<?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.
 */

//@require 'Swift/Mime/HeaderSet.php';
//@require 'Swift/Mime/HeaderFactory.php';

/**
 * A collection of MIME headers.
 * 
 * @package Swift
 * @subpackage Mime
 * 
 * @author Chris Corbyn
 */
class Swift_Mime_SimpleHeaderSet implements Swift_Mime_HeaderSet
{
  
  /** HeaderFactory */
  private $_factory;
  
  /** Collection of set Headers */
  private $_headers = array();
  
  /** Field ordering details */
  private $_order = array();
  
  /** List of fields which are required to be displayed */
  private $_required = array();
  
  /** The charset used by Headers */
  private $_charset;
  
  /**
   * Create a new SimpleHeaderSet with the given $factory.
   * 
   * @param Swift_Mime_HeaderFactory $factory
   * @param string $charset
   */
  public function __construct(Swift_Mime_HeaderFactory $factory,
    $charset = null)
  {
    $this->_factory = $factory;
    if (isset($charset))
    {
      $this->setCharset($charset);
    }
  }
  
  /**
   * Set the charset used by these headers.
   * 
   * @param string $charset
   */
  public function setCharset($charset)
  {
    $this->_charset = $charset;
    $this->_factory->charsetChanged($charset);
    $this->_notifyHeadersOfCharset($charset);
  }
  
  /**
   * Add a new Mailbox Header with a list of $addresses.
   * 
   * @param string $name
   * @param array|string $addresses
   */
  public function addMailboxHeader($name, $addresses = null)
  {
    $this->_storeHeader($name,
      $this->_factory->createMailboxHeader($name, $addresses));
  }
  
  /**
   * Add a new Date header using $timestamp (UNIX time).
   * 
   * @param string $name
   * @param int $timestamp
   */
  public function addDateHeader($name, $timestamp = null)
  {
    $this->_storeHeader($name,
      $this->_factory->createDateHeader($name, $timestamp));
  }
  
  /**
   * Add a new basic text header with $name and $value.
   * 
   * @param string $name
   * @param string $value
   */
  public function addTextHeader($name, $value = null)
  {
    $this->_storeHeader($name,
      $this->_factory->createTextHeader($name, $value));
  }
  
  /**
   * Add a new ParameterizedHeader with $name, $value and $params.
   * 
   * @param string $name
   * @param string $value
   * @param array $params
   */
  public function addParameterizedHeader($name, $value = null,
    $params = array())
  {
    $this->_storeHeader($name,
      $this->_factory->createParameterizedHeader($name, $value,
      $params));
  }
  
  /**
   * Add a new ID header for Message-ID or Content-ID.
   * 
   * @param string $name
   * @param string|array $ids
   */
  public function addIdHeader($name, $ids = null)
  {
    $this->_storeHeader($name, $this->_factory->createIdHeader($name, $ids));
  }
  
  /**
   * Add a new Path header with an address (path) in it.
   * 
   * @param string $name
   * @param string $path
   */
  public function addPathHeader($name, $path = null)
  {
    $this->_storeHeader($name, $this->_factory->createPathHeader($name, $path));
  }
  
  /**
   * Returns true if at least one header with the given $name exists.
   * 
   * If multiple headers match, the actual one may be specified by $index.
   * 
   * @param string $name
   * @param int $index
   * 
   * @return boolean
   */
  public function has($name, $index = 0)
  {
    $lowerName = strtolower($name);
    return array_key_exists($lowerName, $this->_headers)
      && array_key_exists($index, $this->_headers[$lowerName]);
  }
  
  /**
   * Set a header in the HeaderSet.
   * 
   * The header may be a previously fetched header via {@link get()} or it may
   * be one that has been created separately.
   * 
   * If $index is specified, the header will be inserted into the set at this
   * offset.
   * 
   * @param Swift_Mime_Header $header
   * @param int $index
   */
  public function set(Swift_Mime_Header $header, $index = 0)
  {
    $this->_storeHeader($header->getFieldName(), $header, $index);
  }
  
  /**
   * Get the header with the given $name.
   * 
   * If multiple headers match, the actual one may be specified by $index.
   * Returns NULL if none present.
   * 
   * @param string $name
   * @param int $index
   * 
   * @return Swift_Mime_Header
   */
  public function get($name, $index = 0)
  {
    if ($this->has($name, $index))
    {
      $lowerName = strtolower($name);
      return $this->_headers[$lowerName][$index];
    }
  }
  
  /**
   * Get all headers with the given $name.
   * 
   * @param string $name
   * 
   * @return array
   */
  public function getAll($name = null)
  {
    if (!isset($name))
    {
      $headers = array();
      foreach ($this->_headers as $collection)
      {
        $headers = array_merge($headers, $collection);
      }
      return $headers;
    }
    
    $lowerName = strtolower($name);
    if (!array_key_exists($lowerName, $this->_headers))
    {
      return array();
    }
    return $this->_headers[$lowerName];
  }
  
  /**
   * Remove the header with the given $name if it's set.
   * 
   * If multiple headers match, the actual one may be specified by $index.
   * 
   * @param string $name
   * @param int $index
   */
  public function remove($name, $index = 0)
  {
    $lowerName = strtolower($name);
    unset($this->_headers[$lowerName][$index]);
  }
  
  /**
   * Remove all headers with the given $name.
   * 
   * @param string $name
   */
  public function removeAll($name)
  {
    $lowerName = strtolower($name);
    unset($this->_headers[$lowerName]);
  }
  
  /**
   * Create a new instance of this HeaderSet.
   * 
   * @return Swift_Mime_HeaderSet
   */
  public function newInstance()
  {
    return new self($this->_factory);
  }
  
  /**
   * Define a list of Header names as an array in the correct order.
   * 
   * These Headers will be output in the given order where present.
   * 
   * @param array $sequence
   */
  public function defineOrdering(array $sequence)
  {
    $this->_order = array_flip(array_map('strtolower', $sequence));
  }
  
  /**
   * Set a list of header names which must always be displayed when set.
   * 
   * Usually headers without a field value won't be output unless set here.
   * 
   * @param array $names
   */
  public function setAlwaysDisplayed(array $names)
  {
    $this->_required = array_flip(array_map('strtolower', $names));
  }

  /**
   * Notify this observer that the entity's charset has changed.
   * 
   * @param string $charset
   */
  public function charsetChanged($charset)
  {
    $this->setCharset($charset);
  }
  
  /**
   * Returns a string with a representation of all headers.
   * 
   * @return string
   */
  public function toString()
  {
    $string = '';
    $headers = $this->_headers;
    if ($this->_canSort())
    {
      uksort($headers, array($this, '_sortHeaders'));
    }
    foreach ($headers as $collection)
    {
      foreach ($collection as $header)
      {
        if ($this->_isDisplayed($header) || $header->getFieldBody() != '')
        {
          $string .= $header->toString();
        }
      }
    }
    return $string;
  }
  
  /**
   * Returns a string representation of this object.
   *
   * @return string
   *
   * @see toString()
   */
  public function __toString()
  {
    return $this->toString();
  }
  
  // -- Private methods
  
  /** Save a Header to the internal collection */
  private function _storeHeader($name, Swift_Mime_Header $header, $offset = null)
  {
    if (!isset($this->_headers[strtolower($name)]))
    {
      $this->_headers[strtolower($name)] = array();
    }
    if (!isset($offset))
    {
      $this->_headers[strtolower($name)][] = $header;
    }
    else
    {
      $this->_headers[strtolower($name)][$offset] = $header;
    }
  }
  
  /** Test if the headers can be sorted */
  private function _canSort()
  {
    return count($this->_order) > 0;
  }
  
  /** uksort() algorithm for Header ordering */
  private function _sortHeaders($a, $b)
  {
    $lowerA = strtolower($a);
    $lowerB = strtolower($b);
    $aPos = array_key_exists($lowerA, $this->_order)
      ? $this->_order[$lowerA]
      : -1;
    $bPos = array_key_exists($lowerB, $this->_order)
      ? $this->_order[$lowerB]
      : -1;
      
    if ($aPos == -1)
    {
      return 1;
    }
    elseif ($bPos == -1)
    {
      return -1;
    }
    
    return ($aPos < $bPos) ? -1 : 1;
  }
  
  /** Test if the given Header is always displayed */
  private function _isDisplayed(Swift_Mime_Header $header)
  {
    return array_key_exists(strtolower($header->getFieldName()), $this->_required);
  }
  
  /** Notify all Headers of the new charset */
  private function _notifyHeadersOfCharset($charset)
  {
    foreach ($this->_headers as $headerGroup)
    {
      foreach ($headerGroup as $header)
      {
        $header->setCharset($charset);
      }
    }
  }
  
}