<?php

/**
 * @file
 * Business logic for Muamba.
 */

/**
 * Define which status belongs to an ongoing transaction.
 */
function muamba_ongoing() {
  return array(
    MUAMBA_REQUESTED,
    MUAMBA_ACCEPTED,
    MUAMBA_RETURNED,
    MUAMBA_LOST,
  );
}

/**
 * Determine possible actions for a transaction.
 *
 * @param $type
 *   Transaction perspective (sent or received).
 *
 * @param $transaction
 *   Transaction data.
 *
 * @return
 *   Array of available action codes.
 */
function muamba_actions_available($type = 'sent', $transaction = array()) {
  if (empty($transaction)) {
    return array();
  }

  $status = $transaction['status'];

  if ($type == 'sent') {
    switch ($status) {
    case MUAMBA_REQUESTED:
      $actions = array(
        MUAMBA_CANCELLED,
        );
      break;

    case MUAMBA_ACCEPTED:
      $actions = array(
        MUAMBA_RETURNED,
        );
      break;

    case MUAMBA_LOST:
      $actions = array(
        MUAMBA_RETURN,
        );
      break;

    case MUAMBA_REJECTED:
      $actions = array(
        MUAMBA_REQUESTED,
        );
      break;

    default:
      $actions = array();
    }
  }
  else {
    switch ($status) {
    case MUAMBA_REQUESTED:
      $actions = array(
        MUAMBA_REJECTED,
        );

      // Owner can just accept requests for available items.
      if (muamba_check_availability($transaction['nid'])) {
        $actions[] = MUAMBA_ACCEPTED;
      }

      break;

    case MUAMBA_ACCEPTED:
      $actions = array(
        MUAMBA_RECOVERED,
        MUAMBA_LOST,
        );
      break;

    case MUAMBA_RETURNED:
      $actions = array(
        MUAMBA_RECOVERED,
        MUAMBA_LOST,
        );
      break;

    case MUAMBA_LOST:
      $actions = array(
        MUAMBA_RECOVERED,
        );
      break;

    default:
      $actions = array();
    }
  }

  return $actions;
}

/**
 * Transaction management page.
 */
function muamba() {
  global $user;

  $sent     = muamba_transactions_summary(muamba_get_transactions($user->uid));
  $received = muamba_transactions_summary(muamba_get_transactions($user->uid, 'received'));

  $output  = theme('muamba_transactions', array('transactions' => $sent, 'type' => 'sent'));
  $output .= theme('muamba_transactions', array('transactions' => $received, 'type' => 'received'));

  return $output;
}

/**
 * Request an item.
 *
 * @param $nid
 *   Requested item.
 */
function muamba_request($nid) {
  global $user;
  $nid               = (int) $nid;
  $node              = node_load($nid);
  $allow_unavailable = variable_get('muamba_allow_request_unavailable', FALSE);

  // Access check
  if (!muamba_has_request_access($node)) {
    return MENU_NOT_FOUND;
  }

  // Check if user is blocked by the item owner
  if (muamba_user_has_blocked($node, $user)) {
    return t('The item owner has blocked you from asking this item.');
  }

  // Check if the item is available
  if (!muamba_check_availability($nid) && $allow_unavailable == FALSE) {
    return t('Item not available');
  }

  // Check if user already requested the item
  if (muamba_check_user_request($nid, $user->uid)) {
    return t('You already requested this item.');
  }

  // Create transaction
  $transaction = array(
    'nid'     => $nid,
    'owner'   => $node->uid,
    'uid'     => $user->uid,
    'status'  => MUAMBA_REQUESTED,
    'created' => REQUEST_TIME,
    'changed' => REQUEST_TIME,
  );

  // Issue item request
  $transaction['mid'] = db_insert('muamba')
    ->fields($transaction)
    ->execute();

  // Notify item owner
  $subject   = t('Item request: @title', array('@title' => check_plain($node->title)));
  $message   = theme('muamba_request_message', array('transaction' => $transaction));
  $thread    = privatemsg_new_thread(array(user_load($node->uid)), $subject , $message);
  $thread_id = $thread['message']->thread_id;

  // Update request with thread id
  $update = db_update('muamba')
    ->fields(array(
      'thread_id' => $thread_id,
    ))
    ->condition('mid', $transaction['mid'], '=')
    ->execute();

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

/**
 * Accept a transaction request.
 *
 * @param $mid
 *   Transaction id.
 */
function muamba_accept($mid) {
  global $user;
  $mid         = (int) $mid;
  $transaction = muamba_get_transaction($mid);
  $node        = node_load($transaction['nid']);

  // Access check
  if (!muamba_has_management_access($node)) {
    return MENU_NOT_FOUND;
  }

  // Status check
  if ($transaction['status'] != MUAMBA_REQUESTED) {
    return MENU_NOT_FOUND;
  }

  // Update database
  muamba_update_status($mid, MUAMBA_ACCEPTED);

  // Notify item owner
  $message = theme('muamba_accept_message', array('transaction' => $transaction));
  $reply   = privatemsg_reply($transaction['thread_id'], $message);

  // Optionally reject all other pending requests
  if (variable_get('muamba_reject_all_on_accept', FALSE) == TRUE) {
    muamba_reject_all($node);
  }

  return t('Accepted item request.');
}

/**
 * Reject all item requests.
 */
function muamba_reject_all($node) {
  global $user;
  $transactions = muamba_current_transactions($node);

  foreach ($transactions as $transaction) {
    if ($transaction['status'] == MUAMBA_REQUESTED && $transaction['owner'] == $user->uid) {
      muamba_reject($transaction['mid']);
    }
  }
}

/**
 * Reject a transaction request.
 *
 * @param $mid
 *   Transaction id.
 */
function muamba_reject($mid) {
  global $user;
  $mid         = (int) $mid;
  $transaction = muamba_get_transaction($mid);
  $node        = node_load($transaction['nid']);

  // Access check
  if (!muamba_has_management_access($node)) {
    return MENU_NOT_FOUND;
  }

  // Status check
  if ($transaction['status'] != MUAMBA_REQUESTED) {
    return MENU_NOT_FOUND;
  }

  // Update database
  muamba_update_status($mid, MUAMBA_REJECTED);

  // Notify item owner
  $message = theme('muamba_reject_message', array('transaction' => $transaction));
  $reply   = privatemsg_reply($transaction['thread_id'], $message);

  return t('Rejected item request.');
}

/**
 * Cancel a request.
 *
 * @param $mid
 *   Transaction id.
 */
function muamba_cancel($mid) {
  global $user;
  $mid         = (int) $mid;
  $transaction = muamba_get_transaction($mid);
  $node        = node_load($transaction['nid']);

  // Access check
  if ($transaction['uid'] != $user->uid) {
    return MENU_NOT_FOUND;
  }

  // Status check
  if ($transaction['status'] != MUAMBA_REQUESTED) {
    return MENU_NOT_FOUND;
  }

  // Update database
  muamba_update_status($mid, MUAMBA_CANCELLED);

  // Notify item owner
  $message = theme('muamba_cancel_message', array('transaction' => $transaction));
  $reply   = privatemsg_reply($transaction['thread_id'], $message);

  return t('Cancelled item request.');
}

/**
 * Return an item.
 *
 * @param $mid
 *   Transaction id.
 */
function muamba_return($mid) {
  global $user;
  $mid         = (int) $mid;
  $transaction = muamba_get_transaction($mid);
  $node        = node_load($transaction['nid']);

  // Access check
  if ($transaction['uid'] != $user->uid) {
    return MENU_NOT_FOUND;
  }

  // Status check
  if ($transaction['status'] != MUAMBA_ACCEPTED &&
      $transaction['status'] != MUAMBA_LOST) {
    return MENU_NOT_FOUND;
  }

  // Update database
  muamba_update_status($mid, MUAMBA_RETURNED);

  // Notify item owner
  $message = theme('muamba_return_message', array('transaction' => $transaction));
  $reply   = privatemsg_reply($transaction['thread_id'], $message);

  return t('Returned item request.');
}

/**
 * Recover an item.
 *
 * @param $mid
 *   Transaction id.
 */
function muamba_recover($mid) {
  global $user;
  $mid         = (int) $mid;
  $transaction = muamba_get_transaction($mid);
  $node        = node_load($transaction['nid']);

  // Access check
  if (!muamba_has_management_access($node)) {
    return MENU_NOT_FOUND;
  }

  // Status check
  if ($transaction['status'] != MUAMBA_ACCEPTED &&
      $transaction['status'] != MUAMBA_RETURNED &&
      $transaction['status'] != MUAMBA_LOST) {
    return MENU_NOT_FOUND;
  }

  // Update database
  muamba_update_status($mid, MUAMBA_RECOVERED);

  // Notify item owner
  $message = theme('muamba_recover_message', array('transaction' => $transaction));
  $reply   = privatemsg_reply($transaction['thread_id'], $message);

  return t('Item recovered.');  
}

/**
 * Report a lost item.
 *
 * @param $mid
 *   Transaction id.
 */
function muamba_lost($mid) {
  global $user;
  $mid         = (int) $mid;
  $transaction = muamba_get_transaction($mid);
  $node        = node_load($transaction['nid']);

  // Access check
  if (!muamba_has_management_access($node)) {
    return MENU_NOT_FOUND;
  }

  // Status check
  if ($transaction['status'] != MUAMBA_ACCEPTED &&
      $transaction['status'] != MUAMBA_RETURNED) {
    return MENU_NOT_FOUND;
  }

  // Update database
  muamba_update_status($mid, MUAMBA_LOST);

  // Notify item owner
  $message = theme('muamba_lost_message', array('transaction' => $transaction));
  $reply   = privatemsg_reply($transaction['thread_id'], $message);

  return t('Item lost.');
}

/**
 * Display a muamba widget.
 *
 * @param $node
 *   Muamba node id.
 *
 * @return
 *   HTML formatted muamba widget.
 */
function muamba_widget($node, $size = 'small', $messages = FALSE) {
  global $user;

  // Check if widget can be shown
  if ($node->type != MUAMBA_NODE_TYPE || !muamba_has_request_access($node)) {
    return;
  }

  $available = muamba_check_availability($node->nid);

  if ($node->uid != $user->uid) {
    $transactions = muamba_current_transactions($node, $user->uid);
  }
  else {
    $transactions = muamba_current_transactions($node);
  }

  return theme('muamba_widget', array(
    'node'         => $node,
    'transactions' => $transactions,
    'available'    => $available,
    'size'         => $size,
    'messages'     => $messages,
  ));
}

/**
 * Return availability information.
 *
 * @param $nid
 *   Muamba node id.
 *
 * @return
 *   Human-readable availability information.
 */
function muamba_availability_info($nid) {
  global $user;
  $node = node_load($nid);

  if ($node->uid == $user->uid) {
    $transactions = muamba_current_transactions($nid);
    $transaction  = $transactions[0];

    if (!empty($transaction)) {
      // Find the right requester
      foreach ($transactions as $transaction) {
        if ($transaction['status'] != MUAMBA_REQUESTED) {
          $requester = user_load($transaction['uid']);

          return t('No, @status to @user', array(
            '@status' => t(muamba_statuses($transaction['status'])),
            '@user'   => $requester->name,
          ));
        }
      }
    }

    return t('Yes');
  }
  else {
    $transaction = muamba_current_transactions($nid, $user->uid);
    $available   = muamba_check_availability($nid, $user->uid);

    if (!$available) {
      if (isset($transaction['uid']) && $transaction['uid'] == $user->uid) {
        return t('You requested, but it is not available');
      }
      else {
        return t('No');
      }
    }
    else {
      if (isset($transaction['uid']) && $transaction['uid'] == $user->uid) {
        return t('Yes, you requested, status is @status', array(
           '@status' => t(muamba_statuses($transaction['status'])),
         ));
      }
      else {
        return t('Yes');
      }
    }
  }
}