class AsciiSlugger

class AsciiSlugger implements SluggerInterface, LocaleAwareInterface {
    private const LOCALE_TO_TRANSLITERATOR_ID = [
        'am' => 'Amharic-Latin',
        'ar' => 'Arabic-Latin',
        'az' => 'Azerbaijani-Latin',
        'be' => 'Belarusian-Latin',
        'bg' => 'Bulgarian-Latin',
        'bn' => 'Bengali-Latin',
        'de' => 'de-ASCII',
        'el' => 'Greek-Latin',
        'fa' => 'Persian-Latin',
        'he' => 'Hebrew-Latin',
        'hy' => 'Armenian-Latin',
        'ka' => 'Georgian-Latin',
        'kk' => 'Kazakh-Latin',
        'ky' => 'Kirghiz-Latin',
        'ko' => 'Korean-Latin',
        'mk' => 'Macedonian-Latin',
        'mn' => 'Mongolian-Latin',
        'or' => 'Oriya-Latin',
        'ps' => 'Pashto-Latin',
        'ru' => 'Russian-Latin',
        'sr' => 'Serbian-Latin',
        'sr_Cyrl' => 'Serbian-Latin',
        'th' => 'Thai-Latin',
        'tk' => 'Turkmen-Latin',
        'uk' => 'Ukrainian-Latin',
        'uz' => 'Uzbek-Latin',
        'zh' => 'Han-Latin',
    ];
    private \Closure|array $symbolsMap = [
        'en' => [
            '@' => 'at',
            '&' => 'and',
        ],
    ];
    private bool|string $emoji = false;
    
    /**
     * Cache of transliterators per locale.
     *
     * @var \Transliterator[]
     */
    private array $transliterators = [];
    public function __construct(?string $defaultLocale = null, array|\Closure|null $symbolsMap = null) {
        $this->symbolsMap = $symbolsMap ?? $this->symbolsMap;
    }
    public function setLocale(string $locale) : void {
        $this->defaultLocale = $locale;
    }
    public function getLocale() : string {
        return $this->defaultLocale;
    }
    
    /**
     * @param bool|string $emoji true will use the same locale,
     *                           false will disable emoji,
     *                           and a string to use a specific locale
     */
    public function withEmoji(bool|string $emoji = true) : static {
        if (false !== $emoji && !class_exists(EmojiTransliterator::class)) {
            throw new \LogicException(\sprintf('You cannot use the "%s()" method as the "symfony/emoji" package is not installed. Try running "composer require symfony/emoji".', __METHOD__));
        }
        $new = clone $this;
        $new->emoji = $emoji;
        return $new;
    }
    public function slug(string $string, string $separator = '-', ?string $locale = null) : AbstractUnicodeString {
        $locale ??= $this->defaultLocale;
        $transliterator = [];
        if ($locale && ('de' === $locale || str_starts_with($locale, 'de_'))) {
            // Use the shortcut for German in UnicodeString::ascii() if possible (faster and no requirement on intl)
            $transliterator = [
                'de-ASCII',
            ];
        }
        elseif (\function_exists('transliterator_transliterate') && $locale) {
            $transliterator = (array) $this->createTransliterator($locale);
        }
        if ($emojiTransliterator = $this->createEmojiTransliterator($locale)) {
            $transliterator[] = $emojiTransliterator;
        }
        if ($this->symbolsMap instanceof \Closure) {
            // If the symbols map is passed as a closure, there is no need to fallback to the parent locale
            // as the closure can just provide substitutions for all locales of interest.
            $symbolsMap = $this->symbolsMap;
            array_unshift($transliterator, static fn($s) => $symbolsMap($s, $locale));
        }
        $unicodeString = (new UnicodeString($string))->ascii($transliterator);
        if (\is_array($this->symbolsMap)) {
            $map = null;
            if (isset($this->symbolsMap[$locale])) {
                $map = $this->symbolsMap[$locale];
            }
            else {
                $parent = self::getParentLocale($locale);
                if ($parent && isset($this->symbolsMap[$parent])) {
                    $map = $this->symbolsMap[$parent];
                }
            }
            if ($map) {
                foreach ($map as $char => $replace) {
                    $unicodeString = $unicodeString->replace($char, ' ' . $replace . ' ');
                }
            }
        }
        return $unicodeString->replaceMatches('/[^A-Za-z0-9]++/', $separator)
            ->trim($separator);
    }
    private function createTransliterator(string $locale) : ?\Transliterator {
        if (\array_key_exists($locale, $this->transliterators)) {
            return $this->transliterators[$locale];
        }
        // Exact locale supported, cache and return
        if ($id = self::LOCALE_TO_TRANSLITERATOR_ID[$locale] ?? null) {
            return $this->transliterators[$locale] = \Transliterator::create($id . '/BGN') ?? \Transliterator::create($id);
        }
        // Locale not supported and no parent, fallback to any-latin
        if (!($parent = self::getParentLocale($locale))) {
            return $this->transliterators[$locale] = null;
        }
        // Try to use the parent locale (ie. try "de" for "de_AT") and cache both locales
        if ($id = self::LOCALE_TO_TRANSLITERATOR_ID[$parent] ?? null) {
            $transliterator = \Transliterator::create($id . '/BGN') ?? \Transliterator::create($id);
        }
        return $this->transliterators[$locale] = $this->transliterators[$parent] = $transliterator ?? null;
    }
    private function createEmojiTransliterator(?string $locale) : ?EmojiTransliterator {
        if (\is_string($this->emoji)) {
            $locale = $this->emoji;
        }
        elseif (!$this->emoji) {
            return null;
        }
        while (null !== $locale) {
            try {
                return EmojiTransliterator::create("emoji-{$locale}");
            } catch (\IntlException) {
                $locale = self::getParentLocale($locale);
            }
        }
        return null;
    }
    private static function getParentLocale(?string $locale) : ?string {
        if (!$locale) {
            return null;
        }
        if (false === ($str = strrchr($locale, '_'))) {
            // no parent locale
            return null;
        }
        return substr($locale, 0, -\strlen($str));
    }

}