<?php

/**
 * @fils
 * Database functions.
 */

/**
 * 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) {
  $nid = (int) $nid;
  $uid = (int) $uid;

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

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

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

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

  return FALSE;
}

/**
 * Get the requests sent or received.
 *
 * @param $uid
 *   Requester user uid.
 *
 * @param $type
 *   Transaction perspective (sent or received).
 *
 * @param $status
 *   Current transaction status.
 *
 * @return
 *   Array of existing transactions.
 */
function muamba_get_transactions($uid, $type = 'sent', $status = NULL) {
  $uid   = (int) $uid;
  $query = db_select('muamba', 'm');
  $query->fields('m', array('mid', 'nid', 'uid', 'owner', 'status', 'thread_id'));

  if ($type == 'sent') {
    $query->condition('m.uid', $uid, '=');
  }
  else {
    $query->condition('m.owner', $uid, '=');
  }

  if ($status != NULL) {
    $query->condition('m.status', $status, '=');
  }

  $rows    = array();
  $results = $query->execute()->fetchAll();

  // Sanitize the data before handing it off to the theme layer.
  foreach ($results as $entry) {
    $rows[] = array_map('check_plain', (array) $entry);
  }

  return $rows;
}

/**
 * Get a single transaction.
 *
 * @param $id
 *   Transaction id.
 *
 * @param $index
 *   Index (mid or thread_id).
 *
 * @return
 *   Transaction data.
 */
function muamba_get_transaction($id, $index = 'mid') {
  if ($index != 'mid' && $index != 'thread_id') {
    return;
  }

  $query = db_select('muamba', 'm');
  $query->fields('m', array('mid', 'nid', 'uid', 'owner', 'status', 'thread_id'));
  $query->condition('m.'. $index, (int) $id, '=');

  $rows    = array();
  $results = $query->execute()->fetchAll();

  // Sanitize the data before handing it off to the theme layer.
  foreach ($results as $entry) {
    $rows[] = array_map('check_plain', (array) $entry);
  }

  if (isset($rows[0])) {
    return $rows[0];
  }
}

/**
 * Get current transactions for an item. Note that there might
 * be more than one active transaction for a given item if they
 * all are in the "requested" state.
 *
 * @param $data
 *   Item nid or node object.
 *
 * @param $uid
 *   Optional requester user id.
 *
 * @return
 *   Data of the ongoing transactions. If $uid is specified,
 *   then just one transaction is returned. 
 */
function muamba_current_transactions($data, $uid = NULL) {
  if (is_object($data)) {
    $nid = (int) $data->nid;
  }
  else {
    $nid = (int) $data;
  }

  $query = db_select('muamba', 'm');
  $query->fields('m', array('mid', 'nid', 'uid', 'owner', 'status', 'thread_id'));

  $query
    ->condition('m.nid', $nid, '=')
    ->condition('m.active', '1', '=');

  if ($uid != NULL) {
    $query->condition('m.uid', (int) $uid, '=');
  }

  $results = $query->execute()->fetchAll();

  // Sanitize the data before handing it off to the theme layer.
  foreach ($results as $entry) {
    $rows[] = array_map('check_plain', (array) $entry);
  }

  if ($uid != NULL && isset($rows[0])) {
    return $rows[0];
  }

  if (isset($rows)) {
    return $rows;
  }
}

/**
 * Check item availability.
 *
 * @param $data
 *   Item nid or node object.
 *
 * @param $uid
 *   Optional uid parameter to check if item is currently
 *   available to the user.
 *
 * @return
 *   TRUE if item is available, FALSE otherwise.
 */
function muamba_check_availability($data, $uid = NULL) {
  global $user;

  if (is_object($data)) {
    $nid = (int) $data->nid;
  }
  else {
    $nid = (int) $data;
  }

  $query = db_select('muamba', 'm');
  $query->fields('m', array('mid', 'nid', 'uid', 'owner', 'status', 'thread_id'));

  $query
    ->condition('m.nid', $nid, '=')
    ->condition('m.active', '1', '=')
    ->condition('m.status', MUAMBA_REQUESTED, '!=');

  $current = $query->execute()->fetchAll();  

  if (empty($current)) {
    return TRUE;
  }
  elseif ($uid !== NULL && $current[0]->uid == $user->uid) {
    return TRUE;
  }

  return FALSE;
}

/**
 * Update a transaction status.
 *
 * @param $mid
 *   Transaction id.
 *
 * @param $status
 *   New status.
 */
function muamba_update_status($mid, $status) {
  $update = db_update('muamba')
    ->fields(array(
      'status'  => $status,
      'changed' => REQUEST_TIME,
    ))
    ->condition('mid', $mid, '=')
    ->execute();

  // Close transaction depending on the status.
  if (!in_array($status, muamba_ongoing())) {
    muamba_finish($mid);
  }
}

/**
 * Finish a transaction.
 *
 * @param $mid
 *   Transaction id.
 */
function muamba_finish($mid) {
  $update = db_update('muamba')
    ->fields(array(
      'active' => 0,
    ))
    ->condition('mid', $mid, '=')
    ->execute();
}

/**
 * Return total transactions.
 *
 * @param $nid
 *   Muamba node id.
 *
 * @param $type
 *   Type of transactions.
 *
 * @return
 *   Number of transactions.
 */
function muamba_total($nid, $type = 'transactions') {
  $nid   = (int) $nid;
  $query = db_select('muamba', 'm');
  $query->condition('m.nid', $nid, '=');

  if ($type != 'transactions') {
    if ($type == 'requested') {
      $query->condition('m.status', MUAMBA_REQUESTED, '=');
    }
    elseif ($type == 'rejected') {
      $query->condition('m.status', MUAMBA_REJECTED, '=');
    }
    elseif ($type == 'borrowed') {
      $query->condition(
        db_or()
        ->condition('m.status', MUAMBA_ACCEPTED, '=')
        ->condition('m.status', MUAMBA_RETURNED, '=')
        ->condition('m.status', MUAMBA_RECOVERED, '=')
        ->condition('m.status', MUAMBA_LOST, '=')
      );
    }
  }

  return $query->countQuery()->execute()->fetchField();
}