+ setlocale(LC_ALL, $locales);
+}
+
+/**
+ * Build a Generator object representing the cartesian product from given $items.
+ *
+ * Example:
+ * [['a'], ['b', 'c']]
+ * will generate:
+ * [
+ * ['a', 'b'],
+ * ['a', 'c'],
+ * ]
+ *
+ * @param array $items array of array of string
+ *
+ * @return Generator representing the cartesian product of given array.
+ *
+ * @see https://en.wikipedia.org/wiki/Cartesian_product
+ */
+function cartesian_product_generator($items)
+{
+ if (empty($items)) {
+ yield [];
+ }
+ $subArray = array_pop($items);
+ if (empty($subArray)) {
+ return;
+ }
+ foreach (cartesian_product_generator($items) as $item) {
+ foreach ($subArray as $value) {
+ yield $item + [count($item) => $value];
+ }
+ }
+}
+
+/**
+ * Generates a default API secret.
+ *
+ * Note that the random-ish methods used in this function are predictable,
+ * which makes them NOT suitable for crypto.
+ * BUT the random string is salted with the salt and hashed with the username.
+ * It makes the generated API secret secured enough for Shaarli.
+ *
+ * PHP 7 provides random_int(), designed for cryptography.
+ * More info: http://stackoverflow.com/questions/4356289/php-random-string-generator
+
+ * @param string $username Shaarli login username
+ * @param string $salt Shaarli password hash salt
+ *
+ * @return string|bool Generated API secret, 12 char length.
+ * Or false if invalid parameters are provided (which will make the API unusable).
+ */
+function generate_api_secret($username, $salt)
+{
+ if (empty($username) || empty($salt)) {
+ return false;
+ }
+
+ return str_shuffle(substr(hash_hmac('sha512', uniqid($salt), $username), 10, 12));
+}
+
+/**
+ * Trim string, replace sequences of whitespaces by a single space.
+ * PHP equivalent to `normalize-space` XSLT function.
+ *
+ * @param string $string Input string.
+ *
+ * @return mixed Normalized string.
+ */
+function normalize_spaces($string)
+{
+ return preg_replace('/\s{2,}/', ' ', trim($string));
+}
+
+/**
+ * Format the date according to the locale.
+ *
+ * Requires php-intl to display international datetimes,
+ * otherwise default format '%c' will be returned.
+ *
+ * @param DateTime $date to format.
+ * @param bool $time Displays time if true.
+ * @param bool $intl Use international format if true.
+ *
+ * @return bool|string Formatted date, or false if the input is invalid.
+ */
+function format_date($date, $time = true, $intl = true)
+{
+ if (! $date instanceof DateTime) {
+ return false;
+ }
+
+ if (! $intl || ! class_exists('IntlDateFormatter')) {
+ $format = $time ? '%c' : '%x';
+ return strftime($format, $date->getTimestamp());
+ }
+
+ $formatter = new IntlDateFormatter(
+ setlocale(LC_TIME, 0),
+ IntlDateFormatter::LONG,
+ $time ? IntlDateFormatter::LONG : IntlDateFormatter::NONE
+ );
+
+ return $formatter->format($date);
+}
+
+/**
+ * Check if the input is an integer, no matter its real type.
+ *
+ * PHP is a bit messy regarding this:
+ * - is_int returns false if the input is a string
+ * - ctype_digit returns false if the input is an integer or negative
+ *
+ * @param mixed $input value
+ *
+ * @return bool true if the input is an integer, false otherwise
+ */
+function is_integer_mixed($input)
+{
+ if (is_array($input) || is_bool($input) || is_object($input)) {
+ return false;
+ }
+ $input = strval($input);
+ return ctype_digit($input) || (startsWith($input, '-') && ctype_digit(substr($input, 1)));
+}
+
+/**
+ * Convert post_max_size/upload_max_filesize (e.g. '16M') parameters to bytes.
+ *
+ * @param string $val Size expressed in string.
+ *
+ * @return int Size expressed in bytes.
+ */
+function return_bytes($val)
+{
+ if (is_integer_mixed($val) || $val === '0' || empty($val)) {
+ return $val;
+ }
+ $val = trim($val);
+ $last = strtolower($val[strlen($val)-1]);
+ $val = intval(substr($val, 0, -1));
+ switch($last) {
+ case 'g': $val *= 1024;
+ case 'm': $val *= 1024;
+ case 'k': $val *= 1024;
+ }
+ return $val;
+}
+
+/**
+ * Return a human readable size from bytes.
+ *
+ * @param int $bytes value
+ *
+ * @return string Human readable size
+ */
+function human_bytes($bytes)
+{
+ if ($bytes === '') {
+ return t('Setting not set');
+ }
+ if (! is_integer_mixed($bytes)) {
+ return $bytes;
+ }
+ $bytes = intval($bytes);
+ if ($bytes === 0) {
+ return t('Unlimited');
+ }
+
+ $units = [t('B'), t('kiB'), t('MiB'), t('GiB')];
+ for ($i = 0; $i < count($units) && $bytes >= 1024; ++$i) {
+ $bytes /= 1024;
+ }
+
+ return round($bytes) . $units[$i];
+}
+
+/**
+ * Try to determine max file size for uploads (POST).
+ * Returns an integer (in bytes) or formatted depending on $format.
+ *
+ * @param mixed $limitPost post_max_size PHP setting
+ * @param mixed $limitUpload upload_max_filesize PHP setting
+ * @param bool $format Format max upload size to human readable size
+ *
+ * @return int|string max upload file size
+ */
+function get_max_upload_size($limitPost, $limitUpload, $format = true)
+{
+ $size1 = return_bytes($limitPost);
+ $size2 = return_bytes($limitUpload);
+ // Return the smaller of two:
+ $maxsize = min($size1, $size2);
+ return $format ? human_bytes($maxsize) : $maxsize;
+}
+
+/**
+ * Sort the given array alphabetically using php-intl if available.
+ * Case sensitive.
+ *
+ * Note: doesn't support multidimensional arrays
+ *
+ * @param array $data Input array, passed by reference
+ * @param bool $reverse Reverse sort if set to true
+ * @param bool $byKeys Sort the array by keys if set to true, by value otherwise.
+ */
+function alphabetical_sort(&$data, $reverse = false, $byKeys = false)
+{
+ $callback = function ($a, $b) use ($reverse) {
+ // Collator is part of PHP intl.
+ if (class_exists('Collator')) {
+ $collator = new Collator(setlocale(LC_COLLATE, 0));
+ if (!intl_is_failure(intl_get_error_code())) {
+ return $collator->compare($a, $b) * ($reverse ? -1 : 1);
+ }
+ }
+
+ return strcasecmp($a, $b) * ($reverse ? -1 : 1);
+ };
+
+ if ($byKeys) {
+ uksort($data, $callback);
+ } else {
+ usort($data, $callback);
+ }
+}
+
+/**
+ * Wrapper function for translation which match the API
+ * of gettext()/_() and ngettext().
+ *
+ * @param string $text Text to translate.
+ * @param string $nText The plural message ID.
+ * @param int $nb The number of items for plural forms.
+ * @param string $domain The domain where the translation is stored (default: shaarli).
+ *
+ * @return string Text translated.
+ */
+function t($text, $nText = '', $nb = 1, $domain = 'shaarli') {
+ return dn__($domain, $text, $nText, $nb);