<?php
/* $Id: mail.inc,v 1.19 2005/10/30 15:07:58 killes Exp $ */

/**
 * @file
 * Common mail functions for queueing and sending e-mail.
 */

/**
 * Returns available mailer engines.
 *
 * @return an array of mailer engine names.
 */
function mail_get_engines() {
  $engines = array();
  foreach(module_implements('mailengine') as $module) {
    $function = $module .'_mailengine';
    if (function_exists($function)) {
      $engines[$module] = $function('name') .' - '. $function('description');
    }
  }
  return $engines;
}

/**
 * Queue an e-mail
 *
 * @param $addresses
 *  Array of e-mail addresses
 * @param $subject
 *  Mail subject or blank to use node title
 * @param $body 
 *  Body of message
 * @param $additional_headers
 *  Additional Headers for e-mail as an array.
 * @param $additional_parameters
 *  Additional parameters to pass to the MTA, optional
 * @return
 *  Number of envelope addresses or 0 if nothing queued.
 */
function mail_queue($addresses, $subject, $body, $additional_headers, $additional_parameters = '') {
  $mail_id = db_next_id('{mail_queue}_mid');

  $headers = mail_prepare_headers($additional_headers);
  db_query("INSERT INTO {mail_queue} (mid, timestamp, body, headers, subject, parameters) values (%d, %d, '%s', '%s', '%s', '%s')", $mail_id, time(), str_replace("\r", '', $body), $headers, mime_header_encode(strtr($subject, "\r\n", '  ')), $additional_parameters);

  foreach ($addresses as $address) {
    db_query("INSERT INTO {mail_queue_addresses} (mid, address, sent) values (%d, '%s', 0)", $mail_id, mime_header_encode(strtr($address, "\r\n", '  ')));
  }

  watchdog('mail', t('Mail with ID %mail_id queued.', array('%mail_id' =>  theme('placeholder', $mail_id))));
}

/**
 * Send queued e-mail. 
 *
 * @param $mid 
 *  ID of queued e-mail 
 * @return
 *  Number of e-mails sent. 
 */
function mail_queue_send() {
  $max_can_send = variable_get('mail_queue_throttle', 100);

  $last_sent = variable_get('mail_queue_last_sent', 0);
  $can_send = 0;
  if ($max_can_send > 0) {
    $period = time() - $last_sent;
    $can_send = floor($period / 3600 * $max_can_send);
    $can_send = ($can_send < 1) ? 1 : $can_send;
  }
  if ($can_send) {
    $result = db_query('SELECT q.*, a.* FROM {mail_queue} q INNER JOIN {mail_queue_addresses} a ON q.mid = a.mid WHERE a.sent = 0 ORDER BY q.timestamp ASC');

    $mails_sent = array();
    $sent = 0;
    while ($mail = db_fetch_array($result)) {
      if (system_mailengine('send as is', $mail)){
        $sent++;
        db_query('UPDATE {mail_queue_addresses} SET sent = 1 WHERE mid = %d AND aid = %d', $mail['mid'], $mail['aid']);
      }
      else { // We stop sending mail after the first error.
        break;
      }
      if ($sent >= $can_send) { // We stop sending mail after reaching our quota.
        break;
      }
    }

    variable_set('mail_queue_last_sent', time());
    watchdog('mail', format_plural($sent, 'One e-mail from queue sent.', '%count e-mails from queue sent.'));

    return $sent;
  }
}

/**
 * Clear sent messages from the queue.
 */
function mail_queue_clean() {
  // Checks to make sure all the addresses in a given messages' recipient list have been sent
  $result = db_query('SELECT mid, COUNT(*) FROM {mail_queue_addresses} GROUP BY mid HAVING SUM(sent) = COUNT(*)');

  $mail_ids = array(); 
  while ($queue = db_fetch_object($result)) {
    $mail_ids[] = $queue->mid;
  }

  if (count($mail_ids)) {
    db_query('DELETE FROM {mail_queue} WHERE mid IN (%s)', implode(',', $mail_ids));
    db_query('DELETE FROM {mail_queue_addresses} WHERE mid IN (%s)', implode(',', $mail_ids));
  }
}

/**
 * Gives usefull defaults for standard email headers.
 *
 * @param $headers An array of headers
 * @return header string.
 */
function mail_prepare_headers($headers) {
  // Note: This may work or not. The MTA might rewrite the Return-Path, and Errors-To is deprecated.
  // Depending on your MTA and its configuration you can make it work by specifying appropriate arguments in $additional_parameters
  $errors_to = variable_get('site_mail', ini_get('sendmail_from'));
  // allow a mail to overwrite standard headers.
  $all_headers = array_merge(array('Return-Path' => "<$errors_to>", 'Errors-To' => $errors_to, 'From' => variable_get('site_mail', ini_get('sendmail_from')), 'X-Mailer' => 'Drupal', 'MIME-Version' => '1.0', 'Content-Type' => 'text/plain; charset=utf-8; format=flowed', 'Content-Transfer-Encoding' => '8bit'), $headers);
  $headers = '';
  foreach ($all_headers as $key => $value) {
    // We strip newlines to prevent spam attacks
    $value = strtr($value, "\r\n", '  ');
    if ($value != '') {
      $headers .= "$key: $value\n";
    }
  }

  return $headers;
}

/**
 * Converts html to utf-8 encoded text.
 *
 * @param $txt html text that needs formatting.
 * @param $inline Optional. If TRUE put links in the text, 
 *               if FALSE put a footnote into the text and
 *               a list of links below it. Default: FALSE
 *
 * @return formatted text encoded in utf-8
 */
function mail_html_to_text($txt, $inline = FALSE) {
  $pattern = '@(<a href="(.\S+?)"[^>]*>(.+?)</a>)@ei';
  if ($inline) {
    $txt = preg_replace($pattern, "_mail_uri('\\2', '\\3')", $txt);
  }
  else {
    $txt = preg_replace($pattern, "'\\3 ['. _mail_urls('\\2') .']'", $txt);
    $urls = _mail_urls();
    if (count($urls)) {
      $txt .= "\n";
      $i = 0;
      for ($max = count($urls); $i < $max; $i++) {
        $txt .= '['. ($i + 1) .'] '. $urls[$i] ."\n";
      }
    }
    _mail_urls(0, TRUE);
  }

  // some basic html to text conversion
  $txt = preg_replace(_mail_define_search(), _mail_define_replace(), $txt);
  $txt = preg_replace("/\n\s+\n/", "\n\n", $txt);
  $txt = strip_tags($txt);
  $txt = decode_entities($txt);
  return wordwrap($txt, 80);
}

/**
 * Extracts links to local images from html documents.
 *
 * @param $html html text
 * @param $name document name
 *
 * @return an array of arrays
 *            array(array(
 *                     'name' => document name
 *                     'content' => html text, local image urls replaced by Content-IDs,
 *                     'Content-Type' => 'text/html; charset=utf-8')
 *                  array(
 *                     'name' => file name,
 *                     'file' => reference to local file,
 *                     'Content-ID' => generated Content-ID,
 *                     'Content-Type' => derived using mime_content_type 
 *                                       if available, educated guess otherwise
 *                     )
 *                  )
 */
function mail_extract_files($html, $name) {
  $pattern = '@(<img\s+(\S+="\S+"\s+)*src="(.\S+?)"\s+(\S+="\S+"\s*)*/?>)@ei';
  $html = preg_replace($pattern, '"<img \\2src=\"". _mail_file("\\3") ."\" \\4/>"', $html);

  $pattern = '|(<style\s+(\S+="[\S ]+"\s+)*type="(\S+)"\s+(\S+="[\S ]+"\s*)*>@import\s+"(\S+)";\s*</style>)|ei';
  $html = preg_replace($pattern, '"<style \\2type=\"\\3\" \\4>@import \"". _mail_file("\\5", "\\3") ."\";</style>"', $html);

  $pattern = '|(<link\s+(\S+="[\S ]+"\s+)*href="(\S+)"\s+(\S+="[\S ]+"\s*)*>)|ei';
  $html = preg_replace($pattern, '"<link \\2href=\"". _mail_file("\\3") ."\" \\4>"', $html);

  $document = array('name' => $name, 'content' => $html, 'Content-Type' => 'text/html; charset=utf-8');
  $files = _mail_file();

  return array($document) + $files;
}

/**
 * Helper function to extract local files
 *
 * @param $file a link to a file
 *
 * @return an absolute :
 */
function _mail_file($file = NULL, $type = '') {
  static $files = array();

  if ($file && !preg_match('@://@', $file) && file_exists($file)) {
    $content_id = md5($file) .'@'. variable_get('site_name', 'drupal');
    if ($type) {
      $content_type = $type;
    }
    else if (function_exists('mime_content_type')) {
      $content_type = mime_content_type($file);
    }
    $new_file = array('name' => substr($file, strrpos($file, '/') + 1),
                      'file' => $file,
                      'Content-ID' => $content_id,
                     );
    if ($content_type) {
      $new_file['Content-Type'] = $content_type;
    }
    $files[] = $new_file;

    return 'cid:'. $content_id;
  }
  else if ($file) {
    return $file;
  }
  else {
    return $files;
  }
}

/**
 *
 * @param $parts 
 *        an array of parts to be included
 *        each part is itself an array:
 *        array(
 *          'name' => $name the name of the attachement
 *          'content' => $content textual content
 *          'file' => $file a file
 *          'Content-Type' => Content type of either file or content.
 *                            Mandatory for content, optional for file.
 *                            If not present, it will be derived from
 *                            file the file if mime_content_type is available.
 *                            If not, application/octet-stream is used.
 *          'Content-Disposition' => optional, inline is assumed
 *          'Content-Transfer-Encoding' => optional,
 *                                         base64 is assumed for files
 *                                         8bit for other content.
 *          'Content-ID' => optional, for in-mail references to attachements.
 *        )
 *        name is mandatory, one of content and file is required,
 *        they are mutually exclusive.
 *
 * @param $content_type
 *        Content-Type for the combined message, optional, default: multipart/mixed
 *
 * @return
 *     an array containing the elements 'header' and 'body'.
 *     'body' is the mime encoded multipart body of a mail.
 *     'headers' is an array that includes some headers for the mail to be sent.
 */
function mail_multipart_body($parts, $content_type = 'multipart/mixed') {
  $boundary = md5(uniqid(time()));
  $headers['Content-Type'] = "$content_type;\n boundary=\"$boundary\"; type=\"$content_type\"";
  $body = "\r\nThis is a multi-part message in MIME format.\r\n\r\n";
  foreach ($parts as $part) {
    $sub_boundary = md5($part['name'] . uniqid(time()));
    if (isset($part['Content-ID'])) {
      $subheader['Content-ID'] = '<'. $part['Content-ID'] .'>';
    }
    if ($part['Content-Disposition']) {
      $subheader['Content-Disposition'] = $part['Content-Disposition'];
    }
    else {
      $subheader['Content-Disposition'] = 'inline';
    }

    if ($part['content']) {
      $subheader['Content-Type'] = $part['Content-Type'];
      if ($part['Content-Transfer-Encoding']) {
        $subheader['Content-Transfer-Encoding'] = $part['Content-Transfer-Encoding'];
      }
      else {
        $subheader['Content-Transfer-Encoding'] = '8bit';
      }
      $sub_header = "--$boundary\n";
      if (isset($part['Content-ID'])) {
        $sub_header .= 'Content-ID: <'. $part['Content-ID'] .">\n";
      }
      $sub_header .= "Content-Type: ". $subheader['Content-Type'] .";\n name=\"". $part['name'] ."\" boundary=\"$sub_boundary\"\nContent-Transfer-Encoding: ". $subheader['Content-Transfer-Encoding'] ."\nContent-Disposition: ". $subheader['Content-Disposition'] .";\n";
      $body .= $sub_header ."\r\n";
      $body .= $part['content'] ."\r\n";
    }
    else {
      $file_content = file_get_contents($part['file']);

      if ($part['Content-Type']) {
        $subheader['Content-Type'] = $part['Content-Type'];
      }
      else if (function_exists('mime_content_type')) {
        $subheader['Content-Type'] = mime_content_type($part['file']);
      }
      else {
        $subheader['Content-Type'] = 'application/octet-stream';
      }
      if ($part['Content-Transfer-Encoding']) {
        $subheader['Content-Transfer-Encoding'] = $part['Content-Transfer-Encoding'];
      }
      else {
        $subheader['Content-Transfer-Encoding'] = 'base64';
      }
      $sub_header = "--$boundary\n";
      if (isset($part['Content-ID'])) {
        $sub_header .= 'Content-ID: <'. $part['Content-ID'] .">\n";
      }
      $sub_header .= "Content-Type: ". $subheader['Content-Type'] .";\n name=\"". $part['name'] ."\" boundary=\"$sub_boundary\"\nContent-Transfer-Encoding: ". $subheader['Content-Transfer-Encoding'] ."\nContent-Disposition: ". $subheader['Content-Disposition'] .";\n  filename=\"". $part['name'] ."\"\n";
      $body .= $sub_header ."\r\n";
      $body .= chunk_split(base64_encode($file_content)) ."\r\n";
    }
  }
  $body .= "--$boundary--\r\n";

  return array('headers' => $headers, 'body' => $body);
}

/**
 * Helper function to format urls
 *
 */
function _mail_uri($href, $link) {
  $href = _mail_url($href);
  if ($href == $link) {
    $output =  '['.$href.']';
  }
  else {
    $output = $link.' ['.$href.']';
  }
  return $output;
}

/**
 * Helper function to format urls
 *
 * @param $url an url
 *
 * @return an absolute url, sans mailto:
 */
function _mail_url($url) {
  if (preg_match('@://@', $url)) {
    return $url;
  }
  elseif (preg_match('!mailto:!i', $url)) {
    return str_replace('mailto:', '', $url);
  }
  else {
    return url($url, NULL, NULL, TRUE);
  }
}

/**
 * Helper function to store processed urls.
 *
 * @param $url Optional. 
 * @param $refresh Optional. If TRUE refresh the cache.
 *
 * @return a count of stored if $url evaluates to false, the stored urls ortherwise.
 */
function _mail_urls($url = 0, $refresh = FALSE) {
  static $urls = array();

  if($refresh) {
    $urls = array();
  }

  if ($url) {
    $urls[] = _mail_url($url);
    return count($urls);
  }

  return $urls;
}

/**
 *  List of preg* regular expression patterns to search for,
 *  used in conjunction with $replace.
 *  Based on / modified from html2txt.module
 */
function _mail_define_search() {

    $search = array(
        "/\r/",                                       // Non-legal carriage return
        "/[\t]+/",                                    // tabs
        '/<script[^>]*>.*?<\/script>/i',              // <script>s -- which strip_tags supposedly has problems with
        '!<h[12][^>]*>(.+?)</h[12]>!ie',              // h1 - h2
        '/<h3[^>]*>(.+?)<\/h3>/ie',                   // h3
        '/<h[456][^>]*>(.+?)<\/h[456]>/ie',           // h4 - h6
        '!<blockquote[^>]*>!i',                       // <blockquote>
        '!</blockquote>!i',                           // </blockquote>
        '!</?p[^>]*>!i',                              // <p>
        '/<br[^>]*>/i',                               // <br>
        '!</?(b|strong)[^>]*>!i',                     // <b> and <strong>
        '!</?(em|i)[^>]*>!i',                         // <em> and <i>
        '/(<ul[^>]*>|<\/ul>)/i',                      // <ul> and </ul>
        '/(<ol[^>]*>|<\/ol>)/i',                      // <ol> and </ol>
        '/(<dl[^>]*>|<\/dl>)/i',                      // <dl> and </dl>
        '!<li[^>]*>!i',                               // <li>
        '!</li>!i',                                   // </li>
        '!<dt[^>]*>!i',                               // <dt>
        '!</dt>!i',                                   // </dt>
        '!<dd[^>]*>!i',                               // <dd>
        '!</dd>!i',                                   // </dd>
        '/<hr[^>]*>/i',                               // <hr>
        '/(<table[^>]*>|<\/table>)/i',                // <table> and </table>
        '/(<tr[^>]*>|<\/tr>)/i',                      // <tr> and </tr>
        '/<td[^>]*>(.+?)<\/td>/i',                    // <td> and </td>
        '/<th[^>]*>(.+?)<\/th>/i',                    // <th> and </th>
        '/&nbsp;/i',
        '/&quot;/i',
        '/&gt;/i',
        '/&lt;/i',
        '/&amp;/i',
        '/&copy;/i',
        '/&trade;/i',
        '/&#8220;/',
        '/&#8221;/',
        '/&#8211;/',
        '/&#8217;/',
        '/&#38;/',
        '/&#169;/',
        '/&#8482;/',
        '/&#151;/',
        '/&#147;/',
        '/&#148;/',
        '/&#149;/',
        '/&reg;/i',
        '/&bull;/i',
        '/&[&;]+;/i'
    );

    return $search;
}

/**
 *  List of pattern replacements corresponding to patterns searched.
 *  Based on / modified from html2txt.module
 */
function _mail_define_replace() {

    $replace = array(
        '',                                                               // Non-legal carriage return
        ' ',                                                              // Tabs
        '',                                                               // <script>s -- which strip_tags supposedly has problems with
        "\"\n------------\" .'\\1'.\"------------\n\n\"",                 // h1 - h2
        "\"\n\n\\1\n\n\"",                                                // h3
        "\"\n\\1\n\"",                                                    // h4 - h6
        "\n\n\t",                                                         // <blockquote>
        "\n\n",                                                           // </blockquote>
        "\n\n",                                                           // <p>
        "\n",                                                             // <br>
        '*',                                                              // <b> and <strong>
        '/',                                                              // <em> and <i>
        "\n\n",                                                           // <ul> and </ul>
        "\n\n",                                                           // <ol> and </ol>
        "\n\n",                                                           // <dl> and </dl>
        "  * ",                                                           // <li>
        "\n",                                                             // </li>
        "  * ",                                                           // <dt>
        "\n",                                                             // </dt>
        "\t",                                                             // <dd>
        "\n",                                                             // </dd>
        "\n-------------------------\n",                                  // <hr>
        "\n\n",                                                           // <table> and </table>
        "\n",                                                             // <tr> and </tr>
        "\t\t\\1\n",                                                      // <td> and </td>
        "\"\t\t\\1\n\"",                                      // <th> and </th>
        ' ',
        '"',
        '>',
        '<',
        '&',
        '(c)',
        '(tm)',
        '"',
        '"',
        '-',
        "'",
        '&',
        '(c)',
        '(tm)',
        '--',
        '"',
        '"',
        '*',
        '(R)',
        '*',
        ''
    );
    return $replace;
}
?>