<?php
/**
 * Independent locale selection for the plugin interface.
 *
 * @package AIT_Multilingual_Translate
 */

if (!defined('ABSPATH')) {
    exit;
}

final class AITMT_Interface_Language
{
    const DOMAIN = 'ait-multilingual-translate';

    public static function bootstrap()
    {
        add_filter('plugin_locale', array(__CLASS__, 'filter_locale'), 10, 2);
        add_action('init', array(__CLASS__, 'load'), 0);
    }

    public static function choices()
    {
        return array(
            'auto' => __('Use WordPress language', 'ait-multilingual-translate'),
            'en_US' => __('English', 'ait-multilingual-translate'),
            'ru_RU' => __('Russian', 'ait-multilingual-translate'),
            'ka_GE' => __('Georgian', 'ait-multilingual-translate'),
        );
    }

    public static function sanitize($locale)
    {
        $locale = sanitize_text_field((string) $locale);
        return array_key_exists($locale, self::raw_choices()) ? $locale : 'auto';
    }

    public static function selected()
    {
        $options = get_option('aitmt_options', array());
        $options = is_array($options) ? $options : array();
        return self::sanitize(isset($options['interface_language']) ? $options['interface_language'] : 'auto');
    }

    public static function filter_locale($locale, $domain)
    {
        if (self::DOMAIN !== (string) $domain) {
            return $locale;
        }
        $selected = self::selected();
        return 'auto' === $selected ? $locale : $selected;
    }

    public static function load()
    {
        $selected = self::selected();
        if ('auto' === $selected || 'en_US' === $selected) {
            return;
        }

        $mofile = trailingslashit(AITMT_PLUGIN_DIR) . 'languages/' . self::DOMAIN . '-' . $selected . '.mo';
        if (!is_readable($mofile)) {
            return;
        }

        unload_textdomain(self::DOMAIN);
        load_textdomain(self::DOMAIN, $mofile);
    }

    public static function is_rtl()
    {
        $base = strtolower(substr(str_replace('-', '_', self::selected()), 0, 2));
        return in_array($base, array('ar', 'he', 'fa', 'ur'), true);
    }

    private static function raw_choices()
    {
        return array(
            'auto' => true,
            'en_US' => true,
            'ru_RU' => true,
            'ka_GE' => true,
        );
    }
}