<?php
/**
 * Bundled translations.
 *
 * @package Recast\WCS
 */

namespace Recast\WCS\Support;

defined( 'ABSPATH' ) || exit;

/**
 * Loads the translations in the plugin's languages folder when WordPress has none of its own.
 *
 * A language pack from translate.wordpress.org always wins: the bundled files only fill the
 * locales that have no pack yet. This applies to PHP strings and to the admin app's strings.
 */
final class I18n {

	const DOMAIN = 'recast-subscriptions';

	/**
	 * Hooks registration.
	 *
	 * @return void
	 */
	public static function register() {
		add_filter( 'lang_dir_for_domain', array( __CLASS__, 'lang_dir' ), 10, 3 );
		// WordPress before 6.6 has no lang_dir_for_domain filter: load the bundled file directly.
		if ( version_compare( get_bloginfo( 'version' ), '6.6', '<' ) ) {
			$locale = determine_locale();
			if ( ! self::has_pack( $locale ) && self::has_bundled( $locale ) ) {
				load_textdomain( self::DOMAIN, self::dir() . self::DOMAIN . '-' . $locale . '.mo', $locale );
			}
		}
	}

	/**
	 * Points WordPress at the bundled folder when it found no translation for this plugin.
	 *
	 * @param string|false $path   Folder WordPress found, or false.
	 * @param string       $domain Text domain.
	 * @param string       $locale Locale.
	 * @return string|false
	 */
	public static function lang_dir( $path, $domain, $locale ) {
		if ( $path || self::DOMAIN !== $domain || ! self::has_bundled( (string) $locale ) ) {
			return $path;
		}
		return self::dir();
	}

	/**
	 * Folder for the admin app's translations, or '' to let WordPress find them.
	 *
	 * From WordPress 6.6 the lang_dir_for_domain filter covers scripts too, so a language pack
	 * still wins. Before 6.6 the bundled folder is given only when no pack exists.
	 *
	 * @return string
	 */
	public static function script_dir() {
		if ( version_compare( get_bloginfo( 'version' ), '6.6', '>=' ) ) {
			return '';
		}
		$locale = determine_locale();
		return self::has_pack( $locale ) ? '' : self::dir();
	}

	/**
	 * Whether the plugin ships a translation for a locale.
	 *
	 * @param string $locale Locale.
	 * @return bool
	 */
	public static function has_bundled( $locale ) {
		$base = self::dir() . self::DOMAIN . '-' . $locale;
		return file_exists( $base . '.l10n.php' ) || file_exists( $base . '.mo' );
	}

	/**
	 * Whether WordPress has a language pack for this plugin in a locale.
	 *
	 * @param string $locale Locale.
	 * @return bool
	 */
	private static function has_pack( $locale ) {
		$base = WP_LANG_DIR . '/plugins/' . self::DOMAIN . '-' . $locale;
		return file_exists( $base . '.l10n.php' ) || file_exists( $base . '.mo' );
	}

	/**
	 * The bundled languages folder, with a trailing slash.
	 *
	 * @return string
	 */
	private static function dir() {
		return RECAST_DIR . 'languages/';
	}
}