<?php
// $Id: login_destination.module,v 1.10.2.23 2010/10/27 22:12:46 setfree Exp $

/**
 * @file
 * Control where users are directed to, once they login
 */

// Destination constants
define('LOGIN_DEST_STATIC',  'static');
define('LOGIN_DEST_SNIPPET', 'snippet');

// Condition constants
define('LOGIN_COND_ALWAYS',  'always');
define('LOGIN_COND_PAGES',   'pages');
define('LOGIN_COND_SNIPPET', 'snippet');

// Permissions
define('LOGIN_DEST_PERM_ADMIN', 'administer login destination');

/**
 * Implementation of hook_perm().
 */
function login_destination_perm() {
  return array(LOGIN_DEST_PERM_ADMIN);
}

/**
 * Implementation of hook_menu().
 */
function login_destination_menu() {

  $items['admin/user/login_destination'] = array(
    'title' => 'Login Destination',
    'description' => 'Control where users are redirected to, once they login.',
    'page callback' => 'drupal_get_form',
    'page arguments' => array('login_destination_admin_settings'),
    'access arguments' => array(LOGIN_DEST_PERM_ADMIN),
    'type' => MENU_NORMAL_ITEM
  );
  
  return $items;
}

function login_destination_admin_settings() {
  $form = array();

  # on which pages we redirect
  $form['condition'] = array(
    '#type' => 'fieldset',
    '#title' => t('Redirection conditions'),
    '#description' => t('When should redirection happen?'),
    '#collapsible' => TRUE,
    '#collapsed'   => TRUE,
  );
  $form['condition']['ld_condition_type'] = array(
    '#type' => 'radios',
    '#default_value' => variable_get('ld_condition_type', 'always'),
    '#options' => array(
      LOGIN_COND_ALWAYS => t('Always'),
      LOGIN_COND_PAGES => t('List of paths'),
      LOGIN_COND_SNIPPET => t('PHP snippet (experts only)')
    )
  );
  $form['condition']['ld_condition_snippet'] = array(
    '#type' => 'textarea',
    '#default_value' => variable_get('ld_condition_snippet', ''),
    '#title' => t('Redirect condition: <b>IMPORTANT! If using a WYSIWYG editor - ensure that you use its plain text mode! There is a link below the text box.</b>'),
    '#rows' => 4,
    '#description' =>
      t('<b>Always:</b> Redirection happens always. Redirect condition field is ignored.'). '<br/>' .
      t('<b>List of paths mode:</b> Enter a list of paths, one path per one line. Redirection will happen only when logging from specified pages. Example paths are <b>%ex1</b> or <b>%ex2</b>.',
        array('%ex1' => 'contact', '%ex2' => 'user/login')). '<br/>'.
      t('<b>PHP snippet mode:</b> Enter PHP code to find should redirection happen or not (<b>NO %php tags!</b>). It should return a boolean value.',
        array('%php' => '<?php ?>'))
  );
  

  # to where we redirect
  $form['destination'] = array(
    '#type' => 'fieldset',
    '#title' => t('Destination URL settings'),
    '#description' => t('To where exactly should the user be redirected upon login.'),
    '#collapsible' => TRUE,
    '#collapsed'   => TRUE,
  );
  
  $form['destination']['ld_destination'] = array(
    '#type' => 'checkbox',
    '#default_value' => variable_get('ld_destination', TRUE),
    '#title' => t('Return user to where he/she came from. (Preserve destination)'),
    '#description' => t("If checked, 'destination=' parameter specified in the URL will be used to perform redirection.<br />
      <b>NOTE</b>: All options below will be ignored then!."),
  );
  $form['destination']['ld_url_type'] = array(
    '#type' => 'radios',
    '#default_value' => variable_get('ld_url_type', LOGIN_DEST_STATIC),
    '#options' => array(
      LOGIN_DEST_STATIC  => t('Static URL'),
      LOGIN_DEST_SNIPPET => t('PHP snippet (experts only)')
    )
  );
  $form['destination']['ld_url_destination'] = array(
    '#type' => 'textarea',
    '#default_value' => variable_get('ld_url_destination', 'user'),
    '#title' => t('URL: (<b>IMPORTANT! If using a WYSWYG editor - ensure that you use its plain text mode!
      There is a link below the text box.</b> )'),
    '#rows' => 4,
    '#description' =>
      t('<b>Static URL mode:</b> Enter a static path. Do not use a GET query at the end here. Only the first line of text will be used.
      Example paths are %ex1 or %ex2.',
        array('%ex1' => 'node/add', '%ex2' => 'contact')
      ). '<br/>'.

      '<b>' .
      t("PHP snippet mode") .
      ":</b>" .
      t("Enter PHP code to evaluate path") .
      "(<b>" .
      t("NO %php tags!", array('%php' => '<?php ?>')) .
      "</b>)." .
      t("It should return either a string value or an array like in:<br />
        <b> return array('path' => 'node/add/video or alias', 'query' => 'param1=100&param2=200');</b>."
      ),
  );

  return system_settings_form($form);
}
  

/*
 * Reminds you to check things.
 */
function login_destination_admin_settings_validate($form_id, $form){
  // [values] => Array ( [ld_condition_type] => always
  //if (strstr($form['values']['ld_condition_type'] )) {
  
  $vars = array("ld_url_type", "ld_url_destination");
  foreach ($vars as $var) {
    $warn_vars .= "[$var] => '" . $form['values'][$var] . "'\n";
  }
  
    drupal_set_message(
"<pre>
  Your settings: (double-check them)\n" .
  htmlspecialchars(print_r($warn_vars, true) ), "warning") .
"</pre>";
  //}
}


/**
 * Implementation of hook_user().
 *
 * We hook here to redirect.
 */

function login_destination_user($op, &$edit, &$account, $category = NULL) {
  static $login_destination;
  
  // If login and not during an installation profile
 if ( $op == 'login' && !isset($login_destination)) {
    $login_destination = true;
    // module_invoke_all('user', $op, $edit, $account, $category); // Removed: causing other hook_user calls in other modules to be called twice. Doesn't look like this implementation is doing anything useful anyway
    
    $arr = login_destination_calculate_redirection_path_and_query($edit);
    $path  = $arr[0];
    $query = $arr[1];
  
    // if condition is ok and this is not the user_login form - redirect. (on the user_login form we set $form['#redirect'] which
    // takes care of the redirection there.)
    //if (login_destination_apply_redirect() && $edit['form_id'] != "user_login") {      
    if (login_destination_apply_redirect($account)) {
      login_destination_redirect_to_path_and_query($path, $query);
    }
  }
}

function login_destination_redirect_to_path_and_query($path, $query) {  
  $add_to_path = "";
  
  // if external URL
  if (substr($path, 0, 4) == "http") {

    // prepare
    $path = trim($path, "/");
    if (!empty($query) ) { $add_to_path = urlencode("?" . $query); }
    
    // redirect
    $_REQUEST['destination'] = $path .  $add_to_path;
    // drupal_goto($path, urlencode($query), NULL, 301);
    
  }
  // internal
  else {
    //$path = "lorem";
    // prepare
    if (!empty($query) ) { $add_to_path = "?" . $query; }
    
    //redirect
    $_REQUEST['destination'] = $path .  $add_to_path;
    // drupal_goto($path, urlencode($query), NULL, 301);
  }
}

function login_destination_calculate_redirection_path_and_query($form) {
    //$message = print_r($edit, true);
    //watchdog("php", $message, array(), WATCHDOG_NOTICE, NULL);
    // this is a string with the contents of the settings textarea
    $destination_str = variable_get('ld_url_destination', 'user');
    $url_type        = variable_get('ld_url_type', LOGIN_DEST_STATIC);
    
    // override all if "preserve" checkbox set and there is a destination in the URL
    if (variable_get('ld_destination', TRUE) && $_GET['destination']) {
      $url_type        = LOGIN_DEST_STATIC;
      $destination_str = $_GET['destination'];
    }
    
    // if snippet
    if ($url_type == LOGIN_DEST_SNIPPET) {
      $url = eval($destination_str);
      
      // if an array came from the snippet (an array with "path" and "query" keys)
      if (is_array($url) && !empty($url['path'])) {
        // "/" or "/drupal/" or similar
        $base = base_path();
        global $language;
        if (!empty($language->prefix)) {
          // now becomes probably "/en/" or "/drupal/en/"
          $base .= $language->prefix . '/';
        }

        $path  = $url['path'];
        $query = $url['query'];
        
        // strip base from url (isn't this too paranoic?) (won't hurt)
        $path = preg_replace( "!^$base!", '', $path);
      }
      // if the snippet retuned a string
      else {
        $path  = $url;
        $query = NULL;
      }
    }
    // if a static string
    else {
      // take only 1st line
      if (preg_match("!^(.*?)$!", $destination_str, $matches) === 1 ) {
        $path  = $matches[1];
        $query = NULL;
      }
    }

    // support for <front>
    if ($path == "<front>") {
      $path = drupal_get_normal_path(variable_get('site_frontpage', 'node') );
    }
    
    return array($path, $query);
}


/**
 * A helper function to determine whether redirection should happen.
 *
 * @return bool TRUE - apply redirect, FALSE - not to apply redirect.
 */
function login_destination_apply_redirect($account) {
  global $user;  
  // don't redirect on registration's password reset
  // not clear if this affects anything. Can't hurt. At least the wrong redirection does not happen currently. Phew!
  // Also check for force_password_change
  if ((arg(0) == 'user' && arg(1) == 'reset')
    || ($account->force_password_change && $account->uid == $user->uid)) {
    return FALSE;
  }
  $mode = variable_get('ld_condition_type', LOGIN_COND_ALWAYS);
  if ($mode == LOGIN_COND_ALWAYS ) {
    return TRUE;
  }
  else {
    $cond = variable_get('ld_condition_snippet', '');    
    if ($mode == LOGIN_COND_PAGES ) {      
      $page_match = FALSE;
      $path = drupal_get_path_alias($_GET['q']);      
      $page_match = drupal_match_path($path, $cond);
      
      if ($path != $_GET['q']) {
        $page_match = $page_match || drupal_match_path($_GET['q'], $cond);
      }      
      return $page_match;
    }
    elseif ($mode == LOGIN_COND_SNIPPET) {
      return drupal_eval('<?php ' . $cond . ' ?>');
    }
  }
}