<?php
// $Id$

/**
 * @file
 * Plugin to provide access control/visibility based on existence of a specified context
 */

/**
 * Implementation of hook_ctools_access().
 */
function bryn_ctools_context_exists_ctools_access() {
  return array(
    'title' => t("Context exists"),
    'description' => t('Control access by context existence.'),
    'callback' => 'bryn_ctools_context_exists_ctools_access_check',
    'settings form' => 'bryn_ctools_context_exists_ctools_access_settings',
    'settings form submit' => 'bryn_ctools_context_exists_ctools_access_settings_submit',
    'summary' => 'bryn_ctools_context_exists_ctools_access_summary',
    'all contexts' => TRUE,
  );
}

/**
 * Settings form
 */
function bryn_ctools_context_exists_ctools_access_settings(&$form, &$form_state, $conf) {
  $contexts = array();
  foreach ($form_state['contexts'] as $key => $context) {
    // The global logged-in-user context should be dealt with using the user role access plugin
    if ($key != 'logged-in-user')
      $contexts[$key] = $context->keyword . ' (' . $context->identifier . ')';
  }

  $form['settings']['which_context'] = array(
    '#type' => 'select',
    '#title' => t('Which context?'),
    '#options' => $contexts,
    '#default_value' => $conf['which_context'],
  );
  $form['settings']['context_exists'] = array(
    '#type' => 'radios',
    '#title' => t('Exists or doesn\'t exist?'),
    '#options' => array('1' => t('Exists'), '0' => t('Doesn\'t exist')),
    '#default_value' => $conf['context_exists'],
    '#description' => t('Context exists or doesn\'t exist?'),
  );
}

function bryn_ctools_context_exists_ctools_access_settings_submit(&$form, &$form_state) {
  $context = $form_state['contexts'][$form_state['values']['settings']['which_context']];
  $form_state['values']['settings']['context_readable'] = $context->keyword . ' (' . $context->identifier . ')';
}

/**
 * Check for access
 */
function bryn_ctools_context_exists_ctools_access_check($conf, $contexts) {
  if (empty($contexts)) {
    return FALSE;
  }

  if (isset($contexts[$conf['which_context']]->data) && $conf['context_exists'] == '1')) {
    return TRUE;
  }
  else if (!isset($contexts[$conf['which_context']]->data) && $conf['context_exists'] == '0')) {
    return TRUE;
  }
  else {
    return FALSE;
  }
}

/**
 * Provide a summary description based upon the specified context
 */
function bryn_ctools_context_exists_ctools_access_summary($conf, $contexts) {
  return t('Context \'!context\' !exists',
    array('!context' => $conf['context_readable'],
          '!exists' => $conf['context_exists'] ? 'exists' : 'doesn\'t exist')
    );
}