<?php

/*

 * This file is part of SwiftMailer.

 * (c) 2004-2009 Chris Corbyn

 *

 * For the full copyright and license information, please view the LICENSE

 * file that was distributed with this source code.

 */

/**

 * Analyzes UTF-8 characters.

 * @package Swift

 * @subpackage Encoder

 * @author Chris Corbyn

 * @author Xavier De Cock <xdecock@gmail.com>

 */

class Swift_CharacterReader_Utf8Reader

  implements Swift_CharacterReader

{

  /** Pre-computed for optimization */

  private static $length_map=array(

//N=0,1,2,3,4,5,6,7,8,9,A,B,C,D,E,F,

    1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1, //0x0N

    1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1, //0x1N

    1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1, //0x2N

    1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1, //0x3N

    1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1, //0x4N

    1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1, //0x5N

    1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1, //0x6N

    1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1, //0x7N

    0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0, //0x8N

    0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0, //0x9N

    0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0, //0xAN

    0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0, //0xBN

    2,2,2,2,2,2,2,2,2,2,2,2,2,2,2,2, //0xCN

    2,2,2,2,2,2,2,2,2,2,2,2,2,2,2,2, //0xDN

    3,3,3,3,3,3,3,3,3,3,3,3,3,3,3,3, //0xEN

    4,4,4,4,4,4,4,4,5,5,5,5,6,6,0,0  //0xFN

 );

  private static $s_length_map=array(

  "\x00"=>1, "\x01"=>1, "\x02"=>1, "\x03"=>1, "\x04"=>1, "\x05"=>1, "\x06"=>1, "\x07"=>1,

  "\x08"=>1, "\x09"=>1, "\x0a"=>1, "\x0b"=>1, "\x0c"=>1, "\x0d"=>1, "\x0e"=>1, "\x0f"=>1,

  "\x10"=>1, "\x11"=>1, "\x12"=>1, "\x13"=>1, "\x14"=>1, "\x15"=>1, "\x16"=>1, "\x17"=>1,

  "\x18"=>1, "\x19"=>1, "\x1a"=>1, "\x1b"=>1, "\x1c"=>1, "\x1d"=>1, "\x1e"=>1, "\x1f"=>1,

  "\x20"=>1, "\x21"=>1, "\x22"=>1, "\x23"=>1, "\x24"=>1, "\x25"=>1, "\x26"=>1, "\x27"=>1,

  "\x28"=>1, "\x29"=>1, "\x2a"=>1, "\x2b"=>1, "\x2c"=>1, "\x2d"=>1, "\x2e"=>1, "\x2f"=>1,

  "\x30"=>1, "\x31"=>1, "\x32"=>1, "\x33"=>1, "\x34"=>1, "\x35"=>1, "\x36"=>1, "\x37"=>1,

  "\x38"=>1, "\x39"=>1, "\x3a"=>1, "\x3b"=>1, "\x3c"=>1, "\x3d"=>1, "\x3e"=>1, "\x3f"=>1,

  "\x40"=>1, "\x41"=>1, "\x42"=>1, "\x43"=>1, "\x44"=>1, "\x45"=>1, "\x46"=>1, "\x47"=>1,

  "\x48"=>1, "\x49"=>1, "\x4a"=>1, "\x4b"=>1, "\x4c"=>1, "\x4d"=>1, "\x4e"=>1, "\x4f"=>1,

  "\x50"=>1, "\x51"=>1, "\x52"=>1, "\x53"=>1, "\x54"=>1, "\x55"=>1, "\x56"=>1, "\x57"=>1,

  "\x58"=>1, "\x59"=>1, "\x5a"=>1, "\x5b"=>1, "\x5c"=>1, "\x5d"=>1, "\x5e"=>1, "\x5f"=>1,

  "\x60"=>1, "\x61"=>1, "\x62"=>1, "\x63"=>1, "\x64"=>1, "\x65"=>1, "\x66"=>1, "\x67"=>1,

  "\x68"=>1, "\x69"=>1, "\x6a"=>1, "\x6b"=>1, "\x6c"=>1, "\x6d"=>1, "\x6e"=>1, "\x6f"=>1,

  "\x70"=>1, "\x71"=>1, "\x72"=>1, "\x73"=>1, "\x74"=>1, "\x75"=>1, "\x76"=>1, "\x77"=>1,

  "\x78"=>1, "\x79"=>1, "\x7a"=>1, "\x7b"=>1, "\x7c"=>1, "\x7d"=>1, "\x7e"=>1, "\x7f"=>1,

  "\x80"=>0, "\x81"=>0, "\x82"=>0, "\x83"=>0, "\x84"=>0, "\x85"=>0, "\x86"=>0, "\x87"=>0,

  "\x88"=>0, "\x89"=>0, "\x8a"=>0, "\x8b"=>0, "\x8c"=>0, "\x8d"=>0, "\x8e"=>0, "\x8f"=>0,

  "\x90"=>0, "\x91"=>0, "\x92"=>0, "\x93"=>0, "\x94"=>0, "\x95"=>0, "\x96"=>0, "\x97"=>0,

  "\x98"=>0, "\x99"=>0, "\x9a"=>0, "\x9b"=>0, "\x9c"=>0, "\x9d"=>0, "\x9e"=>0, "\x9f"=>0,

  "\xa0"=>0, "\xa1"=>0, "\xa2"=>0, "\xa3"=>0, "\xa4"=>0, "\xa5"=>0, "\xa6"=>0, "\xa7"=>0,

  "\xa8"=>0, "\xa9"=>0, "\xaa"=>0, "\xab"=>0, "\xac"=>0, "\xad"=>0, "\xae"=>0, "\xaf"=>0,

  "\xb0"=>0, "\xb1"=>0, "\xb2"=>0, "\xb3"=>0, "\xb4"=>0, "\xb5"=>0, "\xb6"=>0, "\xb7"=>0,

  "\xb8"=>0, "\xb9"=>0, "\xba"=>0, "\xbb"=>0, "\xbc"=>0, "\xbd"=>0, "\xbe"=>0, "\xbf"=>0,

  "\xc0"=>2, "\xc1"=>2, "\xc2"=>2, "\xc3"=>2, "\xc4"=>2, "\xc5"=>2, "\xc6"=>2, "\xc7"=>2,

  "\xc8"=>2, "\xc9"=>2, "\xca"=>2, "\xcb"=>2, "\xcc"=>2, "\xcd"=>2, "\xce"=>2, "\xcf"=>2,

  "\xd0"=>2, "\xd1"=>2, "\xd2"=>2, "\xd3"=>2, "\xd4"=>2, "\xd5"=>2, "\xd6"=>2, "\xd7"=>2,

  "\xd8"=>2, "\xd9"=>2, "\xda"=>2, "\xdb"=>2, "\xdc"=>2, "\xdd"=>2, "\xde"=>2, "\xdf"=>2,

  "\xe0"=>3, "\xe1"=>3, "\xe2"=>3, "\xe3"=>3, "\xe4"=>3, "\xe5"=>3, "\xe6"=>3, "\xe7"=>3,

  "\xe8"=>3, "\xe9"=>3, "\xea"=>3, "\xeb"=>3, "\xec"=>3, "\xed"=>3, "\xee"=>3, "\xef"=>3,

  "\xf0"=>4, "\xf1"=>4, "\xf2"=>4, "\xf3"=>4, "\xf4"=>4, "\xf5"=>4, "\xf6"=>4, "\xf7"=>4,

  "\xf8"=>5, "\xf9"=>5, "\xfa"=>5, "\xfb"=>5, "\xfc"=>6, "\xfd"=>6, "\xfe"=>0, "\xff"=>0,

 );

  /**

   * Returns the complete charactermap

   *

   * @param string $string

   * @param int $startOffset

   * @param array $currentMap

   * @param mixed $ignoredChars

   */

  public function getCharPositions($string, $startOffset, &$currentMap, &$ignoredChars)

  {

  	if (!isset($currentMap['i']) || !isset($currentMap['p']))

  	{

  	  $currentMap['p'] = $currentMap['i'] = array();

   	}

  	$strlen=strlen($string);

  	$charPos=count($currentMap['p']);

  	$foundChars=0;

  	$invalid=false;

  	for ($i=0; $i<$strlen; ++$i)

  	{

  	  $char=$string[$i];

  	  $size=self::$s_length_map[$char];

  	  if ($size==0)

  	  {

  	    /* char is invalid, we must wait for a resync */

  	  	$invalid=true;

  	  	continue;

   	  }

   	  else

   	  {

   	  	if ($invalid==true)

   	  	{

   	  	  /* We mark the chars as invalid and start a new char */

   	  	  $currentMap['p'][$charPos+$foundChars]=$startOffset+$i;

   	      $currentMap['i'][$charPos+$foundChars]=true;

   	      ++$foundChars;

   	      $invalid=false;

   	  	}

   	  	if (($i+$size) > $strlen){

   	  		$ignoredChars=substr($string, $i);

   	  		break;

   	  	}

   	  	for ($j=1; $j<$size; ++$j)

   	  	{

          $char=$string[$i+$j];

          if ($char>"\x7F" && $char<"\xC0")

          {

            // Valid - continue parsing

          }

          else

          {

            /* char is invalid, we must wait for a resync */

            $invalid=true;

            continue 2;

          }

   	  	}

   	  	/* Ok we got a complete char here */

   	  	$lastChar=$currentMap['p'][$charPos+$foundChars]=$startOffset+$i+$size;

   	  	$i+=$j-1;

   	    ++$foundChars;

   	  }

  	}

  	return $foundChars;

  }

  /**

   * Returns mapType

   * @int mapType

   */

  public function getMapType()

  {

  	return self::MAP_TYPE_POSITIONS;

  }

  /**

   * Returns an integer which specifies how many more bytes to read.

   * A positive integer indicates the number of more bytes to fetch before invoking

   * this method again.

   * A value of zero means this is already a valid character.

   * A value of -1 means this cannot possibly be a valid character.

   * @param string $bytes

   * @return int

   */

  public function validateByteSequence($bytes, $size)

  {

    if ($size<1){

      return -1;

    }

    $needed = self::$length_map[$bytes[0]] - $size;

    return ($needed > -1)

      ? $needed

      : -1

      ;

  }

  /**

   * Returns the number of bytes which should be read to start each character.

   * @return int

   */

  public function getInitialByteSize()

  {

    return 1;

  }

}