<?php

// $Id: mail.inc,v 1.8.2.7 2009/06/18 12:15:44 goba Exp $

/**

 * Compose and optionally send an e-mail message.

 *

 * Sending an e-mail works with defining an e-mail template (subject, text

 * and possibly e-mail headers) and the replacement values to use in the

 * appropriate places in the template. Processed e-mail templates are

 * requested from hook_mail() from the module sending the e-mail. Any module

 * can modify the composed e-mail message array using hook_mail_alter().

 * Finally drupal_mail_send() sends the e-mail, which can be reused

 * if the exact same composed e-mail is to be sent to multiple recipients.

 *

 * Finding out what language to send the e-mail with needs some consideration.

 * If you send e-mail to a user, her preferred language should be fine, so

 * use user_preferred_language(). If you send email based on form values

 * filled on the page, there are two additional choices if you are not

 * sending the e-mail to a user on the site. You can either use the language

 * used to generate the page ($language global variable) or the site default

 * language. See language_default(). The former is good if sending e-mail to

 * the person filling the form, the later is good if you send e-mail to an

 * address previously set up (like contact addresses in a contact form).

 *

 * Taking care of always using the proper language is even more important

 * when sending e-mails in a row to multiple users. Hook_mail() abstracts

 * whether the mail text comes from an administrator setting or is

 * static in the source code. It should also deal with common mail tokens,

 * only receiving $params which are unique to the actual e-mail at hand.

 *

 * An example:

 *

 * @code

 *   function example_notify($accounts) {

 *     foreach ($accounts as $account) {

 *       $params['account'] = $account;

 *       // example_mail() will be called based on the first drupal_mail() parameter.

 *       drupal_mail('example', 'notice', $account->mail, user_preferred_language($account), $params);

 *     }

 *   }

 *

 *   function example_mail($key, &$message, $params) {

 *     $language = $message['language'];

 *     $variables = user_mail_tokens($params['account'], $language);

 *     switch($key) {

 *       case 'notice':

 *         $message['subject'] = t('Notification from !site', $variables, $language->language);

 *         $message['body'][] = t("Dear !username\n\nThere is new content available on the site.", $variables, $language->language);

 *         break;

 *     }

 *   }

 * @endcode

 *

 * @param $module

 *   A module name to invoke hook_mail() on. The {$module}_mail() hook will be

 *   called to complete the $message structure which will already contain common

 *   defaults.

 * @param $key

 *   A key to identify the e-mail sent. The final e-mail id for e-mail altering

 *   will be {$module}_{$key}.

 * @param $to

 *   The e-mail address or addresses where the message will be sent to. The

 *   formatting of this string must comply with RFC 2822. Some examples are:

 *    user@example.com

 *    user@example.com, anotheruser@example.com

 *    User <user@example.com>

 *    User <user@example.com>, Another User <anotheruser@example.com>

 * @param $language

 *   Language object to use to compose the e-mail.

 * @param $params

 *   Optional parameters to build the e-mail.

 * @param $from

 *   Sets From to this value, if given.

 * @param $send

 *   Send the message directly, without calling drupal_mail_send() manually.

 * @return

 *   The $message array structure containing all details of the

 *   message. If already sent ($send = TRUE), then the 'result' element

 *   will contain the success indicator of the e-mail, failure being already

 *   written to the watchdog. (Success means nothing more than the message being

 *   accepted at php-level, which still doesn't guarantee it to be delivered.)

 */

function drupal_mail($module, $key, $to, $language, $params = array(), $from = NULL, $send = TRUE) {

  $default_from = variable_get('site_mail', ini_get('sendmail_from'));

  // Bundle up the variables into a structured array for altering.

  $message = array(

    'id'       => $module .'_'. $key,

    'to'       => $to,

    'from'     => isset($from) ? $from : $default_from,

    'language' => $language,

    'params'   => $params,

    'subject'  => '',

    'body'     => array()

  );

  // Build the default headers

  $headers = array(

    'MIME-Version'              => '1.0',

    'Content-Type'              => 'text/plain; charset=UTF-8; format=flowed; delsp=yes',

    'Content-Transfer-Encoding' => '8Bit',

    'X-Mailer'                  => 'Drupal'

  );

  if ($default_from) {

    // To prevent e-mail from looking like spam, the addresses in the Sender and

    // Return-Path headers should have a domain authorized to use the originating

    // SMTP server. Errors-To is redundant, but shouldn't hurt.

    $headers['From'] = $headers['Sender'] = $headers['Return-Path'] = $headers['Errors-To'] = $default_from;

  }

  if ($from) {

    $headers['From'] = $from;

  }

  $message['headers'] = $headers;

  // Build the e-mail (get subject and body, allow additional headers) by

  // invoking hook_mail() on this module. We cannot use module_invoke() as

  // we need to have $message by reference in hook_mail().

  if (function_exists($function = $module .'_mail')) {

    $function($key, $message, $params);

  }

  // Invoke hook_mail_alter() to allow all modules to alter the resulting e-mail.

  drupal_alter('mail', $message);

  // Concatenate and wrap the e-mail body.

  $message['body'] = is_array($message['body']) ? drupal_wrap_mail(implode("\n\n", $message['body'])) : drupal_wrap_mail($message['body']);

  // Optionally send e-mail.

  if ($send) {

    $message['result'] = drupal_mail_send($message);

    // Log errors

    if (!$message['result']) {

      watchdog('mail', 'Error sending e-mail (from %from to %to).', array('%from' => $message['from'], '%to' => $message['to']), WATCHDOG_ERROR);

      drupal_set_message(t('Unable to send e-mail. Please contact the site administrator if the problem persists.'), 'error');

    }

  }

  return $message;

}

/**

 * Send an e-mail message, using Drupal variables and default settings.

 * More information in the <a href="http://php.net/manual/en/function.mail.php">

 * PHP function reference for mail()</a>. See drupal_mail() for information on

 * how $message is composed.

 *

 * @param $message

 *  Message array with at least the following elements:

 *   - id

 *      A unique identifier of the e-mail type. Examples: 'contact_user_copy',

 *      'user_password_reset'.

 *   - to

 *      The mail address or addresses where the message will be sent to. The

 *      formatting of this string must comply with RFC 2822. Some examples are:

 *       user@example.com

 *       user@example.com, anotheruser@example.com

 *       User <user@example.com>

 *       User <user@example.com>, Another User <anotheruser@example.com>

 *   - subject

 *      Subject of the e-mail to be sent. This must not contain any newline

 *      characters, or the mail may not be sent properly.

 *   - body

 *      Message to be sent. Accepts both CRLF and LF line-endings.

 *      E-mail bodies must be wrapped. You can use drupal_wrap_mail() for

 *      smart plain text wrapping.

 *   - headers

 *      Associative array containing all mail headers.

 * @return

 *   Returns TRUE if the mail was successfully accepted for delivery,

 *   FALSE otherwise.

 */

function drupal_mail_send($message) {

  // Allow for a custom mail backend.

  if (variable_get('smtp_library', '') && file_exists(variable_get('smtp_library', ''))) {

    include_once './'. variable_get('smtp_library', '');

    return drupal_mail_wrapper($message);

  }

  else {

    $mimeheaders = array();

    foreach ($message['headers'] as $name => $value) {

      $mimeheaders[] = $name .': '. mime_header_encode($value);

    }

    return mail(

      $message['to'],

      mime_header_encode($message['subject']),

      // Note: e-mail uses CRLF for line-endings, but PHP's API requires LF.

      // They will appear correctly in the actual e-mail that is sent.

      str_replace("\r", '', $message['body']),

      // For headers, PHP's API suggests that we use CRLF normally,

      // but some MTAs incorrecly replace LF with CRLF. See #234403.

      join("\n", $mimeheaders)

    );

  }

}

/**

 * Perform format=flowed soft wrapping for mail (RFC 3676).

 *

 * We use delsp=yes wrapping, but only break non-spaced languages when

 * absolutely necessary to avoid compatibility issues.

 *

 * We deliberately use LF rather than CRLF, see drupal_mail().

 *

 * @param $text

 *   The plain text to process.

 * @param $indent (optional)

 *   A string to indent the text with. Only '>' characters are repeated on

 *   subsequent wrapped lines. Others are replaced by spaces.

 */

function drupal_wrap_mail($text, $indent = '') {

  // Convert CRLF into LF.

  $text = str_replace("\r", '', $text);

  // See if soft-wrapping is allowed.

  $clean_indent = _drupal_html_to_text_clean($indent);

  $soft = strpos($clean_indent, ' ') === FALSE;

  // Check if the string has line breaks.

  if (strpos($text, "\n") !== FALSE) {

    // Remove trailing spaces to make existing breaks hard.

    $text = preg_replace('/ +\n/m', "\n", $text);

    // Wrap each line at the needed width.

    $lines = explode("\n", $text);

    array_walk($lines, '_drupal_wrap_mail_line', array('soft' => $soft, 'length' => strlen($indent)));

    $text = implode("\n", $lines);

  }

  else {

    // Wrap this line.

    _drupal_wrap_mail_line($text, 0, array('soft' => $soft, 'length' => strlen($indent)));

  }

  // Empty lines with nothing but spaces.

  $text = preg_replace('/^ +\n/m', "\n", $text);

  // Space-stuff special lines.

  $text = preg_replace('/^(>| |From)/m', ' $1', $text);

  // Apply indentation. We only include non-'>' indentation on the first line.

  $text = $indent . substr(preg_replace('/^/m', $clean_indent, $text), strlen($indent));

  return $text;

}

/**

 * Transform an HTML string into plain text, preserving the structure of the

 * markup. Useful for preparing the body of a node to be sent by e-mail.

 *

 * The output will be suitable for use as 'format=flowed; delsp=yes' text

 * (RFC 3676) and can be passed directly to drupal_mail() for sending.

 *

 * We deliberately use LF rather than CRLF, see drupal_mail().

 *

 * This function provides suitable alternatives for the following tags:

 * <a> <em> <i> <strong> <b> <br> <p> <blockquote> <ul> <ol> <li> <dl> <dt>

 * <dd> <h1> <h2> <h3> <h4> <h5> <h6> <hr>

 *

 * @param $string

 *   The string to be transformed.

 * @param $allowed_tags (optional)

 *   If supplied, a list of tags that will be transformed. If omitted, all

 *   all supported tags are transformed.

 * @return

 *   The transformed string.

 */

function drupal_html_to_text($string, $allowed_tags = NULL) {

  // Cache list of supported tags.

  static $supported_tags;

  if (empty($supported_tags)) {

    $supported_tags = array('a', 'em', 'i', 'strong', 'b', 'br', 'p', 'blockquote', 'ul', 'ol', 'li', 'dl', 'dt', 'dd', 'h1', 'h2', 'h3', 'h4', 'h5', 'h6', 'hr');

  }

  // Make sure only supported tags are kept.

  $allowed_tags = isset($allowed_tags) ? array_intersect($supported_tags, $allowed_tags) : $supported_tags;

  // Make sure tags, entities and attributes are well-formed and properly nested.

  $string = _filter_htmlcorrector(filter_xss($string, $allowed_tags));

  // Apply inline styles.

  $string = preg_replace('!</?(em|i)((?> +)[^>]*)?>!i', '/', $string);

  $string = preg_replace('!</?(strong|b)((?> +)[^>]*)?>!i', '*', $string);

  // Replace inline <a> tags with the text of link and a footnote.

  // 'See <a href="http://drupal.org">the Drupal site</a>' becomes

  // 'See the Drupal site [1]' with the URL included as a footnote.

  _drupal_html_to_mail_urls(NULL, TRUE);

  $pattern = '@(<a[^>]+?href="([^"]*)"[^>]*?>(.+?)</a>)@i';

  $string = preg_replace_callback($pattern, '_drupal_html_to_mail_urls', $string);

  $urls = _drupal_html_to_mail_urls();

  $footnotes = '';

  if (count($urls)) {

    $footnotes .= "\n";

    for ($i = 0, $max = count($urls); $i < $max; $i++) {

      $footnotes .= '['. ($i + 1) .'] '. $urls[$i] ."\n";

    }

  }

  // Split tags from text.

  $split = preg_split('/<([^>]+?)>/', $string, -1, PREG_SPLIT_DELIM_CAPTURE);

  // Note: PHP ensures the array consists of alternating delimiters and literals

  // and begins and ends with a literal (inserting $null as required).

  $tag = FALSE; // Odd/even counter (tag or no tag)

  $casing = NULL; // Case conversion function

  $output = '';

  $indent = array(); // All current indentation string chunks

  $lists = array(); // Array of counters for opened lists

  foreach ($split as $value) {

    $chunk = NULL; // Holds a string ready to be formatted and output.

    // Process HTML tags (but don't output any literally).

    if ($tag) {

      list($tagname) = explode(' ', strtolower($value), 2);

      switch ($tagname) {

        // List counters

        case 'ul':

          array_unshift($lists, '*');

          break;

        case 'ol':

          array_unshift($lists, 1);

          break;

        case '/ul':

        case '/ol':

          array_shift($lists);

          $chunk = ''; // Ensure blank new-line.

          break;

        // Quotation/list markers, non-fancy headers

        case 'blockquote':

          // Format=flowed indentation cannot be mixed with lists.

          $indent[] = count($lists) ? ' "' : '>';

          break;

        case 'li':

          $indent[] = is_numeric($lists[0]) ? ' '. $lists[0]++ .') ' : ' * ';

          break;

        case 'dd':

          $indent[] = '    ';

          break;

        case 'h3':

          $indent[] = '.... ';

          break;

        case 'h4':

          $indent[] = '.. ';

          break;

        case '/blockquote':

          if (count($lists)) {

            // Append closing quote for inline quotes (immediately).

            $output = rtrim($output, "> \n") ."\"\n";

            $chunk = ''; // Ensure blank new-line.

          }

          // Fall-through

        case '/li':

        case '/dd':

          array_pop($indent);

          break;

        case '/h3':

        case '/h4':

          array_pop($indent);

        case '/h5':

        case '/h6':

          $chunk = ''; // Ensure blank new-line.

          break;

        // Fancy headers

        case 'h1':

          $indent[] = '======== ';

          $casing = 'drupal_strtoupper';

          break;

        case 'h2':

          $indent[] = '-------- ';

          $casing = 'drupal_strtoupper';

          break;

        case '/h1':

        case '/h2':

          $casing = NULL;

          // Pad the line with dashes.

          $output = _drupal_html_to_text_pad($output, ($tagname == '/h1') ? '=' : '-', ' ');

          array_pop($indent);

          $chunk = ''; // Ensure blank new-line.

          break;

        // Horizontal rulers

        case 'hr':

          // Insert immediately.

          $output .= drupal_wrap_mail('', implode('', $indent)) ."\n";

          $output = _drupal_html_to_text_pad($output, '-');

          break;

        // Paragraphs and definition lists

        case '/p':

        case '/dl':

          $chunk = ''; // Ensure blank new-line.

          break;

      }

    }

    // Process blocks of text.

    else {

      // Convert inline HTML text to plain text.

      $value = trim(preg_replace('/\s+/', ' ', decode_entities($value)));

      if (strlen($value)) {

        $chunk = $value;

      }

    }

    // See if there is something waiting to be output.

    if (isset($chunk)) {

      // Apply any necessary case conversion.

      if (isset($casing)) {

        $chunk = $casing($chunk);

      }

      // Format it and apply the current indentation.

      $output .= drupal_wrap_mail($chunk, implode('', $indent)) ."\n";

      // Remove non-quotation markers from indentation.

      $indent = array_map('_drupal_html_to_text_clean', $indent);

    }

    $tag = !$tag;

  }

  return $output . $footnotes;

}

/**

 * Helper function for array_walk in drupal_wrap_mail().

 *

 * Wraps words on a single line.

 */

function _drupal_wrap_mail_line(&$line, $key, $values) {

  // Use soft-breaks only for purely quoted or unindented text.

  $line = wordwrap($line, 77 - $values['length'], $values['soft'] ? "  \n" : "\n");

  // Break really long words at the maximum width allowed.

  $line = wordwrap($line, 996 - $values['length'], $values['soft'] ? " \n" : "\n");

}

/**

 * Helper function for drupal_html_to_text().

 *