<?php

/*
 +-----------------------------------------------------------------------+
 | program/include/rcube_message.php                                     |
 |                                                                       |
 | This file is part of the RoundCube Webmail client                     |
 | Copyright (C) 2008-2009, RoundCube Dev. - Switzerland                 |
 | Licensed under the GNU GPL                                            |
 |                                                                       |
 | PURPOSE:                                                              |
 |   Logical representation of a mail message with all its data          |
 |   and related functions                                               |
 +-----------------------------------------------------------------------+
 | Author: Thomas Bruederli <roundcube@gmail.com>                        |
 +-----------------------------------------------------------------------+

 $Id: rcube_imap.php 1344 2008-04-30 08:21:42Z thomasb $

*/


/**
 * Logical representation of a mail message with all its data
 * and related functions
 *
 * @package    Mail
 * @author     Thomas Bruederli <roundcube@gmail.com>
 */
class rcube_message
{
  private $app;
  private $imap;
  private $opt = array();
  private $inline_parts = array();
  private $parse_alternative = false;
  
  public $uid = null;
  public $headers;
  public $structure;
  public $parts = array();
  public $mime_parts = array();
  public $attachments = array();
  public $subject = '';
  public $sender = null;
  public $is_safe = false;
  

  /**
   * __construct
   *
   * Provide a uid, and parse message structure.
   *
   * @param string $uid The message UID.
   *
   * @uses rcmail::get_instance()
   * @uses rcube_imap::decode_mime_string()
   * @uses self::set_safe()
   *
   * @see self::$app, self::$imap, self::$opt, self::$structure
   */
  function __construct($uid)
  {
    $this->app = rcmail::get_instance();
    $this->imap = $this->app->imap;
    
    $this->uid = $uid;
    $this->headers = $this->imap->get_headers($uid, NULL, true, true);

    $this->subject = rcube_imap::decode_mime_string($this->headers->subject, $this->headers->charset);
    list(, $this->sender) = each($this->imap->decode_address_list($this->headers->from));
    
    $this->set_safe((intval($_GET['_safe']) || $_SESSION['safe_messages'][$uid]));
    $this->opt = array(
      'safe' => $this->is_safe,
      'prefer_html' => $this->app->config->get('prefer_html'),
      'get_url' => rcmail_url('get', array('_mbox' => $this->imap->get_mailbox_name(), '_uid' => $uid))
    );

    if ($this->structure = $this->imap->get_structure($uid, $this->headers->body_structure)) {
      $this->get_mime_numbers($this->structure);
      $this->parse_structure($this->structure);
    }
    else {
      $this->body = $this->imap->get_body($uid);
    }
    
    // notify plugins and let them analyze this structured message object
    $this->app->plugins->exec_hook('message_load', array('object' => $this));
  }
  
  
  /**
   * Return a (decoded) message header
   *
   * @param string Header name
   * @param bool   Don't mime-decode the value
   * @return string Header value
   */
  public function get_header($name, $raw = false)
  {
    $value = $this->headers->$name;
    return $raw ? $value : $this->imap->decode_header($value);
  }
  
  /**
   * Set is_safe var and session data
   *
   * @param bool enable/disable
   */
  public function set_safe($safe = true)
  {
    $this->is_safe = $safe;
    $_SESSION['safe_messages'][$this->uid] = $this->is_safe;
  }
  
  /**
   * Compose a valid URL for getting a message part
   *
   * @param string Part MIME-ID
   * @return string URL or false if part does not exist
   */
  public function get_part_url($mime_id)
  {
    if ($this->mime_parts[$mime_id])
      return $this->opt['get_url'] . "&_part=" . $mime_id;
    else
      return false;
  }
  
  
  /**
   * Get content of a specific part of this message
   *
   * @param string Part MIME-ID
   * @param resource File pointer to save the message part
   * @return string Part content
   */
  public function get_part_content($mime_id, $fp=NULL)
  {
    if ($part = $this->mime_parts[$mime_id])
      return $this->imap->get_message_part($this->uid, $mime_id, $part, NULL, $fp);
    else
      return null;
  }
  
  
  /**
   * Determine if the message contains a HTML part
   *
   * @return bool True if a HTML is available, False if not
   */
  function has_html_part()
  {
     // check all message parts
     foreach ($this->parts as $pid => $part) {
        $mimetype = strtolower($part->ctype_primary . '/' . $part->ctype_secondary);
        if ($mimetype == 'text/html')
           return true;
     }

     return false;
  }

  /**
   * Return the first HTML part of this message
   *
   * @return string HTML message part content
   */
  function first_html_part()
    {
    // check all message parts
    foreach ($this->mime_parts as $mime_id => $part) {
      $mimetype = strtolower($part->ctype_primary . '/' . $part->ctype_secondary);
      if ($mimetype == 'text/html') {
        return $this->imap->get_message_part($this->uid, $mime_id, $part);
      }
    }
  }


  /**
   * Return the first text part of this message
   *
   * @return string Plain text message/part content
   */
  function first_text_part()
    {
    // no message structure, return complete body
    if (empty($this->parts))
      return $this->body;
      
    $out = null;

    // check all message parts
    foreach ($this->mime_parts as $mime_id => $part) {
      $mimetype = strtolower($part->ctype_primary . '/' . $part->ctype_secondary);

      if ($mimetype == 'text/plain') {
        $out = $this->imap->get_message_part($this->uid, $mime_id, $part);
        break;
      }
      else if ($mimetype == 'text/html') {
        $html_part = $this->imap->get_message_part($this->uid, $mime_id, $part);

        // remove special chars encoding
        $trans = array_flip(get_html_translation_table(HTML_ENTITIES));
        $html_part = strtr($html_part, $trans);

        // create instance of html2text class
        $txt = new html2text($html_part);
        $out = $txt->get_text();
        break;
      }
    }

    return $out;
  }


  /**
   * Raad the message structure returend by the IMAP server
   * and build flat lists of content parts and attachments
   *
   * @param object rcube_message_part Message structure node
   * @param bool  True when called recursively
   */
  private function parse_structure($structure, $recursive = false)
  {
    $message_ctype_primary = strtolower($structure->ctype_primary);
    $message_ctype_secondary = strtolower($structure->ctype_secondary);

    // show message headers
    if ($recursive && is_array($structure->headers) && isset($structure->headers['subject'])) {
      $c = new stdClass;
      $c->type = 'headers';
      $c->headers = &$structure->headers;
      $this->parts[] = $c;
    }

    // print body if message doesn't have multiple parts
    if ($message_ctype_primary == 'text' && !$recursive) {
      $structure->type = 'content';
      $this->parts[] = &$structure;
    }
    // the same for pgp signed messages
    else if ($message_ctype_primary == 'application' && $message_ctype_secondary == 'pgp' && !$recursive) {
      $structure->type = 'content';
      $this->parts[] = &$structure;
    }
    // message contains alternative parts
    else if ($message_ctype_primary == 'multipart' && ($message_ctype_secondary == 'alternative') && is_array($structure->parts)) {
      // get html/plaintext parts
      $plain_part = $html_part = $print_part = $related_part = null;

      foreach ($structure->parts as $p => $sub_part) {
        $rel_parts = $attachmnts = null;
        $sub_ctype_primary = strtolower($sub_part->ctype_primary);
        $sub_ctype_secondary = strtolower($sub_part->ctype_secondary);
        
        // check if sub part is 
        if ($sub_ctype_primary=='text' && $sub_ctype_secondary=='plain')
          $plain_part = $p;
        else if ($sub_ctype_primary=='text' && $sub_ctype_secondary=='html')
          $html_part = $p;
        else if ($sub_ctype_primary=='text' && $sub_ctype_secondary=='enriched')
          $enriched_part = $p;
        else if ($sub_ctype_primary=='multipart' && in_array($sub_ctype_secondary, array('related', 'mixed', 'alternative')))
          $related_part = $p;
      }

      // parse related part (alternative part could be in here)
      if ($related_part !== null && !$this->parse_alternative) {
        $this->parse_alternative = true;
        $this->parse_structure($structure->parts[$related_part], true);
        $this->parse_alternative = false;
        
        // if plain part was found, we should unset it if html is preferred
        if ($this->opt['prefer_html'] && count($this->parts))
          $plain_part = null;
      }

      // choose html/plain part to print
      if ($html_part !== null && $this->opt['prefer_html']) {
        $print_part = &$structure->parts[$html_part];
      }
      else if ($enriched_part !== null) {
        $print_part = &$structure->parts[$enriched_part];
      }
      else if ($plain_part !== null) {
        $print_part = &$structure->parts[$plain_part];
      }

      // add the right message body
      if (is_object($print_part)) {
        $print_part->type = 'content';
        $this->parts[] = $print_part;
      }
      // show plaintext warning
      else if ($html_part !== null && empty($this->parts)) {
        $c = new stdClass;
        $c->type = 'content';
        $c->body = rcube_label('htmlmessage');
        $c->ctype_primary = 'text';
        $c->ctype_secondary = 'plain';

        $this->parts[] = $c;
      }

      // add html part as attachment
      if ($html_part !== null && $structure->parts[$html_part] !== $print_part) {
        $html_part = &$structure->parts[$html_part];
        $html_part->filename = rcube_label('htmlmessage');
        $html_part->mimetype = 'text/html';

        $this->attachments[] = $html_part;
      }
    }
    // this is an ecrypted message -> create a plaintext body with the according message
    else if ($message_ctype_primary == 'multipart' && $message_ctype_secondary == 'encrypted') {
      $p = new stdClass;
      $p->type = 'content';
      $p->ctype_primary = 'text';
      $p->ctype_secondary = 'plain';
      $p->body = rcube_label('encryptedmessage');
      $p->size = strlen($p->body);
      
      // maybe some plugins are able to decode this encrypted message part
      $data = $this->app->plugins->exec_hook('message_part_encrypted', array('object' => $this, 'struct' => $structure, 'part' => $p));
      if (is_array($data['parts'])) {
        $this->parts = array_merge($this->parts, $data['parts']);
      }
      else if ($data['part']) {
        $this->parts[] = $p;
      }
    }
    // message contains multiple parts
    else if (is_array($structure->parts) && !empty($structure->parts)) {
      // iterate over parts
      for ($i=0; $i < count($structure->parts); $i++) {
        $mail_part = &$structure->parts[$i];
        $primary_type = strtolower($mail_part->ctype_primary);
        $secondary_type = strtolower($mail_part->ctype_secondary);

        // multipart/alternative
        if ($primary_type=='multipart') {
          $this->parse_structure($mail_part, true);
        }
        // part text/[plain|html] OR message/delivery-status
        else if (($primary_type == 'text' && ($secondary_type == 'plain' || $secondary_type == 'html') && $mail_part->disposition != 'attachment') ||
                 ($primary_type == 'message' && ($secondary_type == 'delivery-status' || $secondary_type == 'disposition-notification'))) {

          // add text part if we're not in alternative mode or if it matches the prefs
          if (!$this->parse_alternative ||
              ($secondary_type == 'html' && $this->opt['prefer_html']) ||
              ($secondary_type == 'plain' && !$this->opt['prefer_html'])) {
            $mail_part->type = 'content';
            $this->parts[] = $mail_part;
          }

          // list as attachment as well
          if (!empty($mail_part->filename))
            $this->attachments[] = $mail_part;
        }
        // part message/*
        else if ($primary_type=='message') {
          $this->parse_structure($mail_part, true);
          
          // list as attachment as well (mostly .eml)
          if (!empty($mail_part->filename))
            $this->attachments[] = $mail_part;
        }
        // ignore "virtual" protocol parts
        else if ($primary_type == 'protocol')
          continue;
          
        // part is Microsoft Outlook TNEF (winmail.dat)
        else if ($primary_type == 'application' && $secondary_type == 'ms-tnef') {
          foreach ((array)$this->imap->tnef_decode($mail_part, $structure->headers['uid']) as $tnef_part) {
            $this->mime_parts[$tnef_part->mime_id] = $tnef_part;
            $this->attachments[] = $tnef_part;
          }
        }

        // part is a file/attachment
        else if (preg_match('/^(inline|attach)/', $mail_part->disposition) ||
                 $mail_part->headers['content-id'] || (empty($mail_part->disposition) && $mail_part->filename)) {

          // skip apple resource forks
          if ($message_ctype_secondary == 'appledouble' && $secondary_type == 'applefile')
            continue;

          // part belongs to a related message and is linked
          if ($message_ctype_secondary == 'related'
              && preg_match('!^image/!', $mail_part->mimetype)
              && ($mail_part->headers['content-id'] || $mail_part->headers['content-location'])) {
            if ($mail_part->headers['content-id'])
              $mail_part->content_id = preg_replace(array('/^</', '/>$/'), '', $mail_part->headers['content-id']);
            if ($mail_part->headers['content-location'])
              $mail_part->content_location = $mail_part->headers['content-base'] . $mail_part->headers['content-location'];
              
            $this->inline_parts[] = $mail_part;
          }
          // is a regular attachment
          else if (preg_match('!^[a-z]+/[a-z0-9-.+]+$!i', $mail_part->mimetype)) {
            if (!$mail_part->filename)
              $mail_part->filename = 'Part '.$mail_part->mime_id;
            $this->attachments[] = $mail_part;
          }
        }
      }

      // if this was a related part try to resolve references
      if ($message_ctype_secondary == 'related' && sizeof($this->inline_parts)) {
        $a_replaces = array();

        foreach ($this->inline_parts as $inline_object) {
          $part_url = $this->get_part_url($inline_object->mime_id);
          if ($inline_object->content_id)
            $a_replaces['cid:'.$inline_object->content_id] = $part_url;
          if ($inline_object->content_location)
            $a_replaces[$inline_object->content_location] = $part_url;
        }

        // add replace array to each content part
        // (will be applied later when part body is available)
        foreach ($this->parts as $i => $part) {
          if ($part->type == 'content')
            $this->parts[$i]->replaces = $a_replaces;
        }
      }
    }

    // message is single part non-text
    else if ($structure->filename) {
      $this->attachments[] = $structure;
    }
  }


  /**
   * Fill aflat array with references to all parts, indexed by part numbers
   *
   * @param object rcube_message_part Message body structure
   */
  private function get_mime_numbers(&$part)
  {
    if (strlen($part->mime_id))
      $this->mime_parts[$part->mime_id] = &$part;
      
    if (is_array($part->parts))
      for ($i=0; $i<count($part->parts); $i++)
        $this->get_mime_numbers($part->parts[$i]);
  }


}