<?php
class DKeywordAlias
{
	private $_aliasmap;
	private $_aliaskey;

	public static function GetInstance()
	{
		if ( !isset($GLOBALS['_DKeywordAlias_']) )
			$GLOBALS['_DKeywordAlias_'] = new DKeywordAlias();
		return $GLOBALS['_DKeywordAlias_'];
	}

	public static function NormalizedKey($rawkey)
	{
		$tool = DKeywordAlias::GetInstance();
		return $tool->get_normalized_key($rawkey);
	}

	public static function GetShortPrintKey($normalizedkey)
	{
		$tool = DKeywordAlias::GetInstance();
		return $tool->get_short_print_key($normalizedkey);
	}

	private function __construct()
	{
		$this->define_alias();
		$this->_aliaskey = array();
		foreach ($this->_aliasmap as $nk => $sk) {
			$this->_aliaskey[strtolower($sk)] = $nk;
		}

	}

	private function get_normalized_key($rawkey)
	{
		$key = strtolower($rawkey);
		if ( isset($this->_aliaskey[$key]) )
			return $this->_aliaskey[$key];
		else
			return $key;
	}

	private function get_short_print_key($normalizedkey)
	{
		if ( isset($this->_aliasmap[$normalizedkey]) )
			return $this->_aliasmap[$normalizedkey];
		else
			return NULL;
	}


	private function define_alias()
	{
		// key is all lower case, value is output case
		$this->_aliasmap = array(
				//'accesscontrol' => 'acc',
				//'address' => 'addr',
		);

	}
}