<?php

/**
 * @brief translation support
 *
 * Get the language setting directly from system variables, bypassing Config::get()
 * as database may not yet be configured.
 *
 * If possible, we use the value from the browser.
 *
 */

use Friendica\Core\Config;

require_once "include/dba.php";

/**
 * @brief get the prefered language from the HTTP_ACCEPT_LANGUAGE header
 */
function get_browser_language() {

	if (x($_SERVER, 'HTTP_ACCEPT_LANGUAGE')) {
		// break up string into pieces (languages and q factors)
		preg_match_all('/([a-z]{1,8}(-[a-z]{1,8})?)\s*(;\s*q\s*=\s*(1|0\.[0-9]+))?/i',
			$_SERVER['HTTP_ACCEPT_LANGUAGE'], $lang_parse);

		$lang_list = [];
		if (count($lang_parse[1])) {
			// go through the list of prefered languages and add a generic language
			// for sub-linguas (e.g. de-ch will add de) if not already in array
			for ($i = 0; $i < count($lang_parse[1]); $i++) {
				$lang_list[] = strtolower($lang_parse[1][$i]);
				if (strlen($lang_parse[1][$i])>3 ) {
					$dashpos = strpos($lang_parse[1][$i], '-');
					if (!in_array(substr($lang_parse[1][$i], 0, $dashpos), $lang_list ) ) {
						$lang_list[] = strtolower(substr($lang_parse[1][$i], 0, $dashpos));
					}
				}
			}
		}
	}

	// check if we have translations for the preferred languages and pick the 1st that has
	for ($i = 0; $i < count($lang_list); $i++) {
		$lang = $lang_list[$i];
		if ($lang === 'en' || (file_exists("view/lang/$lang") && is_dir("view/lang/$lang"))) {
			$preferred = $lang;
			break;
		}
	}
	if (isset($preferred)) {
		return $preferred;
	}

	// in case none matches, get the system wide configured language, or fall back to English
	return Config::get('system', 'language', 'en');
}


function push_lang($language) {
	global $lang, $a;

	$a->langsave = $lang;

	if ($language === $lang) {
		return;
	}

	if (isset($a->strings) && count($a->strings)) {
		$a->stringsave = $a->strings;
	}
	$a->strings = array();
	load_translation_table($language);
	$lang = $language;
}

function pop_lang() {
	global $lang, $a;

	if ($lang === $a->langsave) {
		return;
	}

	if (isset($a->stringsave)) {
		$a->strings = $a->stringsave;
	} else {
		$a->strings = array();
	}

	$lang = $a->langsave;
}

// l

/**
 * load string translation table for alternate language
 *
 * first plugin strings are loaded, then globals
 *
 * @param string $lang language code to load
 */
function load_translation_table($lang) {
	$a = get_app();

	$a->strings = array();
	// load enabled plugins strings
	$plugins = dba::select('addon', array('name'), array('installed' => true));
	while ($p = dba::fetch($plugins)) {
		$name = $p['name'];
		if (file_exists("addon/$name/lang/$lang/strings.php")) {
			include("addon/$name/lang/$lang/strings.php");
		}
	}

	if (file_exists("view/lang/$lang/strings.php")) {
		include("view/lang/$lang/strings.php");
	}

}

/**
 * @brief Return the localized version of the provided string with optional string interpolation
 *
 * This function takes a english string as parameter, and if a localized version
 * exists for the current language, substitutes it before performing an eventual
 * string interpolation (sprintf) with additional optional arguments.
 *
 * Usages:
 * - t('This is an example')
 * - t('URL %s returned no result', $url)
 * - t('Current version: %s, new version: %s', $current_version, $new_version)
 *
 * @param string $s
 * @return string
 */
function t($s)
{
	$a = get_app();

	if (x($a->strings, $s)) {
		$t = $a->strings[$s];
		$s = is_array($t) ? $t[0] : $t;
	}
	if (func_num_args() > 1) {
		$args = array_slice(func_get_args(), 1);
		$s = @vsprintf($s, $args);
	}

	return $s;
}

/**
 * @brief Return the localized version of a singular/plural string with optional string interpolation
 *
 * This function takes two english strings as parameters, singular and plural, as
 * well as a count. If a localized version exists for the current language, they
 * are used instead. Discrimination between singular and plural is done using the
 * localized function if any or the default one. Finally, a string interpolation
 * is performed using the count as parameter.
 *
 * Usages:
 * - tt('Like', 'Likes', $count)
 * - tt("%s user deleted", "%s users deleted", count($users))
 *
 * @global type $lang
 * @param string $singular
 * @param string $plural
 * @param int $count
 * @return string
 */
function tt($singular, $plural, $count)
{
	global $lang;
	$a = get_app();

	if (x($a->strings, $singular)) {
		$t = $a->strings[$singular];
		if (is_array($t)) {
			$plural_function = 'string_plural_select_' . str_replace('-', '_', $lang);
			if (function_exists($plural_function)) {
				$plural_function = 'string_plural_select_default';
			}
			$i = $plural_function($count);
			$s = $t[$i];
		} else {
			$s = $t;
		}
	} elseif (string_plural_select_default($count)) {
		$s = $plural;
	} else {
		$s = $singular;
	}

	$s = @sprintf($s, $count);

	return $s;
}

// provide a fallback which will not collide with
// a function defined in any language file
function string_plural_select_default($n)
{
	return $n != 1;
}



/**
 * @brief Return installed languages codes as associative array
 *
 * Scans the view/lang directory for the existence of "strings.php" files, and
 * returns an alphabetical list of their folder names (@-char language codes).
 * Adds the english language if it's missing from the list.
 *
 * Ex: array('de' => 'de', 'en' => 'en', 'fr' => 'fr', ...)
 *
 * @return array
 */
function get_available_languages() {
	$langs = array();
	$strings_file_paths = glob('view/lang/*/strings.php');

	if (is_array($strings_file_paths) && count($strings_file_paths)) {
		if (!in_array('view/lang/en/strings.php', $strings_file_paths)) {
			$strings_file_paths[] = 'view/lang/en/strings.php';
		}
		asort($strings_file_paths);
		foreach ($strings_file_paths as $strings_file_path) {
			$path_array = explode('/', $strings_file_path);
			$langs[$path_array[2]] = $path_array[2];
		}
	}
	return $langs;
}