<?php
/*
	Written by Gary Hollands - 2008
	With help from Ian Thomas of Tantric Technologies
	Partially adapted from http://www.phptutorial.info/scripts/languagesscript.html
	An advert for these websites - www.solriche.co.uk, www.tantric.coop, www.ttc-hosting.co.uk
	This work is available under the terms of the GNU General Public License, http://www.gnu.org/licenses/gpl.html
*/
class browser_language_detect {
		var $base_language;
		var $default_language;
		var $languages_from_browser;
		var $pos;
		var $full_data;

	function browser_language_detect($default_language){//$default_language is set by the site administrator and matches one of the available languages
		$this->base_language = '';
		$base_language = '';
		$this->default_language = $default_language;

		//An array of available languages based on the ISO 639-1 standard
		$available_languages_array = array(
		"ar",		// "Arabic",
		"en",		// "English",
		"de",		// "German",
		"el",		// "Greek",
		"es",		// "Spanish",
		"fr",		// "French",
		"it",		// "Italian",
		"zh",		// "Chinese",
		);
		
		//GH - strtolower changes the returned string to lower case to match the keys of the $languages_array
		if (isset($_SERVER['HTTP_ACCEPT_LANGUAGE'])){
			$languages_from_browser = strtolower($_SERVER["HTTP_ACCEPT_LANGUAGE"]);
		}else{
			$languages_from_browser = null;// it'a bot or search engine
		}
		//Get position of ";" in languages (for values such as "en,es;q=0.5")
		$pos = stripos($languages_from_browser,";");
		if ($pos>0){
		//Get the string from the first character onwards excluding chars after the ; character.
			$languages_from_browser = substr($languages_from_browser,0,$pos);
		}
		//chop string into chunks using ; as delimiter
		$full_data = array_map("trim", explode(";", $languages_from_browser));
		//further chop the string using , to leave the full language-country pair.
		$full_data = array_map("trim", explode(",", $full_data[0]));
		$this->full_browser_string = $full_data[0];
		$browser_string = $this->full_browser_string;

		/******************************* Next Bit *******************************/
		//Now need to compare the results to the available languages in the $available_languages_array to find if there is a match or not
		//If there is a match the matched language become the default language and is loaded either in the form of web pages or dictionaries
		//If there is no match then the language default remains the $default_language set by the user.

		//We look through to find an exact match of the language-country pair to the $available_languages_array
		foreach ($available_languages_array as $arrayItem){
			if ($arrayItem == $browser_string){
				$default_language = $arrayItem;
				$this->default_language = $arrayItem;//Load the relevant dictionaries or language files
				return;
			} 
		}
		//Else find the language (1st 2 letters) part of the language country pair and set the default language to the language part.
		foreach ($available_languages_array as $arrayItem){
			$pos=stripos($browser_string,"-");
			if ($pos>0){
				$base_language = substr($browser_string,0,$pos);
			}
			if ($arrayItem == $base_language){
				$default_language = $arrayItem;
				$this->default_language = $arrayItem;//Load the relevant dictionaries or language files
				return;
			}
		}	   
		// Didn't find a matching language in the $available_languages_array, load the relevant dictionaries or language files.
		$this->default_language = $default_language;
	}
}
$default_language = 'en';//Default page language is set by the site administrator
$locale = new browser_language_detect($default_language);
?>