<?php
/**
 * Copyright (c) Facebook, Inc. and its affiliates. All Rights Reserved
 *
 * This source code is licensed under the license found in the
 * LICENSE file in the root directory of this source tree.
 *
 * @package FacebookCommerce
 */

namespace SkyVerge\WooCommerce\Facebook;

defined( 'ABSPATH' ) or exit;

/**
 * Helper class with utility methods for handling locales in Facebook.
 *
 * @since 2.2.0
 */
class Locale {


	/** @var string default locale */
	const DEFAULT_LOCALE = 'en_US';


	/** @var string[] an array of supported locale identifiers */
	private static $supported_locales = array(
		'af_ZA',
		'ar_AR',
		'as_IN',
		'az_AZ',
		'be_BY',
		'bg_BG',
		'bn_IN',
		'br_FR',
		'bs_BA',
		'ca_ES',
		'cb_IQ',
		'co_FR',
		'cs_CZ',
		'cx_PH',
		'cy_GB',
		'da_DK',
		'de_DE',
		'el_GR',
		'en_GB',
		'en_US',
		'es_ES',
		'es_LA',
		'et_EE',
		'eu_ES',
		'fa_IR',
		'ff_NG',
		'fi_FI',
		'fo_FO',
		'fr_CA',
		'fr_FR',
		'fy_NL',
		'ga_IE',
		'gl_ES',
		'gn_PY',
		'gu_IN',
		'ha_NG',
		'he_IL',
		'hi_IN',
		'hr_HR',
		'hu_HU',
		'hy_AM',
		'id_ID',
		'is_IS',
		'it_IT',
		'ja_JP',
		'ja_KS',
		'jv_ID',
		'ka_GE',
		'kk_KZ',
		'km_KH',
		'kn_IN',
		'ko_KR',
		'ku_TR',
		'lt_LT',
		'lv_LV',
		'mg_MG',
		'mk_MK',
		'ml_IN',
		'mn_MN',
		'mr_IN',
		'ms_MY',
		'mt_MT',
		'my_MM',
		'nb_NO',
		'ne_NP',
		'nl_BE',
		'nl_NL',
		'nn_NO',
		'or_IN',
		'pa_IN',
		'pl_PL',
		'ps_AF',
		'pt_BR',
		'pt_PT',
		'qz_MM',
		'ro_RO',
		'ru_RU',
		'rw_RW',
		'sc_IT',
		'si_LK',
		'sk_SK',
		'sl_SI',
		'so_SO',
		'sq_AL',
		'sr_RS',
		'sv_SE',
		'sw_KE',
		'sz_PL',
		'ta_IN',
		'te_IN',
		'tg_TJ',
		'th_TH',
		'tl_PH',
		'tr_TR',
		'tz_MA',
		'uk_UA',
		'ur_PK',
		'uz_UZ',
		'vi_VN',
		'zh_CN',
		'zh_HK',
		'zh_TW',
	);


	/**
	 * Gets a list of locales supported by Facebook.
	 *
	 * @link https://developers.facebook.com/docs/messenger-platform/messenger-profile/supported-locales/
	 * If the Locale extension is not available, will attempt to match locales to WordPress available language names.
	 *
	 * @since 2.2.0
	 *
	 * @return array associative array of locale identifiers and language labels
	 */
	public static function get_supported_locales() {

		$locales = array();

		if ( class_exists( 'Locale' ) ) {

			foreach ( self::$supported_locales as $locale ) {

				if ( $name = \Locale::getDisplayName( $locale, substr( $locale, 0, 2 ) ) ) {

					$locales[ $locale ] = ucfirst( $name );
				}
			}
		} else {

			include_once ABSPATH . '/wp-admin/includes/translation-install.php';

			$translations = wp_get_available_translations();

			foreach ( self::$supported_locales as $locale ) {

				if ( isset( $translations[ $locale ]['native_name'] ) ) {

					$locales[ $locale ] = $translations[ $locale ]['native_name'];

				} else { // generic match e.g. <it>_IT, <it>_CH (any language in the the <it> group )

					$matched_locale = substr( $locale, 0, 2 );

					if ( isset( $translations[ $matched_locale ]['native_name'] ) ) {
						$locales[ $locale ] = $translations[ $matched_locale ]['native_name'];
					}
				}
			}

			// always include US English
			$locales['en_US'] = _x( 'English (United States)', 'language', 'facebook-for-woocommerce' );
		}

		/**
		 * Filters the locales supported by Facebook Messenger.
		 *
		 * @since 1.10.0
		 *
		 * @param array $locales locales supported by Facebook, in $locale => $name format
		 */
		$locales = (array) apply_filters( 'wc_facebook_messenger_supported_locales', array_unique( $locales ) );

		natcasesort( $locales );

		return $locales;
	}


	/**
	 * Determines if a locale is supported by Facebook.
	 *
	 * @since 2.2.0
	 *
	 * @param string $locale a locale identifier
	 * @return bool
	 */
	public static function is_supported_locale( $locale ) {

		return array_key_exists( $locale, self::get_supported_locales() );
	}


}
