $app->getParam('preg_u'), '/^-+|-+$/' . $app->getParam('preg_u')], ['-', '-', '', ''], simplifyAccents($str))));
}

/**
 * Converts a string of text into a safe file name by removing non-ASCII characters and non-word characters.
 *
 * @access  public
 * @param   string  $file_name  A name of a file.
 * @return  string              The same name, but cleaned.
 */
function cleanFileName($file_name)
{
    $app =& App::getInstance();

    $file_name = preg_replace(['/[^a-zA-Z0-9()@._=+-]+/' . $app->getParam('preg_u'), '/^_+|_+$/' . $app->getParam('preg_u')], ['_', ''], simplifyAccents($file_name));
    return mb_substr($file_name, 0, 250);
}

/**
 * Returns the extension of a file name, or an empty string if none exists.
 *
 * @access  public
 * @param   string  $file_name  A name of a file, with extension after a dot.
 * @return  string              The value found after the dot
 */
function getFilenameExtension($file_name)
{
    preg_match('/.*?\.(\w+)$/i', trim($file_name), $ext);
    return isset($ext[1]) ? $ext[1] : '';
}

/*
* Convert a php.ini value (8M, 512K, etc), into integer value of bytes.
*
* @access   public
* @param    string  $val    Value from php config, e.g., upload_max_filesize.
* @return   int             Value converted to bytes as an integer.
* @author   Quinn Comendant <quinn@strangecode.com>
* @version  1.0
* @since    20 Aug 2014 14:32:41
*/
function phpIniGetBytes($val)
{
    $val = trim(ini_get($val));
    if ($val != '') {
        $unit = strtolower($val[mb_strlen($val) - 1]);
        $val = preg_replace('/\D/', '', $val);

        switch ($unit) {
            // No `break`, so these multiplications are cumulative.
            case 'g':
                $val *= 1024;
            case 'm':
                $val *= 1024;
            case 'k':
                $val *= 1024;
        }
    }

    return (int)$val;
}

/**
 * Tests the existence of a file anywhere in the include path.
 * Replaced by stream_resolve_include_path() in PHP 5 >= 5.3.2
 *
 * @param   string  $file   File in include path.
 * @return  mixed           False if file not found, the path of the file if it is found.
 * @author  Quinn Comendant <quinn@strangecode.com>
 * @since   03 Dec 2005 14:23:26
 */
function fileExistsIncludePath($file)
{
    $app =& App::getInstance();

    foreach (explode(PATH_SEPARATOR, get_include_path()) as $path) {
        $fullpath = $path . DIRECTORY_SEPARATOR . $file;
        if (file_exists($fullpath)) {
            $app->logMsg(sprintf('Found file "%s" at path: %s', $file, $fullpath), LOG_DEBUG, __FILE__, __LINE__);
            return $fullpath;
        } else {
            $app->logMsg(sprintf('File "%s" not found in include_path: %s', $file, get_include_path()), LOG_DEBUG, __FILE__, __LINE__);
            return false;
        }
    }
}

/**
 * Returns stats of a file from the include path.
 *
 * @param   string  $file   File in include path.
 * @param   mixed   $stat   Which statistic to return (or null to return all).
 * @return  mixed           Value of requested key from fstat(), or false on error.
 * @author  Quinn Comendant <quinn@strangecode.com>
 * @since   03 Dec 2005 14:23:26
 */
function statIncludePath($file, $stat=null)
{
    // Open file pointer read-only using include path.
    if ($fp = fopen($file, 'r', true)) {
        // File opened successfully, get stats.
        $stats = fstat($fp);
        fclose($fp);
        // Return specified stats.
        return is_null($stat) ? $stats : $stats[$stat];
    } else {
        return false;
    }
}

/*
* Writes content to the specified file. This function emulates the functionality of file_put_contents from PHP 5.
* It makes an exclusive lock on the file while writing.
*
* @access   public
* @param    string  $filename   Path to file.
* @param    string  $content    Data to write into file.
* @return   bool                Success or failure.
* @author   Quinn Comendant <quinn@strangecode.com>
* @since    11 Apr 2006 22:48:30
*/
function filePutContents($filename, $content)
{
    $app =& App::getInstance();

    // Open file for writing and truncate to zero length.
    if ($fp = fopen($filename, 'w')) {
        if (flock($fp, LOCK_EX)) {
            if (!fwrite($fp, $content, mb_strlen($content))) {
                $app->logMsg(sprintf('Failed writing to file: %s', $filename), LOG_ERR, __FILE__, __LINE__);
                fclose($fp);
                return false;
            }
            flock($fp, LOCK_UN);
        } else {
            $app->logMsg(sprintf('Could not lock file for writing: %s', $filename), LOG_ERR, __FILE__, __LINE__);
            fclose($fp);
            return false;
        }
        fclose($fp);
        // Success!
        $app->logMsg(sprintf('Wrote to file: %s', $filename), LOG_DEBUG, __FILE__, __LINE__);
        return true;
    } else {
        $app->logMsg(sprintf('Could not open file for writing: %s', $filename), LOG_ERR, __FILE__, __LINE__);
        return false;
    }
}

/**
 * If $var is net set or null, set it to $default. Otherwise leave it alone.
 * Returns the final value of $var. Use to find a default value of one is not available.
 *
 * @param  mixed $var       The variable that is being set.
 * @param  mixed $default   What to set it to if $val is not currently set.
 * @return mixed            The resulting value of $var.
 */
function setDefault(&$var, $default='')
{
    if (!isset($var)) {
        $var = $default;
    }
    return $var;
}

/**
 * Like preg_quote() except for arrays, it takes an array of strings and puts
 * a backslash in front of every character that is part of the regular
 * expression syntax.
 *
 * @param  array $array    input array
 * @param  array $delim    optional character that will also be escaped.
 * @return array    an array with the same values as $array1 but shuffled
 */
function pregQuoteArray($array, $delim='/')
{
    if (!empty($array)) {
        if (is_array($array)) {
            foreach ($array as $key=>$val) {
                $quoted_array[$key] = preg_quote($val, $delim);
            }
            return $quoted_array;
        } else {
            return preg_quote($array, $delim);
        }
    }
}

/**
 * Converts a PHP Array into encoded URL arguments and return them as an array.
 *
 * @param  mixed $data        An array to transverse recursively, or a string
 *                            to use directly to create url arguments.
 * @param  string $prefix     The name of the first dimension of the array.
 *                            If not specified, the first keys of the array will be used.
 * @return array              URL with array elements as URL key=value arguments.
 */
function urlEncodeArray($data, $prefix='', $_return=true)
{
    // Data is stored in static variable.
    static $args = array();

    if (is_array($data)) {
        foreach ($data as $key => $val) {
            // If the prefix is empty, use the $key as the name of the first dimension of the "array".
            // ...otherwise, append the key as a new dimension of the "array".
            $new_prefix = ('' == $prefix) ? urlencode($key) : $prefix . '[' . urlencode($key) . ']';
            // Enter recursion.
            urlEncodeArray($val, $new_prefix, false);
        }
    } else {
        // We've come to the last dimension of the array, save the "array" and its value.
        $args[$prefix] = urlencode($data);
    }

    if ($_return) {
        // This is not a recursive execution. All recursion is complete.
        // Reset static var and return the result.
        $ret = $args;
        $args = array();
        return is_array($ret) ? $ret : array();
    }
}

/**
 * Converts a PHP Array into encoded URL arguments and return them in a string.
 *
 * Todo: probably update to use the built-in http_build_query().
 *
 * @param  mixed $data        An array to transverse recursively, or a string
 *                            to use directly to create url arguments.
 * @param  string $prefix     The name of the first dimension of the array.
 *                            If not specified, the first keys of the array will be used.
 * @return string url         A string ready to append to a url.
 */
function urlEncodeArrayToString($data, $prefix='')
{
    $array_args = urlEncodeArray($data, $prefix);
    $url_args = '';
    $delim = '';
    foreach ($array_args as $key=>$val) {
        $url_args .= $delim . $key . '=' . $val;
        $delim = ini_get('arg_separator.output');
    }
    return $url_args;
}

/**
 * Fills an array with the result from a multiple ereg search.
 * Courtesy of Bruno - rbronosky@mac.com - 10-May-2001
 *
 * @param  mixed $pattern   regular expression needle
 * @param  mixed $string   haystack
 * @return array    populated with each found result
 */
function eregAll($pattern, $string)
{
    do {
        if (!mb_ereg($pattern, $string, $temp)) {
             continue;
        }
        $string = str_replace($temp[0], '', $string);
        $results[] = $temp;
    } while (mb_ereg($pattern, $string, $temp));
    return $results;
}

/**
 * Prints the word "checked" if a variable is set, and optionally matches
 * the desired value, otherwise prints nothing,
 * used for printing the word "checked" in a checkbox form input.
 *
 * @param  mixed $var     the variable to compare
 * @param  mixed $value   optional, what to compare with if a specific value is required.
 */
function frmChecked($var, $value=null)
{
    if (func_num_args() == 1 && $var) {
        // 'Checked' if var is true.
        echo ' checked="checked" ';
    } else if (func_num_args() == 2 && $var == $value) {
        // 'Checked' if var and value match.
        echo ' checked="checked" ';
    } else if (func_num_args() == 2 && is_array($var)) {
        // 'Checked' if the value is in the key or the value of an array.
        if (isset($var[$value])) {
            echo ' checked="checked" ';
        } else if (in_array($value, $var)) {
            echo ' checked="checked" ';
        }
    }
}

/**
 * prints the word "selected" if a variable is set, and optionally matches
 * the desired value, otherwise prints nothing,
 * otherwise prints nothing, used for printing the word "checked" in a
 * select form input
 *
 * @param  mixed $var     the variable to compare
 * @param  mixed $value   optional, what to compare with if a specific value is required.
 */
function frmSelected($var, $value=null)
{
    if (func_num_args() == 1 && $var) {
        // 'selected' if var is true.
        echo ' selected="selected" ';
    } else if (func_num_args() == 2 && $var == $value) {
        // 'selected' if var and value match.
        echo ' selected="selected" ';
    } else if (func_num_args() == 2 && is_array($var)) {
        // 'selected' if the value is in the key or the value of an array.
        if (isset($var[$value])) {
            echo ' selected="selected" ';
        } else if (in_array($value, $var)) {
            echo ' selected="selected" ';
        }
    }
}

/**
 * Adds slashes to values of an array and converts the array to a comma
 * delimited list. If value provided is a string return the string
 * escaped.  This is useful for putting values coming in from posted
 * checkboxes into a SET column of a database.
 *
 *
 * @param  array $in      Array to convert.
 * @return string         Comma list of array values.
 */
function escapedList($in, $separator="', '")
{
    require_once dirname(__FILE__) . '/DB.inc.php';
    $db =& DB::getInstance();

    if (is_array($in) && !empty($in)) {
        return join($separator, array_map(array($db, 'escapeString'), $in));
    } else {
        return $db->escapeString($in);
    }
}

/**
 * Converts a human string date into a SQL-safe date.  Dates nearing
 * infinity use the date 2038-01-01 so conversion to unix time format
 * remain within valid range.
 *
 * @param  array $date     String date to convert.
 * @param  array $format   Date format to pass to date(). Default produces MySQL datetime: YYYY-MM-DD hh:mm:ss
 * @return string          SQL-safe date.
 */
function strToSQLDate($date, $format='Y-m-d H:i:s')
{
    require_once dirname(__FILE__) . '/DB.inc.php';
    $db =& DB::getInstance();

    if ($db->isConnected() && mb_strpos($db->getParam('zero_date'), '-') !== false) {
        // Mysql version >= 5.7.4 stopped allowing a "zero" date of 0000-00-00.
        // https://dev.mysql.com/doc/refman/5.7/en/sql-mode.html#sqlmode_no_zero_date
        $zero_date_parts = explode('-', $db->getParam('zero_date'));
        $zero_y = $zero_date_parts[0];
        $zero_m = $zero_date_parts[1];
        $zero_d = $zero_date_parts[2];
    } else {
        $zero_y = '0000';
        $zero_m = '00';
        $zero_d = '00';
    }
    // Translate the human string date into SQL-safe date format.
    if (empty($date) || mb_strpos($date, sprintf('%s-%s-%s', $zero_y, $zero_m, $zero_d)) !== false || strtotime($date) === -1 || strtotime($date) === false || strtotime($date) === null) {
        // Return a string of zero time, formatted the same as $format.
        return strtr($format, array(
            'Y' => $zero_y,
            'm' => $zero_m,
            'd' => $zero_d,
            'H' => '00',
            'i' => '00',
            's' => '00',
        ));
    } else {
        return date($format, strtotime($date));
    }
}

/**
 * If magic_quotes_gpc is in use, run stripslashes() on $var. If $var is an
 * array, stripslashes is run on each value, recursively, and the stripped
 * array is returned.
 *
 * @param  mixed $var   The string or array to un-quote, if necessary.
 * @return mixed        $var, minus any magic quotes.
 */
function dispelMagicQuotes($var, $always=false)
{
    static $magic_quotes_gpc;

    if (!isset($magic_quotes_gpc)) {
        $magic_quotes_gpc = version_compare(PHP_VERSION, '5.4.0', '<') ? get_magic_quotes_gpc() : false;
    }

    if ($always || $magic_quotes_gpc) {
        if (!is_array($var)) {
            $var = stripslashes($var);
        } else {
            foreach ($var as $key=>$val) {
                if (is_array($val)) {
                    $var[$key] = dispelMagicQuotes($val, $always);
                } else {
                    $var[$key] = stripslashes($val);
                }
            }
        }
    }
    return $var;
}

/**
 * Get a form variable from GET or POST data, stripped of magic
 * quotes if necessary.
 *
 * @param string $key       The name of a $_REQUEST key (optional).
 * @param string $default   The value to return if the variable is set (optional).
 * @return mixed      A cleaned GET or POST array if no key specified.
 * @return string     A cleaned form value if set, or $default.
 */
function getFormData($key=null, $default=null)
{
    $app =& App::getInstance();

    if (null === $key) {
        // Return entire array.
        switch (strtoupper(getenv('REQUEST_METHOD'))) {
        case 'POST':
            return dispelMagicQuotes($_POST, $app->getParam('always_dispel_magicquotes'));

        case 'GET':
            return dispelMagicQuotes($_GET, $app->getParam('always_dispel_magicquotes'));

        default:
            return dispelMagicQuotes($_REQUEST, $app->getParam('always_dispel_magicquotes'));
        }
    }

    if (isset($_REQUEST[$key])) {
        // $key is found in the flat array of REQUEST.
        return dispelMagicQuotes($_REQUEST[$key], $app->getParam('always_dispel_magicquotes'));
    } else if (mb_strpos($key, '[') !== false && isset($_REQUEST[strtok($key, '[')]) && preg_match_all('/\[([a-z0-9._~-]+)\]/', $key, $matches)) {
        // $key is formatted with sub-keys, e.g., getFormData('foo[bar][baz]') and top level key (`foo`) exists in REQUEST.
        // Extract these as sub-keys and access REQUEST as a multi-dimensional array, e.g., $_REQUEST[foo][bar][baz].
        $leaf = $_REQUEST[strtok($key, '[')];
        foreach ($matches[1] as $subkey) {
            if (is_array($leaf) && isset($leaf[$subkey])) {
                $leaf = $leaf[$subkey];
            } else {
                $leaf = null;
            }
        }
        return $leaf;
    } else {
        return $default;
    }
}

function getPost($key=null, $default=null)
{
    $app =& App::getInstance();

    if (null === $key) {
        return dispelMagicQuotes($_POST, $app->getParam('always_dispel_magicquotes'));
    }
    if (isset($_POST[$key])) {
        return dispelMagicQuotes($_POST[$key], $app->getParam('always_dispel_magicquotes'));
    } else {
        return $default;
    }
}

function getGet($key=null, $default=null)
{
    $app =& App::getInstance();

    if (null === $key) {
        return dispelMagicQuotes($_GET, $app->getParam('always_dispel_magicquotes'));
    }
    if (isset($_GET[$key])) {
        return dispelMagicQuotes($_GET[$key], $app->getParam('always_dispel_magicquotes'));
    } else {
        return $default;
    }
}

/*
* Sets a $_GET or $_POST variable.
*
* @access   public
* @param    string  $key    The key of the request array to set.
* @param    mixed   $val    The value to save in the request array.
* @return   void
* @author   Quinn Comendant <quinn@strangecode.com>
* @version  1.0
* @since    01 Nov 2009 12:25:29
*/
function putFormData($key, $val)
{
    switch (strtoupper(getenv('REQUEST_METHOD'))) {
    case 'POST':
        $_POST[$key] = $val;
        break;

    case 'GET':
        $_GET[$key] = $val;
        break;
    }

    $_REQUEST[$key] = $val;
}

/*
* Generates a base-65-encoded sha512 hash of $string truncated to $length.
*
* @access   public
* @param    string  $string Input string to hash.
* @param    int     $length Length of output hash string.
* @return   string          String of hash.
* @author   Quinn Comendant <quinn@strangecode.com>
* @version  1.0
* @since    03 Apr 2016 19:48:49
*/
function hash64($string, $length=18)
{
    $app =& App::getInstance();

    return mb_substr(preg_replace('/[^\w]/' . $app->getParam('preg_u'), '', base64_encode(hash('sha512', $string, true))), 0, $length);
}

/**
 * Signs a value using md5 and a simple text key. In order for this
 * function to be useful (i.e. secure) the salt must be kept secret, which
 * means keeping it as safe as database credentials. Putting it into an
 * environment variable set in httpd.conf is a good place.
 *
 * @access  public
 * @param   string  $val    The string to sign.
 * @param   string  $salt   (Optional) A text key to use for computing the signature.
 * @param   string  $length (Optional) The length of the added signature. Longer signatures are safer. Must match the length passed to verifySignature() for the signatures to match.
 * @return  string  The original value with a signature appended.
 */
function addSignature($val, $salt=null, $length=18)
{
    $app =& App::getInstance();

    if ('' == trim($val)) {
        $app->logMsg(sprintf('Cannot add signature to an empty string.', null), LOG_INFO, __FILE__, __LINE__);
        return '';
    }

    if (!isset($salt)) {
        $salt = $app->getParam('signing_key');
    }

    switch ($app->getParam('signing_method')) {
    case 'sha512+base64':
        return $val . '-' . mb_substr(preg_replace('/[^\w]/' . $app->getParam('preg_u'), '', base64_encode(hash('sha512', $val . $salt, true))), 0, $length);

    case 'md5':
    default:
        return $val . '-' . mb_strtolower(mb_substr(md5($salt . md5($val . $salt)), 0, $length));
    }
}

/**
 * Strips off the signature appended by addSignature().
 *
 * @access  public
 * @param   string  $signed_val     The string to sign.
 * @return  string  The original value with a signature removed.
 */
function removeSignature($signed_val)
{
    if (empty($signed_val) || mb_strpos($signed_val, '-') === false) {
        return '';
    }
    return mb_substr($signed_val, 0, mb_strrpos($signed_val, '-'));
}

/**
 * Verifies a signature appended to a value by addSignature().
 *
 * @access  public
 * @param   string  $signed_val A value with appended signature.
 * @param   string  $salt       (Optional) A text key to use for computing the signature.
 * @param   string  $length (Optional) The length of the added signature.
 * @return  bool    True if the signature matches the var.
 */
function verifySignature($signed_val, $salt=null, $length=18)
{
    // Strip the value from the signed value.
    $val = removeSignature($signed_val);
    // If the signed value matches the original signed value we consider the value safe.
    if ('' != $signed_val && $signed_val == addSignature($val, $salt, $length)) {
        // Signature verified.
        return true;
    } else {
        $app =& App::getInstance();
        $app->logMsg(sprintf('Failed signature (%s should be %s)', $signed_val, addSignature($val, $salt, $length)), LOG_DEBUG, __FILE__, __LINE__);
        return false;
    }
}

/**
 * Sends empty output to the browser and flushes the php buffer so the client
 * will see data before the page is finished processing.
 */
function flushBuffer()
{
    echo str_repeat('          ', 205);
    flush();
}

/**
 * A stub for apps that still use this function.
 *
 * @access  public
 * @return  void
 */
function mailmanAddMember($email, $list, $send_welcome_message=false)
{
    $app =& App::getInstance();
    $app->logMsg(sprintf('mailmanAddMember called and ignored: %s, %s, %s', $email, $list, $send_welcome_message), LOG_WARNING, __FILE__, __LINE__);
}

/**
 * A stub for apps that still use this function.
 *
 * @access  public
 * @return  void
 */
function mailmanRemoveMember($email, $list, $send_user_ack=false)
{
    $app =& App::getInstance();
    $app->logMsg(sprintf('mailmanRemoveMember called and ignored: %s, %s, %s', $email, $list, $send_user_ack), LOG_WARNING, __FILE__, __LINE__);
}

/*
* Returns the remote IP address, taking into consideration proxy servers.
*
* If strict checking is enabled, we will only trust REMOTE_ADDR or an HTTP header
* value if REMOTE_ADDR is a trusted proxy (configured as an array in $cfg['trusted_proxies']).
*
* @access   public
* @param    bool $dolookup            Resolve to IP to a hostname?
* @param    bool $trust_all_proxies   Should we trust any IP address set in HTTP_* variables? Set to FALSE for secure usage.
* @return   mixed Canonicalized IP address (or a corresponding hostname if $dolookup is true), or false if no IP was found.
* @author   Alix Axel <http://stackoverflow.com/a/2031935/277303>
* @author   Corey Ballou <http://blackbe.lt/advanced-method-to-obtain-the-client-ip-in-php/>
* @author   Quinn Comendant <quinn@strangecode.com>
* @version  1.0
* @since    12 Sep 2014 19:07:46
*/
function getRemoteAddr($dolookup=false, $trust_all_proxies=true)
{
    global $cfg;

    if (!isset($_SERVER['REMOTE_ADDR'])) {
        // In some cases this won't be set, e.g., CLI scripts.
        return null;
    }

    // Use an HTTP header value only if $trust_all_proxies is true or when REMOTE_ADDR is in our $cfg['trusted_proxies'] array.
    // $cfg['trusted_proxies'] is an array of proxy server addresses we expect to see in REMOTE_ADDR.
    if ($trust_all_proxies || isset($cfg['trusted_proxies']) && is_array($cfg['trusted_proxies']) && in_array($_SERVER['REMOTE_ADDR'], $cfg['trusted_proxies'], true)) {
        // Then it's probably safe to use an IP address value set in an HTTP header.
        // Loop through possible IP address headers from those most likely to contain the correct value first.
        // HTTP_CLIENT_IP: set by Apache Module mod_remoteip
        // HTTP_REAL_IP: set by Nginx Module ngx_http_realip_module
        // HTTP_CF_CONNECTING_IP: set by Cloudflare proxy
        // HTTP_X_FORWARDED_FOR: defacto standard for web proxies
        foreach (array('HTTP_CLIENT_IP', 'HTTP_REAL_IP', 'HTTP_CF_CONNECTING_IP', 'HTTP_X_FORWARDED_FOR', 'HTTP_X_FORWARDED', 'HTTP_X_CLUSTER_CLIENT_IP', 'HTTP_FORWARDED_FOR', 'HTTP_FORWARDED') as $key) {
            // Loop through and if
            if (array_key_exists($key, $_SERVER)) {
                foreach (explode(',', $_SERVER[$key]) as $addr) {
                    // Strip non-address data to avoid "PHP Warning:  inet_pton(): Unrecognized address for=189.211.197.173 in ./Utilities.inc.php on line 1293"
                    $addr = preg_replace('/[^=]=/', '', $addr);
                    $addr = canonicalIPAddr(trim($addr));
                    if (false !== filter_var($addr, FILTER_VALIDATE_IP, FILTER_FLAG_IPV6 | FILTER_FLAG_IPV4 | FILTER_FLAG_NO_PRIV_RANGE | FILTER_FLAG_NO_RES_RANGE)) {
                        return $dolookup && '' != $addr ? gethostbyaddr($addr) : $addr;
                    }
                }
            }
        }
    }

    $addr = canonicalIPAddr(trim($_SERVER['REMOTE_ADDR']));
    return $dolookup && $addr ? gethostbyaddr($addr) : $addr;
}

/*
* Converts an ipv4 IP address in hexadecimal form into canonical form (i.e., it removes the prefix).
*
* @access   public
* @param    string  $addr   IP address.
* @return   string          Canonical IP address.
* @author   Sander Steffann <http://stackoverflow.com/a/12436099/277303>
* @author   Quinn Comendant <quinn@strangecode.com>
* @version  1.0
* @since    15 Sep 2012
*/
function canonicalIPAddr($addr)
{
    if (!preg_match('/^([0-9a-f:]+|[0-9.])$/', $addr)) {
        // Definitely not an IPv6 or IPv4 address.
        return $addr;
    }

    // Known prefix
    $v4mapped_prefix_bin = pack('H*', '00000000000000000000ffff');

    // Parse
    $addr_bin = inet_pton($addr);

    // Check prefix
    if (substr($addr_bin, 0, strlen($v4mapped_prefix_bin)) == $v4mapped_prefix_bin) {
        // Strip prefix
        $addr_bin = substr($addr_bin, strlen($v4mapped_prefix_bin));
    }

    // Convert back to printable address in canonical form
    return inet_ntop($addr_bin);
}

/**
 * Tests whether a given IP address can be found in an array of IP address networks.
 * Elements of networks array can be single IP addresses or an IP address range in CIDR notation
 * See: http://en.wikipedia.org/wiki/Classless_inter-domain_routing
 *
 * @access  public
 * @param   string  IP address to search for.
 * @param   array   Array of networks to search within.
 * @return  mixed   Returns the network that matched on success, false on failure.
 */
function ipInRange($addr, $networks)
{
    if (!is_array($networks)) {
        $networks = array($networks);
    }

    $addr_binary = sprintf('%032b', ip2long($addr));
    foreach ($networks as $network) {
        if (mb_strpos($network, '/') !== false) {
            // IP is in CIDR notation.
            list($cidr_ip, $cidr_bitmask) = explode('/', $network);
            $cidr_ip_binary = sprintf('%032b', ip2long($cidr_ip));
            if (mb_substr($addr_binary, 0, $cidr_bitmask) === mb_substr($cidr_ip_binary, 0, $cidr_bitmask)) {
               // IP address is within the specified IP range.
               return $network;
            }
        } else {
            if ($addr === $network) {
               // IP address exactly matches.
               return $network;
            }
        }
    }

    return false;
}

/**
 * If the given $url is on the same web site, return true. This can be used to
 * prevent from sending sensitive info in a get query (like the SID) to another
 * domain.
 *
 * @param  string $url    the URI to test.
 * @return bool True if given $url is our domain or has no domain (is a relative url), false if it's another.
 */
function isMyDomain($url)
{
    static $urls = array();

    if (!isset($urls[$url])) {
        if (!preg_match('!^https?://!i', $url)) {
            // If we can't find a domain we assume the URL is local (i.e. "/my/url/path/" or "../img/file.jpg").
            $urls[$url] = true;
        } else {
            $urls[$url] = preg_match('!^https?://' . preg_quote(getenv('HTTP_HOST'), '!') . '!i', $url);
        }
    }
    return $urls[$url];
}

/**
 * Takes a URL and returns it without the query or anchor portion
 *
 * @param  string $url   any kind of URI
 * @return string        the URI with ? or # and everything after removed
 */
function stripQuery($url)
{
    $app =& App::getInstance();

    return preg_replace('/[?#].*$/' . $app->getParam('preg_u'), '', $url);
}

/*
* Merge query arguments into a URL.
* Usage:
* Add ?lang=it or replace an existing ?lang= argument:
* $url = urlMerge('https://example.com/?lang=en', ['lang' => 'it']).
*
* @access   public
* @param    string  $url        Original URL.
* @param    array   $new_args   New/modified query arguments.
* @return   string              Modified URL.
* @author   Quinn Comendant <quinn@strangecode.com>
* @since    20 Feb 2021 21:21:53
*/
function urlMergeQuery($url, Array $new_args)
{
    $u = parse_url($url);
    if (isset($u['query']) && '' != $u['query']) {
        parse_str($u['query'], $args);
    } else {
        $args = [];
    }
    $u['query'] = http_build_query(array_merge($args, $new_args));
    return sprintf('%s%s%s%s%s',
        (isset($u['scheme'])    && '' != $u['scheme']   ? $u['scheme'] . '://' : ''),
        (isset($u['host'])      && '' != $u['host']     ? $u['host']           : ''),
        (isset($u['path'])      && '' != $u['path']     ? $u['path']           : '/'),
        (isset($u['query'])     && '' != $u['query']    ? '?' . $u['query']    : ''),
        (isset($u['fragment'])  && '' != $u['fragment'] ? '#' . $u['fragment'] : '')
    );
}

/**
 * Returns a fully qualified URL to the current script, including the query. If you don't need the scheme://, use REQUEST_URI instead.
 *
 * @return string    a full url to the current script
 */
function absoluteMe()
{
    $app =& App::getInstance();

    $safe_http_host = preg_replace('/[^a-z\d.:-]/' . $app->getParam('preg_u'), '', getenv('HTTP_HOST'));
    return sprintf('%s://%s%s', (getenv('HTTPS') ? 'https' : 'http'), $safe_http_host, getenv('REQUEST_URI'));
}

/**
 * Compares the current url with the referring url.
 *
 * @param  bool $exclude_query  Remove the query string first before comparing.
 * @return bool                 True if the current URL is the same as the referring URL, false otherwise.
 */
function refererIsMe($exclude_query=false)
{
    $current_url = absoluteMe();
    $referrer_url = getenv('HTTP_REFERER');

    // If one of the hostnames is an IP address, compare only the path of both.
    if (preg_match('/\d{1,3}\.\d{1,3}\.\d{1,3}\.\d{1,3}/', parse_url($current_url, PHP_URL_HOST)) || preg_match('/\d{1,3}\.\d{1,3}\.\d{1,3}\.\d{1,3}/', parse_url($referrer_url, PHP_URL_HOST))) {
        $current_url = preg_replace('@^https?://[^/]+@u', '', $current_url);
        $referrer_url = preg_replace('@^https?://[^/]+@u', '', $referrer_url);
    }

    if ($exclude_query) {
        return (stripQuery($current_url) == stripQuery($referrer_url));
    } else {
        $app =& App::getInstance();
        $app->logMsg(sprintf('refererIsMe comparison: %s == %s', $current_url, $referrer_url), LOG_DEBUG, __FILE__, __LINE__);
        return ($current_url == $referrer_url);
    }
}

/*
* Returns true if the given URL resolves to a resource with a HTTP 2xx or 3xx header response.
* The download will abort if it retrieves >= 10KB of data to avoid downloading large files.
* We couldn't use CURLOPT_NOBODY (a HEAD request) because some services don't behave without a GET request (ahem, BBC).
* This function may not be very portable, if the server doesn't support CURLOPT_PROGRESSFUNCTION.
*
* @access   public
* @param    string  $url     URL to a file.
* @param    int     $timeout The maximum number of seconds to allow the HTTP query to execute.
* @return   bool             True if the resource exists, false otherwise.
* @author   Quinn Comendant <quinn@strangecode.com>
* @version  2.0
* @since    02 May 2015 15:10:09
*/
function httpExists($url, $timeout=5)
{
    $ch = curl_init($url);
    curl_setopt($ch, CURLOPT_TIMEOUT, $timeout);
    curl_setopt($ch, CURLOPT_IPRESOLVE, CURL_IPRESOLVE_V4);
    curl_setopt($ch, CURLOPT_FOLLOWLOCATION, true);
    curl_setopt($ch, CURLOPT_SSL_VERIFYPEER, true);
    curl_setopt($ch, CURLOPT_USERAGENT, "Mozilla/5.0 (Macintosh; Intel Mac OS X 10_12_5) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/58.0.3029.110 Safari/537.36");
    curl_setopt($ch, CURLOPT_RETURNTRANSFER, true); // Don't pass through data to the browser.
    curl_setopt($ch, CURLOPT_BUFFERSIZE, 128); // Frequent progress function calls.
    curl_setopt($ch, CURLOPT_NOPROGRESS, false); // Required to use CURLOPT_PROGRESSFUNCTION.
    // Function arguments for CURLOPT_PROGRESSFUNCTION changed with php 5.5.0.
    if (version_compare(PHP_VERSION, '5.5.0', '>=')) {
        curl_setopt($ch, CURLOPT_PROGRESSFUNCTION, function($ch, $dltot, $dlcur, $ultot, $ulcur){
            // Return a non-zero value to abort the transfer. In which case, the transfer will set a CURLE_ABORTED_BY_CALLBACK error
            // 10KB should be enough to catch a few 302 redirect headers and get to the actual content.
            return ($dlcur > 10*1024) ? 1 : 0;
        });
    } else {
        curl_setopt($ch, CURLOPT_PROGRESSFUNCTION, function($dltot, $dlcur, $ultot, $ulcur){
            // Return a non-zero value to abort the transfer. In which case, the transfer will set a CURLE_ABORTED_BY_CALLBACK error
            // 10KB should be enough to catch a few 302 redirect headers and get to the actual content.
            return ($dlcur > 10*1024) ? 1 : 0;
        });
    }
    curl_exec($ch);
    $http_code = curl_getinfo($ch, CURLINFO_HTTP_CODE);
    return preg_match('/^[23]\d\d$/', $http_code);
}

/*
* Get a HTTP response header.
*
* @access   public
* @param    string  $url    URL to hit.
* @param    string  $key    Name of the header to return.
* @param    array   $valid_response_codes   Array of acceptable HTTP return codes.
* @return   string  Value of the http header.
* @author   Quinn Comendant <quinn@strangecode.com>
* @since    28 Oct 2020 20:00:36
*/
function getHttpHeader($url, $key, Array $valid_response_codes=[200])
{
    $headers = @get_headers($url, 1);

    if ($headers && preg_match(sprintf('/\b(%s)\b/', join('|', $valid_response_codes)), $headers[0])) {
        $headers = array_change_key_case($headers, CASE_LOWER);
        $key = strtolower($key);
        if (isset($headers[$key])) {
            return $headers[$key];
        }
    }

    return false;
}

/*
* Load JSON data from a file and return it as an array (as specified by the json_decode options passed below.)
*
* @access   public
* @param    string  $filename   Name of the file to load. Just exist in the include path.
* @param    bool    $assoc      When TRUE, returned objects will be converted into associative arrays.
* @param    int     $depth      Recursion depth.
* @param    const   $options    Bitmask of JSON_BIGINT_AS_STRING, JSON_INVALID_UTF8_IGNORE, JSON_INVALID_UTF8_SUBSTITUTE, JSON_OBJECT_AS_ARRAY, JSON_THROW_ON_ERROR.
* @return   array               Array of data from the file, or null if there was a problem.
* @author   Quinn Comendant <quinn@strangecode.com>
* @since    09 Oct 2019 21:32:47
*/
function jsonDecodeFile($filename, $assoc=true, $depth=512, $options=0)
{
    $app =& App::getInstance();

    if (false === ($resolved_filename = stream_resolve_include_path($filename))) {
        $app->logMsg(sprintf('JSON file "%s" not found in path "%s"', $filename, get_include_path()), LOG_ERR, __FILE__, __LINE__);
        return null;
    }

    if (!is_readable($resolved_filename)) {
        $app->logMsg(sprintf('JSON file is unreadable: %s', $resolved_filename), LOG_ERR, __FILE__, __LINE__);
        return null;
    }

    if (null === ($data = json_decode(file_get_contents($resolved_filename), $assoc, $depth, $options))) {
        $app->logMsg(sprintf('JSON is unparsable: %s', $resolved_filename), LOG_ERR, __FILE__, __LINE__);
        return null;
    }

    return $data;
}

/*
* Get IP address status from IP Intelligence. https://getipintel.net/free-proxy-vpn-tor-detection-api/#expected_output
*
* @access   public
* @param    string  $ip         IP address to check.
* @param    float   $threshold  Return true if the IP score is above this threshold (0-1).
* @param    string  $email      Requester email address.
* @return   boolean             True if the IP address appears to be a robot, proxy, or VPN.
*                               False if the IP address is a residential or business IP address, or the API failed to return a valid response.
* @author   Quinn Comendant <quinn@strangecode.com>
* @since    26 Oct 2019 15:39:17
*/
function IPIntelligenceBadIP($ip, $threshold=0.95, $email='hello@strangecode.com')
{
    $app =& App::getInstance();

    $ch = curl_init(sprintf('http://check.getipintel.net/check.php?ip=%s&contact=%s', urlencode($ip), urlencode($email)));
    curl_setopt($ch, CURLOPT_TIMEOUT, 2);
    curl_setopt($ch, CURLOPT_RETURNTRANSFER, true);
    $response = curl_exec($ch);
    $errorno = curl_errno($ch);
    $error = curl_error($ch);
    $http_code = curl_getinfo($ch, CURLINFO_HTTP_CODE);
    curl_close($ch);

    if ($errorno == CURLE_OPERATION_TIMEOUTED) {
        $http_code = 408;
    }

    switch ($http_code) {
    case 200:
    case 400:
        // Check response value, below.
        break;

    case 408:
        $app->logMsg(sprintf('IP Intelligence timeout', null), LOG_WARNING, __FILE__, __LINE__);
        return false;
    case 429:
        $app->logMsg(sprintf('IP Intelligence number of allowed queries exceeded (rate limit 15 requests/minute)', null), LOG_WARNING, __FILE__, __LINE__);
        return false;
    default:
        $app->logMsg(sprintf('IP Intelligence unexpected response (%s): %s: %s', $http_code, $error, $response), LOG_ERR, __FILE__, __LINE__);
        return false;
    }

    switch ($response) {
    case -1:
        $app->logMsg('IP Intelligence: Invalid no input', LOG_WARNING, __FILE__, __LINE__);
        return false;
    case -2:
        $app->logMsg('IP Intelligence: Invalid IP address', LOG_WARNING, __FILE__, __LINE__);
        return false;
    case -3:
        $app->logMsg('IP Intelligence: Unroutable or private address', LOG_WARNING, __FILE__, __LINE__);
        return false;
    case -4:
        $app->logMsg('IP Intelligence: Unable to reach database', LOG_WARNING, __FILE__, __LINE__);
        return false;
    case -5:
        $app->logMsg('IP Intelligence: Banned: exceeded query limits, no permission, or invalid email address', LOG_WARNING, __FILE__, __LINE__);
        return false;
    case -6:
        $app->logMsg('IP Intelligence: Invalid contact information', LOG_WARNING, __FILE__, __LINE__);
        return false;
    default:
        if (!is_numeric($response) || $response < 0) {
            $app->logMsg(sprintf('IP Intelligence: Unknown status for IP (%s): %s', $response, $ip), LOG_NOTICE, __FILE__, __LINE__);
            return false;
        }
        if ($response >= $threshold) {
            $app->logMsg(sprintf('IP Intelligence: Bad IP (%s): %s', $response, $ip), LOG_NOTICE, __FILE__, __LINE__);
            return true;
        }
        $app->logMsg(sprintf('IP Intelligence: Good IP (%s): %s', $response, $ip), LOG_NOTICE, __FILE__, __LINE__);
        return false;
    }
}

/*
* Test if a string is valid json.
* https://stackoverflow.com/questions/6041741/fastest-way-to-check-if-a-string-is-json-in-php
*
* @access   public
* @param    string  $str  The string to test.
* @return   boolean       True if the string is valid json.
* @author   Quinn Comendant <quinn@strangecode.com>
* @since    06 Dec 2020 18:41:51
*/
function isJSON($str)
{
    json_decode($str);
    return (json_last_error() === JSON_ERROR_NONE);
}