<?php

/**
 * @file
 * Multiple-user Asset Manager and Borrowing Ambient.
 */

/**
 * Request an item.
 *
 * @param $nid
 *   Requested item.
 */
function muamba_request($nid) {
  // Sanitize
  $nid  = (int) $nid;
  $node = node_load($nid);

  if (!$node || $node->type != MUAMBA_NODE_TYPE) {
    drupal_not_found();
  }

  global $user;

  // TODO: check if user has permission to access the node.
  // TODO: check if user is not blocked by privatemsg?

  // Check if user already requested the item
  if (muamba_check_user_request($nid, $user->uid)) {
    // TODO
  }

  // Issue item request
  // TODO

  // Notify item owner
  privatemsg_new_thread(array(user_load($node->uid)), t('Item request'), 'User has requested an item');

  // User output
  return t('You have requested an item');
}

/**
 * Check if user already requested an item.
 *
 * @param $nid
 *   Item nid.
 *
 * @param $uid
 *   Requester user nid.
 *
 * @return
 *   TRUE if user already requested an item, FALSE otherwise.
 */
function muamba_check_user_request($nid, $uid) {
  if (!is_int($nid) || !is_int($uid)) {
    return FALSE;
  }

  $query = db_select('muamba', 'm');

  $query
    ->condition('m.nid', $nid, '=')
    ->condition('m.uid', $uid, '=');

  $result = $query->countQuery()->execute()->fetchField();

  if ($result > 0) {
    return TRUE;
  }

  return FALSE;
}

/**
 * Release an item requested by a given user.
 *
 * @param $nid
 *   Item nid.
 *
 * @param $uid
 *   Requester user uid.
 *
 * @todo
 */
function muamba_release($nid, $uid) {
  global $user;

  $nid  = (int) $nid;
  $node = node_load($nid);

  if (!$node || $node->type != MUAMBA_NODE_TYPE) {
    drupal_not_found();
  }

  if ($node->uid != $user->uid) {
    // TODO: not node owner
  }
}

/**
 * Get the requests sent or received.
 *
 * @param $uid
 *   Requester user uid.
 *
 * @todo
 */
function muamba_get_requests($nid, $type = 'sent') {
}