<?php

/**
 * @file
 * Component module for sending Mime-encoded emails.
 */

/**
 * Implements hook_menu().
 */
function mimemail_menu() {
  $path = drupal_get_path('module', 'mimemail') . '/includes';
  // Configuration links.
  $items['admin/config/system/mimemail'] = array(
    'title' => 'Mime Mail',
    'description' => 'Manage mime mail system settings.',
    'page callback' => 'drupal_get_form',
    'page arguments' => array('mimemail_admin_settings'),
    'access arguments' => array('administer site configuration'),
    'file' => 'mimemail.admin.inc',
    'file path' => $path,
  );
  $items['mimemail'] = array(
    'page callback' => 'mimemail_post',
    'access callback' => 'mimemail_incoming_access',
    'type' => MENU_CALLBACK,
    'file' => 'mimemail.incoming.inc',
    'file path' => $path,
  );
  return $items;
}

/**
 * Implements hook_permission().
 */
function mimemail_permission() {
  return array(
    'edit mimemail user settings' => array(
      'title' => t('Edit Mime Mail user settings'),
      'description' => t('Edit user specific settings for Mime Mail.'),
    ),
    'send arbitrary files' => array(
      'title' => t('Send arbitrary files'),
      'description' => t('Attach or embed files located outside the public files directory.'),
      'restrict access' => TRUE,
    ),
  );
}

/**
 * Access callback to process incoming messages.
 */
function mimemail_incoming_access() {
  return variable_get('mimemail_incoming', FALSE);
}

/**
 * Implements hook_field_extra_fields().
 */
function mimemail_field_extra_fields() {
  $extra['user']['user'] = array(
    'form' => array(
      'mimemail' => array(
        'label' => t('Email'),
        'description' => t('Mime Mail module settings form elements.'),
        'weight' => 0,
      ),
    ),
    'display' => array(
      'mimemail' => array(
        'label' => t('Email'),
        'description' => t('Mime Mail module settings form elements.'),
        'weight' => 0,
      ),
    ),
  );

  return $extra;
}

/**
 * Implements hook_user_view().
 */
function mimemail_user_view($account, $view_mode, $langcode) {
  $account->content['mimemail'] = array(
    '#type' => 'user_profile_category',
    '#title' => t('Email'),
  );

  $account->content['mimemail']['textonly'] = array(
    '#type' => 'user_profile_item',
    '#title' => t('Plaintext email only'),
    '#markup' => empty($account->data['mimemail_textonly']) ? t('No') : t('Yes'),
  );
}

/**
 * Implements hook_form_FORM_ID_alter().
 *
 * Adds the Mime Mail settings on the user settings page.
 */
function mimemail_form_user_profile_form_alter(&$form, &$form_state) {
  if ($form['#user_category'] == 'account') {
    $account = $form['#user'];
    $form['mimemail'] = array(
      '#type' => 'fieldset',
      '#title' => t('Email settings'),
      '#weight' => 5,
      '#collapsible' => TRUE,
      '#access' => user_access('edit mimemail user settings'),
    );
    $form['mimemail']['mimemail_textonly'] = array(
      '#type' => 'checkbox',
      '#title' => t('Plaintext email only'),
      '#default_value' => !empty($account->data['mimemail_textonly']) ? $account->data['mimemail_textonly'] : FALSE,
      '#description' => t('Check this option if you do not wish to receive email messages with graphics and styles.'),
    );
  }
}

/**
 * Implements hook_user_presave().
 */
function mimemail_user_presave(&$edit, $account, $category) {
  $edit['data']['mimemail_textonly'] = isset($edit['mimemail_textonly']) ? $edit['mimemail_textonly'] : 0;
}

/**
 * Implements hook_theme().
 */
function mimemail_theme() {
  module_load_include('inc', 'mimemail', 'theme/mimemail.theme');
  return mimemail_theme_theme();
}

/**
 * Implements hook_mail().
 */
function mimemail_mail($key, &$message, $params) {
  $context = $params['context'];
  $options = array('clear' => TRUE);

  // Prepare the array of the attachments.
  $attachments = array();
  $attachments_string = trim($params['attachments']);
  if (!empty($attachments_string)) {
    $attachment_lines = array_filter(explode("\n", trim($attachments_string)));
    foreach ($attachment_lines as $filepath) {
      $attachments[] = array(
        'filepath' => trim($filepath),
      );
    }
  }

  // We handle different address headers if set.
  $address_headers = array(
    'cc' => 'Cc',
    'bcc' => 'Bcc',
    'reply-to' => 'Reply-to',
    'list-unsubscribe' => 'List-Unsubscribe',
  );
  foreach ($address_headers as $param_key => $address_header) {
    $params[$param_key] = empty($params[$param_key]) ? array() : explode(',', $params[$param_key]);
    if (!empty($params[$param_key])) {
      foreach ($params[$param_key] as $key => $address) {
        $params[$param_key][$key] = token_replace($address, $context, $options);
      }
      $message['headers'][$address_header] = implode(',', $params[$param_key]);
    }
  }

  $message['to'] = token_replace($message['to'], $context, $options);
  $message['subject'] = token_replace($context['subject'], $context, $options);
  $message['body'][] = token_replace($context['body'], $context, $options);
  $message['params']['plaintext'] = token_replace($params['plaintext'], $context, $options);
  $message['params']['attachments'] = $attachments;
}

/**
 * Retreives a list of all available mailer engines.
 *
 * @return array
 *   Mailer engine names.
 */
function mimemail_get_engines() {
  $engines = array();
  foreach (module_implements('mailengine') as $module) {
    $engines[$module] = module_invoke($module, 'mailengine', 'list');
  }
  return $engines;
}

/**
 * Implements hook_mailengine().
 *
 * @param string $op
 *   The operation to perform on the message.
 * @param array $message
 *   The message to perform the operation on.
 *
 * @return boolean
 *   Returns TRUE if the operation was successful or FALSE if it was not.
 */
function mimemail_mailengine($op, $message = array()) {
  module_load_include('inc', 'mimemail');

  switch ($op) {
    case 'list':
      $engine = array(
        'name' => t('Mime Mail'),
        'description' => t("Default mailing engine."),
      );
      return $engine;
    case 'settings':
      // Not implemented.
      break;
    case 'multiple':
    case 'single':
    case 'send':
      // Default values.
      $default = array(
        'to' => '',
        'subject' => '',
        'body' => '',
        'from' => '',
        'headers' => ''
      );
      $message = array_merge($default, $message);

      // If 'Return-Path' isn't already set in php.ini, we pass it separately
      // as an additional parameter instead of in the header.
      // However, if PHP's 'safe_mode' is on, this is not allowed.
      if (isset($message['headers']['Return-Path']) && !ini_get('safe_mode')) {
        $return_path_set = strpos(ini_get('sendmail_path'), ' -f');
        if (!$return_path_set) {
          $return_path = trim($message['headers']['Return-Path'], '<>');
          unset($message['headers']['Return-Path']);
        }
      }

      $crlf = variable_get('mimemail_crlf', MAIL_LINE_ENDINGS);

      $recipients = (!is_array($message['to'])) ? array($message['to']) : $message['to'];
      $subject = mime_header_encode($message['subject']);
      $body = preg_replace('@\r?\n@', $crlf, $message['body']);
      $headers = mimemail_rfc_headers($message['headers']);

      $result = TRUE;
      foreach ($recipients as $to) {
        if (isset($return_path) && !empty($return_path)) {
          if (isset($_SERVER['WINDIR']) || strpos($_SERVER['SERVER_SOFTWARE'], 'Win32') !== FALSE) {
            // On Windows, PHP will use the value of sendmail_from for the
            // Return-Path header.
            $old_from = ini_get('sendmail_from');
            ini_set('sendmail_from', $return_path);
            $result = @mail($to, $subject, $body, $headers) && $result;
            ini_set('sendmail_from', $old_from);
          }
          else {
            // On most non-Windows systems, the "-f" option to the sendmail command
            // is used to set the Return-Path.
            $result = @mail($to, $subject, $body, $headers, '-f' . $return_path) && $result;
          }
        }
        else {
          // The optional $additional_parameters argument to mail() is not allowed
          // if safe_mode is enabled. Passing any value throws a PHP warning and
          // makes mail() return FALSE.
          $result = @mail($to, $subject, $body, $headers) && $result;
        }
      }

      return $result;
  }

  return FALSE;
}

/**
 * Prepares the message for sending.
 *
 * @param array $message
 *   An array containing the message data. The optional parameters are:
 *   - plain: Whether to send the message as plaintext only or HTML. If evaluates to TRUE,
 *     then the message will be sent as plaintext.
 *   - plaintext: Optional plaintext portion of a multipart email.
 *   - attachments: An array of arrays which describe one or more attachments.
 *     Existing files can be added by path, dinamically-generated files
 *     can be added by content. The internal array contains the following elements:
 *      - filepath: Relative Drupal path to an existing file (filecontent is NULL).
 *      - filecontent: The actual content of the file (filepath is NULL).
 *      - filename: The filename of the file.
 *      - filemime: The MIME type of the file.
 *      The array of arrays looks something like this:
 *      Array
 *      (
 *        [0] => Array
 *        (
 *         [filepath] => '/sites/default/files/attachment.txt'
 *         [filecontent] => 'My attachment.'
 *         [filename] => 'attachment.txt'
 *         [filemime] => 'text/plain'
 *        )
 *      )
 *
 * @return array
 *   All details of the message.
 */
function mimemail_prepare_message($message) {
  module_load_include('inc', 'mimemail');

  $module = $message['module'];
  $key = $message['key'];
  $to = $message['to'];
  $from = $message['from'];
  $subject = $message['subject'];
  $body = $message['body'];

  $headers = isset($message['params']['headers']) ? $message['params']['headers'] : array();
  $plain = isset($message['params']['plain']) ? $message['params']['plain'] : NULL;
  $plaintext = isset($message['params']['plaintext']) ? $message['params']['plaintext'] : NULL;
  $attachments = isset($message['params']['attachments']) ? $message['params']['attachments'] : array();

  $site_name = variable_get('site_name', 'Drupal');
  $site_mail = variable_get('site_mail', ini_get('sendmail_from'));
  $simple_address = variable_get('mimemail_simple_address', 0);

  // Override site mails default sender when using default engine.
  if ((empty($from) || $from == $site_mail)
      && variable_get('mimemail_engine', 'mimemail') == 'mimemail') {
    $mimemail_name = variable_get('mimemail_name', $site_name);
    $mimemail_mail = variable_get('mimemail_mail', $site_mail);
    $from = array(
      'name' => !empty($mimemail_name) ? $mimemail_name : $site_name,
      'mail' => !empty($mimemail_mail) ? $mimemail_mail : $site_mail,
    );
  }

  // Body is empty, this is a plaintext message.
  if (empty($body)) {
    $plain = TRUE;
  }
  // Try to determine recipient's text mail preference.
  elseif (is_null($plain)) {
    if (is_object($to) && isset($to->data['mimemail_textonly'])) {
      $plain = $to->data['mimemail_textonly'];
    }
    elseif (is_string($to) && valid_email_address($to)) {
      if (is_object($account = user_load_by_mail($to)) && isset($account->data['mimemail_textonly'])) {
        $plain = $account->data['mimemail_textonly'];
        // Might as well pass the user object to the address function.
        $to = $account;
      }
    }
  }

  // Removing newline character introduced by _drupal_wrap_mail_line();
  $subject = str_replace(array("\n"), '', trim(drupal_html_to_text($subject)));

  $hook = array(
    'mimemail_message__' . $key,
    'mimemail_message__' . $module .'__'. $key,
  );

  $variables = array(
    'module' => $module,
    'key' => $key,
    'recipient' => $to,
    'subject' => $subject,
    'body' => $body
  );

  $body = theme($hook, $variables);

  foreach (module_implements('mail_post_process') as $module) {
    $function = $module . '_mail_post_process';
    $function($body, $key);
  }

  $plain = $plain || variable_get('mimemail_textonly', 0);
  $from = mimemail_address($from);
  $mail = mimemail_html_body($body, $subject, $plain, $plaintext, $attachments);
  $headers = array_merge($message['headers'], $headers, $mail['headers']);

  $message['to'] = mimemail_address($to, $simple_address);
  $message['from'] = $from;
  $message['subject'] = $subject;
  $message['body'] = $mail['body'];
  $message['headers'] = mimemail_headers($headers, $from);

  return $message;
}