<?php

/**
 * @file
 * Reroute E-mails based on specific rules.
 */
//=============================================================================
//                          Constant Initalization
//=============================================================================
define('ADVANCED_MAIL_REROUTE_ALLOW', 0);
define('ADVANCED_MAIL_REROUTE_BLOCK', 1);
define('ADVANCED_MAIL_REROUTE_REROUTE', 2);
define('ADVANCED_MAIL_REROUTE_OVERRIDE_DISABLED', 3);
define('ADVANCED_MAIL_REROUTE_DEFAULT_RULE', 'Allow');

//=============================================================================
//                           Hook Implementations
//=============================================================================
/**
 * Implementation of hook_menu()
 */
function advanced_mail_reroute_menu() {
  $items = array();
  $items['admin/config/advanced_mail_reroute_rules'] = array(
    'title' => 'Advanced mail reroute rules',
    'description' => t('Configure which mail will be allowed through, blocked or rerouted'),
    'page callback' => 'drupal_get_form',
    'page arguments' => array('advanced_mail_reroute_settings_form'),
    'access arguments' => array('administer advanced mail reroute')
  );
  $items['admin/reports/advanced_mail_reroute_log'] = array(
    'title' => 'Advanced mail reroute log',
    'description' => t('View which mail was allowed through, blocked or rerouted'),
    'page callback' => 'advanced_mail_reroute_log',
    'access arguments' => array('administer site configuration'),
  );  
  
  return $items;
}

/**
 * Implementation of hook_help()
 */
function advanced_mail_reroute_help($section='') {
  $output = '';
  
  switch ($section) {
    case "admin/help#advanced_mail_reroute":
      $output = '<p>'. t("Used to reroute all mail or specific mail based on their mail id.") .'</p>';
      break;
  }
  
  return $output;
}

/**
 * Implementation of hook_theme
 */
function advanced_mail_reroute_theme($existing, $type, $theme, $path) {
  return array(
    'advanced_mail_reroute_table' => array(
      'arguments' => array('element' => NULL),
    )
  );
}

/**
 * Implementation of hook_perm()
 */
function advanced_mail_reroute_perm() {
    return array('administer advanced mail reroute');
}

/**
 * Implementation of hook_elements()
 */
function advanced_mail_reroute_elements() {
  return array(
    'advanced_mail_reroute_table' => array(
      '#input' => TRUE,
      '#process' => array('advanced_mail_reroute_table_process'),
      '#element_validate' => array('advanced_mail_reroute_table_validate') 
    )
  );
}

/**
 * Implementation of hook_mail_alter()
 */
function advanced_mail_reroute_mail_alter(&$message) {  
  $num_rows = db_result(db_query("SELECT COUNT(*) FROM {advanced_mail_reroute_rules} WHERE mailkey='%s'", $message['id']));
  
  // fetch or create new rule
  if ($num_rows > 0) {
    $result = db_query("SELECT reroute_rule, email FROM {advanced_mail_reroute_rules} WHERE mailkey='%s'", $message['id']);
    $rule = db_fetch_array($result);
  }
  else {
    $rule = array(
      'reroute_rule' => variable_get('advanced_mail_reroute_default_rule', ADVANCED_MAIL_REROUTE_ALLOW),
      'email' => ''
    );
        
    db_query("INSERT INTO {advanced_mail_reroute_rules} (mailkey, reroute_rule, email) VALUES ('%s', %d, '')", $message['id'], $rule['reroute_rule']);
  }

  // apply override rule
  $reroute_override_rule = variable_get('advanced_mail_reroute_override', ADVANCED_MAIL_REROUTE_OVERRIDE_DISABLED);
  if ($reroute_override_rule != ADVANCED_MAIL_REROUTE_OVERRIDE_DISABLED) {
    $rule['reroute_rule'] = $reroute_override_rule;
    
    if ($rule['reroute_rule'] == ADVANCED_MAIL_REROUTE_REROUTE) {
      $rule['email'] = variable_get('advanced_mail_reroute_primary_email', variable_get('site_mail', NULL));
    }
  }
  else if ($rule['reroute_rule'] == ADVANCED_MAIL_REROUTE_REROUTE && empty($rule['email'])) {
    $rule['email'] = variable_get('advanced_mail_reroute_primary_email', variable_get('site_mail', NULL));
  }

  // log message
  if (variable_get('advanced_mail_reroute_log_enabled', TRUE)) {
    _advanced_mail_reroute_log($message['id'], $message['from'], $message['to'], $rule['reroute_rule'], $rule['email']);
  }
  
  // perform action
  switch ($rule['reroute_rule']) {
    case ADVANCED_MAIL_REROUTE_ALLOW:
      break;
    case ADVANCED_MAIL_REROUTE_BLOCK:
	$message['to'] = NULL;
      
   	// Remove warning about Drupal being unable to send email.
        $warnings = drupal_get_messages('warning');
        foreach($warnings['warning'] as $warning) {
  	  if($error != 'Unable to send e-mail') {
            drupal_set_message($warning, 'warning');
          }
        }
      
      break;
    case ADVANCED_MAIL_REROUTE_REROUTE:
      _advanced_mail_reroute_reroute($message, $rule['email']);
      break;
  }
}

//=============================================================================
//                           Callback Functions
//=============================================================================
function advanced_mail_reroute_settings_form() {  
  drupal_add_js(drupal_get_path('module', 'advanced_mail_reroute') .'/advanced_mail_reroute.js');

  $override_value_to_index = array(
    ADVANCED_MAIL_REROUTE_OVERRIDE_DISABLED => 0,
    ADVANCED_MAIL_REROUTE_ALLOW => 1,
    ADVANCED_MAIL_REROUTE_BLOCK => 2,
    ADVANCED_MAIL_REROUTE_REROUTE => 3
  );
  
  $override_value = variable_get('advanced_mail_reroute_override', ADVANCED_MAIL_REROUTE_OVERRIDE_DISABLED);

  $form['#tree'] = TRUE;
  
  $form['main_settings'] = array(
    '#type' => 'fieldset',
    '#title' => t('Main settings'),
    '#collapsible' => TRUE
  );
  $form['main_settings']['override'] = array(
    '#type' => 'select',
    '#title' => t('Override rule'),
    '#options' => array(t('- Disabled -'), t('Allow all emails through'), t('Block all emails'), t('Redirect all emails to primary email address')),
    '#default_value' => $override_value_to_index[$override_value],
    '#description' => t('This will override any settings in the Mailkey rules table')
  );
  $form['main_settings']['primary_email'] = array(
    '#type' => 'textfield',
    '#title' => t('Primary E-mail'),
    '#default_value' => variable_get('advanced_mail_reroute_primary_email', variable_get('site_mail', '')),
    '#description' => t('By default all E-mails will be sent to this address'),
  );
  $form['main_settings']['enable_logging'] = array(
    '#type' => 'checkbox',
    '#title' => t('Enable logging'),
    '#default_value' => variable_get('advanced_mail_reroute_enable_logging', TRUE),
  );
  
  $mailkey_rules_description = t('This table is automatically updated as new mailkeys are discovered.');
  
  if (variable_get('advanced_mail_reroute_override', ADVANCED_MAIL_REROUTE_OVERRIDE_DISABLED) != ADVANCED_MAIL_REROUTE_OVERRIDE_DISABLED) {
    $mailkey_rules_description .= ' <div style="color: red; display: block;">'. t('Override is currently enabled. All rules below will be ignored.') .'</div>';
  }
  
  $form['mailkey_rules'] = array(
    '#type' => 'fieldset',
    '#title' => t('Reroute rules'),
    '#collapsible' => TRUE,
    '#description' => $mailkey_rules_description,
  );
  $form['mailkey_rules']['default_rule'] = array(
    '#type' => 'select',
    '#title' => t('Default rule for new mailkeys'),
    '#options' =>  array('Allow', 'Block', 'Reroute'),
    '#default_value' => variable_get('advanced_mail_reroute_default_rule', ADVANCED_MAIL_REROUTE_DEFAULT_RULE),
  );
  $form['mailkey_rules']['table'] = array(
    '#type' => 'advanced_mail_reroute_table'
  );
  
  $form['new_rule'] = array(
    '#type' => 'fieldset',
    '#title' => t('New rule'),
    '#collapsible' => TRUE,
    '#collapsed' => TRUE
  );
  $form['new_rule']['mailkey'] = array(
    '#type' => 'textfield',
    '#title' => t('Mailkey')
  );
  $form['new_rule']['rule'] = array(
    '#type' => 'select',
    '#title' => t('Rule'),
    '#options' =>  array('Allow', 'Block', 'Reroute'),
    '#default_value' => variable_get('advanced_mail_reroute_default_rule', ADVANCED_MAIL_REROUTE_DEFAULT_RULE),
    '#attributes' => array('class' => 'advanced-mail-reroute-rule')
  );
  $form['new_rule']['email'] = array(
    '#type' => 'textfield',
    '#title' => t('E-mail'),
    '#description' => t("When reroute is selected you may enter an optional email if"),
    '#attributes' => array('class' => 'advanced-mail-reroute-email')
  );
  
  $form['submit'] = array(
    '#type' => 'submit',
    '#value' => t('Save'),
  );

  return $form;
}

function advanced_mail_reroute_settings_form_validate($form_id, $form_values) {
  if (!valid_email_address($form_values['values']['main_settings']['primary_email'])) {
    form_set_error('main_settings][primary_email', t('Invalid email entered for primary email'));
  }

  $new_rule = $form_values['values']['new_rule'];
  
  if (!empty($new_rule['mailkey']) && $new_rule['rule'] == ADVANCED_MAIL_REROUTE_REROUTE &&
      !empty($new_rule['email']) && !valid_email_address($new_rule['email'])) {
    form_set_error('new_rule][email', t('Invalid email entered for new mailkey rule'));
  }
  
  
}

function advanced_mail_reroute_settings_form_submit($form_id, $form_state) {
  $override_index_to_value = array(
    0 => ADVANCED_MAIL_REROUTE_OVERRIDE_DISABLED,
    1 => ADVANCED_MAIL_REROUTE_ALLOW,
    2 => ADVANCED_MAIL_REROUTE_BLOCK,
    3 => ADVANCED_MAIL_REROUTE_REROUTE
  );
  
  $override_index = $form_state['values']['main_settings']['override'];
  
  variable_set('advanced_mail_reroute_override', $override_index_to_value[$override_index]);
  variable_set('advanced_mail_reroute_primary_email', $form_state['values']['main_settings']['primary_email']);
  variable_set('advanced_mail_reroute_enable_logging', $form_state['values']['main_settings']['enable_logging']);
  variable_set('advanced_mail_reroute_default_rule', $form_state['values']['mailkey_rules']['default_rule']);

  $new_rule = $form_state['values']['new_rule'];
  
  if (!empty($new_rule['mailkey'])) {
    $email = ($new_rule['rule'] == ADVANCED_MAIL_REROUTE_REROUTE ? $new_rule['email'] : '');
    
    db_query("INSERT INTO {advanced_mail_reroute_rules} (mailkey, reroute_rule, email) VALUES ('%s', %d, '%s')",
      $new_rule['mailkey'], $new_rule['rule'], $new_rule['email']);
  }

  $table = $form_state['values']['mailkey_rules']['table']['mailkeys'];
  
  if (!empty($table)) {
    foreach ($table as $key => $value) {
      if ($value['remove']) {
        db_query("DELETE FROM {advanced_mail_reroute_rules} WHERE mailkey ='%s'", $value['mailkey']);
      }
      else {
        $email = ($value['rule'] == ADVANCED_MAIL_REROUTE_REROUTE ? $value['email'] : '');
        db_query("UPDATE {advanced_mail_reroute_rules} SET reroute_rule = %d, email = '%s' WHERE mailkey = '%s'", $value['rule'], $email, $value['mailkey']);  
      }
    }
  }
}

function advanced_mail_reroute_table_process($element, $form_state) {  
  $result = db_query('SELECT mailkey, reroute_rule, email FROM {advanced_mail_reroute_rules}');
    
  while ($row = db_fetch_object($result)) {
    $element['mailkeys']['M'. $row->mailkey] = array(  // prefix with 'M' so mailkeys which begin with a '#' won't get discarded in the theme function
      'mailkey' => array(
        '#type' => 'hidden',
        '#value' => $row->mailkey,
      ),
      'rule' => array(
        '#type' => 'select',
        '#options' => array('Allow', 'Block', 'Reroute'),
        '#default_value' => $row->reroute_rule,
        '#attributes' => array('class' => 'advanced-mail-reroute-rule')
      ),
      'email' => array(
        '#type' => 'textfield',
        '#default_value' => $row->email,
        '#size' => 25,
        '#attributes' => array('class' => 'advanced-mail-reroute-email')
      ),
      'remove' => array(
        '#type' => 'checkbox',
        '#default_value' => 0
      )
    );
  }
  
  return $element;
}

function advanced_mail_reroute_table_validate($element, $form_state) {
  if (!empty($form_state['values']['new_rule']['mailkey'])) {
    $num_rows = db_result(db_query("SELECT COUNT(*) FROM {advanced_mail_reroute_rules} WHERE mailkey='%s'", $form_state['values']['new_rule']['mailkey']));
  
    if ($num_rows > 0) {
      form_set_error('new_rule][mailkey', t('Mailkey for new rule already exists'));
    }
  }
  
  if (!empty($form_state['values']['mailkey_rules']['table']['mailkeys'])) {
    foreach ($form_state['values']['mailkey_rules']['table']['mailkeys'] as $key => $value) {
      if ($value['rule'] == ADVANCED_MAIL_REROUTE_REROUTE &&
          !empty($value['email']) &&
          !$value['remove'] &&
          !valid_email_address($value['email'])) {
        form_set_error($key, t("Invalid email entered for mailkey rule '". substr($key, 1) ."'"));
      }
    }
  }
}

function theme_advanced_mail_reroute_table($element) {
  if (isset($element['mailkeys'])) {
    foreach ($element['mailkeys'] as $mailkey => $row) {
      if ($mailkey[0] == 'M') {  // drupal inserts a lot of other stuff beginning with '#' so we want to skip past that.
        $rows[] = array(
          $row['mailkey']['#value'],
          theme('select', $row['rule']),
          theme('textfield', $row['email']),
          theme('checkbox', $row['remove'])
        );
      }
    }
  }
  
  if (!isset($rows)) {
    $rows[] = array(array('data' => t('No rules available.'), 'colspan' => 5));
  }
  
  $header = array(t('Mailkey'), t('Rule'), t('E-mail'), t('Remove'));
  $output = theme('table', $header, $rows);
 
  return $output;
}

/*
function advanced_mail_reroute_log() {
  $actions = array('Allowed', 'Blocked', 'Rerouted');
  
  $header = array(
    array('data' => t('Time'), 'field' => 'timestamp', 'sort' => 'desc'),
    array('data' => t('Mailkey'), 'field' => 'mailkey'),
    array('data' => t('From'), 'field' => 'from_email'),
    array('data' => t('To'), 'field' => 'to_email'),
    array('data' => t('Action'), 'field' => 'reroute_rule')
  );

  $result = pager_query("SELECT timestamp, mailkey, from_email, to_email, reroute_rule, reroute_email FROM {advanced_mail_reroute_log}"
        . tablesort_sql($header), 30, 0, "SELECT COUNT(id) FROM {advanced_mail_reroute_log}");
    
  while ($row = db_fetch_object($result)) {    
    $action_taken = $actions[$row->reroute_rule];
    
    if ($row->reroute_rule == ADVANCED_MAIL_REROUTE_REROUTE) {
      $action_taken .= ' to '. $row->reroute_email;
    }
    
    $rows[] = array(date('Y-m-d H:i:s', $row->timestamp), $row->mailkey, $row->from_email, $row->to_email, $action_taken);
  }
  
  if (!$rows) {
    $rows[] = array(array('data' => t('No log messages available.'), 'colspan' => 5));
  }
  
  $content = theme('table', $header, $rows);
  $content .= theme('pager', NULL, 30, 0);
  
  return $content;
}*/


function advanced_mail_reroute_log() {
  //if ($node = node_load(arg(1))) {
  	
    $header = array(
      array('data' => t('Time'), 'field' => 'timestamp', 'sort' => 'desc'),
      array('data' => t('Mailkey'), 'field' => 'mailkey'),
      array('data' => t('From'), 'field' => 'from_email'),
      array('data' => t('To'), 'field' => 'to_email'),
      array('data' => t('Action'), 'field' => 'reroute_rule')
    );
  
    $query = db_select('advanced_mail_reroute_log', 'amr', array('target' => 'slave'))->extend('PagerDefault')->extend('TableSort');
    $query
    ->fields('amr', array('timestamp', 'mailkey', 'from_email', 'to_email', 'reroute_rule', 'reroute_email'))
    ->limit(30)
    ->orderByHeader($header);

    $result = $query->execute();
    $rows = array();
  	 foreach ($result as $log) {
      $rows[] = array(
        array('data' => format_date($log->timestamp, 'short'), 'class' => array('nowrap')),
      );
  	 }

    //drupal_set_title($node->title);
    $build['advanced_mail_reroute_table'] = array(
      '#theme' => 'table',
      '#header' => $header,
      '#rows' => $rows,
      '#empty' => t('No logs available.'),
    );
    $build['advanced_mail_reroute_pager'] = array('#theme' => 'pager');
    return $build;
  //}
  //else {
  //  drupal_not_found();
  //}
}

//=============================================================================
//                           Private Functions
//=============================================================================
function _advanced_mail_reroute_log($mailkey, $from, $to, $reroute_rule, $reroute_email = '') {
    db_query("INSERT INTO {advanced_mail_reroute_log} (timestamp, mailkey, from_email, to_email, reroute_rule, reroute_email)
      VALUES (%d, '%s', '%s', '%s', %d, '%s')", time(), $mailkey, $from, $to, $reroute_rule, $reroute_email);
}

function _advanced_mail_reroute_reroute(&$message, $reroute_to) {
  $message['body'] = is_array($message['body']) ? implode("\n\n", $message['body']) : $message['body'];
  
  global $base_url;
  $message['subject'] = 'Rerouted email: '. $message['subject'];
  
  // Format copied from reroute_email module: http://drupal.org/project/reroute_email
  $body_header  = "This email was rerouted.\n";
  $body_header .= "Web site: @site\n";
  $body_header .= "Mail key: @key\n";
  $body_header .= "Originally to: <@to>\n";
  $body_header .= "-----------------------\n";

  $body_header = t($body_header, array('@site' => $base_url, '@to' => $message['to'], '@key' => $message['id']));

  $message['body'] = $body_header . (is_array($message['body']) ? implode("\n\n", $message['body']) : $message['body']);
  $message['to'] = $reroute_to;
}