<?php
if ( ! defined( 'ABSPATH' ) ) {
	exit;
}

require_once( QTRANSLATE_DIR . '/modules/qtx_modules_handler.php' );

function qtranxf_init_language() {
	global $q_config, $pagenow;
	//qtranxf_dbg_log('1.qtranxf_init_language:');

	qtranxf_loadConfig();

	// 'url_info' hash is not for external use, it is subject to change at any time.
	// 'url_info' is preserved on reloadConfig
	if ( ! isset( $q_config['url_info'] ) ) {
		$q_config['url_info'] = array();
	}

	$url_info                   = &$q_config['url_info'];
	$url_info['cookie_enabled'] = isset( $_COOKIE[ QTX_COOKIE_NAME_FRONT ] ) || isset( $_COOKIE[ QTX_COOKIE_NAME_ADMIN ] );
	if ( $url_info['cookie_enabled'] ) {
		if ( isset( $_COOKIE[ QTX_COOKIE_NAME_FRONT ] ) ) {
			$url_info['cookie_lang_front'] = $_COOKIE[ QTX_COOKIE_NAME_FRONT ];
		}
		if ( isset( $_COOKIE[ QTX_COOKIE_NAME_ADMIN ] ) ) {
			$url_info['cookie_lang_admin'] = $_COOKIE[ QTX_COOKIE_NAME_ADMIN ];
		}
	}

	if ( WP_DEBUG ) {
		$url_info['pagenow']        = $pagenow;
		$url_info['REQUEST_METHOD'] = isset( $_SERVER['REQUEST_METHOD'] ) ? $_SERVER['REQUEST_METHOD'] : '';
		if ( defined( 'WP_ADMIN' ) && WP_ADMIN ) {
			$url_info['WP_ADMIN'] = true;
		}
		if ( defined( 'DOING_AJAX' ) ) {
			$url_info['DOING_AJAX_POST'] = $_POST;
		}
		if ( defined( 'DOING_CRON' ) ) {
			$url_info['DOING_CRON_POST'] = $_POST;
		}
	}

	// fill url_info similarly to qtranxf_parseURL
	$url_info['scheme'] = is_ssl() ? 'https' : 'http';
	// see https://wordpress.org/support/topic/messy-wp-cronphp-command-line-output
	$url_info['host'] = isset( $_SERVER['HTTP_HOST'] ) ? $_SERVER['HTTP_HOST'] : '';
	$url_info['path'] = strtok( $_SERVER['REQUEST_URI'], '?' );
	if ( ! empty ( $_SERVER['QUERY_STRING'] ) ) {
		$url_info['query'] = qtranxf_sanitize_url( $_SERVER['QUERY_STRING'] ); // to prevent xss

		if ( isset( $_GET['qtranslate-mode'] ) && $_GET['qtranslate-mode'] == 'raw' ) {
			$url_info['qtranslate-mode']      = 'raw';
			$url_info['doing_front_end']      = true;
			$q_config['url_info']             = $url_info;
			$q_config['url_info']['language'] = $q_config['default_language'];
			$q_config['language']             = $q_config['default_language'];

			return;
		}
	}

	// TODO fix qtranslate-slug still using 'original_url' field and remove it from here, this has no sense!
	$url_info['original_url'] = $_SERVER['REQUEST_URI'];

	//qtranxf_dbg_log('qtranxf_init_language: SERVER: ',$_SERVER);
	$url_info['language'] = qtranxf_detect_language( $url_info );
	$q_config['language'] = apply_filters( 'qtranslate_language', $url_info['language'], $url_info );
	//qtranxf_dbg_log('qtranxf_init_language: detected: url_info: ',$url_info);

	if ( $q_config['url_info']['doing_front_end'] && qtranxf_can_redirect() ) {
		$lang     = $q_config['language'];
		$url_orig = $url_info['scheme'] . '://' . $_SERVER['HTTP_HOST'] . $_SERVER['REQUEST_URI'];
		$url_lang = qtranxf_convertURL( '', $lang ); // uses $q_config['url_info'] and caches information, which will be needed later anyway.
		if ( ! isset( $url_info['doredirect'] ) && $url_orig != $url_lang ) {
			$url_info['doredirect'] = '$url_orig != $url_lang';
		}
		if ( isset( $url_info['doredirect'] ) ) {
			/**
			 * Filter provides a chance to alter redirect behaviour.
			 *
			 * @param string $url_lang proposed target URL for the active language to redirect to.
			 * @param string $url_orig original URL supplied to browser, which needs to be standardized.
			 * @param array $url_info a hash of various information parsed from original URL, coockies and other site configuration. The key names should be self-explanatory.
			 *
			 * @return mixed A new URL to be redirected to instead of $url_lang or "false" to cancel redirection.
			 */
			$target = apply_filters( 'qtranslate_language_detect_redirect', $url_lang, $url_orig, $url_info );
			//qtranxf_dbg_log('qtranxf_init_language: doredirect to '.$lang.PHP_EOL .'urlorg:'.$url_orig.PHP_EOL .'target:'.$target.PHP_EOL .'url_info: ',$url_info);
			if ( $target !== false && $target != $url_orig ) {
				wp_redirect( $target );
				nocache_headers(); // prevent browser from caching redirection
				exit();
			} else {
				// neutral path
				$url_info['doredirect'] .= ' - cancelled, because it goes to the same target - neutral URL';
				if ( $pagenow == 'index.php' && $q_config['url_mode'] == QTX_URL_PATH ) {
					$_SERVER['REQUEST_URI'] = trailingslashit( $url_info['path-base'] ) . $lang . $url_info['wp-path']; // should not hurt?
				}
			}
			//qtranxf_dbg_log('qtranxf_init_language: doredirect canceled: $url_info: ',$url_info);
		}
	} elseif ( isset( $url_info['doredirect'] ) ) {
		$url_info['doredirect'] .= ' - cancelled by can_redirect';
		//qtranxf_dbg_log('qtranxf_init_language: doredirect canceled: $url_info: ',$url_info);
	}

	// TODO clarify fix url to prevent xss - how does this prevents xss?
	// $q_config['url_info']['url'] = qtranxf_convertURL(add_query_arg('lang',$q_config['default_language'],$q_config['url_info']['url']));

	// qtranslate_hooks.php has to go before load_plugin_textdomain()
	require_once( dirname( __FILE__ ) . '/qtranslate_hooks.php' );//common hooks moved here from qtranslate.php since 3.2.9.2, because they all need language already detected

	// load plugin translations
	// since 3.2-b3 moved it here as https://codex.wordpress.org/Function_Reference/load_plugin_textdomain seem to recommend to run load_plugin_textdomain in 'plugins_loaded' action, which is this function responds to
	qtranxf_load_plugin_textdomain();

	/**
	 * allow other plugins to initialize whatever they need before the fork between front and admin.
	 */
	do_action( 'qtranslate_load_front_admin', $url_info );

	if ( $q_config['url_info']['doing_front_end'] ) {
		require_once( QTRANSLATE_DIR . '/qtranslate_frontend.php' );
	} else {
		require_once( QTRANSLATE_DIR . '/admin/qtx_admin.php' );
	}
	apply_filters( 'wp_translator', null );//create QTX_Translator object

	qtranxf_load_option_qtrans_compatibility();

	QTX_Modules_Handler::load_modules_enabled();

	/**
	 * allow other plugins and modules to initialize whatever they need for language
	 */
	do_action( 'qtranslate_init_language', $url_info );
	//qtranxf_dbg_log('qtranxf_init_language: done: url_info: ',$url_info);
}

add_action( 'plugins_loaded', 'qtranxf_init_language', 2 ); // user is not authenticated yet

function qtranxf_detect_language( &$url_info ) {
	global $q_config;

	if ( defined( 'WP_ADMIN' ) || defined( 'WP_CLI' ) ) {
		$siteinfo                     = qtranxf_get_site_info();
		$url_info['path-base']        = $siteinfo['path'];
		$url_info['path-base-length'] = $siteinfo['path-length'];
	} else {
		qtranxf_complete_url_info( $url_info );
		if ( ! isset( $url_info['path-base'] ) ) {
			// path did not match neither 'site' nor 'home', but it came to this code, then redirect to home.
			// may happen for testing
			$target = get_option( 'home' );
			wp_redirect( $target );
			exit();
		}
		$url_info['doing_front_end'] = true;
	}

	$lang = qtranxf_parse_language_info( $url_info );

	// REST calls should be deterministic (stateless), no special language detection e.g. based on cookie
	if ( qtranxf_is_rest_request_expected() ) {
		if ( ! isset( $lang ) ) {
			$lang = $q_config['default_language'];
		}
		$url_info['language'] = $lang;

		return $lang;
	}

	if ( ( ! $lang || ! isset( $url_info['doing_front_end'] ) )
	     && ( defined( 'DOING_AJAX' ) || ! $url_info['cookie_enabled'] )
	     && isset( $_SERVER['HTTP_REFERER'] )
	) {
		// get language from HTTP_REFERER, if needed, and detect front- vs back-end
		$http_referer             = $_SERVER['HTTP_REFERER'];
		$url_info['http_referer'] = $http_referer;
		if ( strpos( $http_referer, '/wp-admin' ) !== false ) {
			$url_info['referer_admin'] = true;
			if ( ! isset( $url_info['doing_front_end'] ) ) {
				$url_info['doing_front_end'] = false;
			}
		} else {
			$ref_info = qtranxf_parseURL( $http_referer );
			if ( ! qtranxf_external_host( $ref_info['host'] ) ) {
				// determine $ref_info['path-base']
				qtranxf_complete_url_info( $ref_info );
				if ( isset( $ref_info['path-base'] ) ) {
					$url_info['internal_referer'] = true;
					if ( ! $lang || ! ( isset( $url_info['doing_front_end'] ) || isset( $ref_info['doing_front_end'] ) ) ) {
						$lang = qtranxf_parse_language_info( $ref_info, true );
						if ( $lang === false ) {
							unset( $url_info['internal_referer'] );
						}
					}
					$url_info['referer_language'] = $lang;
					if ( ! isset( $url_info['doing_front_end'] ) && isset( $ref_info['doing_front_end'] ) ) {
						$url_info['doing_front_end'] = $ref_info['doing_front_end'];
					}
				}
			}
			if ( ! $lang && $q_config['hide_default_language']
			     && isset( $url_info['doing_front_end'] ) && $url_info['doing_front_end'] ) {
				$lang = $q_config['default_language'];
			}
		}
	}

	if ( ! isset( $url_info['doing_front_end'] ) ) {
		$url_info['doing_front_end'] = ! defined( 'WP_ADMIN' );
	}

	if ( ! $lang ) {
		if ( $url_info['doing_front_end'] ) {
			$lang = qtranxf_detect_language_front( $url_info );
		} else {
			$lang = qtranxf_detect_language_admin( $url_info );
		}
	}

	$url_info['language']   = $lang;
	$url_info['set_cookie'] = ! defined( 'DOING_AJAX' );

	/**
	 * Hook for possible other methods
	 * Set $url_info['language'] with the result
	 */
	$url_info = apply_filters( 'qtranslate_detect_language', $url_info );
	$lang     = $url_info['language'];
	//qtranxf_dbg_log('qtranxf_detect_language: detected: url_info: ',$url_info);
	if ( $url_info['set_cookie'] ) {
		qtranxf_set_language_cookie( $lang );
	}

	return $lang;
}

/**
 * Expects to be set before call:
 * - $url_info['host']
 * - $url_info['path']
 * - $url_info['query']
 * - $url_info['path-base']
 * - $url_info['path-base-length']
 */
function qtranxf_parse_language_info( &$url_info, $link = false ) {
	global $q_config;

	qtranxf_complete_url_info_path( $url_info );
	if ( ! isset( $url_info['wp-path'] ) ) {
		return false;   // url is not from this WP installation
	}

	$doredirect = false;

	if ( ! defined( 'WP_ADMIN' ) || $link ) {
		$lang     = null;
		$url_mode = $q_config['url_mode'];
		switch ( $url_mode ) {
			case QTX_URL_PATH:
				if ( ! empty( $url_info['wp-path'] ) && preg_match( '!^/([a-z]{2})(/|$)!i', $url_info['wp-path'], $match ) ) {
					$lang = qtranxf_resolveLangCase( $match[1], $doredirect );
					if ( $lang ) {
						$url_info['lang_url']        = $lang;
						$url_info['wp-path']         = substr( $url_info['wp-path'], 3 );
						$url_info['doing_front_end'] = true;
						if ( WP_DEBUG ) {
							$url_info['url_mode'] = 'pre-path';
						}
					}
				}
				break;

			case QTX_URL_DOMAIN:
				if ( ! empty( $url_info['host'] ) ) {
					if ( preg_match( '#^([a-z]{2})\.#i', $url_info['host'], $match ) ) {
						$lang = qtranxf_resolveLangCase( $match[1], $doredirect );
						if ( $lang ) {
							$url_info['lang_url']        = $lang;
							$url_info['host']            = substr( $url_info['host'], 3 );
							$url_info['doing_front_end'] = true;
							if ( WP_DEBUG ) {
								$url_info['url_mode'] = 'pre-domain';
							}
						}
					}
				}
				break;

			case QTX_URL_DOMAINS:
				if ( ! empty( $url_info['host'] ) ) {
					foreach ( $q_config['enabled_languages'] as $lang ) {//todo should have hash host->lang
						if ( ! isset( $q_config['domains'][ $lang ] ) ) {
							continue;
						}
						if ( $q_config['domains'][ $lang ] != $url_info['host'] ) {
							continue;
						}
						$url_info['lang_url'] = $lang;
						if ( $lang != $q_config['default_language'] || strpos( get_option( 'siteurl' ), $url_info['host'] ) === false ) {
							$url_info['doing_front_end'] = true;
						}
						if ( WP_DEBUG ) {
							$url_info['url_mode'] = 'per-domain';
						}
						break;
					}
				}
				break;

			default:
				/**
				 * Hook for possible other methods
				 * Set, if applicable:
				 * $url_info['lang_url']
				 * $url_info['doing_front_end']
				 * $url_info['path'] - convert to language neutral or default
				 */
				$url_info = apply_filters( 'qtranslate_parse_language_info_mode', $url_info, $q_config['url_mode'] );
				break;
		}
	}

	$lang = null;
	if ( ! $link ) {
		if ( isset( $_GET['lang'] ) ) {
			$lang = qtranxf_resolveLangCase( $_GET['lang'], $doredirect );
			if ( $lang ) {
				$url_info['lang_query_get'] = $lang;
			}
		} else if ( isset( $_POST['lang'] ) ) {
			$lang = qtranxf_resolveLangCase( $_POST['lang'], $doredirect );
		}
	} elseif ( ! empty( $url_info['query'] ) && preg_match( '/(^|&|&amp;|&#038;|\?)lang=([a-z]{2})/i', $url_info['query'], $match ) ) { //rx is changed in 3.4.6.5: https://github.com/qTranslate-Team/qtranslate-x/issues/288
		$lang = qtranxf_resolveLangCase( $match[2], $doredirect );
	}

	if ( $lang ) {
		$url_info['lang_query'] = $lang;
		qtranxf_del_query_arg( $url_info['query'], 'lang' );
		if ( $q_config['url_mode'] != QTX_URL_QUERY ) {
			$doredirect = true;
		}
		//}
	} else if ( isset( $url_info['lang_url'] ) ) {
		$lang = $url_info['lang_url'];
		if ( $q_config['hide_default_language'] && $lang == $q_config['default_language'] ) {
			$doredirect = true;
		}
	}

	if ( $lang ) {
		$url_info['language'] = $lang;
	}

	if ( $doredirect ) {
		$url_info['doredirect'] = 'detected in parse_language_info';
	}

	if ( ! isset( $url_info['doing_front_end'] ) ) {
		$language_neutral_path             = qtranxf_language_neutral_path( $url_info['wp-path'] );
		$url_info['language_neutral_path'] = $language_neutral_path;
		if ( ! $language_neutral_path ) {
			$url_info['doing_front_end'] = true;
		}
	}

	/**
	 * Hook for possible other methods
	 * Set $url_info['language'] with the result
	 */
	$url_info = apply_filters( 'qtranslate_parse_language_info', $url_info, $link ); // slug?

	if ( isset( $url_info['language'] ) ) {
		$lang = $url_info['language'];
	}

	return $lang;
}

function qtranxf_detect_language_admin( &$url_info ) {
	require_once( dirname( __FILE__ ) . '/admin/qtx_admin_utils.php' );
	$url_info = apply_filters( 'qtranslate_detect_admin_language', $url_info );

	return $url_info['lang_admin'];
}

function qtranxf_detect_language_front( &$url_info ) {
	global $q_config;

	$lang = null;
	if ( isset( $_COOKIE[ QTX_COOKIE_NAME_FRONT ] ) ) {
		$cs                            = null;
		$lang                          = qtranxf_resolveLangCase( $_COOKIE[ QTX_COOKIE_NAME_FRONT ], $cs );
		$url_info['lang_cookie_front'] = $lang;
	}

	if ( ! $lang && $q_config['detect_browser_language']
	     && ( ! isset( $_SERVER['HTTP_REFERER'] ) || strpos( $_SERVER['HTTP_REFERER'], $url_info['host'] ) === false )//external referrer or no referrer
	     && ( empty( $url_info['wp-path'] ) || $url_info['wp-path'] == '/' ) // home page is requested
	) {
		$lang                     = qtranxf_http_negotiate_language();
		$url_info['lang_browser'] = $lang;
	}

	if ( ! $lang ) {
		$lang = $q_config['default_language'];
	}

	if ( ! isset( $url_info['doredirect'] )
	     && ( ! $q_config['hide_default_language'] || $lang != $q_config['default_language'] )
	) {
		$url_info['doredirect'] = 'language needs to be shown in url';
	}

	return $lang;
}

function qtranxf_setcookie_language( $lang, $cookie_name, $cookie_path ) {
	global $q_config;

	// only meant for server-side, set 'httponly' flag
	setcookie( $cookie_name, $lang, strtotime( '+1year' ), $cookie_path, null, $q_config['use_secure_cookie'], true );
}

function qtranxf_set_language_cookie( $lang ) {
	global $q_config;

	if ( defined( 'WP_ADMIN' ) ) {
		qtranxf_setcookie_language( $lang, QTX_COOKIE_NAME_ADMIN, ADMIN_COOKIE_PATH );
	} elseif ( ! $q_config['disable_client_cookies'] ) {
		qtranxf_setcookie_language( $lang, QTX_COOKIE_NAME_FRONT, COOKIEPATH );
	}
}

function qtranxf_get_browser_language() {
	//qtranxf_dbg_log('qtranxf_get_browser_language: HTTP_ACCEPT_LANGUAGE:',$_SERVER["HTTP_ACCEPT_LANGUAGE"]);
	if ( ! isset( $_SERVER["HTTP_ACCEPT_LANGUAGE"] ) ) {
		return null;
	}
	if ( ! preg_match_all( "#([^;,]+)(;[^,0-9]*([0-9.]+)[^,]*)?#i", $_SERVER["HTTP_ACCEPT_LANGUAGE"], $matches, PREG_SET_ORDER ) ) {
		return null;
	}
	$prefered_languages = array();
	$priority           = 1.0;
	foreach ( $matches as $match ) {
		if ( ! isset( $match[3] ) ) {
			$pr       = $priority;
			$priority -= 0.001;
		} else {
			$pr = floatval( $match[3] );
		}
		$prefered_languages[ $match[1] ] = $pr;
	}
	arsort( $prefered_languages, SORT_NUMERIC );
	//qtranxf_dbg_log('qtranxf_get_browser_language: prefered_languages:',$prefered_languages);
	foreach ( $prefered_languages as $language => $priority ) {
		$lang = qtranxf_match_language_locale( $language );
		if ( $lang ) {
			return $lang;
		}
	}

	return null;
}

function qtranxf_http_negotiate_language() {
	global $q_config;
	if ( function_exists( 'http_negotiate_language' ) ) {
		$default_language = $q_config['default_language'];
		$supported        = array();
		$supported[]      = qtranxf_html_locale( $q_config['locale'][ $default_language ] ); // needs to be the first
		if ( ! empty( $q_config['locale_html'][ $default_language ] ) ) {
			$supported[] = $q_config['locale_html'][ $default_language ];
		}
		foreach ( $q_config['enabled_languages'] as $lang ) {
			if ( $lang == $default_language ) {
				continue;
			}
			$supported[] = qtranxf_html_locale( $q_config['locale'][ $lang ] );
			if ( ! empty( $q_config['locale_html'][ $lang ] ) ) {
				$supported[] = $q_config['locale_html'][ $lang ];
			}
		}
		$locale_negotiated = http_negotiate_language( $supported );

		return qtranxf_match_language_locale( $locale_negotiated );
	} else {
		return qtranxf_get_browser_language();
	}
}

function qtranxf_resolveLangCase( $lang, &$caseredirect ) {
	if ( qtranxf_isEnabled( $lang ) ) {
		return $lang;
	}
	$lng = strtolower( $lang );
	if ( qtranxf_isEnabled( $lng ) ) {
		$caseredirect = true;

		return $lng;
	}
	$lng = strtoupper( $lang );
	if ( qtranxf_isEnabled( $lng ) ) {
		$caseredirect = true;

		return $lng;
	}

	return false;
}

function qtranxf_load_option_qtrans_compatibility() {
	global $q_config;
	qtranxf_load_option_bool( 'qtrans_compatibility', false );
	$q_config['qtrans_compatibility'] = apply_filters( 'qtranslate_compatibility', $q_config['qtrans_compatibility'] );
	if ( ! isset( $q_config['qtrans_compatibility'] ) || ! $q_config['qtrans_compatibility'] ) {
		return;
	}
	require_once( dirname( __FILE__ ) . '/qtranslate_compatibility.php' );
}

function qtranxf_load_plugin_textdomain() {
	$domain   = 'qtranslate';
	$lang_dir = qtranxf_plugin_dirname() . '/lang';
	if ( load_plugin_textdomain( $domain, false, $lang_dir ) ) {
		return true;
	}

	return false;
}

/**
 * Response to action 'init', which runs after user is authenticated.
 * Currently unused.
 * Is in use by 3rd-party plugins (for example, alo_easymail) to test q-X presence,
 * which they should have done by testing "if ( defined( 'QTRANSLATE_FILE' )" instead.
 * @since 3.4
 */
// TODO this function should be removed but some legacy plugins might still use this to check if q-XT is enabled...
function qtranxf_init() {
	//qtranxf_dbg_log('3.qtranxf_init:');
}

add_action( 'init', 'qtranxf_init', 2 ); // user is authenticated

function qtranxf_front_header_css_default() {
	global $q_config;
	$flag_location = qtranxf_flag_location();
	$css           = '';
	foreach ( $q_config['enabled_languages'] as $lang ) {
		$css .= '.qtranxs_flag_' . $lang . ' {background-image: url(' . $flag_location . $q_config['flag'][ $lang ] . '); background-repeat: no-repeat;}' . PHP_EOL;
	}

	return $css;
}

function qtranxf_flag_location() {
	global $q_config;

	return trailingslashit( content_url() ) . $q_config['flag_location'];
}

function qtranxf_flag_location_default() {
	return qtranxf_plugin_dirname_from_wp_content() . '/flags/';
}

function qtranxf_load_option_flag_location( $nm ) {
	global $q_config;
	$default_value = qtranxf_flag_location_default();
	$option_value  = get_option( 'qtranslate_' . $nm );
	if ( $option_value === false ) {
		$q_config[ $nm ] = $default_value;
	} else {
		// url fix for upgrading users
		$flag_location = trailingslashit( preg_replace( '#^wp-content/#', '', $option_value ) );
		if ( file_exists( trailingslashit( WP_CONTENT_DIR ) . $flag_location ) && $default_value != $flag_location ) {
			$q_config[ $nm ] = $flag_location;
		} else {
			$q_config[ $nm ] = $default_value;
			delete_option( 'qtranslate_' . $nm );
		}
	}
}

function qtranxf_validateBool( $var, $default_value ) {
	if ( $var === '0' ) {
		return false;
	} elseif ( $var === '1' ) {
		return true;
	} else {
		return $default_value;
	}
}

function qtranxf_load_option( $name, $default_value = null ) {
	global $q_config, $qtranslate_options;
	$val = get_option( 'qtranslate_' . $name );
	if ( $val === false ) {
		if ( is_null( $default_value ) ) {
			if ( ! isset( $qtranslate_options['default_value'][ $name ] ) ) {
				return;
			}
			$default_value = $qtranslate_options['default_value'][ $name ];
		}
		if ( is_string( $default_value ) && function_exists( $default_value ) ) {
			$val = call_user_func( $default_value );
		} else {
			$val = $default_value;
		}
	}
	$q_config[ $name ] = $val;
}

function qtranxf_load_option_array( $name, $default_value = null ) {
	global $q_config;
	$vals = get_option( 'qtranslate_' . $name );
	if ( $vals === false ) {
		if ( is_null( $default_value ) ) {
			return;
		}
		if ( is_string( $default_value ) ) {
			if ( function_exists( $default_value ) ) {
				$vals = call_user_func( $default_value );
			} else {
				$vals = preg_split( '/[\s,]+/', $default_value, null, PREG_SPLIT_NO_EMPTY );
			}
		} else if ( is_array( $default_value ) ) {
			$vals = $default_value;
		}
	}
	if ( ! is_array( $vals ) ) {
		return;
	}

	// clean up array due to previous configuration imperfections
	foreach ( $vals as $key => $val ) {
		if ( ! empty( $val ) ) {
			continue;
		}
		unset( $vals[ $key ] );
		if ( ! empty( $vals ) ) {
			continue;
		}
		delete_option( 'qtranslate_' . $name );
		break;
	}
	$q_config[ $name ] = $vals;
}

function qtranxf_load_option_bool( $name, $default_value = null ) {
	global $q_config;
	$val = get_option( 'qtranslate_' . $name );
	if ( $val === false ) {
		if ( ! is_null( $default_value ) ) {
			$q_config[ $name ] = $default_value;
		}
	} else {
		switch ( $val ) {
			case '0':
				$q_config[ $name ] = false;
				break;
			case '1':
				$q_config[ $name ] = true;
				break;
			default:
				$val = strtolower( $val );
				switch ( $val ) {
					case 'n':
					case 'no':
						$q_config[ $name ] = false;
						break;
					case 'y':
					case 'yes':
						$q_config[ $name ] = true;
						break;
					default:
						$q_config[ $name ] = ! empty( $val );
						break;
				}
				break;
		}
	}
}

function qtranxf_load_option_func( $name, $opn = null, $func = null ) {
	global $q_config;
	if ( ! $opn ) {
		$opn = 'qtranslate_' . $name;
	}
	$val = get_option( $opn );
	if ( $val === false ) {
		if ( ! $func ) {
			$func = 'qtranxf_default_' . $name;
		}
		$val = call_user_func( $func );
	}
	$q_config[ $name ] = $val;
}

function qtranxf_is_permalink_structure_query() {
	$permalink_structure = get_option( 'permalink_structure' );

	//qtranxf_dbg_echo('qtranxf_is_permalink_structure_query: ', $permalink_structure);
	return empty( $permalink_structure ) || strpos( $permalink_structure, '?' ) !== false || strpos( $permalink_structure, 'index.php' ) !== false;
}

function qtranxf_loadConfig() {
	global $qtranslate_options, $q_config;
	qtranxf_set_default_options( $qtranslate_options );

	$q_config = array();

	qtranxf_load_option_func( 'default_language' );
	qtranxf_load_option_array( 'enabled_languages' );

	qtranxf_load_option_flag_location( 'flag_location' );
	qtranxf_load_languages_enabled();

	foreach ( $qtranslate_options['front']['int'] as $name => $def ) {
		qtranxf_load_option( $name, $def );
	}

	foreach ( $qtranslate_options['front']['bool'] as $name => $def ) {
		qtranxf_load_option_bool( $name, $def );
	}

	foreach ( $qtranslate_options['front']['str'] as $name => $def ) {
		qtranxf_load_option( $name, $def );
	}

	foreach ( $qtranslate_options['front']['text'] as $name => $def ) {
		qtranxf_load_option( $name, $def );
	}

	foreach ( $qtranslate_options['front']['array'] as $name => $def ) {
		qtranxf_load_option_array( $name, $def );
	}

	qtranxf_load_option_array( 'term_name', array() );

	if ( $q_config['filter_options_mode'] == QTX_FILTER_OPTIONS_LIST ) {
		qtranxf_load_option_array( 'filter_options', QTX_FILTER_OPTIONS_DEFAULT );
	}

	$url_mode = $q_config['url_mode'];
	// check for invalid permalink/url mode combinations
	if ( qtranxf_is_permalink_structure_query() ) {
		switch ( $url_mode ) {
			case QTX_URL_QUERY:
			case QTX_URL_DOMAIN:
			case QTX_URL_DOMAINS:
				break;
			default:
				$q_config['url_mode'] = $url_mode = QTX_URL_QUERY;
				break;
		}
	}

	switch ( $url_mode ) {
		case QTX_URL_DOMAINS:
			$q_config['domains'] = array();
			qtranxf_load_option_array( 'domains' );
			//qtranxf_dbg_echo('domains loaded: ',$q_config['domains']);
			foreach ( $q_config['enabled_languages'] as $lang ) {
				if ( isset( $q_config['domains'][ $lang ] ) ) {
					continue;
				}
				$homeinfo                     = qtranxf_get_home_info();
				$q_config['domains'][ $lang ] = $lang . '.' . $homeinfo['host'];
			}
			$q_config['disable_client_cookies'] = true;
			$q_config['hide_default_language']  = false;
			break;
		case QTX_URL_QUERY:
		case QTX_URL_PATH:
			$q_config['disable_client_cookies'] = false;
			qtranxf_load_option_bool( 'disable_client_cookies' );
			break;
		case QTX_URL_DOMAIN:
		default:
			$q_config['disable_client_cookies'] = true;
			break;
	}

	$ignore_file_types = get_option( 'qtranslate_ignore_file_types' );
	$val               = explode( ',', QTX_IGNORE_FILE_TYPES );
	if ( ! empty( $ignore_file_types ) ) {
		$vals = preg_split( '/[\s,]+/', strtolower( $ignore_file_types ), null, PREG_SPLIT_NO_EMPTY );
		foreach ( $vals as $v ) {
			if ( empty( $v ) ) {
				continue;
			}
			if ( in_array( $v, $val ) ) {
				continue;
			}
			$val[] = $v;
		}
	}
	$q_config['ignore_file_types'] = $val;

	if ( empty( $q_config['front_config'] ) ) {
		// TODO this should be granulated to load only what is needed
		require_once( QTRANSLATE_DIR . '/admin/qtx_activation_hook.php' );
		require_once( QTRANSLATE_DIR . '/admin/qtx_admin_options_update.php' );
		qtranxf_update_i18n_config();
	}

	/**
	 * Opportunity to load additional front-end features.
	 */
	do_action( 'qtranslate_loadConfig' );
}

// check if it is a link to an ignored file type
function qtranxf_ignored_file_type( $path ) {
	global $q_config;
	//qtranxf_dbg_echo('qtranxf_ignored_file_type: pathinfo:',$pathinfo);
	$i = strpos( $path, '?' );
	if ( $i !== false ) {
		$path = substr( $path, 0, $i );
	}
	$i = strpos( $path, '#' );
	if ( $i !== false ) {
		$path = substr( $path, 0, $i );
	}
	$i = strrpos( $path, '.' );
	//qtranxf_dbg_echo('qtranxf_ignored_file_type: path='.$path.'; i='.$i);
	if ( $i === false ) {
		return false;
	}
	$ext = substr( $path, $i + 1 );

	//qtranxf_dbg_echo('qtranxf_ignored_file_type: ext='.$ext);
	return in_array( $ext, $q_config['ignore_file_types'] );
}

function qtranxf_language_neutral_path( $path ) {
	//qtranxf_dbg_log('qtranxf_language_neutral_path: path='.$path);
	if ( empty( $path ) ) {
		return false;
	}
	static $language_neutral_path_cache;
	if ( isset( $language_neutral_path_cache[ $path ] ) ) {
		//qtranxf_dbg_log('qtranxf_language_neutral_path: cached='.$language_neutral_path_cache[$path].': path='.$path);
		return $language_neutral_path_cache[ $path ];
	}
	if ( preg_match( '#^/(wp-.*\.php|wp-login/|wp-admin/|xmlrpc.php|robots.txt|oauth/)#', $path ) ) {
		$language_neutral_path_cache[ $path ] = true;

		//qtranxf_dbg_log('qtranxf_language_neutral_path: preg_match: path='.$path);
		return true;
	}
	if ( qtranxf_ignored_file_type( $path ) ) {
		$language_neutral_path_cache[ $path ] = true;

		//qtranxf_dbg_log('qtranxf_language_neutral_path: file_type: path='.$path);
		return true;
	}
	$language_neutral_path_cache[ $path ] = false;

	return false;
}

/**
 * @since 3.0
 */
function qtranxf_url_del_language( &$urlinfo ) {
	global $q_config;

	if ( ! empty( $urlinfo['query'] ) ) {
		$query = &$urlinfo['query'];
		// &amp; workaround
		if ( strpos( $query, '&amp;' ) !== false ) {
			$query                = str_replace( '&amp;', '&', $query );
			$urlinfo['query_amp'] = true;
		}
		if ( strpos( $urlinfo['query'], '&#038;' ) !== false ) {
			$query                = str_replace( '&#038;', '&', $query );
			$urlinfo['query_amp'] = true;
		}
		qtranxf_del_query_arg( $query, 'lang' );
	}

	$url_mode = $q_config['url_mode'];
	switch ( $url_mode ) {
		case QTX_URL_PATH:
			// might already have language information
			if ( ! empty( $urlinfo['wp-path'] ) && preg_match( '!^/([a-z]{2})(/|$)!i', $urlinfo['wp-path'], $match ) ) {
				if ( qtranxf_isEnabled( $match[1] ) ) {
					// found language information, remove it
					$urlinfo['wp-path'] = substr( $urlinfo['wp-path'], 3 );
				}
			}
			break;

		case QTX_URL_DOMAIN:
			// remove language information
			$homeinfo        = qtranxf_get_home_info();
			$urlinfo['host'] = $homeinfo['host'];
			break;

		case QTX_URL_DOMAINS:
			$urlinfo['host'] = $q_config['domains'][ $q_config['default_language'] ];
			break;

		case QTX_URL_QUERY:
			break;

		default:
			$urlinfo = apply_filters( 'qtranslate_url_del_language', $urlinfo, $url_mode );
			break;
	}
	//qtranxf_dbg_log('qtranxf_url_del_language: $urlinfo:',$urlinfo);
}

function qtranxf_url_set_language( $urlinfo, $lang, $showLanguage ) {
	global $q_config;
	$urlinfo = qtranxf_copy_url_info( $urlinfo );
	//qtranxf_dbg_log('qtranxf_url_set_language: $urlinfo:',$urlinfo);
	if ( $showLanguage ) {
		$url_mode = $q_config['url_mode'];
		switch ( $url_mode ) {
			case QTX_URL_PATH:
				//qtranxf_dbg_log_if(!isset($urlinfo['wp-path']),'qtranxf_url_set_language: wp-path not set $urlinfo:',$urlinfo,true);
				$urlinfo['wp-path'] = '/' . $lang . $urlinfo['wp-path'];
				break;

			case QTX_URL_DOMAIN:
				$urlinfo['host'] = $lang . '.' . $urlinfo['host'];
				//qtranxf_dbg_log('qtranxf_url_set_language: QTX_URL_DOMAIN: urlinfo:',$urlinfo);
				break;

			case QTX_URL_DOMAINS:
				$urlinfo['host'] = $q_config['domains'][ $lang ];
				break;

			case QTX_URL_QUERY:
				qtranxf_add_query_arg( $urlinfo['query'], 'lang=' . $lang );
				break;
		}
		$urlinfo = apply_filters( 'qtranslate_url_set_language', $urlinfo, $lang, $url_mode );
	}


	// see if cookies are activated
	if ( ! $showLanguage//there still is no language information in the converted URL
	     && ! $q_config['url_info']['cookie_enabled']// there will be no way to take language from the cookie
	     && $q_config['language'] != $q_config['default_language']//we need to be able to get language other than default
	     && empty( $q_config['url_info']['lang_url'] )//we will not be able to get language from referrer path
	     && empty( $q_config['url_info']['lang_query_get'] )//we will not be able to get language from referrer query
	) {
		// :( now we have to make unpretty URLs
		qtranxf_add_query_arg( $urlinfo['query'], 'lang=' . $lang );
	}

	// &amp; workaround
	if ( isset( $urlinfo['query_amp'] ) ) {
		$urlinfo['query'] = str_replace( '&', '&amp;', $urlinfo['query'] );
	}

	return $urlinfo;
}

function qtranxf_get_url_for_language( $url, $lang, $showLanguage = true ) {
	global $q_config;
	static $url_cache = array();
	//qtranxf_dbg_log('qtranxf_get_url_for_language: $url_cache:',$url_cache);
	if ( ! isset( $url_cache[ $url ] ) ) {
		$url_cache[ $url ] = array();
	}
	$urlinfo = &$url_cache[ $url ];

	if ( $showLanguage ) {
		if ( isset( $urlinfo[ $lang ] ) ) {
			//qtranxf_dbg_log('qtranxf_get_url_for_language: cached: lang='.$lang.': ',$urlinfo);
			return $urlinfo[ $lang ];
		}
	} else {
		if ( isset( $urlinfo['bare'] ) ) {
			//qtranxf_dbg_log('qtranxf_get_url_for_language: cached: bare: ',$urlinfo);
			return $urlinfo['bare'];
		}
	}

	if ( isset( $urlinfo['language_neutral'] ) ) {
		//qtranxf_dbg_log('qtranxf_get_url_for_language: cached: language_neutral: ',$urlinfo);
		return $urlinfo['language_neutral'];
	}

	$homeinfo = qtranxf_get_home_info();
	if ( ! isset( $urlinfo['url_parsed'] ) ) {
		if ( empty( $url ) ) {
			$urlinfo = qtranxf_copy_url_info( $q_config['url_info'] );

			if ( isset( $urlinfo['wp-path'] ) && qtranxf_language_neutral_path( $urlinfo['wp-path'] ) ) {
				//qtranxf_dbg_log('qtranxf_get_url_for_language: language_neutral: wp-path: url='.$url.':',$urlinfo);
				$complete = qtranxf_buildURL( $urlinfo, $homeinfo );
				if ( ! isset( $url_cache[ $complete ] ) ) {
					$url_cache[ $complete ] = $urlinfo;
				}
				$urlinfo['language_neutral'] = $complete;

				return $complete;
			}

		} else {
			$urlinfo = qtranxf_get_url_info( $url );

			// check if it's an external link
			if ( ! isset( $urlinfo['wp-path'] ) ) {
				$urlinfo['language_neutral'] = $url;

				//qtranxf_dbg_log('qtranxf_get_url_for_language: language_neutral: external path: ',$urlinfo);
				return $url;
			}

			if ( empty( $urlinfo['host'] ) ) {
				if ( empty( $urlinfo['wp-path'] ) ) {
					if ( empty( $urlinfo['query'] ) ) {
						$urlinfo['language_neutral'] = $url;

						//qtranxf_dbg_log('qtranxf_get_url_for_language: language_neutral: relative path: ',$urlinfo);
						return $url;
					}
				} else {
					switch ( $urlinfo['wp-path'][0] ) {
						case '/':
							break;
						case '#':
						{
							$urlinfo['language_neutral'] = $url;

							//qtranxf_dbg_log('qtranxf_get_url_for_language: language_neutral: relative hash: ',$urlinfo);
							return $url;
						}
						default:
							$urlinfo['wp-path'] = trailingslashit( $q_config['url_info']['wp-path'] ) . $urlinfo['wp-path'];
							break;
					}
				}
			} elseif ( qtranxf_external_host_ex( $urlinfo['host'], $homeinfo ) ) {
				$urlinfo['language_neutral'] = $url;

				//qtranxf_dbg_log('qtranxf_get_url_for_language: language_neutral: external host: ',$urlinfo);
				return $url;
			}

			if ( qtranxf_language_neutral_path( $urlinfo['wp-path'] ) ) {
				$urlinfo['language_neutral'] = $url;

				//qtranxf_dbg_log('qtranxf_get_url_for_language: language_neutral: wp-path: ',$urlinfo);
				return $url;
			}

			qtranxf_url_del_language( $urlinfo );
		}
		$urlinfo['url_parsed'] = $url;
	}

	$urlinfo_lang = qtranxf_url_set_language( $urlinfo, $lang, $showLanguage );
	$complete     = qtranxf_buildURL( $urlinfo_lang, $homeinfo );

	if ( $showLanguage ) {
		$urlinfo[ $lang ] = $complete;
	} else {
		$urlinfo['bare'] = $complete;
	}
	if ( ! isset( $url_cache[ $complete ] ) ) {
		$url_cache[ $complete ] = $urlinfo;
	}

	//qtranxf_dbg_log('done: qtranxf_get_url_for_language('.$lang.($showLanguage?', true':', false').'): $urlinfo=',$urlinfo,false);
	return $complete;
}

/**
 * Encode URL $url with language $lang.
 *
 * @param (string) $url URL to be converted.
 * @param (string) $lang two-letter language code of the language to convert $url to.
 * @param (bool) $forceadmin $url is not converted on admin side, unless $forceadmin is set to true.
 * @param (bool) $showDefaultLanguage When set to true, $url is always encoded with a language, otherwise it senses option "Hide URL language information for default language" to keep $url consistent with the currently active language.
 *
 * If you need a URL to switch the language, set $showDefaultLanguage=true, if you need a URL to keep the current language, set it to false.
 */
function qtranxf_convertURL( $url = '', $lang = '', $forceadmin = false, $showDefaultLanguage = false ) {
	global $q_config;

	if ( empty( $lang ) ) {
		$lang = $q_config['language'];
	}
	if ( empty( $url ) ) {
		if ( $q_config['url_info']['doing_front_end'] && defined( 'QTS_VERSION' ) && $q_config['url_mode'] != QTX_URL_QUERY ) {
			// quick workaround, but need a permanent solution
			$url = qts_get_url( $lang );
			//qtranxf_dbg_log('qtranxf_convertURL: qts_get_url: url=', $url);
			if ( ! empty( $url ) ) {
				if ( $showDefaultLanguage && $q_config['hide_default_language'] && $lang == $q_config['default_language'] ) {
					$url = qtranxf_convertURL( $url, $lang, $forceadmin, true );
				}

				return $url;
			}
		}
	}
	if ( ! $q_config['url_info']['doing_front_end'] && ! $forceadmin ) {
		return $url;
	}
	if ( ! qtranxf_isEnabled( $lang ) ) {
		return '';
	}

	if ( ! $showDefaultLanguage ) {
		$showDefaultLanguage = ! $q_config['hide_default_language'];
	}
	$showLanguage = $showDefaultLanguage || $lang != $q_config['default_language'];
	//qtranxf_dbg_log('qtranxf_convertURL('.$url.','.$lang.'): showLanguage=',$showLanguage);
	$complete = qtranxf_get_url_for_language( $url, $lang, $showLanguage );

	//qtranxf_dbg_log('qtranxf_convertURL: complete: ',$complete);
	return $complete;
}

function qtranxf_convertURLs( $url, $lang = '', $forceadmin = false, $showDefaultLanguage = false ) {
	global $q_config;
	if ( empty( $lang ) ) {
		$lang = $q_config['language'];
	}
	if ( is_array( $url ) ) {
		foreach ( $url as $k => $value ) {
			$url[ $k ] = qtranxf_convertURLs( $value, $lang, $forceadmin, $showDefaultLanguage );
		}

		return $url;
	} else if ( is_string( $url ) && ! empty( $url ) ) {
		return qtranxf_convertURL( $url, $lang, $forceadmin, $showDefaultLanguage );
	}

	return $url;
}

/**
 * split text at all language comments and quick tags
 * @since 3.3.6 swirly bracket encoding added
 */
function qtranxf_get_language_blocks( $text ) {
	$split_regex = "#(<!--:[a-z]{2}-->|<!--:-->|\[:[a-z]{2}\]|\[:\]|\{:[a-z]{2}\}|\{:\})#ism";

	return preg_split( $split_regex, $text, - 1, PREG_SPLIT_NO_EMPTY | PREG_SPLIT_DELIM_CAPTURE );
}

function qtranxf_split( $text ) {
	$blocks = qtranxf_get_language_blocks( $text );

	return qtranxf_split_blocks( $blocks );
}

/*
 * @since 3.4.5.2 $found added
**/
function qtranxf_split_blocks( $blocks, &$found = array() ) {
	global $q_config;
	$result = array();
	foreach ( $q_config['enabled_languages'] as $language ) {
		$result[ $language ] = '';
	}
	$current_language = false;
	foreach ( $blocks as $block ) {
		// detect c-tags
		if ( preg_match( "#^<!--:([a-z]{2})-->$#ism", $block, $matches ) ) {
			$current_language = $matches[1];
			continue;
			// detect b-tags
		} elseif ( preg_match( "#^\[:([a-z]{2})]$#ism", $block, $matches ) ) {
			$current_language = $matches[1];
			continue;
			// detect s-tags @since 3.3.6 swirly bracket encoding added
		} elseif ( preg_match( "#^{:([a-z]{2})}$#ism", $block, $matches ) ) {
			$current_language = $matches[1];
			continue;
		}
		switch ( $block ) {
			case '[:]':
			case '{:}':
			case '<!--:-->':
				$current_language = false;
				break;
			default:
				// correctly categorize text block
				if ( $current_language ) {
					if ( ! isset( $result[ $current_language ] ) ) {
						$result[ $current_language ] = '';
					}
					$result[ $current_language ] .= $block;
					$found[ $current_language ]  = true;
					$current_language            = false;
				} else {
					foreach ( $q_config['enabled_languages'] as $language ) {
						$result[ $language ] .= $block;
					}
				}
				break;
		}
	}
	// it gets trimmed later in qtranxf_use() anyway, better to do it here
	foreach ( $result as $lang => $text ) {
		$result[ $lang ] = trim( $text );
	}

	return $result;
}

/**
 * gets only part with encoded languages
 */
function qtranxf_split_languages( $blocks ) {
	$result           = array();
	$current_language = false;
	foreach ( $blocks as $block ) {
		// detect c-tags
		if ( preg_match( "#^<!--:([a-z]{2})-->$#ism", $block, $matches ) ) {
			$current_language = $matches[1];
			continue;
			// detect b-tags
		} elseif ( preg_match( "#^\[:([a-z]{2})]$#ism", $block, $matches ) ) {
			$current_language = $matches[1];
			continue;
			// detect s-tags @since 3.3.6 swirly bracket encoding added
		} elseif ( preg_match( "#^{:([a-z]{2})}$#ism", $block, $matches ) ) {
			$current_language = $matches[1];
			continue;
		}
		switch ( $block ) {
			case '[:]':
			case '{:}':
			case '<!--:-->':
				$current_language = false;
				break;
			default:
				// correctly categorize text block
				if ( $current_language ) {
					if ( ! isset( $result[ $current_language ] ) ) {
						$result[ $current_language ] = '';
					}
					$result[ $current_language ] .= $block;
					$current_language            = false;
				}
				break;
		}
	}
	// it gets trimmed later in qtranxf_getAvailableLanguages() anyway, better to do it here
	foreach ( $result as $lang => $text ) {
		$result[ $lang ] = trim( $text );
	}

	return $result;
}

function qtranxf_allthesame( $texts ) {
	$text = null;
	// take first not empty
	foreach ( $texts as $lang => $lang_text ) {
		if ( ! $lang_text || $lang_text == '' ) {
			continue;
		}
		$text = $lang_text;
		break;
	}
	if ( empty( $text ) ) {
		return '';
	}
	foreach ( $texts as $lang => $lang_text ) {
		if ( $lang_text != $text ) {
			return null;
		}
	}

	return $text;
}

function qtranxf_join_c( $texts ) {
	$text = qtranxf_allthesame( $texts );
	if ( ! is_null( $text ) ) {
		return $text;
	}
	$text = '';
	foreach ( $texts as $lang => $lang_text ) {
		if ( empty( $lang_text ) ) {
			continue;
		}
		$text .= '<!--:' . $lang . '-->' . $lang_text . '<!--:-->';
	}

	return $text;
}

function qtranxf_join_b_no_closing( $texts ) {
	$text = qtranxf_allthesame( $texts );
	if ( ! is_null( $text ) ) {
		return $text;
	}
	$text = '';
	foreach ( $texts as $lang => $lang_text ) {
		if ( empty( $lang_text ) ) {
			continue;
		}
		$text .= '[:' . $lang . ']' . $lang_text;
	}

	return $text;
}

function qtranxf_join_b( $texts ) {
	$text = qtranxf_allthesame( $texts );
	if ( ! is_null( $text ) ) {
		return $text;
	}
	$text = '';
	foreach ( $texts as $lang => $lang_text ) {
		if ( empty( $lang_text ) ) {
			continue;
		}
		$text .= '[:' . $lang . ']' . $lang_text;
	}
	if ( ! empty( $text ) ) {
		$text .= '[:]';
	}

	return $text;
}

/**
 * @since 3.3.6 swirly bracket encoding
 */
function qtranxf_join_s( $texts ) {
	$text = qtranxf_allthesame( $texts );
	if ( ! is_null( $text ) ) {
		return $text;
	}
	$text = '';
	foreach ( $texts as $lang => $lang_text ) {
		if ( empty( $lang_text ) ) {
			continue;
		}
		$text .= '{:' . $lang . '}' . $lang_text;
	}
	if ( ! empty( $text ) ) {
		$text .= '{:}';
	}

	return $text;
}

/**
 * Prepares multilingual text leaving text that matches $regex_sep outside of language tags.
 * @since 3.4.6.2
 */
function qtranxf_join_byseparator( $texts, $regex_sep ) {
	$text = qtranxf_allthesame( $texts );
	if ( ! is_null( $text ) ) {
		return $text;
	}

	$lines = array();
	foreach ( $texts as $lang => $lang_text ) {
		$lines[ $lang ] = preg_split( $regex_sep, $lang_text, null, PREG_SPLIT_DELIM_CAPTURE );
	}

	$text = '';
	while ( true ) {
		$done    = true;
		$to_join = array();
		$sep     = '';
		foreach ( $lines as $lang => $lang_lines ) {
			$t = next( $lang_lines );
			if ( $t === false ) {
				continue;
			}
			if ( preg_match( $regex_sep, $t ) ) {
				$sep = $t;
				$t   = next( $lang_lines );
			}
			$done             = false;
			$to_join[ $lang ] = $t;
		}
		if ( $done ) {
			break;
		}
		$text .= qtranxf_join_b( $to_join ) . $sep;
	}

	return $text;
}

/**
 * Prepare multilingal text leaving new line outside of language tags '[:]'.
 */
function qtranxf_join_byline( $texts ) {
	$text = qtranxf_allthesame( $texts );
	if ( ! is_null( $text ) ) {
		return $text;
	}

	$lines = array();
	foreach ( $texts as $lang => $text ) {
		$lines[ $lang ] = preg_split( '/\r?\n\r?/', $text );
	}

	$text = '';
	for ( $i = 0; true; ++ $i ) {
		$done    = true;
		$to_join = array();
		foreach ( $lines as $lang => $lang_lines ) {
			if ( sizeof( $lang_lines ) <= $i ) {
				continue;
			}
			$done = false;
			$line = $lang_lines[ $i ];
			if ( ! $line || $line == '' ) {
				continue;
			}
			$to_join[ $lang ] = $line;
		}
		if ( $done ) {
			break;
		}
		$text .= qtranxf_join_b( $to_join ) . PHP_EOL;
	}

	return $text;
}

function qtranxf_use( $lang, $text, $show_available = false, $show_empty = false ) {
	// return full string if language is not enabled
	if ( is_array( $text ) ) {
		// handle arrays recursively
		foreach ( $text as $key => $t ) {
			$text[ $key ] = qtranxf_use( $lang, $t, $show_available, $show_empty );
		}

		return $text;
	}

	if ( is_object( $text ) || $text instanceof __PHP_Incomplete_Class ) {
		foreach ( get_object_vars( $text ) as $key => $t ) {
			if ( ! isset( $text->$key ) ) {
				continue;
			}
			$text->$key = qtranxf_use( $lang, $t, $show_available, $show_empty );
		}

		return $text;
	}

	// prevent filtering weird data types and save some resources
	if ( ! is_string( $text ) || empty( $text ) ) {
		return $text;
	}

	return qtranxf_use_language( $lang, $text, $show_available, $show_empty );
}

/** when $text is already known to be string */
function qtranxf_use_language( $lang, $text, $show_available = false, $show_empty = false ) {
	$blocks = qtranxf_get_language_blocks( $text );
	if ( count( $blocks ) <= 1 )//no language is encoded in the $text, the most frequent case
	{
		return $text;
	}

	return qtranxf_use_block( $lang, $blocks, $show_available, $show_empty );
}

function qtranxf_use_block( $lang, $blocks, $show_available = false, $show_empty = false ) {
	//qtranxf_dbg_log('qtranxf_use_block:('.$lang.') $blocks: ', $blocks);
	$available_langs = array();
	$content         = qtranxf_split_blocks( $blocks, $available_langs );
	//qtranxf_dbg_log('qtranxf_use_block: $content: ',$content);
	//qtranxf_dbg_log('qtranxf_use_block: $available_langs: ',$available_langs);
	return qtranxf_use_content( $lang, $content, $available_langs, $show_available, $show_empty );
}

function qtranxf_use_content( $lang, $content, $available_langs, $show_available = false, $show_empty = false ) {
	global $q_config;
	// show the content in the requested language, if available
	if ( ! empty( $available_langs[ $lang ] ) ) {
		return $content[ $lang ];
	} elseif ( $show_empty ) {
		return '';
	}

	// content is not available in requested language (bad!!) what now?
	$alangs = array();
	foreach ( $q_config['enabled_languages'] as $language ) {
		if ( empty( $available_langs[ $language ] ) ) {
			continue;
		}
		$alangs[] = $language;
	}
	if ( empty( $alangs ) ) {
		return '';
	}

	$available_langs = $alangs;
	// set alternative language to the first available in the order of enabled languages
	$alt_lang    = current( $available_langs );
	$alt_content = $content[ $alt_lang ];

	if ( ! $show_available ) {
		if ( $q_config['show_displayed_language_prefix'] ) {
			return '(' . $q_config['language_name'][ $alt_lang ] . ') ' . $alt_content;
		} else {
			return $alt_content;
		}
	}
	//qtranxf_dbg_log('$alt_content=',$alt_content);

	// display selection for available languages
	$language_list = '';
	if ( preg_match( '/%LANG:([^:]*):([^%]*)%/', $q_config['not_available'][ $lang ], $match ) ) {
		$normal_separator = $match[1];
		$end_separator    = $match[2];
		// build available languages string backward
		$i = 0;
		foreach ( array_reverse( $available_langs ) as $language ) {
			if ( $i == 1 ) {
				$language_list = $end_separator . $language_list;
			} elseif ( $i > 1 ) {
				$language_list = $normal_separator . $language_list;
			}
			$language_name = qtranxf_getLanguageName( $language );
			//$language_list = '&ldquo;<a href="'.qtranxf_convertURL('', $language, false, true).'" class="qtranxs-available-language-link qtranxs-available-language-link-'.$language.'">'.$language_name.'</a>&rdquo;'.$language_list;
			$language_list = '<a href="' . qtranxf_convertURL( '', $language, false, true ) . '" class="qtranxs-available-language-link qtranxs-available-language-link-' . $language . '" title="' . $q_config['language_name'][ $language ] . '">' . $language_name . '</a>' . $language_list;
			++ $i;
		}
	}
	//qtranxf_dbg_log('$language_list=',$language_list);

	$msg    = preg_replace( '/%LANG:([^:]*):([^%]*)%/', $language_list, $q_config['not_available'][ $lang ] );
	$output = '<p class="qtranxs-available-languages-message qtranxs-available-languages-message-' . $lang . '">' . $msg . '</p>';
	if ( ! empty( $q_config['show_alternative_content'] ) && $q_config['show_alternative_content'] ) {
		$output .= $alt_content;
	}

	return apply_filters( 'i18n_content_translation_not_available', $output, $lang, $language_list, $alt_lang, $alt_content, $msg, $q_config );
}

function qtranxf_showAllSeparated( $text ) {
	if ( empty( $text ) ) {
		return $text;
	}
	global $q_config;
	$result = '';
	foreach ( qtranxf_getSortedLanguages() as $language ) {
		$result .= $q_config['language_name'][ $language ] . ':' . PHP_EOL . qtranxf_use( $language, $text ) . PHP_EOL . PHP_EOL;
	}

	return $result;
}

/**
 * Add specific rewrites to handle API REST for the default language, when hidden in QTX_URL_PATH mode.
 * Most of the requests don't need this, as they are handled through custom home_url with the language.
 * Note: to make it work you have to flush your rewrite rules by saving the permalink structures from the admin page!
 *
 * Example with 'en' as default language and hidden option enabled:
 *   /wp-json/wp/...    -> home_url = '/' (default, hidden)
 *   /fr/wp-json/wp/... -> home_url = '/fr'
 *   /en/wp-json/wp/... -> home_url = '/' (default, hidden but requested) -> fails with standard rewrites (404)
 * This function allows to handle specifically this last case.
 *
 * @see rest_api_register_rewrites in wp_includes/rest-api.php
 */
function qtranxf_rest_api_register_rewrites() {
	global $q_config;
	if ( ! $q_config['hide_default_language'] || $q_config['url_mode'] !== QTX_URL_PATH ) {
		return;
	}

	global $wp_rewrite;
	$default_lang = $q_config['default_language'];
	add_rewrite_rule( '^' . $default_lang . '/' . rest_get_url_prefix() . '/?$', 'index.php?rest_route=/', 'top' );
	add_rewrite_rule( '^' . $default_lang . '/' . rest_get_url_prefix() . '/(.*)?', 'index.php?rest_route=/$matches[1]', 'top' );
	add_rewrite_rule( '^' . $default_lang . '/' . $wp_rewrite->index . '/' . rest_get_url_prefix() . '/?$', 'index.php?rest_route=/', 'top' );
	add_rewrite_rule( '^' . $default_lang . '/' . $wp_rewrite->index . '/' . rest_get_url_prefix() . '/(.*)?', 'index.php?rest_route=/$matches[1]', 'top' );
}

add_action( 'init', 'qtranxf_rest_api_register_rewrites', 11 );
