<?php /* $Id: mimemail.module,v 1.24 2008-03-01 05:11:52 vauxia Exp $ */

/**
 * @file Component module for sending Mime-encoded emails
 * 
 */
 
/**
 * Implementation of hook_menu()
 */
function mimemail_menu() {
  $items[] = array(
    'path' => 'admin/settings/mimemail',
    'title' => t('Mail'),
    'description' => t('HTML E-mail settings'),
    'callback' => 'drupal_get_form',
    'callback arguments' => 'mimemail_settings',
    'access' => user_access('administer site configuration'),
    'type' => MENU_NORMAL_ITEM,
  );
  $items[] = array(
    'path' => 'mimemail',
    'callback' => 'mimemail_post',
    'access' => variable_get('mimemail_incoming', FALSE),
    'type' => MENU_CALLBACK,
  );
  return $items;
}

function mimemail_settings() {

  // override the smtp_library value if mimemail is chosen to handle all mail
  // this will cause drupal_mail to call mimemail()
  if (variable_get('mimemail_alter', 0)) {
    if (!strpos(variable_get('smtp_library', ''), 'mimemail')) {
      variable_set('smtp_library', drupal_get_filename('module', 'mimemail'));
    }
  }
  else {
    if (strpos(variable_get('smtp_library', ''), 'mimemail')) {
      db_query("DELETE FROM {variable} WHERE name = 'smtp_library'");
    }
  }

  $engines = mimemail_get_engines();
  
  $form = array();
  $form['site_mail'] = array(
    '#type'          => 'textfield', 
    '#title'         => t('E-mail address'), 
    '#default_value' => variable_get('site_mail', ini_get('sendmail_from')), 
    '#size'          => 60, 
    '#maxlength'     => 128, 
    '#description'   => t('A valid e-mail address for this website, used by the auto-mailer during registration, new password requests, notifications, etc.')
  );
  $form['mimemail']['mimemail_alter'] = array(
    '#type'          => 'checkbox',
    '#title'         => t('Use mime mail for all messages'),
    '#default_value' => variable_get('mimemail_alter', 0),
    '#description'   => t('Use the mime mail module to deliver all site messages.  With this option, system emails will have styles and formatting'),
  );
  $form['mimemail']['mimemail_textonly'] = array(
    '#type'          => 'checkbox',
    '#title'         => t('Plaintext email only'),
    '#default_value' => variable_get('mimemail_textonly', 0),
    '#description'   => t('This option disables the use of email messages with graphics and styles.  All messages will be converted to plain text.'),
  );

  $form['mimemail']['incoming'] = array(
    '#type'          => 'fieldset',
    '#title'         => t('Advanced Settings'),
    '#collapsible'   => TRUE,
    '#collapsed'     => TRUE,
  );
  $form['mimemail']['incoming']['mimemail_incoming'] = array(
    '#type'          => 'checkbox',
    '#title'         => t('Process incoming messages posted to this site'),
    '#default_value' => variable_get('mimemail_incoming', 0),
    '#description'   => t('This is an advanced setting that should not be enabled unless you know what you are doing'),
  );
  $form['mimemail']['incoming']['mimemail_key'] = array(
    '#type'          => 'textfield',
    '#title'         => t('Message validation string'),
    '#default_value' => variable_get('mimemail_key', md5(rand())),
    '#required'      => TRUE,
    '#description'   => t('This string will be used to validate incoming messages.  It can be anything, but must be used on both sides of the transfer'),
  );
  
  // hide the settings if only 1 engine is available
  if (count($engines) == 1) {
    variable_set('mimemail_engine', key($engines));
    $form['mimemail_engine'] = array(
        '#type'          => 'hidden',
        '#title'         => t('E-mail engine'), 
        '#default_value' => variable_get('mimemail_engine', 'mail'), 
        '#options'       => $engines, 
        '#description'   => t('Choose an e-mail engine for sending mails from your site.')
    );
  }
  else {
    $form['mimemail_engine'] = array(
        '#type'          => 'select',
        '#title'         => t('E-mail engine'), 
        '#default_value' => variable_get('mimemail_engine', 'mail'), 
        '#options'       => $engines, 
        '#description'   => t('Choose an e-mail engine for sending mails from your site.')
    );
  }

  if (variable_get('mimemail_engine', 0)) {
    $settings = module_invoke(variable_get('mimemail_engine', 'mail'), 'mailengine', 'settings');
    if ($settings) {
        $form['mimemail_engine_settings'] = array(
          '#type'        => 'fieldset', 
          '#title'       => t('Engine specific settings'),
      );
      foreach ($settings as $name => $value) {
        $form['mimemail_engine_settings'][$name] = $value;
      }
    }
  }
  else {
    drupal_set_message(t('Please choose a mail engine.'), 'error');
  }

  return system_settings_form($form);
}

/**
 * Implementation of hook_user()
 */
function mimemail_user($op, &$edit, &$user, $category='') {
  if ( $op == 'form' && $category == 'account') { 
    $form = array();
    $form['mimemail'] = array(
        '#type'          => 'fieldset',
        '#title'         => t('Email settings'),
        '#weight'        => 5, 
        '#collapsible' => true,
    );
    $form['mimemail']['mimemail_textonly'] = array(
      '#type'           => 'checkbox',
      '#title'           => t('Plaintext email only'),
      '#default_value'   => $user->mimemail_textonly,
      '#description'     => t('Check this option if you do not wish to receive email messages with graphics and styles'),
    );
    return $form;
  } 
  return;
}

/**
 * Send a mime-encoded email
 * 
 * @param $sender The email address or user object
 * @param $recipient An email address or user object * @param $subject An subject line string
 * @param $body An HTML body
 * @param $plaintext Whether to send message as plaintext only
 * @param $headers Optional e-mail headers in a keyed array
 * @param $text Optional plaintext portion of a multipart e-mail (instead of auto-generated)
 * 
 * @return result from mail() call
 */
function mimemail_prepare($sender, $recipient, $subject, $body, $plaintext=null, $headers=array(), $text=null, $attachments=array(), $mailkey = '') {

  require_once dirname(__FILE__) .'/mimemail.inc';

  if (is_null($sender)) {        // use site default for sender
    $sender = array(
        'name' => variable_get('site_name', 'Drupal'),
        'mail' => variable_get('site_mail', ini_get('sendmail_from')),
    );
  }
  
  // try to determine recpient's text mail preference
  if (is_null($plaintext)) {
    if (is_object($recipient)) {
      if (isset($recipient->mimemail_textonly)) {
        $plaintext = $recipient->mimemail_textonly;
      }
    }
    elseif (is_string($recipient) && valid_email_address($recipient)) {
      if (is_object($r = user_load(array('mail' => $recipient))) && isset($r->mimemail_textonly)) {
        $plaintext = $r->mimemail_textonly;
        $recipient = $r; // might as well pass the user object to the address function
      }
    }
  }
  $subject = mime_header_encode($subject);
  
  $plaintext = $plaintext || variable_get('mimemail_textonly', 0);
  $sender    = mimemail_address($sender);
  $mail      = mimemail_html_body(theme('mimemail_message', $body, $mailkey), $subject, $plaintext, $text, $attachments);
  $headers   = array_merge($headers, $mail['headers']);
  $message   = array(
    'address' => mimemail_address($recipient),
    'subject' => $subject,
    'body'    => $mail['body'],
    'sender'  => $sender,
    'headers' => mimemail_headers($headers, $sender),
  );

  return $message;
}

function mimemail($sender, $recipient, $subject, $body, $plaintext = NULL, $headers=array(), $text = NULL, $attachments = array(), $mailkey = '') {

  $engine = variable_get('mimemail_engine', 'mimemail') .'_mailengine';
  
  if (!function_exists($engine)) {
    return false;
  }

  $engine_prepare = variable_get('mimemail_engine', 'mimemail') .'_prepare';
  if (function_exists($engine_prepare)) {
    $message = $engine_prepare($sender, $recipient, $subject, $body, $plaintext, $headers, $text, $attachments, $mailkey);
  }
  else {
    $message = mimemail_prepare($sender, $recipient, $subject, $body, $plaintext, $headers, $text, $attachments, $mailkey);
  }

  return $engine('send', $message);

  return false;
}

/**
 * Returns available mailer engines.
 *
 * @return an array of mailer engine names.
 */
function mimemail_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;
}

/**
 * Default mailengine
 */
function mimemail_mailengine($op, $message = array()) {
  //default values
  $message = array_merge( array(
      'address' => '', 
      'subject' => '', 
      'body' => '', 
      'sender' => '', 
      'headers' => '', 
      ), $message);
      
  switch ($op) {
    case 'name':
      return t('Mime Mail');
      
    case 'description':
      return t("Default mailing engine using drupal_mail().");
      
    case 'settings': //not implemented
      return false;
      
    case 'multiple':
    case 'single':
    case 'send':
      if (!is_array($message['address'])) {
        $message['address'] = array($message['address']);
      }
      $status = true;
      foreach ($message['address'] as $a) {
        $status = mail(
          $a,
          $message['subject'],
          $message['body'],
          mimemail_rfc_headers($message['headers'])
        ) && $status;
    
      }
      return $status;
  }

  return false;
}

if (strpos(variable_get('smtp_library', ''), 'mimemail')
  && !function_exists('drupal_mail_wrapper')) {

  function drupal_mail_wrapper($mailkey, $to, $subject, $body, $from, $headers) {
    return mimemail($from, $to, $subject, $body, NULL, $headers, NULL, array(), $mailkey);
  }
} 

function mimemail_mail_alter($mailkey, &$recipient, &$subject, &$body, &$sender, &$headers) {

  if (!variable_get('mimemail_alter', 0)) return;

  // attempt to fixup non-html messages that are being sent through drupal_mail
  // I'm open to suggestions for better ways of doing this
  $body = check_markup($body, FILTER_FORMAT_DEFAULT);
  return;
}

function mimemail_post() {
  $message = $_POST['message'];
  $token   = $_POST['token'];
  $hash    = md5(variable_get('mimemail_key', '**') . $message );

  if ($hash != $token) {
    watchdog('access denied', t('Authentication error for POST e-mail'), WATCHDOG_WARNING);
    return drupal_access_denied();
  }
  return mimemail_incoming($message);
}

function mimemail_incoming($message) {
  require_once dirname(__FILE__) .'/mimemail.inc';
  $mail = mimemail_parse($message);

  foreach (module_implements('mimemail_incoming_alter') as $module) { 
    call_user_func_array($module .'_mimemail_incoming_alter', $mail); 
  }

  module_invoke_all('mimemail_incoming', $mail);
}

/**
 * Formats an address string 
 * TODO could use some enhancement and stress testing 
 * 
 * @param $address - a user object, a text email address or an array containing name, mail
 * @return formatted address string
 */
function mimemail_address($address) {
  
  if (is_array($address)) {
    
    // it's an array containing 'mail' and/or 'name'
    if (isset($address['mail'])) {
      $output = '';
      if (empty($address['name'])) {
        return $address['mail'];
      } 
      else {
        return '"'. addslashes($address['name']) .'" <'. $address['mail'] .'>';
      }
    }
    
    // it's an array of address items
    $addresses = array();
    foreach ($address as $a) {
      $addresses[] = mimemail_address($a);
    }
    return $addresses;
  }
  
  // it's a user object
  if (is_object($address) && isset($address->mail)) {
    return '"'. addslashes($address->name) .'" <'. $address->mail .'>';
  }
  
  // it's formatted or unformatted string
  // TODO shouldn't assume it's valid - should try to re-parse
  if (is_string($address)) {
    return $address;
  }

  // it's null.  return the site default address
  if (is_null($address)) {
    return array(
      'name' => variable_get('site_name', 'Drupal'),
      'mail' => variable_get('site_mail', ini_get('sendmail_from')),
    );
  }

  return false;
}

/**
 * Themeable message body
 */
function theme_mimemail_message($body, $mailkey = null) {
  $output = '<html><head>';
  $output .= '<meta http-equiv="Content-Type" content="text/html; charset=utf-8" />';

  // attempt to include a mail-specific version of the css.
  // if you want smaller mail messages, add a mail.css file to your theme
  $styles = path_to_theme() .'/mail.css';

  $output .= '<style type="text/css"><!--';
  if (!file_exists($styles)) {
    // embed a version of all style definitions
    $styles = preg_replace('|<style.*"'. base_path() .'([^"]*)".*|', '\1', drupal_get_css());
  }
  foreach (explode("\n", $styles) as $style) {
    $output .= file_get_contents($style);
  }
  $output .= '--></style></head><body id="mimemail-body"><div id="center"><div id="main">'. $body .'</div></div></body></html>';
  // compress output
  return preg_replace('/\s+|\n|\r|^\s|\s$/', ' ', $output);
}