<?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 US-ASCII characters.
 * @package Swift
 * @subpackage Encoder
 * @author Chris Corbyn
 */
class Swift_CharacterReader_UsAsciiReader
  implements Swift_CharacterReader
{
  /**
   * Returns the complete charactermap
   *
   * @param string $string
   * @param int $startOffset
   * @param string $ignoredChars
   */
  public function getCharPositions($string, $startOffset, &$currentMap, &$ignoredChars)
  {
  	$strlen=strlen($string);
  	$ignoredChars='';
  	for( $i = 0; $i < $strlen; ++$i)
  	{
  	  if ($string[$i]>"\x07F")
  	  { // Invalid char
  	  	$currentMap[$i+$startOffset]=$string[$i];
  	  }
  	}
  	return $strlen;
  }
  
  /**
   * Returns mapType
   * @int mapType
   */
  public function getMapType()
  {
  	return self::MAP_TYPE_INVALID;
  }
 
  /**
   * 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)
  {
    $byte = reset($bytes);
    if (1 == count($bytes) && $byte >= 0x00 && $byte <= 0x7F)
    {
      return 0;
    }
    else
    {
      return -1;
    }
  }

  /**
   * Returns the number of bytes which should be read to start each character.
   * @return int
   */
  public function getInitialByteSize()
  {
    return 1;
  }

}
