class Random

abstract class Random {
    
    /**
     * The random generator.
     */
    protected static RandomUtility $randomGenerator;
    
    /**
     * Gets the random generator for the utility methods.
     *
     * @return \Drupal\Component\Utility\Random
     *   The random generator.
     */
    public static function getGenerator() : RandomUtility {
        if (!isset(static::$randomGenerator)) {
            static::$randomGenerator = new RandomUtility();
        }
        return static::$randomGenerator;
    }
    
    /**
     * Generates a pseudo-random string of ASCII characters of codes 32 to 126.
     *
     * Do not use this method when special characters are not possible (e.g., in
     * machine or file names that have already been validated); instead, use
     * \Drupal\Tests\RandomGeneratorTrait::randomMachineName(). If $length is
     * greater than 3 the random string will include at least one ampersand ('&')
     * and at least one greater than ('>') character to ensure coverage for
     * special characters and avoid the introduction of random test failures.
     *
     * @param int $length
     *   Length of random string to generate.
     *
     * @return string
     *   Pseudo-randomly generated unique string including special characters.
     *
     * @see \Drupal\Component\Utility\Random::string()
     */
    public static function string(int $length = 8) : string {
        if ($length < 4) {
            return static::getGenerator()->string($length, TRUE, [
                static::class,
                'stringValidate',
            ]);
        }
        // To prevent the introduction of random test failures, ensure that the
        // returned string contains a character that needs to be escaped in HTML by
        // injecting an ampersand into it.
        $replacement_pos = intval($length / 2);
        // Remove 2 from the length to account for the ampersand and greater than
        // characters.
        $string = static::getGenerator()->string($length - 2, TRUE, [
            static::class,
            'stringValidate',
        ]);
        return substr_replace($string, '>&', $replacement_pos, 0);
    }
    
    /**
     * Callback for random string validation.
     *
     * @see \Drupal\Component\Utility\Random::string()
     *
     * @param string $string
     *   The random string to validate.
     *
     * @return bool
     *   TRUE if the random string is valid, FALSE if not.
     */
    public static function stringValidate(string $string) : bool {
        // Consecutive spaces causes issues for link validation.
        if (preg_match('/\\s{2,}/', $string)) {
            return FALSE;
        }
        // Starting or ending with a space means that length might not be what is
        // expected.
        if (preg_match('/^\\s|\\s$/', $string)) {
            return FALSE;
        }
        return TRUE;
    }
    
    /**
     * Generates a unique random string containing letters and numbers.
     *
     * Do not use this method when testing non validated user input. Instead, use
     * \Drupal\Tests\RandomGeneratorTrait::randomString().
     *
     * @param int $length
     *   Length of random string to generate.
     *
     * @return string
     *   Randomly generated unique string.
     *
     * @see \Drupal\Component\Utility\Random::name()
     */
    public static function machineName(int $length = 8) : string {
        return static::getGenerator()->machineName($length, TRUE);
    }
    
    /**
     * Generates a random PHP object.
     *
     * @param int $size
     *   The number of random keys to add to the object.
     *
     * @return object
     *   The generated object, with the specified number of random keys. Each key
     *   has a random string value.
     *
     * @see \Drupal\Component\Utility\Random::object()
     */
    public static function object(int $size = 4) : \stdClass {
        return static::getGenerator()->object($size);
    }

}