<?php
// $Id$

/**
 * @file
 * Plugin to provide access control/visibility based on a field's length
 * or contents.
 */

/**
 * Implementation of hook_ctools_access().
 */
function ctools_context_field_ctools_access() {
  return array(
    'title' => t('Check a context\'s field'),
    'description' => t('Control access by performing certain checks on a field in a context.'),
    'callback' => 'ctools_context_field_ctools_access_check',
    'settings form' => 'ctools_context_field_ctools_access_settings',
    'summary' => 'ctools_context_field_ctools_access_summary',
    'all contexts' => TRUE,
  );
}

/**
 * Settings form for the 'by role' access plugin.
 */
function ctools_context_field_ctools_access_settings(&$form, &$form_state, $conf) {
  $fields = array();
  foreach ($form_state['contexts'] as $key => $context) {
    foreach ($context->data as $k => $v) {
      $fields[$key . '.' . $k] = '(' . $context->identifier . ') ' . $k;
    }
  }

  $form['settings']['which_field'] = array(
    '#type' => 'select',
    '#title' => t('Which context and field?'),
    '#options' => $fields,
    '#default_value' => $conf['which_field'],
  );

  $form['settings']['operator'] = array(
    '#type' => 'radios',
    '#title' => t('Operator to perform on the field'),
    '#options' => array(
      'field length is greater than' => t('Field length is greater than'),
      'field length is equal to' => t('Field length is equal to'),
      'field length is less than' => t('Field length is less than'),
      'field equals' => t('Field is set to'),
      'field does not equal' => t('Field is NOT set to'),
    ),
    '#default_value' => $conf['operator'],
  );

  $form['settings']['operator_arg'] = array(
    '#type' => 'textfield',
    '#title' => t('Argument to the operator'),
    '#description' => t('For example, greater than what?  Set to what?'),
    '#default_value' => $conf['operator_arg'],
  );
}

/**
 * Check for access.
 */
function ctools_context_field_ctools_access_check($conf, $contexts) {
  // As far as I know there should always be a context at this point, but this
  // is safe.
  if (empty($contexts)) {
    return FALSE;
  }

  list($context, $field) = explode('.', $conf['which_field']);

  switch ($conf['operator']) {
    case 'field length is greater than':
      if (drupal_strlen($contexts[$context]->data->$field) <= $conf['operator_arg']) {
        return FALSE;
      }
      break;
    case 'field length is equal to':
      if (drupal_strlen($contexts[$context]->data->$field) != $conf['operator_arg']) {
        return FALSE;
      }
      break;
    case 'field length is less than':
      if (drupal_strlen($contexts[$context]->data->$field) >= $conf['operator_arg']) {
        return FALSE;
      }
      break;
    case 'field equals':
      if ($contexts[$context]->data->$field != $conf['operator_arg']) {
        return FALSE;
      }
      break;
    case 'field does not equal':
      if ($contexts[$context]->data->$field == $conf['operator_arg']) {
        return FALSE;
      }
      break;
    default:
      break;
  }

  return TRUE;
}

/**
 * Provide a summary description based upon the checked roles.
 */
function ctools_context_field_ctools_access_summary($conf, $context) {
  list($context_id, $field) = explode('.', $conf['which_field']);
  $op_str = str_replace('field', 'field %field', $conf['operator']);

  return t('context %context ' . $op_str . ' "!operator_arg"',
    array('%context' => $context_id,
          '%field' => $field,
          '!operator_arg' => $conf['operator_arg'])
    );
}