<?php

namespace Masterminds\HTML5\Parser;

use Masterminds\HTML5\Entities;

/**
* Manage entity references.
*
* This is a simple resolver for HTML5 character reference entitites. See Entities for the list of supported entities.
*/
class CharacterReference
{
protected static $numeric_mask = array(
0x0,
0x2FFFF,
0,
0xFFFF,
);

/**
* Given a name (e.g. 'amp'), lookup the UTF-8 character ('&').
*
* @param string $name The name to look up.
*
* @return string The character sequence. In UTF-8 this may be more than one byte.
*/
public static function lookupName($name)
{
// Do we really want to return NULL here? or FFFD
return isset(Entities::$byName[$name]) ? Entities::$byName[$name] : null;
}

/**
* Given a decimal number, return the UTF-8 character.
*
* @param $int
*
* @return false|string|string[]|null
*/
public static function lookupDecimal($int)
{
$entity = '&#' . $int . ';';

// UNTESTED: This may fail on some planes. Couldn't find full documentation
// on the value of the mask array.
return mb_decode_numericentity($entity, static::$numeric_mask, 'utf-8');
}

/**
* Given a hexidecimal number, return the UTF-8 character.
*
* @param $hexdec
*
* @return false|string|string[]|null
*/
public static function lookupHex($hexdec)
{
return static::lookupDecimal(hexdec($hexdec));
}
}