<?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.

 */

/**

 * Handles binary/7/8-bit Transfer Encoding in Swift Mailer.

 * @package Swift

 * @subpackage Mime

 * @author Chris Corbyn

 */

class Swift_Mime_ContentEncoder_PlainContentEncoder

  implements Swift_Mime_ContentEncoder

{

  /**

   * The name of this encoding scheme (probably 7bit or 8bit).

   * @var string

   * @access private

   */

  private $_name;

  /**

   * True if canonical transformations should be done.

   * @var boolean

   * @access private

   */

  private $_canonical;

  /**

   * Creates a new PlainContentEncoder with $name (probably 7bit or 8bit).

   * @param string $name

   * @param boolean $canonical If canonicalization transformation should be done.

   */

  public function __construct($name, $canonical = false)

  {

    $this->_name = $name;

    $this->_canonical = $canonical;

  }

  /**

   * Encode a given string to produce an encoded string.

   * @param string $string

   * @param int $firstLineOffset, ignored

   * @param int $maxLineLength - 0 means no wrapping will occur

   * @return string

   */

  public function encodeString($string, $firstLineOffset = 0,

    $maxLineLength = 0)

  {

    if ($this->_canonical)

    {

      $string = $this->_canonicalize($string);

    }

    return $this->_safeWordWrap($string, $maxLineLength, "\r\n");

  }

  /**

   * Encode stream $in to stream $out.

   * @param Swift_OutputByteStream $in

   * @param Swift_InputByteStream $out

   * @param int $firstLineOffset, ignored

   * @param int $maxLineLength, optional, 0 means no wrapping will occur

   */

  public function encodeByteStream(

    Swift_OutputByteStream $os, Swift_InputByteStream $is, $firstLineOffset = 0,

    $maxLineLength = 0)

  {

    $leftOver = '';

    while (false !== $bytes = $os->read(8192))

    {

      $toencode = $leftOver . $bytes;

      if ($this->_canonical)

      {

        $toencode = $this->_canonicalize($toencode);

      }

      $wrapped = $this->_safeWordWrap($toencode, $maxLineLength, "\r\n");

      $lastLinePos = strrpos($wrapped, "\r\n");

      $leftOver = substr($wrapped, $lastLinePos);

      $wrapped = substr($wrapped, 0, $lastLinePos);

      $is->write($wrapped);

    }

    if (strlen($leftOver))

    {

      $is->write($leftOver);

    }

  }

  /**

   * Get the name of this encoding scheme.

   * @return string

   */

  public function getName()

  {

    return $this->_name;

  }

  /**

   * Not used.

   */

  public function charsetChanged($charset)

  {

  }

  // -- Private methods

  /**

   * A safer (but weaker) wordwrap for unicode.

   * @param string $string

   * @param int $length

   * @param string $le

   * @return string

   * @access private

   */

  private function _safeWordwrap($string, $length = 75, $le = "\r\n")

  {

    if (0 >= $length)

    {

      return $string;

    }

    $originalLines = explode($le, $string);

    $lines = array();

    $lineCount = 0;

    foreach ($originalLines as $originalLine)

    {

      $lines[] = '';

      $currentLine =& $lines[$lineCount++];

      //$chunks = preg_split('/(?<=[\ \t,\.!\?\-&\+\/])/', $originalLine);

      $chunks = preg_split('/(?<=\s)/', $originalLine);

      foreach ($chunks as $chunk)

      {

        if (0 != strlen($currentLine)

          && strlen($currentLine . $chunk) > $length)

        {

          $lines[] = '';

          $currentLine =& $lines[$lineCount++];

        }

        $currentLine .= $chunk;

      }

    }

    return implode("\r\n", $lines);

  }

  /**

   * Canonicalize string input (fix CRLF).

   * @param string $string

   * @return string

   * @access private

   */

  private function _canonicalize($string)

  {

    return str_replace(

      array("\r\n", "\r", "\n"),

      array("\n", "\n", "\r\n"),

      $string

      );

  }

}