<?php
// XString.php
// Created: 2022-02-03
// Updated: 2023-01-05

namespace Index;

use InvalidArgumentException;

/**
 * Provides various helper methods for strings.
 */
final class XString {
    /**
     * Default character set for the random method.
     *
     * @var string
     */
    public const RANDOM_CHARS = 'AaBbCcDdEeFfGgHhIiJjKkLlMmNnOoPpQqRrSsTtUuVvWwXxYyZz0123456789';

    public static function toBool(string $value): bool {
        return boolval($value);
    }

    public static function toInt(string $value, int $base = 10): int {
        return $base === 10 ? (int)$value : intval($value, $base);
    }

    public static function toFloat(string $value): float {
        return (float)$value;
    }

    public static function escape(
        string $value,
        int $flags = ENT_COMPAT | ENT_HTML5,
        ?string $encoding = null,
        bool $doubleEncoding = true
    ): string {
        return htmlspecialchars($value, $flags, $encoding, $doubleEncoding);
    }

    /**
     * Check if a string is null or empty.
     *
     * @param IString|string|null $string String ot check for emptiness.
     * @return bool true if the string is empty, false if not.
     */
    public static function nullOrEmpty(IString|string|null $string): bool {
        if($string === null)
            return true;
        if($string instanceof IString)
            return $string->isEmpty();
        return empty($string);
    }

    /**
     * Check if a string is null or whitespace.
     *
     * @param IString|string|null $string String to check for whitespace.
     * @return bool true if the string is whitespace, false if not.
     */
    public static function nullOrWhitespace(IString|string|null $string): bool {
        if($string === null)
            return true;
        return empty(trim((string)$string));
    }

    /**
     * Generates a random string of user specified length.
     *
     * @param int $length Desired length of the string.
     * @param string $chars Set of characters to pick from. Default set contains the alphabet in upper- and lowercase and numbers 0 thru 9.
     * @return string The generated string.
     */
    public static function random(int $length, string $chars = self::RANDOM_CHARS): string {
        if($length < 1)
            throw new InvalidArgumentException('$length must be at least 1.');
        if($chars === '')
            throw new InvalidArgumentException('$chars may not be empty.');

        $string = '';
        $count = strlen($chars) - 1;

        while($length-- > 0)
            $string .= $chars[random_int(0, $count)];

        return $string;
    }
}