<?php

/* ------------------------------------------------------------------------- */
/* idna_convert.class.php - Encode / Decode Internationalized Domain Names   */
/* (c) 2004-2006 phlyLabs, Berlin (http://phlylabs.de)                       */
/* All rights reserved                                                       */
/* v0.4.4                                                                    */
/* ------------------------------------------------------------------------- */
// {{{ license
/* vim: set expandtab tabstop=4 shiftwidth=4 softtabstop=4 foldmethod=marker: */
//
// +----------------------------------------------------------------------+
// | This library is free software; you can redistribute it and/or modify |
// | it under the terms of the GNU Lesser General Public License as       |
// | published by the Free Software Foundation; either version 2.1 of the |
// | License, or (at your option) any later version.                      |
// |                                                                      |
// | This library is distributed in the hope that it will be useful, but  |
// | WITHOUT ANY WARRANTY; without even the implied warranty of           |
// | MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU    |
// | Lesser General Public License for more details.                      |
// |                                                                      |
// | You should have received a copy of the GNU Lesser General Public     |
// | License along with this library; if not, write to the Free Software  |
// | Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307 |
// | USA.                                                                 |
// +----------------------------------------------------------------------+
//
// }}}

/**
 * Encode/decode Internationalized Domain Names.
 *
 * The class allows to convert internationalized domain names
 * (see RFC 3490 for details) as they can be used with various registries worldwide
 * to be translated between their original (localized) form and their encoded form
 * as it will be used in the DNS (Domain Name System).
 *
 * The class provides two public methods, encode() and decode(), which do exactly
 * what you would expect them to do. You are allowed to use complete domain names,
 * simple strings and complete email addresses as well. That means, that you might
 * use any of the following notations:
 *
 * - www.nörgler.com
 * - xn--nrgler-wxa
 * - xn--brse-5qa.xn--knrz-1ra.info
 *
 * Unicode input might be given as either UTF-8 string, UCS-4 string or UCS-4
 * array. Unicode output is available in the same formats.
 * You can select your preferred format via {@link set_paramter()}.
 *
 * ACE input and output is always expected to be ASCII.
 *
 * @author  Matthias Sommerfeld <mso@phlylabs.de>
 * @version 0.4.3
 *
 */

class idna_convert
{
	// {{{ npdata

	/**
	 * Holds all relevant mapping tables, loaded from a seperate file on construct
	 * See RFC3454 for details
	 *
	 * @var array
	 * @access private
	 */

	var $_np_ = array();

	// }}}
	// Internal settings, do not mess with them

	var $_punycode_prefix = 'xn--';
	var $_invalid_ucs = 0x80000000;
	var $_max_ucs = 0x10FFFF;
	var $_base = 36;
	var $_tmin = 1;
	var $_tmax = 26;
	var $_skew = 38;
	var $_damp = 700;
	var $_initial_bias = 72;
	var $_initial_n = 0x80;
	var $_sbase = 0xAC00;
	var $_lbase = 0x1100;
	var $_vbase = 0x1161;
	var $_tbase = 0x11a7;
	var $_lcount = 19;
	var $_vcount = 21;
	var $_tcount = 28;
	var $_ncount = 588;

	// _vcount * _tcount

	var $_scount = 11172;

	// _lcount * _tcount * _vcount

	var $_error = false;

	// See set_parameter() for details of how to change the following settings
	// from within your script / application

	var $_api_encoding = 'utf8';

	// Default input charset is UTF-8

	var $_allow_overlong = false;

	// Overlong UTF-8 encodings are forbidden

	var $_strict_mode = false;

	// Behave strict or not
	// The constructor

	function idna_convert($options = false)
	{
		$this->slast = $this->_sbase + $this->_lcount * $this->_vcount * $this->_tcount;

		if(function_exists('file_get_contents'))
		{
			$this->_np_ = unserialize(file_get_contents(dirname(__FILE__) . '/npdata.ser'));
		}
		else
		{
			$this->_np_ = unserialize(join('', file(dirname(__FILE__) . '/npdata.ser')));
		}

		// If parameters are given, pass these to the respective method

		if(is_array($options))
		{
			return $this->set_parameter($options);
		}

		return true;
	}

	/**
	 * Sets a new option value. Available options and values:
	 * [encoding - Use either UTF-8, UCS4 as array or UCS4 as string as input ('utf8' for UTF-8,
	 *         'ucs4_string' and 'ucs4_array' respectively for UCS4); The output is always UTF-8]
	 * [overlong - Unicode does not allow unnecessarily long encodings of chars,
	 *             to allow this, set this parameter to true, else to false;
	 *             default is false.]
	 * [strict - true: strict mode, good for registration purposes - Causes errors
	 *           on failures; false: loose mode, ideal for "wildlife" applications
	 *           by silently ignoring errors and returning the original input instead
	 *
	 * @param    mixed     Parameter to set (string: single parameter; array of Parameter => Value pairs)
	 * @param    string    Value to use (if parameter 1 is a string)
	 * @return   boolean   true on success, false otherwise
	 * @access   public
	 */

	function set_parameter($option, $value = false)
	{
		if(!is_array($option))
		{
			$option = array(
				$option => $value
			);
		}

		foreach($option as $k => $v)
		{
			switch($k)
			{
				case 'encoding':

					switch($v)
					{
						case 'utf8':
						case 'ucs4_string':
						case 'ucs4_array':
							$this->_api_encoding = $v;
							break;
						default:
							$this->_error('Set Parameter: Unknown parameter ' . $v . ' for option ' . $k);
							return false;
					}

					break;
				case 'overlong':
					$this->_allow_overlong = ($v) ? true : false;
					break;
				case 'strict':
					$this->_strict_mode = ($v) ? true : false;
					break;
				default:
					$this->_error('Set Parameter: Unknown option ' . $k);
					return false;
			}
		}

		return true;
	}

	/**
	 * Decode a given ACE domain name
	 * @param    string   Domain name (ACE string)
	 * [@param    string   Desired output encoding, see {@link set_parameter}]
	 * @return   string   Decoded Domain name (UTF-8 or UCS-4)
	 * @access   public
	 */

	function decode($input, $one_time_encoding = false)
	{
		// Optionally set

		if($one_time_encoding)
		{
			switch($one_time_encoding)
			{
				case 'utf8':
				case 'ucs4_string':
				case 'ucs4_array':
					break;
				default:
					$this->_error('Unknown encoding ' . $one_time_encoding);
					return false;
			}
		}

		// Make sure to drop any newline characters around

		$input = trim($input);

		// Negotiate input and try to determine, wether it is a plain string,
		// an email address or something like a complete URL

		if(strpos($input, '@'))
		{
			// Maybe it is an email address
			// No no in strict mode

			if($this->_strict_mode)
			{
				$this->_error('Only simple domain name parts can be handled in strict mode');
				return false;
			}

			list($email_pref, $input) = explode('@', $input, 2);
			$arr = explode('.', $input);
			foreach($arr as $k => $v)
			{
				$conv = $this->_decode($v);

				if($conv)$arr[$k] = $conv;
			}

			$return = $email_pref . '@' . join('.', $arr);
		}
		elseif(preg_match('![:\./]!', $input))
		{
			// Or a complete domain name (with or without paths / parameters)
			// No no in strict mode

			if($this->_strict_mode)
			{
				$this->_error('Only simple domain name parts can be handled in strict mode');
				return false;
			}

			$parsed = parse_url($input);

			if(isset($parsed['host']))
			{
				$arr = explode('.', $parsed['host']);
				foreach($arr as $k => $v)
				{
					$conv = $this->_decode($v);

					if($conv)$arr[$k] = $conv;
				}

				$parsed['host'] = join('.', $arr);
				$return = (empty($parsed['scheme']) ? '' : $parsed['scheme'] . (strtolower($parsed['scheme']) == 'mailto' ? ':' : '://')) . (empty($parsed['user']) ? '' : $parsed['user'] . (empty($parsed['pass']) ? '' : ':' . $parsed['pass']) . '@') . $parsed['host'] . (empty($parsed['port']) ? '' : ':' . $parsed['port']) . $parsed['path'] . (empty($parsed['query']) ? '' : '?' . $parsed['query']) . (empty($parsed['fragment']) ? '' : '#' . $parsed['fragment']);
			}
			else
			{
				// parse_url seems to have failed, try without it

				$arr = explode('.', $input);
				foreach($arr as $k => $v)
				{
					$conv = $this->_decode($v);

					if($conv)$arr[$k] = $conv;
				}

				$return = join('.', $arr);
			}
		}
		else
		{
			// Otherwise we consider it being a pure domain name string

			$return = $this->_decode($input);
		}

		// The output is UTF-8 by default, other output formats need conversion here
		// If one time encoding is given, use this, else the objects property

		switch(($one_time_encoding) ? $one_time_encoding : $this->_api_encoding)
		{
			case 'utf8':
				return $return;
				break;
			case 'ucs4_string':
				return $this->_ucs4_to_ucs4_string($this->_utf8_to_ucs4($return));
				break;
			case 'ucs4_array':
				return $this->_utf8_to_ucs4($return);
				break;
			default:
				$this->_error('Unsupported output format');
				return false;
		}
	}

	/**
	 * Encode a given UTF-8 domain name
	 * @param    string   Domain name (UTF-8 or UCS-4)
	 * [@param    string   Desired input encoding, see {@link set_parameter}]
	 * @return   string   Encoded Domain name (ACE string)
	 * @access   public
	 */

	function encode($decoded, $one_time_encoding = false)
	{
		// Forcing conversion of input to UCS4 array
		// If one time encoding is given, use this, else the objects property

		switch(($one_time_encoding) ? $one_time_encoding : $this->_api_encoding)
		{
			case 'utf8':
				$decoded = $this->_utf8_to_ucs4($decoded);
				break;
			case 'ucs4_string':
				$decoded = $this->_ucs4_string_to_ucs4($decoded);
			case 'ucs4_array':
				break;
			default:

				// $this->_error('Unsupported input format: '.$this->_api_encoding);

				$this->_error('Unsupported input format');
				return false;
		}

		// No input, no output, what else did you expect?

		if(empty($decoded))return '';

		// Anchors for iteration

		$last_begin = 0;

		// Output string

		$output = '';
		foreach($decoded as $k => $v)
		{
			// Make sure to use just the plain dot

			switch($v)
			{
				case 0x3002:
				case 0xFF0E:
				case 0xFF61:
					$decoded[$k] = 0x2E;

					// It's right, no break here
					// The codepoints above have to be converted to dots anyway
					// Stumbling across an anchoring character

					
				case 0x2E:
				case 0x2F:
				case 0x3A:
				case 0x3F:
				case 0x40:

					// Neither email addresses nor URLs allowed in strict mode

					if($this->_strict_mode)
					{
						$this->_error('Neither email addresses nor URLs are allowed in strict mode.');
						return false;
					}
					else
					{
						// Skip first char

						if($k)
						{
							$encoded = '';
							$encoded = $this->_encode(array_slice($decoded, $last_begin, (($k) - $last_begin)));

							if($encoded)
							{
								$output.= $encoded;
							}
							else
							{
								$output.= $this->_ucs4_to_utf8(array_slice($decoded, $last_begin, (($k) - $last_begin)));
							}

							$output.= chr($decoded[$k]);
						}

						$last_begin = $k + 1;
					}
			}
		}

		// Catch the rest of the string

		if($last_begin)
		{
			$inp_len = sizeof($decoded);
			$encoded = '';
			$encoded = $this->_encode(array_slice($decoded, $last_begin, (($inp_len) - $last_begin)));

			if($encoded)
			{
				$output.= $encoded;
			}
			else
			{
				$output.= $this->_ucs4_to_utf8(array_slice($decoded, $last_begin, (($inp_len) - $last_begin)));
			}

			return $output;
		}
		else
		{
			if($output = $this->_encode($decoded))
			{
				return $output;
			}
			else
			{
				return $this->_ucs4_to_utf8($decoded);
			}
		}
	}

	/**
	 * Use this method to get the last error ocurred
	 * @param    void
	 * @return   string   The last error, that occured
	 * @access   public
	 */

	function get_last_error()
	{
		return $this->_error;
	}

	/**
	 * The actual decoding algorithm
	 * @access   private
	 */

	function _decode($encoded)
	{
		// We do need to find the Punycode prefix

		if(!preg_match('!^' . preg_quote($this->_punycode_prefix, '!') . '!', $encoded))
		{
			$this->_error('This is not a punycode string');
			return false;
		}

		$encode_test = preg_replace('!^' . preg_quote($this->_punycode_prefix, '!') . '!', '', $encoded);

		// If nothing left after removing the prefix, it is hopeless

		if(!$encode_test)
		{
			$this->_error('The given encoded string was empty');
			return false;
		}

		// Find last occurence of the delimiter

		$delim_pos = strrpos($encoded, '-');

		if($delim_pos > strlen($this->_punycode_prefix))
		{
			for ($k = strlen($this->_punycode_prefix);$k < $delim_pos;++$k)
			{
				$decoded[] = ord($encoded{$k});
			}
		}
		else
		{
			$decoded = array();
		}

		$deco_len = count($decoded);
		$enco_len = strlen($encoded);

		// Wandering through the strings; init

		$is_first = true;
		$bias = $this->_initial_bias;
		$idx = 0;
		$char = $this->_initial_n;
		for ($enco_idx = ($delim_pos) ? ($delim_pos + 1) : 0;$enco_idx < $enco_len;++$deco_len)
		{
			for ($old_idx = $idx, $w = 1, $k = $this->_base;1;$k+= $this->_base)
			{
				$digit = $this->_decode_digit($encoded{$enco_idx++});
				$idx+= $digit * $w;
				$t = ($k <= $bias) ? $this->_tmin : (($k >= $bias + $this->_tmax) ? $this->_tmax : ($k - $bias));

				if($digit < $t)break;
				$w = (int)($w * ($this->_base - $t));
			}

			$bias = $this->_adapt($idx - $old_idx, $deco_len + 1, $is_first);
			$is_first = false;
			$char+= (int)($idx / ($deco_len + 1));
			$idx%= ($deco_len + 1);

			if($deco_len > 0)
			{
				// Make room for the decoded char

				for ($i = $deco_len;$i > $idx;$i--)
				{
					$decoded[$i] = $decoded[($i - 1)];
				}
			}

			$decoded[$idx++] = $char;
		}

		return $this->_ucs4_to_utf8($decoded);
	}

	/**
	 * The actual encoding algorithm
	 * @access   private
	 */

	function _encode($decoded)
	{
		// We cannot encode a domain name containing the Punycode prefix

		$extract = strlen($this->_punycode_prefix);
		$check_pref = $this->_utf8_to_ucs4($this->_punycode_prefix);
		$check_deco = array_slice($decoded, 0, $extract);

		if($check_pref == $check_deco)
		{
			$this->_error('This is already a punycode string');
			return false;
		}

		// We will not try to encode strings consisting of basic code points only

		$encodable = false;
		foreach($decoded as $k => $v)
		{
			if($v > 0x7a)
			{
				$encodable = true;
				break;
			}
		}

		if(!$encodable)
		{
			$this->_error('The given string does not contain encodable chars');
			return false;
		}

		// Do NAMEPREP

		$decoded = $this->_nameprep($decoded);

		if(!$decoded
		   || !is_array($decoded))return false;

		// NAMEPREP failed

		$deco_len = count($decoded);

		if(!$deco_len)return false;

		// Empty array

		$codecount = 0;

		// How many chars have been consumed

		$encoded = '';

		// Copy all basic code points to output

		for ($i = 0;$i < $deco_len;++$i)
		{
			$test = $decoded[$i];

			// Will match [-0-9a-zA-Z]

			if((0x2F < $test && $test < 0x40)
			   || (0x40 < $test && $test < 0x5B)
			   || (0x60 < $test && $test <= 0x7B)
			   || (0x2D == $test))
			{
				$encoded.= chr($decoded[$i]);
				$codecount++;
			}
		}

		if($codecount == $deco_len)return $encoded;

		// All codepoints were basic ones
		// Start with the prefix; copy it to output

		$encoded = $this->_punycode_prefix . $encoded;

		// If we have basic code points in output, add an hyphen to the end

		if($codecount)$encoded.= '-';

		// Now find and encode all non-basic code points

		$is_first = true;
		$cur_code = $this->_initial_n;
		$bias = $this->_initial_bias;
		$delta = 0;

		while($codecount < $deco_len)
		{
			// Find the smallest code point >= the current code point and
			// remember the last ouccrence of it in the input

			for ($i = 0, $next_code = $this->_max_ucs;$i < $deco_len;$i++)
			{
				if($decoded[$i] >= $cur_code
				   && $decoded[$i] <= $next_code)
				{
					$next_code = $decoded[$i];
				}
			}

			$delta+= ($next_code - $cur_code) * ($codecount + 1);
			$cur_code = $next_code;

			// Scan input again and encode all characters whose code point is $cur_code

			for ($i = 0;$i < $deco_len;$i++)
			{
				if($decoded[$i] < $cur_code)
				{
					$delta++;
				}
				elseif($decoded[$i] == $cur_code)
				{
					for ($q = $delta, $k = $this->_base;1;$k+= $this->_base)
					{
						$t = ($k <= $bias) ? $this->_tmin : (($k >= $bias + $this->_tmax) ? $this->_tmax : $k - $bias);

						if($q < $t)break;
						$encoded.= $this->_encode_digit(ceil($t + (($q - $t) % ($this->_base - $t))));
						$q = (int)(($q - $t) / ($this->_base - $t));
					}

					$encoded.= $this->_encode_digit($q);
					$bias = $this->_adapt($delta, $codecount + 1, $is_first);
					$codecount++;
					$delta = 0;
					$is_first = false;
				}
			}

			$delta++;
			$cur_code++;
		}

		return $encoded;
	}

	/**
	 * Adapt the bias according to the current code point and position
	 * @access   private
	 */

	function _adapt($delta, $npoints, $is_first)
	{
		$delta = (int)($is_first ? ($delta / $this->_damp) : ($delta / 2));
		$delta+= (int)($delta / $npoints);
		for ($k = 0;$delta > (($this->_base - $this->_tmin) * $this->_tmax) / 2;$k+= $this->_base)
		{
			$delta = (int)($delta / ($this->_base - $this->_tmin));
		}

		return (int)($k + ($this->_base - $this->_tmin + 1) * $delta / ($delta + $this->_skew));
	}

	/**
	 * Encoding a certain digit
	 * @access   private
	 */

	function _encode_digit($d)
	{
		return chr($d + 22 + 75 * ($d < 26));
	}

	/**
	 * Decode a certain digit
	 * @access   private
	 */

	function _decode_digit($cp)
	{
		$cp = ord($cp);
		return ($cp - 48 < 10) ? $cp - 22 : (($cp - 65 < 26) ? $cp - 65 : (($cp - 97 < 26) ? $cp - 97 : $this->_base));
	}

	/**
	 * Internal error handling method
	 * @access   private
	 */

	function _error($error = '')
	{
		$this->_error = $error;
	}

	/**
	 * Do Nameprep according to RFC3491 and RFC3454
	 * @param    array    Unicode Characters
	 * @return   string   Unicode Characters, Nameprep'd
	 * @access   private
	 */

	function _nameprep($input)
	{
		$output = array();
		$error = false;

		//
		// Mapping
		// Walking through the input array, performing the required steps on each of
		// the input chars and putting the result into the output array
		// While mapping required chars we apply the cannonical ordering
		// $this->_show_hex($input);

		foreach($input as $v)
		{
			// Map to nothing == skip that code point

			if(in_array($v, $this->_np_['map_nothing']))continue;

			// Try to find prohibited input

			if(in_array($v, $this->_np_['prohibit'])
			   || in_array($v, $this->_np_['general_prohibited']))
			{
				$this->_error('NAMEPREP: Prohibited input U+' . sprintf('%08X', $v));
				return false;
			}

			foreach($this->_np_['prohibit_ranges'] as $range)
			{
				if($range[0] <= $v
				   && $v <= $range[1])
				{
					$this->_error('NAMEPREP: Prohibited input U+' . sprintf('%08X', $v));
					return false;
				}
			}

			//
			// Hangul syllable decomposition

			if(0xAC00 <= $v
			   && $v <= 0xD7AF)
			{
				foreach($this->_hangul_decompose($v) as $out)
				{
					$output[] = $out;
				}

				// There's a decomposition mapping for that code point
			}
			elseif(isset($this->_np_['replacemaps'][$v]))
			{
				foreach($this->_apply_cannonical_ordering($this->_np_['replacemaps'][$v]) as $out)
				{
					$output[] = $out;
				}
			}
			else
			{
				$output[] = $v;
			}
		}

		// Before applying any Combining, try to rearrange any Hangul syllables

		$output = $this->_hangul_compose($output);

		//
		// Combine code points
		//

		$last_class = 0;
		$last_starter = 0;
		$out_len = count($output);
		for ($i = 0;$i < $out_len;++$i)
		{
			$class = $this->_get_combining_class($output[$i]);

			if((!$last_class || $last_class > $class)
			   && $class)
			{
				// Try to match

				$seq_len = $i - $last_starter;
				$out = $this->_combine(array_slice($output, $last_starter, $seq_len));

				// On match: Replace the last starter with the composed character and remove
				// the now redundant non-starter(s)

				if($out)
				{
					$output[$last_starter] = $out;

					if(count($out) != $seq_len)
					{
						for ($j = $i + 1;$j < $out_len;++$j)
						{
							$output[$j - 1] = $output[$j];
						}

						unset($output[$out_len]);
					}

					// Rewind the for loop by one, since there can be more possible compositions

					$i--;
					$out_len--;
					$last_class = ($i == $last_starter) ? 0 : $this->_get_combining_class($output[$i - 1]);
					continue;
				}
			}

			if(!$class)
			{
				// The current class is 0

				$last_starter = $i;
			}

			$last_class = $class;
		}

		return $output;
	}

	/**
	 * Decomposes a Hangul syllable
	 * (see http://www.unicode.org/unicode/reports/tr15/#Hangul
	 * @param    integer  32bit UCS4 code point
	 * @return   array    Either Hangul Syllable decomposed or original 32bit value as one value array
	 * @access   private
	 */

	function _hangul_decompose($char)
	{
		$sindex = $char - $this->_sbase;

		if($sindex < 0
		   || $sindex >= $this->_scount)
		{
			return array(
				$char
			);
		}

		$result = array();
		$T = $this->_tbase + ($sindex % $this->_tcount);
		$result[] = (int)($this->_lbase + $sindex / $this->_ncount);
		$result[] = (int)$this->_vbase + (($sindex % $this->_ncount) / $this->_tcount);

		if($T != $this->_tbase)$result[] = $T;
		return $result;
	}

	/**
	 * Ccomposes a Hangul syllable
	 * (see http://www.unicode.org/unicode/reports/tr15/#Hangul
	 * @param    array    Decomposed UCS4 sequence
	 * @return   array    UCS4 sequence with syllables composed
	 * @access   private
	 */

	function _hangul_compose($input)
	{
		$inp_len = count($input);

		if(!$inp_len)return array();
		$result = array();
		$last = $input[0];
		$result[] = $last;

		// copy first char from input to output

		for ($i = 1;$i < $inp_len;++$i)
		{
			$char = $input[$i];

			// Find out, wether two current characters from L and V

			$lindex = $last - $this->_lbase;

			if(0 <= $lindex
			   && $lindex < $this->_lcount)
			{
				$vindex = $char - $this->_vbase;

				if(0 <= $vindex
				   && $vindex < $this->_vcount)
				{
					// create syllable of form LV

					$last = ($this->_sbase + ($lindex * $this->_vcount + $vindex) * $this->_tcount);
					$out_off = count($result) - 1;
					$result[$out_off] = $last;

					// reset last

					continue;

					// discard char
				}
			}

			// Find out, wether two current characters are LV and T

			$sindex = $last - $this->_sbase;

			if(0 <= $sindex
			   && $sindex < $this->_scount
			   && ($sindex % $this->_tcount) == 0)
			{
				$tindex = $char - $this->_tbase;

				if(0 <= $tindex
				   && $tindex <= $this->_tcount)
				{
					// create syllable of form LVT

					$last+= $tindex;
					$out_off = count($result) - 1;
					$result[$out_off] = $last;

					// reset last

					continue;

					// discard char
				}
			}

			// if neither case was true, just add the character

			$last = $char;
			$result[] = $char;
		}

		return $result;
	}

	/**
	 * Returns the combining class of a certain wide char
	 * @param    integer    Wide char to check (32bit integer)
	 * @return   integer    Combining class if found, else 0
	 * @access   private
	 */

	function _get_combining_class($char)
	{
		return isset($this->_np_['norm_combcls'][$char]) ? $this->_np_['norm_combcls'][$char] : 0;
	}

	/**
	 * Apllies the cannonical ordering of a decomposed UCS4 sequence
	 * @param    array      Decomposed UCS4 sequence
	 * @return   array      Ordered USC4 sequence
	 * @access   private
	 */

	function _apply_cannonical_ordering($input)
	{
		$swap = true;
		$size = count($input);

		while($swap)
		{
			$swap = false;
			$last = $this->_get_combining_class($input[0]);
			for ($i = 0;$i < $size - 1;++$i)
			{
				$next = $this->_get_combining_class($input[$i + 1]);

				if($next != 0
				   && $last > $next)
				{
					// Move item leftward until it fits

					for ($j = $i + 1;$j > 0;--$j)
					{
						if($this->_get_combining_class($input[$j - 1]) <= $next)break;
						$t = $input[$j];
						$input[$j] = $input[$j - 1];
						$input[$j - 1] = $t;
						$swap = 1;
					}

					// Reentering the loop looking at the old character again

					$next = $last;
				}

				$last = $next;
			}
		}

		return $input;
	}

	/**
	 * Do composition of a sequence of starter and non-starter
	 * @param    array      UCS4 Decomposed sequence
	 * @return   array      Ordered USC4 sequence
	 * @access   private
	 */

	function _combine($input)
	{
		$inp_len = count($input);
		foreach($this->_np_['replacemaps'] as $np_src => $np_target)
		{
			if($np_target[0] != $input[0])continue;

			if(count($np_target) != $inp_len)continue;
			$hit = false;
			foreach($input as $k2 => $v2)
			{
				if($v2 == $np_target[$k2])
				{
					$hit = true;
				}
				else
				{
					$hit = false;
					break;
				}
			}

			if($hit)return $np_src;
		}

		return false;
	}

	/**
	 * This converts an UTF-8 encoded string to its UCS-4 representation
	 * By talking about UCS-4 "strings" we mean arrays of 32bit integers representing
	 * each of the "chars". This is due to PHP not being able to handle strings with
	 * bit depth different from 8. This apllies to the reverse method _ucs4_to_utf8(), too.
	 * The following UTF-8 encodings are supported:
	 * bytes bits  representation
	 * 1        7  0xxxxxxx
	 * 2       11  110xxxxx 10xxxxxx
	 * 3       16  1110xxxx 10xxxxxx 10xxxxxx
	 * 4       21  11110xxx 10xxxxxx 10xxxxxx 10xxxxxx
	 * 5       26  111110xx 10xxxxxx 10xxxxxx 10xxxxxx 10xxxxxx
	 * 6       31  1111110x 10xxxxxx 10xxxxxx 10xxxxxx 10xxxxxx 10xxxxxx
	 * Each x represents a bit that can be used to store character data.
	 * The five and six byte sequences are part of Annex D of ISO/IEC 10646-1:2000
	 * @access   private
	 */

	function _utf8_to_ucs4($input)
	{
		$output = array();
		$out_len = 0;
		$inp_len = strlen($input);
		$mode = 'next';
		$test = 'none';
		for ($k = 0;$k < $inp_len;++$k)
		{
			$v = ord($input{$k});

			// Extract byte from input string

			if($v < 128)
			{
				// We found an ASCII char - put into stirng as is

				$output[$out_len] = $v;
				++$out_len;

				if('add' == $mode)
				{
					$this->_error('Conversion from UTF-8 to UCS-4 failed: malformed input at byte ' . $k);
					return false;
				}

				continue;
			}

			if('next' == $mode)
			{
				// Try to find the next start byte; determine the width of the Unicode char

				$start_byte = $v;
				$mode = 'add';
				$test = 'range';

				if($v >> 5 == 6)
				{
					// &110xxxxx 10xxxxx

					$next_byte = 0;

					// Tells, how many times subsequent bitmasks must rotate 6bits to the left

					$v = ($v - 192) << 6;
				}
				elseif($v >> 4 == 14)
				{
					// &1110xxxx 10xxxxxx 10xxxxxx

					$next_byte = 1;
					$v = ($v - 224) << 12;
				}
				elseif($v >> 3 == 30)
				{
					// &11110xxx 10xxxxxx 10xxxxxx 10xxxxxx

					$next_byte = 2;
					$v = ($v - 240) << 18;
				}
				elseif($v >> 2 == 62)
				{
					// &111110xx 10xxxxxx 10xxxxxx 10xxxxxx 10xxxxxx

					$next_byte = 3;
					$v = ($v - 248) << 24;
				}
				elseif($v >> 1 == 126)
				{
					// &1111110x 10xxxxxx 10xxxxxx 10xxxxxx 10xxxxxx 10xxxxxx

					$next_byte = 4;
					$v = ($v - 252) << 30;
				}
				else
				{
					$this->_error('This might be UTF-8, but I don\'t understand it at byte ' . $k);
					return false;
				}

				if('add' == $mode)
				{
					$output[$out_len] = (int)$v;
					++$out_len;
					continue;
				}
			}

			if('add' == $mode)
			{
				if(!$this->_allow_overlong
				   && $test == 'range')
				{
					$test = 'none';

					if(($v < 0xA0 && $start_byte == 0xE0)
					   || ($v < 0x90 && $start_byte == 0xF0)
					   || ($v > 0x8F && $start_byte == 0xF4))
					{
						$this->_error('Bogus UTF-8 character detected (out of legal range) at byte ' . $k);
						return false;
					}
				}

				if($v >> 6 == 2)
				{
					// Bit mask must be 10xxxxxx

					$v = ($v - 128) << ($next_byte * 6);
					$output[($out_len - 1)]+= $v;
					--$next_byte;
				}
				else
				{
					$this->_error('Conversion from UTF-8 to UCS-4 failed: malformed input at byte ' . $k);
					return false;
				}

				if($next_byte < 0)
				{
					$mode = 'next';
				}
			}
		}

		// for

		return $output;
	}

	/**
	 * Convert UCS-4 string into UTF-8 string
	 * See _utf8_to_ucs4() for details
	 * @access   private
	 */

	function _ucs4_to_utf8($input)
	{
		$output = '';
		$k = 0;
		foreach($input as $v)
		{
			++$k;

			// $v = ord($v);

			if($v < 128)
			{
				// 7bit are transferred literally

				$output.= chr($v);
			}
			elseif($v < (1 << 11))
			{
				// 2 bytes

				$output.= chr(192 + ($v >> 6)) . chr(128 + ($v & 63));
			}
			elseif($v < (1 << 16))
			{
				// 3 bytes

				$output.= chr(224 + ($v >> 12)) . chr(128 + (($v >> 6) & 63)) . chr(128 + ($v & 63));
			}
			elseif($v < (1 << 21))
			{
				// 4 bytes

				$output.= chr(240 + ($v >> 18)) . chr(128 + (($v >> 12) & 63)) . chr(128 + (($v >> 6) & 63)) . chr(128 + ($v & 63));
			}
			elseif($v < (1 << 26))
			{
				// 5 bytes

				$output.= chr(248 + ($v >> 24)) . chr(128 + (($v >> 18) & 63)) . chr(128 + (($v >> 12) & 63)) . chr(128 + (($v >> 6) & 63)) . chr(128 + ($v & 63));
			}
			elseif($v < (1 << 31))
			{
				// 6 bytes

				$output.= chr(252 + ($v >> 30)) . chr(128 + (($v >> 24) & 63)) . chr(128 + (($v >> 18) & 63)) . chr(128 + (($v >> 12) & 63)) . chr(128 + (($v >> 6) & 63)) . chr(128 + ($v & 63));
			}
			else
			{
				$this->_error('Conversion from UCS-4 to UTF-8 failed: malformed input at byte ' . $k);
				return false;
			}
		}

		return $output;
	}

	/**
	 * Convert UCS-4 array into UCS-4 string
	 *
	 * @access   private
	 */

	function _ucs4_to_ucs4_string($input)
	{
		$output = '';

		// Take array values and split output to 4 bytes per value
		// The bit mask is 255, which reads &11111111

		foreach($input as $v)
		{
			$output.= chr(($v >> 24) & 255) . chr(($v >> 16) & 255) . chr(($v >> 8) & 255) . chr($v & 255);
		}

		return $output;
	}

	/**
	 * Convert UCS-4 strin into UCS-4 garray
	 *
	 * @access   private
	 */

	function _ucs4_string_to_ucs4($input)
	{
		$output = array();
		$inp_len = strlen($input);

		// Input length must be dividable by 4

		if($inp_len % 4)
		{
			$this->_error('Input UCS4 string is broken');
			return false;
		}

		// Empty input - return empty output

		if(!$inp_len)return $output;
		for ($i = 0, $out_len = - 1;$i < $inp_len;++$i)
		{
			// Increment output position every 4 input bytes

			if(!($i % 4))
			{
				$out_len++;
				$output[$out_len] = 0;
			}

			$output[$out_len]+= ord($input{$i}) << (8 * (3 - ($i % 4)));
		}

		return $output;
	}
}

/**
 * Adapter class for aligning the API of idna_convert with that of Net_IDNA
 * @author  Matthias Sommerfeld <mso@phlylabs.de>
 */

class Net_IDNA_php4 extends idna_convert
{
	/**
	 * Sets a new option value. Available options and values:
	 * [encoding - Use either UTF-8, UCS4 as array or UCS4 as string as input ('utf8' for UTF-8,
	 *         'ucs4_string' and 'ucs4_array' respectively for UCS4); The output is always UTF-8]
	 * [overlong - Unicode does not allow unnecessarily long encodings of chars,
	 *             to allow this, set this parameter to true, else to false;
	 *             default is false.]
	 * [strict - true: strict mode, good for registration purposes - Causes errors
	 *           on failures; false: loose mode, ideal for "wildlife" applications
	 *           by silently ignoring errors and returning the original input instead
	 *
	 * @param    mixed     Parameter to set (string: single parameter; array of Parameter => Value pairs)
	 * @param    string    Value to use (if parameter 1 is a string)
	 * @return   boolean   true on success, false otherwise
	 * @access   public
	 */

	function setParams($option, $param = false)
	{
		return $this->IC->set_parameters($option, $param);
	}
}

?>