class CountryManager

class CountryManager implements CountryManagerInterface {
    
    /**
     * The module handler service.
     *
     * @var \Drupal\Core\Extension\ModuleHandlerInterface
     */
    protected $moduleHandler;
    
    /**
     * An array of country code => country name pairs.
     */
    protected $countries;
    
    /**
     * Constructor.
     *
     * @param \Drupal\Core\Extension\ModuleHandlerInterface $module_handler
     */
    public function __construct(ModuleHandlerInterface $module_handler) {
        $this->moduleHandler = $module_handler;
    }
    
    /**
     * Get an array of all two-letter country code => country name pairs.
     *
     * @return array
     *   An array of country code => country name pairs.
     */
    public static function getStandardList() {
        $countries = [
            'AC' => t('Ascension Island'),
            'AD' => t('Andorra'),
            'AE' => t('United Arab Emirates'),
            'AF' => t('Afghanistan'),
            'AG' => t('Antigua & Barbuda'),
            'AI' => t('Anguilla'),
            'AL' => t('Albania'),
            'AM' => t('Armenia'),
            'AN' => t('Netherlands Antilles'),
            'AO' => t('Angola'),
            'AQ' => t('Antarctica'),
            'AR' => t('Argentina'),
            'AS' => t('American Samoa'),
            'AT' => t('Austria'),
            'AU' => t('Australia'),
            'AW' => t('Aruba'),
            'AX' => t('Åland Islands'),
            'AZ' => t('Azerbaijan'),
            'BA' => t('Bosnia & Herzegovina'),
            'BB' => t('Barbados'),
            'BD' => t('Bangladesh'),
            'BE' => t('Belgium'),
            'BF' => t('Burkina Faso'),
            'BG' => t('Bulgaria'),
            'BH' => t('Bahrain'),
            'BI' => t('Burundi'),
            'BJ' => t('Benin'),
            'BL' => t('St. Barthélemy'),
            'BM' => t('Bermuda'),
            'BN' => t('Brunei'),
            'BO' => t('Bolivia'),
            'BQ' => t('Caribbean Netherlands'),
            'BR' => t('Brazil'),
            'BS' => t('Bahamas'),
            'BT' => t('Bhutan'),
            'BV' => t('Bouvet Island'),
            'BW' => t('Botswana'),
            'BY' => t('Belarus'),
            'BZ' => t('Belize'),
            'CA' => t('Canada'),
            'CC' => t('Cocos (Keeling) Islands'),
            'CD' => t('Congo - Kinshasa'),
            'CF' => t('Central African Republic'),
            'CG' => t('Congo - Brazzaville'),
            'CH' => t('Switzerland'),
            'CI' => t('Côte d’Ivoire'),
            'CK' => t('Cook Islands'),
            'CL' => t('Chile'),
            'CM' => t('Cameroon'),
            'CN' => t('China'),
            'CO' => t('Colombia'),
            'CP' => t('Clipperton Island'),
            'CR' => t('Costa Rica'),
            'CU' => t('Cuba'),
            'CV' => t('Cape Verde'),
            'CW' => t('Curaçao'),
            'CX' => t('Christmas Island'),
            'CY' => t('Cyprus'),
            'CZ' => t('Czechia'),
            'DE' => t('Germany'),
            'DG' => t('Diego Garcia'),
            'DJ' => t('Djibouti'),
            'DK' => t('Denmark'),
            'DM' => t('Dominica'),
            'DO' => t('Dominican Republic'),
            'DZ' => t('Algeria'),
            'EA' => t('Ceuta & Melilla'),
            'EC' => t('Ecuador'),
            'EE' => t('Estonia'),
            'EG' => t('Egypt'),
            'EH' => t('Western Sahara'),
            'ER' => t('Eritrea'),
            'ES' => t('Spain'),
            'ET' => t('Ethiopia'),
            'FI' => t('Finland'),
            'FJ' => t('Fiji'),
            'FK' => t('Falkland Islands'),
            'FM' => t('Micronesia'),
            'FO' => t('Faroe Islands'),
            'FR' => t('France'),
            'GA' => t('Gabon'),
            'GB' => t('United Kingdom'),
            'GD' => t('Grenada'),
            'GE' => t('Georgia'),
            'GF' => t('French Guiana'),
            'GG' => t('Guernsey'),
            'GH' => t('Ghana'),
            'GI' => t('Gibraltar'),
            'GL' => t('Greenland'),
            'GM' => t('Gambia'),
            'GN' => t('Guinea'),
            'GP' => t('Guadeloupe'),
            'GQ' => t('Equatorial Guinea'),
            'GR' => t('Greece'),
            'GS' => t('South Georgia & South Sandwich Islands'),
            'GT' => t('Guatemala'),
            'GU' => t('Guam'),
            'GW' => t('Guinea-Bissau'),
            'GY' => t('Guyana'),
            'HK' => t('Hong Kong SAR China'),
            'HM' => t('Heard & McDonald Islands'),
            'HN' => t('Honduras'),
            'HR' => t('Croatia'),
            'HT' => t('Haiti'),
            'HU' => t('Hungary'),
            'IC' => t('Canary Islands'),
            'ID' => t('Indonesia'),
            'IE' => t('Ireland'),
            'IL' => t('Israel'),
            'IM' => t('Isle of Man'),
            'IN' => t('India'),
            'IO' => t('British Indian Ocean Territory'),
            'IQ' => t('Iraq'),
            'IR' => t('Iran'),
            'IS' => t('Iceland'),
            'IT' => t('Italy'),
            'JE' => t('Jersey'),
            'JM' => t('Jamaica'),
            'JO' => t('Jordan'),
            'JP' => t('Japan'),
            'KE' => t('Kenya'),
            'KG' => t('Kyrgyzstan'),
            'KH' => t('Cambodia'),
            'KI' => t('Kiribati'),
            'KM' => t('Comoros'),
            'KN' => t('St. Kitts & Nevis'),
            'KP' => t('North Korea'),
            'KR' => t('South Korea'),
            'KW' => t('Kuwait'),
            'KY' => t('Cayman Islands'),
            'KZ' => t('Kazakhstan'),
            'LA' => t('Laos'),
            'LB' => t('Lebanon'),
            'LC' => t('St. Lucia'),
            'LI' => t('Liechtenstein'),
            'LK' => t('Sri Lanka'),
            'LR' => t('Liberia'),
            'LS' => t('Lesotho'),
            'LT' => t('Lithuania'),
            'LU' => t('Luxembourg'),
            'LV' => t('Latvia'),
            'LY' => t('Libya'),
            'MA' => t('Morocco'),
            'MC' => t('Monaco'),
            'MD' => t('Moldova'),
            'ME' => t('Montenegro'),
            'MF' => t('St. Martin'),
            'MG' => t('Madagascar'),
            'MH' => t('Marshall Islands'),
            'MK' => t('North Macedonia'),
            'ML' => t('Mali'),
            'MM' => t('Myanmar (Burma)'),
            'MN' => t('Mongolia'),
            'MO' => t('Macao SAR China'),
            'MP' => t('Northern Mariana Islands'),
            'MQ' => t('Martinique'),
            'MR' => t('Mauritania'),
            'MS' => t('Montserrat'),
            'MT' => t('Malta'),
            'MU' => t('Mauritius'),
            'MV' => t('Maldives'),
            'MW' => t('Malawi'),
            'MX' => t('Mexico'),
            'MY' => t('Malaysia'),
            'MZ' => t('Mozambique'),
            'NA' => t('Namibia'),
            'NC' => t('New Caledonia'),
            'NE' => t('Niger'),
            'NF' => t('Norfolk Island'),
            'NG' => t('Nigeria'),
            'NI' => t('Nicaragua'),
            'NL' => t('Netherlands'),
            'NO' => t('Norway'),
            'NP' => t('Nepal'),
            'NR' => t('Nauru'),
            'NU' => t('Niue'),
            'NZ' => t('New Zealand'),
            'OM' => t('Oman'),
            'PA' => t('Panama'),
            'PE' => t('Peru'),
            'PF' => t('French Polynesia'),
            'PG' => t('Papua New Guinea'),
            'PH' => t('Philippines'),
            'PK' => t('Pakistan'),
            'PL' => t('Poland'),
            'PM' => t('St. Pierre & Miquelon'),
            'PN' => t('Pitcairn Islands'),
            'PR' => t('Puerto Rico'),
            'PS' => t('Palestinian Territories'),
            'PT' => t('Portugal'),
            'PW' => t('Palau'),
            'PY' => t('Paraguay'),
            'QA' => t('Qatar'),
            'QO' => t('Outlying Oceania'),
            'RE' => t('Réunion'),
            'RO' => t('Romania'),
            'RS' => t('Serbia'),
            'RU' => t('Russia'),
            'RW' => t('Rwanda'),
            'SA' => t('Saudi Arabia'),
            'SB' => t('Solomon Islands'),
            'SC' => t('Seychelles'),
            'SD' => t('Sudan'),
            'SE' => t('Sweden'),
            'SG' => t('Singapore'),
            'SH' => t('St. Helena'),
            'SI' => t('Slovenia'),
            'SJ' => t('Svalbard & Jan Mayen'),
            'SK' => t('Slovakia'),
            'SL' => t('Sierra Leone'),
            'SM' => t('San Marino'),
            'SN' => t('Senegal'),
            'SO' => t('Somalia'),
            'SR' => t('Suriname'),
            'SS' => t('South Sudan'),
            'ST' => t('São Tomé & Príncipe'),
            'SV' => t('El Salvador'),
            'SX' => t('Sint Maarten'),
            'SY' => t('Syria'),
            'SZ' => t('Eswatini'),
            'TA' => t('Tristan da Cunha'),
            'TC' => t('Turks & Caicos Islands'),
            'TD' => t('Chad'),
            'TF' => t('French Southern Territories'),
            'TG' => t('Togo'),
            'TH' => t('Thailand'),
            'TJ' => t('Tajikistan'),
            'TK' => t('Tokelau'),
            'TL' => t('Timor-Leste'),
            'TM' => t('Turkmenistan'),
            'TN' => t('Tunisia'),
            'TO' => t('Tonga'),
            'TR' => t('Turkey'),
            'TT' => t('Trinidad & Tobago'),
            'TV' => t('Tuvalu'),
            'TW' => t('Taiwan'),
            'TZ' => t('Tanzania'),
            'UA' => t('Ukraine'),
            'UG' => t('Uganda'),
            'UM' => t('U.S. Outlying Islands'),
            'US' => t('United States'),
            'UY' => t('Uruguay'),
            'UZ' => t('Uzbekistan'),
            'VA' => t('Vatican City'),
            'VC' => t('St. Vincent & Grenadines'),
            'VE' => t('Venezuela'),
            'VG' => t('British Virgin Islands'),
            'VI' => t('U.S. Virgin Islands'),
            'VN' => t('Vietnam'),
            'VU' => t('Vanuatu'),
            'WF' => t('Wallis & Futuna'),
            'WS' => t('Samoa'),
            'XK' => t('Kosovo'),
            'YE' => t('Yemen'),
            'YT' => t('Mayotte'),
            'ZA' => t('South Africa'),
            'ZM' => t('Zambia'),
            'ZW' => t('Zimbabwe'),
        ];
        // Sort the list.
        natcasesort($countries);
        return $countries;
    }
    
    /**
     * Get an array of country code => country name pairs, altered by alter hooks.
     *
     * @return array
     *   An array of country code => country name pairs.
     *
     * @see \Drupal\Core\Locale\CountryManager::getStandardList()
     */
    public function getList() {
        // Populate the country list if it is not already populated.
        if (!isset($this->countries)) {
            $this->countries = static::getStandardList();
            $this->moduleHandler
                ->alter('countries', $this->countries);
        }
        return $this->countries;
    }

}