eventespresso / event-espresso-core

modules/ticket_sales_monitor/EED_Ticket_Sales_Monitor.module.php

Indentation +1049 added lines, -1049 removed lines

@@ -20,1054 +20,1054 @@
 class EED_Ticket_Sales_Monitor extends EED_Module
 {
 
-    const debug = false;
-
-    private static $nl = '';
-
-    /**
-     * an array of raw ticket data from EED_Ticket_Selector
-     *
-     * @var array $ticket_selections
-     */
-    protected $ticket_selections = array();
-
-    /**
-     * the raw ticket data from EED_Ticket_Selector is organized in rows
-     * according to how they are displayed in the actual Ticket_Selector
-     * this tracks the current row being processed
-     *
-     * @var int $current_row
-     */
-    protected $current_row = 0;
-
-    /**
-     * an array for tracking names of tickets that have sold out
-     *
-     * @var array $sold_out_tickets
-     */
-    protected $sold_out_tickets = array();
-
-    /**
-     * an array for tracking names of tickets that have had their quantities reduced
-     *
-     * @var array $decremented_tickets
-     */
-    protected $decremented_tickets = array();
-
-
-    /**
-     * set_hooks - for hooking into EE Core, other modules, etc
-     *
-     * @return    void
-     */
-    public static function set_hooks()
-    {
-        self::$nl = defined('EE_TESTS_DIR') ? "\n" : '<br />';
-        // release tickets for expired carts
-        add_action(
-            'EED_Ticket_Selector__process_ticket_selections__before',
-            array('EED_Ticket_Sales_Monitor', 'release_tickets_for_expired_carts'),
-            1
-        );
-        // check ticket reserves AFTER MER does it's check (hence priority 20)
-        add_filter(
-            'FHEE__EE_Ticket_Selector___add_ticket_to_cart__ticket_qty',
-            array('EED_Ticket_Sales_Monitor', 'validate_ticket_sale'),
-            20,
-            3
-        );
-        // add notices for sold out tickets
-        add_action(
-            'AHEE__EE_Ticket_Selector__process_ticket_selections__after_tickets_added_to_cart',
-            array('EED_Ticket_Sales_Monitor', 'post_notices'),
-            10
-        );
-
-        // handle tickets deleted from cart
-        add_action(
-            'FHEE__EED_Multi_Event_Registration__delete_ticket__ticket_removed_from_cart',
-            array('EED_Ticket_Sales_Monitor', 'ticket_removed_from_cart'),
-            10,
-            2
-        );
-        // handle emptied carts
-        add_action(
-            'AHEE__EE_Session__reset_cart__before_reset',
-            array('EED_Ticket_Sales_Monitor', 'session_cart_reset'),
-            10,
-            1
-        );
-        add_action(
-            'AHEE__EED_Multi_Event_Registration__empty_event_cart__before_delete_cart',
-            array('EED_Ticket_Sales_Monitor', 'session_cart_reset'),
-            10,
-            1
-        );
-        // handle cancelled registrations
-        add_action(
-            'AHEE__EE_Session__reset_checkout__before_reset',
-            array('EED_Ticket_Sales_Monitor', 'session_checkout_reset'),
-            10,
-            1
-        );
-        // cron tasks
-        add_action(
-            'AHEE__EE_Cron_Tasks__process_expired_transactions__abandoned_transaction',
-            array('EED_Ticket_Sales_Monitor', 'process_abandoned_transactions'),
-            10,
-            1
-        );
-        add_action(
-            'AHEE__EE_Cron_Tasks__process_expired_transactions__incomplete_transaction',
-            array('EED_Ticket_Sales_Monitor', 'process_abandoned_transactions'),
-            10,
-            1
-        );
-        add_action(
-            'AHEE__EE_Cron_Tasks__process_expired_transactions__failed_transaction',
-            array('EED_Ticket_Sales_Monitor', 'process_failed_transactions'),
-            10,
-            1
-        );
-    }
-
-
-    /**
-     * set_hooks_admin - for hooking into EE Admin Core, other modules, etc
-     *
-     * @return void
-     */
-    public static function set_hooks_admin()
-    {
-        EED_Ticket_Sales_Monitor::set_hooks();
-    }
-
-
-    /**
-     * @return EED_Ticket_Sales_Monitor|EED_Module
-     */
-    public static function instance()
-    {
-        return parent::get_instance(__CLASS__);
-    }
-
-
-    /**
-     * @param WP_Query $WP_Query
-     * @return    void
-     */
-    public function run($WP_Query)
-    {
-    }
-
-
-
-    /********************************** PRE_TICKET_SALES  **********************************/
-
-
-    /**
-     * Retrieves grand totals from the line items that have no TXN ID
-     * and timestamps less than the current time minus the session lifespan.
-     * These are carts that have been abandoned before the "registrant" even attempted to checkout.
-     * We're going to release the tickets for these line items before attempting to add more to the cart.
-     *
-     * @return void
-     * @throws DomainException
-     * @throws EE_Error
-     * @throws InvalidArgumentException
-     * @throws InvalidDataTypeException
-     * @throws InvalidInterfaceException
-     * @throws UnexpectedEntityException
-     */
-    public static function release_tickets_for_expired_carts()
-    {
-        if (self::debug) {
-            echo self::$nl . self::$nl . __LINE__ . ') ' . __METHOD__ . '()';
-        }
-        do_action('AHEE__EED_Ticket_Sales_Monitor__release_tickets_for_expired_carts__begin');
-        $expired_ticket_IDs = array();
-        /** @var EventEspresso\core\domain\values\session\SessionLifespan $session_lifespan */
-        $session_lifespan = LoaderFactory::getLoader()->getShared(
-            'EventEspresso\core\domain\values\session\SessionLifespan'
-        );
-        $timestamp = $session_lifespan->expiration();
-        $expired_ticket_line_items = EEM_Line_Item::instance()->getTicketLineItemsForExpiredCarts($timestamp);
-        if (self::debug) {
-            echo self::$nl . ' . time(): ' . time();
-            echo self::$nl . ' . time() as date: ' . date('Y-m-d H:i a');
-            echo self::$nl . ' . session expiration: ' . $session_lifespan->expiration();
-            echo self::$nl . ' . session expiration as date: ' . date('Y-m-d H:i a', $session_lifespan->expiration());
-            echo self::$nl . ' . timestamp: ' . $timestamp;
-            echo self::$nl . ' . $expired_ticket_line_items: ' . count($expired_ticket_line_items);
-        }
-        if (! empty($expired_ticket_line_items)) {
-            foreach ($expired_ticket_line_items as $expired_ticket_line_item) {
-                if (! $expired_ticket_line_item instanceof EE_Line_Item) {
-                    continue;
-                }
-                $expired_ticket_IDs[ $expired_ticket_line_item->OBJ_ID() ] = $expired_ticket_line_item->OBJ_ID();
-                if (self::debug) {
-                    echo self::$nl . ' . $expired_ticket_line_item->OBJ_ID(): ' . $expired_ticket_line_item->OBJ_ID();
-                    echo self::$nl . ' . $expired_ticket_line_item->timestamp(): '
-                         . date(
-                             'Y-m-d h:i a',
-                             $expired_ticket_line_item->timestamp(true)
-                         );
-                }
-            }
-            if (! empty($expired_ticket_IDs)) {
-                EED_Ticket_Sales_Monitor::release_reservations_for_tickets(
-                    \EEM_Ticket::instance()->get_tickets_with_IDs($expired_ticket_IDs),
-                    array(),
-                    __FUNCTION__
-                );
-                // now  let's get rid of expired line items so that they can't interfere with tracking
-                EED_Ticket_Sales_Monitor::clear_expired_line_items_with_no_transaction($timestamp);
-            }
-        }
-        do_action(
-            'AHEE__EED_Ticket_Sales_Monitor__release_tickets_for_expired_carts__end',
-            $expired_ticket_IDs,
-            $expired_ticket_line_items
-        );
-    }
-
-
-
-    /********************************** VALIDATE_TICKET_SALE  **********************************/
-
-
-    /**
-     * callback for 'FHEE__EED_Ticket_Selector__process_ticket_selections__valid_post_data'
-     *
-     * @param int       $qty
-     * @param EE_Ticket $ticket
-     * @return bool
-     * @throws UnexpectedEntityException
-     * @throws EE_Error
-     */
-    public static function validate_ticket_sale($qty = 1, EE_Ticket $ticket)
-    {
-        $qty = absint($qty);
-        if ($qty > 0) {
-            $qty = EED_Ticket_Sales_Monitor::instance()->_validate_ticket_sale($ticket, $qty);
-        }
-        if (self::debug) {
-            echo self::$nl . self::$nl . __LINE__ . ') ' . __METHOD__ . '()';
-            echo self::$nl . self::$nl . '<b> RETURNED QTY: ' . $qty . '</b>';
-        }
-        return $qty;
-    }
-
-
-    /**
-     * checks whether an individual ticket is available for purchase based on datetime, and ticket details
-     *
-     * @param   EE_Ticket $ticket
-     * @param int         $qty
-     * @return int
-     * @throws UnexpectedEntityException
-     * @throws EE_Error
-     */
-    protected function _validate_ticket_sale(EE_Ticket $ticket, $qty = 1)
-    {
-        if (self::debug) {
-            echo self::$nl . self::$nl . __LINE__ . ') ' . __METHOD__ . '() ';
-        }
-        if (! $ticket instanceof EE_Ticket) {
-            return 0;
-        }
-        if (self::debug) {
-            echo self::$nl . '<b> . ticket->ID: ' . $ticket->ID() . '</b>';
-            echo self::$nl . ' . original ticket->reserved: ' . $ticket->reserved();
-        }
-        $ticket->refresh_from_db();
-        // first let's determine the ticket availability based on sales
-        $available = $ticket->qty('saleable');
-        if (self::debug) {
-            echo self::$nl . ' . . . ticket->qty: ' . $ticket->qty();
-            echo self::$nl . ' . . . ticket->sold: ' . $ticket->sold();
-            echo self::$nl . ' . . . ticket->reserved: ' . $ticket->reserved();
-            echo self::$nl . ' . . . ticket->qty(saleable): ' . $ticket->qty('saleable');
-            echo self::$nl . ' . . . available: ' . $available;
-        }
-        if ($available < 1) {
-            $this->_ticket_sold_out($ticket);
-            return 0;
-        }
-        if (self::debug) {
-            echo self::$nl . ' . . . qty: ' . $qty;
-        }
-        if ($available < $qty) {
-            $qty = $available;
-            if (self::debug) {
-                echo self::$nl . ' . . . QTY ADJUSTED: ' . $qty;
-            }
-            $this->_ticket_quantity_decremented($ticket);
-        }
-        if ($this->_reserve_ticket($ticket, $qty)) {
-            return $qty;
-        } else {
-            return 0;
-        }
-    }
-
-
-    /**
-     * increments ticket reserved based on quantity passed
-     *
-     * @param    EE_Ticket $ticket
-     * @param int          $quantity
-     * @return bool indicating success or failure
-     * @throws EE_Error
-     */
-    protected function _reserve_ticket(EE_Ticket $ticket, $quantity = 1)
-    {
-        if (self::debug) {
-            echo self::$nl . self::$nl . ' . . . INCREASE RESERVED: ' . $quantity;
-        }
-        return $ticket->increaseReserved($quantity, 'TicketSalesMonitor:' . __LINE__);
-    }
-
-
-    /**
-     * @param  EE_Ticket $ticket
-     * @param  int       $quantity
-     * @return bool
-     * @throws EE_Error
-     */
-    protected function _release_reserved_ticket(EE_Ticket $ticket, $quantity = 1)
-    {
-        if (self::debug) {
-            echo self::$nl . ' . . . ticket->ID: ' . $ticket->ID();
-            echo self::$nl . ' . . . ticket->reserved before: ' . $ticket->reserved();
-        }
-        $ticket->decreaseReserved($quantity, true, 'TicketSalesMonitor:' . __LINE__);
-        if (self::debug) {
-            echo self::$nl . ' . . . ticket->reserved after: ' . $ticket->reserved();
-        }
-        return $ticket->save() ? 1 : 0;
-    }
-
-
-    /**
-     * removes quantities within the ticket selector based on zero ticket availability
-     *
-     * @param    EE_Ticket $ticket
-     * @return    void
-     * @throws UnexpectedEntityException
-     * @throws EE_Error
-     */
-    protected function _ticket_sold_out(EE_Ticket $ticket)
-    {
-        if (self::debug) {
-            echo self::$nl . self::$nl . __LINE__ . ') ' . __METHOD__ . '() ';
-            echo self::$nl . ' . . ticket->name: ' . $this->_get_ticket_and_event_name($ticket);
-        }
-        $this->sold_out_tickets[] = $this->_get_ticket_and_event_name($ticket);
-    }
-
-
-    /**
-     * adjusts quantities within the ticket selector based on decreased ticket availability
-     *
-     * @param    EE_Ticket $ticket
-     * @return void
-     * @throws UnexpectedEntityException
-     * @throws EE_Error
-     */
-    protected function _ticket_quantity_decremented(EE_Ticket $ticket)
-    {
-        if (self::debug) {
-            echo self::$nl . self::$nl . __LINE__ . ') ' . __METHOD__ . '() ';
-            echo self::$nl . ' . . ticket->name: ' . $this->_get_ticket_and_event_name($ticket);
-        }
-        $this->decremented_tickets[] = $this->_get_ticket_and_event_name($ticket);
-    }
-
-
-    /**
-     * builds string out of ticket and event name
-     *
-     * @param    EE_Ticket $ticket
-     * @return string
-     * @throws UnexpectedEntityException
-     * @throws EE_Error
-     */
-    protected function _get_ticket_and_event_name(EE_Ticket $ticket)
-    {
-        $event = $ticket->get_related_event();
-        if ($event instanceof EE_Event) {
-            $ticket_name = sprintf(
-                _x('%1$s for %2$s', 'ticket name for event name', 'event_espresso'),
-                $ticket->name(),
-                $event->name()
-            );
-        } else {
-            $ticket_name = $ticket->name();
-        }
-        return $ticket_name;
-    }
-
-
-
-    /********************************** EVENT CART  **********************************/
-
-
-    /**
-     * releases or reserves ticket(s) based on quantity passed
-     *
-     * @param  EE_Line_Item $line_item
-     * @param  int          $quantity
-     * @return void
-     * @throws EE_Error
-     * @throws InvalidArgumentException
-     * @throws InvalidDataTypeException
-     * @throws InvalidInterfaceException
-     */
-    public static function ticket_quantity_updated(EE_Line_Item $line_item, $quantity = 1)
-    {
-        $ticket = EEM_Ticket::instance()->get_one_by_ID(absint($line_item->OBJ_ID()));
-        if ($ticket instanceof EE_Ticket) {
-            $ticket->add_extra_meta(
-                EE_Ticket::META_KEY_TICKET_RESERVATIONS,
-                __LINE__ . ') ' . __METHOD__ . '()'
-            );
-            if ($quantity > 0) {
-                EED_Ticket_Sales_Monitor::instance()->_reserve_ticket($ticket, $quantity);
-            } else {
-                EED_Ticket_Sales_Monitor::instance()->_release_reserved_ticket($ticket, $quantity);
-            }
-        }
-    }
-
-
-    /**
-     * releases reserved ticket(s) based on quantity passed
-     *
-     * @param  EE_Ticket $ticket
-     * @param  int       $quantity
-     * @return void
-     * @throws EE_Error
-     */
-    public static function ticket_removed_from_cart(EE_Ticket $ticket, $quantity = 1)
-    {
-        $ticket->add_extra_meta(
-            EE_Ticket::META_KEY_TICKET_RESERVATIONS,
-            __LINE__ . ') ' . __METHOD__ . '()'
-        );
-        EED_Ticket_Sales_Monitor::instance()->_release_reserved_ticket($ticket, $quantity);
-    }
-
-
-
-    /********************************** POST_NOTICES  **********************************/
-
-
-    /**
-     * @return void
-     * @throws EE_Error
-     * @throws InvalidArgumentException
-     * @throws ReflectionException
-     * @throws InvalidDataTypeException
-     * @throws InvalidInterfaceException
-     */
-    public static function post_notices()
-    {
-        EED_Ticket_Sales_Monitor::instance()->_post_notices();
-    }
-
-
-    /**
-     * @return void
-     * @throws EE_Error
-     * @throws InvalidArgumentException
-     * @throws ReflectionException
-     * @throws InvalidDataTypeException
-     * @throws InvalidInterfaceException
-     */
-    protected function _post_notices()
-    {
-        if (self::debug) {
-            echo self::$nl . self::$nl . __LINE__ . ') ' . __METHOD__ . '() ';
-        }
-        $refresh_msg = '';
-        $none_added_msg = '';
-        if (defined('DOING_AJAX') && DOING_AJAX) {
-            $refresh_msg = __(
-                'Please refresh the page to view updated ticket quantities.',
-                'event_espresso'
-            );
-            $none_added_msg = __('No tickets were added for the event.', 'event_espresso');
-        }
-        if (! empty($this->sold_out_tickets)) {
-            EE_Error::add_attention(
-                sprintf(
-                    apply_filters(
-                        'FHEE__EED_Ticket_Sales_Monitor___post_notices__sold_out_tickets_notice',
-                        __(
-                            'We\'re sorry...%1$sThe following items have sold out since you first viewed this page, and can no longer be registered for:%1$s%1$s%2$s%1$s%1$sPlease note that availability can change at any time due to cancellations, so please check back again later if registration for this event(s) is important to you.%1$s%1$s%3$s%1$s%4$s%1$s',
-                            'event_espresso'
-                        )
-                    ),
-                    '<br />',
-                    implode('<br />', $this->sold_out_tickets),
-                    $none_added_msg,
-                    $refresh_msg
-                )
-            );
-            // alter code flow in the Ticket Selector for better UX
-            add_filter('FHEE__EED_Ticket_Selector__process_ticket_selections__tckts_slctd', '__return_true');
-            add_filter('FHEE__EED_Ticket_Selector__process_ticket_selections__success', '__return_false');
-            $this->sold_out_tickets = array();
-            // and reset the cart
-            EED_Ticket_Sales_Monitor::session_cart_reset(EE_Registry::instance()->SSN);
-        }
-        if (! empty($this->decremented_tickets)) {
-            EE_Error::add_attention(
-                sprintf(
-                    apply_filters(
-                        'FHEE__EED_Ticket_Sales_Monitor___ticket_quantity_decremented__notice',
-                        __(
-                            'We\'re sorry...%1$sDue to sales that have occurred since you first viewed the last page, the following items have had their quantities adjusted to match the current available amount:%1$s%1$s%2$s%1$s%1$sPlease note that availability can change at any time due to cancellations, so please check back again later if registration for this event(s) is important to you.%1$s%1$s%3$s%1$s%4$s%1$s',
-                            'event_espresso'
-                        )
-                    ),
-                    '<br />',
-                    implode('<br />', $this->decremented_tickets),
-                    $none_added_msg,
-                    $refresh_msg
-                )
-            );
-            $this->decremented_tickets = array();
-        }
-    }
-
-
-
-    /********************************** RELEASE_ALL_RESERVED_TICKETS_FOR_TRANSACTION  **********************************/
-
-
-    /**
-     * releases reserved tickets for all registrations of an EE_Transaction
-     * by default, will NOT release tickets for finalized transactions
-     *
-     * @param    EE_Transaction $transaction
-     * @return int
-     * @throws EE_Error
-     * @throws InvalidSessionDataException
-     */
-    protected function _release_all_reserved_tickets_for_transaction(EE_Transaction $transaction)
-    {
-        if (self::debug) {
-            echo self::$nl . self::$nl . __LINE__ . ') ' . __METHOD__ . '() ';
-            echo self::$nl . ' . transaction->ID: ' . $transaction->ID();
-            echo self::$nl . ' . TXN status_ID: ' . $transaction->status_ID();
-        }
-        // check if 'finalize_registration' step has been completed...
-        $finalized = $transaction->reg_step_completed('finalize_registration');
-        if (self::debug) {
-            // DEBUG LOG
-            EEH_Debug_Tools::log(
-                __CLASS__,
-                __FUNCTION__,
-                __LINE__,
-                array('finalized' => $finalized),
-                false,
-                'EE_Transaction: ' . $transaction->ID()
-            );
-        }
-        // how many tickets were released
-        $count = 0;
-        if (self::debug) {
-            echo self::$nl . ' . . . TXN finalized: ' . $finalized;
-        }
-        $release_tickets_with_TXN_status = array(
-            EEM_Transaction::failed_status_code,
-            EEM_Transaction::abandoned_status_code,
-            EEM_Transaction::incomplete_status_code,
-        );
-        $events = array();
-        // if the session is getting cleared BEFORE the TXN has been finalized or the transaction is not completed
-        if (! $finalized || in_array($transaction->status_ID(), $release_tickets_with_TXN_status, true)) {
-            // cancel any reserved tickets for registrations that were not approved
-            $registrations = $transaction->registrations();
-            if (self::debug) {
-                echo self::$nl . ' . . . # registrations: ' . count($registrations);
-                $reg = reset($registrations);
-                $ticket = $reg->ticket();
-                if ($ticket instanceof EE_Ticket) {
-                    $ticket->add_extra_meta(
-                        EE_Ticket::META_KEY_TICKET_RESERVATIONS,
-                        __LINE__ . ') Release All Tickets TXN:' . $transaction->ID()
-                    );
-                }
-            }
-            if (! empty($registrations)) {
-                foreach ($registrations as $registration) {
-                    if ($registration instanceof EE_Registration
-                        && $this->_release_reserved_ticket_for_registration($registration, $transaction)
-                    ) {
-                        $count++;
-                        $events[ $registration->event_ID() ] = $registration->event();
-                    }
-                }
-            }
-        }
-        if ($events !== array()) {
-            foreach ($events as $event) {
-                /** @var EE_Event $event */
-                $event->perform_sold_out_status_check();
-            }
-        }
-        return $count;
-    }
-
-
-    /**
-     * releases reserved tickets for an EE_Registration
-     * by default, will NOT release tickets for APPROVED registrations
-     *
-     * @param EE_Registration $registration
-     * @param EE_Transaction  $transaction
-     * @return int
-     * @throws EE_Error
-     */
-    protected function _release_reserved_ticket_for_registration(
-        EE_Registration $registration,
-        EE_Transaction $transaction
-    ) {
-        $STS_ID = $transaction->status_ID();
-        if (self::debug) {
-            echo self::$nl . self::$nl . __LINE__ . ') ' . __METHOD__ . '() ';
-            echo self::$nl . ' . . registration->ID: ' . $registration->ID();
-            echo self::$nl . ' . . registration->status_ID: ' . $registration->status_ID();
-            echo self::$nl . ' . . transaction->status_ID(): ' . $STS_ID;
-        }
-        if (// release Tickets for Failed Transactions and Abandoned Transactions
-            $STS_ID === EEM_Transaction::failed_status_code
-            || $STS_ID === EEM_Transaction::abandoned_status_code
-            || (
-                // also release Tickets for Incomplete Transactions, but ONLY if the Registrations are NOT Approved
-                $STS_ID === EEM_Transaction::incomplete_status_code
-                && $registration->status_ID() !== EEM_Registration::status_id_approved
-            )
-        ) {
-            if (self::debug) {
-                echo self::$nl . self::$nl . ' . . RELEASE RESERVED TICKET';
-                $rsrvd = $registration->get_extra_meta(EE_Registration::HAS_RESERVED_TICKET_KEY, true);
-                echo self::$nl . ' . . . registration HAS_RESERVED_TICKET_KEY: ';
-                var_dump($rsrvd);
-            }
-            $registration->release_reserved_ticket(true, 'TicketSalesMonitor:' . __LINE__);
-            return 1;
-        }
-        return 0;
-    }
-
-
-
-    /********************************** SESSION_CART_RESET  **********************************/
-
-
-    /**
-     * callback hooked into 'AHEE__EE_Session__reset_cart__before_reset'
-     *
-     * @param EE_Session $session
-     * @return void
-     * @throws EE_Error
-     * @throws InvalidArgumentException
-     * @throws ReflectionException
-     * @throws InvalidDataTypeException
-     * @throws InvalidInterfaceException
-     */
-    public static function session_cart_reset(EE_Session $session)
-    {
-        // don't release tickets if checkout was already reset
-        if (did_action('AHEE__EE_Session__reset_checkout__before_reset')) {
-            return;
-        }
-        if (self::debug) {
-            echo self::$nl . self::$nl . __LINE__ . ') ' . __METHOD__ . '() ';
-        }
-        // first check of the session has a valid Checkout object
-        $checkout = $session->checkout();
-        if ($checkout instanceof EE_Checkout) {
-            // and use that to clear ticket reservations because it will update the associated registration meta data
-            EED_Ticket_Sales_Monitor::instance()->_session_checkout_reset($checkout);
-            return;
-        }
-        $cart = $session->cart();
-        if ($cart instanceof EE_Cart) {
-            if (self::debug) {
-                echo self::$nl . self::$nl . ' cart instance of EE_Cart: ';
-            }
-            EED_Ticket_Sales_Monitor::instance()->_session_cart_reset($cart, $session);
-        } else {
-            if (self::debug) {
-                echo self::$nl . self::$nl . ' invalid EE_Cart: ';
-                var_export($cart, true);
-            }
-        }
-    }
-
-
-    /**
-     * releases reserved tickets in the EE_Cart
-     *
-     * @param EE_Cart $cart
-     * @return void
-     * @throws EE_Error
-     * @throws InvalidArgumentException
-     * @throws ReflectionException
-     * @throws InvalidDataTypeException
-     * @throws InvalidInterfaceException
-     */
-    protected function _session_cart_reset(EE_Cart $cart, EE_Session $session)
-    {
-        if (self::debug) {
-            echo self::$nl . self::$nl . __LINE__ . ') ' . __METHOD__ . '() ';
-        }
-        $ticket_line_items = $cart->get_tickets();
-        if (empty($ticket_line_items)) {
-            return;
-        }
-        if (self::debug) {
-            echo '<br /> . ticket_line_item count: ' . count($ticket_line_items);
-        }
-        foreach ($ticket_line_items as $ticket_line_item) {
-            if (self::debug) {
-                echo self::$nl . ' . ticket_line_item->ID(): ' . $ticket_line_item->ID();
-            }
-            if ($ticket_line_item instanceof EE_Line_Item && $ticket_line_item->OBJ_type() === 'Ticket') {
-                if (self::debug) {
-                    echo self::$nl . ' . . ticket_line_item->OBJ_ID(): ' . $ticket_line_item->OBJ_ID();
-                }
-                $ticket = EEM_Ticket::instance()->get_one_by_ID($ticket_line_item->OBJ_ID());
-                if ($ticket instanceof EE_Ticket) {
-                    if (self::debug) {
-                        echo self::$nl . ' . . ticket->ID(): ' . $ticket->ID();
-                        echo self::$nl . ' . . ticket_line_item->quantity(): ' . $ticket_line_item->quantity();
-                    }
-                    $ticket->add_extra_meta(
-                        EE_Ticket::META_KEY_TICKET_RESERVATIONS,
-                        __LINE__ . ') ' . __METHOD__ . '() SID = ' . $session->id()
-                    );
-                    $this->_release_reserved_ticket($ticket, $ticket_line_item->quantity());
-                }
-            }
-        }
-        if (self::debug) {
-            echo self::$nl . self::$nl . ' RESET COMPLETED ';
-        }
-    }
-
-
-
-    /********************************** SESSION_CHECKOUT_RESET  **********************************/
-
-
-    /**
-     * callback hooked into 'AHEE__EE_Session__reset_checkout__before_reset'
-     *
-     * @param EE_Session $session
-     * @return void
-     * @throws EE_Error
-     * @throws InvalidSessionDataException
-     */
-    public static function session_checkout_reset(EE_Session $session)
-    {
-        // don't release tickets if cart was already reset
-        if (did_action('AHEE__EE_Session__reset_cart__before_reset')) {
-            return;
-        }
-        $checkout = $session->checkout();
-        if ($checkout instanceof EE_Checkout) {
-            EED_Ticket_Sales_Monitor::instance()->_session_checkout_reset($checkout);
-        }
-    }
-
-
-    /**
-     * releases reserved tickets for the EE_Checkout->transaction
-     *
-     * @param EE_Checkout $checkout
-     * @return void
-     * @throws EE_Error
-     * @throws InvalidSessionDataException
-     */
-    protected function _session_checkout_reset(EE_Checkout $checkout)
-    {
-        if (self::debug) {
-            echo self::$nl . self::$nl . __LINE__ . ') ' . __METHOD__ . '() ';
-        }
-        // we want to release the each registration's reserved tickets if the session was cleared, but not if this is a revisit
-        if ($checkout->revisit || ! $checkout->transaction instanceof EE_Transaction) {
-            return;
-        }
-        $this->_release_all_reserved_tickets_for_transaction($checkout->transaction);
-    }
-
-
-
-    /********************************** SESSION_EXPIRED_RESET  **********************************/
-
-
-    /**
-     * @param    EE_Session $session
-     * @return    void
-     */
-    public static function session_expired_reset(EE_Session $session)
-    {
-    }
-
-
-
-    /********************************** PROCESS_ABANDONED_TRANSACTIONS  **********************************/
-
-
-    /**
-     * releases reserved tickets for all registrations of an ABANDONED EE_Transaction
-     * by default, will NOT release tickets for free transactions, or any that have received a payment
-     *
-     * @param EE_Transaction $transaction
-     * @return void
-     * @throws EE_Error
-     * @throws InvalidSessionDataException
-     */
-    public static function process_abandoned_transactions(EE_Transaction $transaction)
-    {
-        // is this TXN free or has any money been paid towards this TXN? If so, then leave it alone
-        if ($transaction->is_free() || $transaction->paid() > 0) {
-            if (self::debug) {
-                // DEBUG LOG
-                EEH_Debug_Tools::log(
-                    __CLASS__,
-                    __FUNCTION__,
-                    __LINE__,
-                    array($transaction),
-                    false,
-                    'EE_Transaction: ' . $transaction->ID()
-                );
-            }
-            return;
-        }
-        // have their been any successful payments made ?
-        $payments = $transaction->payments();
-        foreach ($payments as $payment) {
-            if ($payment instanceof EE_Payment && $payment->status() === EEM_Payment::status_id_approved) {
-                if (self::debug) {
-                    // DEBUG LOG
-                    EEH_Debug_Tools::log(
-                        __CLASS__,
-                        __FUNCTION__,
-                        __LINE__,
-                        array($payment),
-                        false,
-                        'EE_Transaction: ' . $transaction->ID()
-                    );
-                }
-                return;
-            }
-        }
-        // since you haven't even attempted to pay for your ticket...
-        EED_Ticket_Sales_Monitor::instance()->_release_all_reserved_tickets_for_transaction($transaction);
-    }
-
-
-
-    /********************************** PROCESS_FAILED_TRANSACTIONS  **********************************/
-
-
-    /**
-     * releases reserved tickets for absolutely ALL registrations of a FAILED EE_Transaction
-     *
-     * @param EE_Transaction $transaction
-     * @return void
-     * @throws EE_Error
-     * @throws InvalidSessionDataException
-     */
-    public static function process_failed_transactions(EE_Transaction $transaction)
-    {
-        // since you haven't even attempted to pay for your ticket...
-        EED_Ticket_Sales_Monitor::instance()->_release_all_reserved_tickets_for_transaction($transaction);
-    }
-
-
-
-    /********************************** RESET RESERVATION COUNTS  *********************************/
-
-
-    /**
-     * Resets the ticket and datetime reserved counts.
-     *
-     * For all the tickets with reservations, recalculates what their actual reserved counts should be based
-     * on the valid transactions.
-     *
-     * @return int number of tickets whose reservations were released.
-     * @throws EE_Error
-     * @throws DomainException
-     * @throws InvalidDataTypeException
-     * @throws InvalidInterfaceException
-     * @throws InvalidArgumentException
-     * @throws UnexpectedEntityException
-     * @throws ReflectionException
-     */
-    public static function reset_reservation_counts()
-    {
-        /** @var EE_Line_Item[] $valid_reserved_tickets */
-        $valid_reserved_tickets = array();
-        /** @var EE_Transaction[] $transactions_in_progress */
-        $transactions_in_progress = EEM_Transaction::instance()->get_transactions_in_progress();
-        foreach ($transactions_in_progress as $transaction) {
-            // if this TXN has been fully completed, then skip it
-            if ($transaction->reg_step_completed('finalize_registration')) {
-                continue;
-            }
-            $total_line_item = $transaction->total_line_item();
-            // $transaction_in_progress->line
-            if (! $total_line_item instanceof EE_Line_Item) {
-                throw new DomainException(
-                    esc_html__(
-                        'Transaction does not have a valid Total Line Item associated with it.',
-                        'event_espresso'
-                    )
-                );
-            }
-            $valid_reserved_tickets += EED_Ticket_Sales_Monitor::get_ticket_line_items_for_grand_total(
-                $total_line_item
-            );
-        }
-        $total_line_items = EEM_Line_Item::instance()->get_total_line_items_for_active_carts();
-        foreach ($total_line_items as $total_line_item) {
-            $valid_reserved_tickets += EED_Ticket_Sales_Monitor::get_ticket_line_items_for_grand_total(
-                $total_line_item
-            );
-        }
-        $tickets_with_reservations = EEM_Ticket::instance()->get_tickets_with_reservations();
-        return EED_Ticket_Sales_Monitor::release_reservations_for_tickets(
-            $tickets_with_reservations,
-            $valid_reserved_tickets,
-            __FUNCTION__
-        );
-    }
-
-
-    /**
-     * @param EE_Line_Item $total_line_item
-     * @return EE_Line_Item[]
-     */
-    private static function get_ticket_line_items_for_grand_total(EE_Line_Item $total_line_item)
-    {
-        /** @var EE_Line_Item[] $valid_reserved_tickets */
-        $valid_reserved_tickets = array();
-        $ticket_line_items = EEH_Line_Item::get_ticket_line_items($total_line_item);
-        foreach ($ticket_line_items as $ticket_line_item) {
-            if ($ticket_line_item instanceof EE_Line_Item) {
-                $valid_reserved_tickets[$ticket_line_item->ID()] = $ticket_line_item;
-            }
-        }
-        return $valid_reserved_tickets;
-    }
-
-
-    /**
-     * @param EE_Ticket[]    $tickets_with_reservations
-     * @param EE_Line_Item[] $valid_reserved_ticket_line_items
-     * @return int
-     * @throws UnexpectedEntityException
-     * @throws DomainException
-     * @throws EE_Error
-     */
-    private static function release_reservations_for_tickets(
-        array $tickets_with_reservations,
-        array $valid_reserved_ticket_line_items = array(),
-        $source
-    ) {
-        if (self::debug) {
-            echo self::$nl . self::$nl . __LINE__ . ') ' . __METHOD__ . '()';
-        }
-        $total_tickets_released = 0;
-        $sold_out_events = array();
-        foreach ($tickets_with_reservations as $ticket_with_reservations) {
-            if (! $ticket_with_reservations instanceof EE_Ticket) {
-                continue;
-            }
-            $reserved_qty = $ticket_with_reservations->reserved();
-            if (self::debug) {
-                echo self::$nl . ' . $ticket_with_reservations->ID(): ' . $ticket_with_reservations->ID();
-                echo self::$nl . ' . $reserved_qty: ' . $reserved_qty;
-            }
-            foreach ($valid_reserved_ticket_line_items as $valid_reserved_ticket_line_item) {
-                if ($valid_reserved_ticket_line_item instanceof EE_Line_Item
-                    && $valid_reserved_ticket_line_item->OBJ_ID() === $ticket_with_reservations->ID()
-                ) {
-                    if (self::debug) {
-                        echo self::$nl . ' . $valid_reserved_ticket_line_item->quantity(): '
-                             . $valid_reserved_ticket_line_item->quantity();
-                    }
-                    $reserved_qty -= $valid_reserved_ticket_line_item->quantity();
-                }
-            }
-            if ($reserved_qty > 0) {
-                $ticket_with_reservations->add_extra_meta(
-                    EE_Ticket::META_KEY_TICKET_RESERVATIONS,
-                    __LINE__ . ') ' . $source . '()'
-                );
-                $ticket_with_reservations->decreaseReserved($reserved_qty, true, 'TicketSalesMonitor:' . __LINE__);
-                $ticket_with_reservations->save();
-                $total_tickets_released += $reserved_qty;
-                $event = $ticket_with_reservations->get_related_event();
-                // track sold out events
-                if ($event instanceof EE_Event && $event->is_sold_out()) {
-                    $sold_out_events[] = $event;
-                }
-            }
-        }
-        if (self::debug) {
-            echo self::$nl . ' . $total_tickets_released: ' . $total_tickets_released;
-        }
-        // double check whether sold out events should remain sold out after releasing tickets
-        if ($sold_out_events !== array()) {
-            foreach ($sold_out_events as $sold_out_event) {
-                /** @var EE_Event $sold_out_event */
-                $sold_out_event->perform_sold_out_status_check();
-            }
-        }
-        return $total_tickets_released;
-    }
-
-
-
-    /********************************** SHUTDOWN  **********************************/
-
-
-    /**
-     * @param int $timestamp
-     * @return false|int
-     * @throws EE_Error
-     * @throws InvalidArgumentException
-     * @throws InvalidDataTypeException
-     * @throws InvalidInterfaceException
-     */
-    public static function clear_expired_line_items_with_no_transaction($timestamp = 0)
-    {
-        /** @type WPDB $wpdb */
-        global $wpdb;
-        if (! absint($timestamp)) {
-            /** @var EventEspresso\core\domain\values\session\SessionLifespan $session_lifespan */
-            $session_lifespan = LoaderFactory::getLoader()->getShared(
-                'EventEspresso\core\domain\values\session\SessionLifespan'
-            );
-            $timestamp = $session_lifespan->expiration();
-        }
-        return $wpdb->query(
-            $wpdb->prepare(
-                'DELETE FROM ' . EEM_Line_Item::instance()->table() . '
+	const debug = false;
+
+	private static $nl = '';
+
+	/**
+	 * an array of raw ticket data from EED_Ticket_Selector
+	 *
+	 * @var array $ticket_selections
+	 */
+	protected $ticket_selections = array();
+
+	/**
+	 * the raw ticket data from EED_Ticket_Selector is organized in rows
+	 * according to how they are displayed in the actual Ticket_Selector
+	 * this tracks the current row being processed
+	 *
+	 * @var int $current_row
+	 */
+	protected $current_row = 0;
+
+	/**
+	 * an array for tracking names of tickets that have sold out
+	 *
+	 * @var array $sold_out_tickets
+	 */
+	protected $sold_out_tickets = array();
+
+	/**
+	 * an array for tracking names of tickets that have had their quantities reduced
+	 *
+	 * @var array $decremented_tickets
+	 */
+	protected $decremented_tickets = array();
+
+
+	/**
+	 * set_hooks - for hooking into EE Core, other modules, etc
+	 *
+	 * @return    void
+	 */
+	public static function set_hooks()
+	{
+		self::$nl = defined('EE_TESTS_DIR') ? "\n" : '<br />';
+		// release tickets for expired carts
+		add_action(
+			'EED_Ticket_Selector__process_ticket_selections__before',
+			array('EED_Ticket_Sales_Monitor', 'release_tickets_for_expired_carts'),
+			1
+		);
+		// check ticket reserves AFTER MER does it's check (hence priority 20)
+		add_filter(
+			'FHEE__EE_Ticket_Selector___add_ticket_to_cart__ticket_qty',
+			array('EED_Ticket_Sales_Monitor', 'validate_ticket_sale'),
+			20,
+			3
+		);
+		// add notices for sold out tickets
+		add_action(
+			'AHEE__EE_Ticket_Selector__process_ticket_selections__after_tickets_added_to_cart',
+			array('EED_Ticket_Sales_Monitor', 'post_notices'),
+			10
+		);
+
+		// handle tickets deleted from cart
+		add_action(
+			'FHEE__EED_Multi_Event_Registration__delete_ticket__ticket_removed_from_cart',
+			array('EED_Ticket_Sales_Monitor', 'ticket_removed_from_cart'),
+			10,
+			2
+		);
+		// handle emptied carts
+		add_action(
+			'AHEE__EE_Session__reset_cart__before_reset',
+			array('EED_Ticket_Sales_Monitor', 'session_cart_reset'),
+			10,
+			1
+		);
+		add_action(
+			'AHEE__EED_Multi_Event_Registration__empty_event_cart__before_delete_cart',
+			array('EED_Ticket_Sales_Monitor', 'session_cart_reset'),
+			10,
+			1
+		);
+		// handle cancelled registrations
+		add_action(
+			'AHEE__EE_Session__reset_checkout__before_reset',
+			array('EED_Ticket_Sales_Monitor', 'session_checkout_reset'),
+			10,
+			1
+		);
+		// cron tasks
+		add_action(
+			'AHEE__EE_Cron_Tasks__process_expired_transactions__abandoned_transaction',
+			array('EED_Ticket_Sales_Monitor', 'process_abandoned_transactions'),
+			10,
+			1
+		);
+		add_action(
+			'AHEE__EE_Cron_Tasks__process_expired_transactions__incomplete_transaction',
+			array('EED_Ticket_Sales_Monitor', 'process_abandoned_transactions'),
+			10,
+			1
+		);
+		add_action(
+			'AHEE__EE_Cron_Tasks__process_expired_transactions__failed_transaction',
+			array('EED_Ticket_Sales_Monitor', 'process_failed_transactions'),
+			10,
+			1
+		);
+	}
+
+
+	/**
+	 * set_hooks_admin - for hooking into EE Admin Core, other modules, etc
+	 *
+	 * @return void
+	 */
+	public static function set_hooks_admin()
+	{
+		EED_Ticket_Sales_Monitor::set_hooks();
+	}
+
+
+	/**
+	 * @return EED_Ticket_Sales_Monitor|EED_Module
+	 */
+	public static function instance()
+	{
+		return parent::get_instance(__CLASS__);
+	}
+
+
+	/**
+	 * @param WP_Query $WP_Query
+	 * @return    void
+	 */
+	public function run($WP_Query)
+	{
+	}
+
+
+
+	/********************************** PRE_TICKET_SALES  **********************************/
+
+
+	/**
+	 * Retrieves grand totals from the line items that have no TXN ID
+	 * and timestamps less than the current time minus the session lifespan.
+	 * These are carts that have been abandoned before the "registrant" even attempted to checkout.
+	 * We're going to release the tickets for these line items before attempting to add more to the cart.
+	 *
+	 * @return void
+	 * @throws DomainException
+	 * @throws EE_Error
+	 * @throws InvalidArgumentException
+	 * @throws InvalidDataTypeException
+	 * @throws InvalidInterfaceException
+	 * @throws UnexpectedEntityException
+	 */
+	public static function release_tickets_for_expired_carts()
+	{
+		if (self::debug) {
+			echo self::$nl . self::$nl . __LINE__ . ') ' . __METHOD__ . '()';
+		}
+		do_action('AHEE__EED_Ticket_Sales_Monitor__release_tickets_for_expired_carts__begin');
+		$expired_ticket_IDs = array();
+		/** @var EventEspresso\core\domain\values\session\SessionLifespan $session_lifespan */
+		$session_lifespan = LoaderFactory::getLoader()->getShared(
+			'EventEspresso\core\domain\values\session\SessionLifespan'
+		);
+		$timestamp = $session_lifespan->expiration();
+		$expired_ticket_line_items = EEM_Line_Item::instance()->getTicketLineItemsForExpiredCarts($timestamp);
+		if (self::debug) {
+			echo self::$nl . ' . time(): ' . time();
+			echo self::$nl . ' . time() as date: ' . date('Y-m-d H:i a');
+			echo self::$nl . ' . session expiration: ' . $session_lifespan->expiration();
+			echo self::$nl . ' . session expiration as date: ' . date('Y-m-d H:i a', $session_lifespan->expiration());
+			echo self::$nl . ' . timestamp: ' . $timestamp;
+			echo self::$nl . ' . $expired_ticket_line_items: ' . count($expired_ticket_line_items);
+		}
+		if (! empty($expired_ticket_line_items)) {
+			foreach ($expired_ticket_line_items as $expired_ticket_line_item) {
+				if (! $expired_ticket_line_item instanceof EE_Line_Item) {
+					continue;
+				}
+				$expired_ticket_IDs[ $expired_ticket_line_item->OBJ_ID() ] = $expired_ticket_line_item->OBJ_ID();
+				if (self::debug) {
+					echo self::$nl . ' . $expired_ticket_line_item->OBJ_ID(): ' . $expired_ticket_line_item->OBJ_ID();
+					echo self::$nl . ' . $expired_ticket_line_item->timestamp(): '
+						 . date(
+							 'Y-m-d h:i a',
+							 $expired_ticket_line_item->timestamp(true)
+						 );
+				}
+			}
+			if (! empty($expired_ticket_IDs)) {
+				EED_Ticket_Sales_Monitor::release_reservations_for_tickets(
+					\EEM_Ticket::instance()->get_tickets_with_IDs($expired_ticket_IDs),
+					array(),
+					__FUNCTION__
+				);
+				// now  let's get rid of expired line items so that they can't interfere with tracking
+				EED_Ticket_Sales_Monitor::clear_expired_line_items_with_no_transaction($timestamp);
+			}
+		}
+		do_action(
+			'AHEE__EED_Ticket_Sales_Monitor__release_tickets_for_expired_carts__end',
+			$expired_ticket_IDs,
+			$expired_ticket_line_items
+		);
+	}
+
+
+
+	/********************************** VALIDATE_TICKET_SALE  **********************************/
+
+
+	/**
+	 * callback for 'FHEE__EED_Ticket_Selector__process_ticket_selections__valid_post_data'
+	 *
+	 * @param int       $qty
+	 * @param EE_Ticket $ticket
+	 * @return bool
+	 * @throws UnexpectedEntityException
+	 * @throws EE_Error
+	 */
+	public static function validate_ticket_sale($qty = 1, EE_Ticket $ticket)
+	{
+		$qty = absint($qty);
+		if ($qty > 0) {
+			$qty = EED_Ticket_Sales_Monitor::instance()->_validate_ticket_sale($ticket, $qty);
+		}
+		if (self::debug) {
+			echo self::$nl . self::$nl . __LINE__ . ') ' . __METHOD__ . '()';
+			echo self::$nl . self::$nl . '<b> RETURNED QTY: ' . $qty . '</b>';
+		}
+		return $qty;
+	}
+
+
+	/**
+	 * checks whether an individual ticket is available for purchase based on datetime, and ticket details
+	 *
+	 * @param   EE_Ticket $ticket
+	 * @param int         $qty
+	 * @return int
+	 * @throws UnexpectedEntityException
+	 * @throws EE_Error
+	 */
+	protected function _validate_ticket_sale(EE_Ticket $ticket, $qty = 1)
+	{
+		if (self::debug) {
+			echo self::$nl . self::$nl . __LINE__ . ') ' . __METHOD__ . '() ';
+		}
+		if (! $ticket instanceof EE_Ticket) {
+			return 0;
+		}
+		if (self::debug) {
+			echo self::$nl . '<b> . ticket->ID: ' . $ticket->ID() . '</b>';
+			echo self::$nl . ' . original ticket->reserved: ' . $ticket->reserved();
+		}
+		$ticket->refresh_from_db();
+		// first let's determine the ticket availability based on sales
+		$available = $ticket->qty('saleable');
+		if (self::debug) {
+			echo self::$nl . ' . . . ticket->qty: ' . $ticket->qty();
+			echo self::$nl . ' . . . ticket->sold: ' . $ticket->sold();
+			echo self::$nl . ' . . . ticket->reserved: ' . $ticket->reserved();
+			echo self::$nl . ' . . . ticket->qty(saleable): ' . $ticket->qty('saleable');
+			echo self::$nl . ' . . . available: ' . $available;
+		}
+		if ($available < 1) {
+			$this->_ticket_sold_out($ticket);
+			return 0;
+		}
+		if (self::debug) {
+			echo self::$nl . ' . . . qty: ' . $qty;
+		}
+		if ($available < $qty) {
+			$qty = $available;
+			if (self::debug) {
+				echo self::$nl . ' . . . QTY ADJUSTED: ' . $qty;
+			}
+			$this->_ticket_quantity_decremented($ticket);
+		}
+		if ($this->_reserve_ticket($ticket, $qty)) {
+			return $qty;
+		} else {
+			return 0;
+		}
+	}
+
+
+	/**
+	 * increments ticket reserved based on quantity passed
+	 *
+	 * @param    EE_Ticket $ticket
+	 * @param int          $quantity
+	 * @return bool indicating success or failure
+	 * @throws EE_Error
+	 */
+	protected function _reserve_ticket(EE_Ticket $ticket, $quantity = 1)
+	{
+		if (self::debug) {
+			echo self::$nl . self::$nl . ' . . . INCREASE RESERVED: ' . $quantity;
+		}
+		return $ticket->increaseReserved($quantity, 'TicketSalesMonitor:' . __LINE__);
+	}
+
+
+	/**
+	 * @param  EE_Ticket $ticket
+	 * @param  int       $quantity
+	 * @return bool
+	 * @throws EE_Error
+	 */
+	protected function _release_reserved_ticket(EE_Ticket $ticket, $quantity = 1)
+	{
+		if (self::debug) {
+			echo self::$nl . ' . . . ticket->ID: ' . $ticket->ID();
+			echo self::$nl . ' . . . ticket->reserved before: ' . $ticket->reserved();
+		}
+		$ticket->decreaseReserved($quantity, true, 'TicketSalesMonitor:' . __LINE__);
+		if (self::debug) {
+			echo self::$nl . ' . . . ticket->reserved after: ' . $ticket->reserved();
+		}
+		return $ticket->save() ? 1 : 0;
+	}
+
+
+	/**
+	 * removes quantities within the ticket selector based on zero ticket availability
+	 *
+	 * @param    EE_Ticket $ticket
+	 * @return    void
+	 * @throws UnexpectedEntityException
+	 * @throws EE_Error
+	 */
+	protected function _ticket_sold_out(EE_Ticket $ticket)
+	{
+		if (self::debug) {
+			echo self::$nl . self::$nl . __LINE__ . ') ' . __METHOD__ . '() ';
+			echo self::$nl . ' . . ticket->name: ' . $this->_get_ticket_and_event_name($ticket);
+		}
+		$this->sold_out_tickets[] = $this->_get_ticket_and_event_name($ticket);
+	}
+
+
+	/**
+	 * adjusts quantities within the ticket selector based on decreased ticket availability
+	 *
+	 * @param    EE_Ticket $ticket
+	 * @return void
+	 * @throws UnexpectedEntityException
+	 * @throws EE_Error
+	 */
+	protected function _ticket_quantity_decremented(EE_Ticket $ticket)
+	{
+		if (self::debug) {
+			echo self::$nl . self::$nl . __LINE__ . ') ' . __METHOD__ . '() ';
+			echo self::$nl . ' . . ticket->name: ' . $this->_get_ticket_and_event_name($ticket);
+		}
+		$this->decremented_tickets[] = $this->_get_ticket_and_event_name($ticket);
+	}
+
+
+	/**
+	 * builds string out of ticket and event name
+	 *
+	 * @param    EE_Ticket $ticket
+	 * @return string
+	 * @throws UnexpectedEntityException
+	 * @throws EE_Error
+	 */
+	protected function _get_ticket_and_event_name(EE_Ticket $ticket)
+	{
+		$event = $ticket->get_related_event();
+		if ($event instanceof EE_Event) {
+			$ticket_name = sprintf(
+				_x('%1$s for %2$s', 'ticket name for event name', 'event_espresso'),
+				$ticket->name(),
+				$event->name()
+			);
+		} else {
+			$ticket_name = $ticket->name();
+		}
+		return $ticket_name;
+	}
+
+
+
+	/********************************** EVENT CART  **********************************/
+
+
+	/**
+	 * releases or reserves ticket(s) based on quantity passed
+	 *
+	 * @param  EE_Line_Item $line_item
+	 * @param  int          $quantity
+	 * @return void
+	 * @throws EE_Error
+	 * @throws InvalidArgumentException
+	 * @throws InvalidDataTypeException
+	 * @throws InvalidInterfaceException
+	 */
+	public static function ticket_quantity_updated(EE_Line_Item $line_item, $quantity = 1)
+	{
+		$ticket = EEM_Ticket::instance()->get_one_by_ID(absint($line_item->OBJ_ID()));
+		if ($ticket instanceof EE_Ticket) {
+			$ticket->add_extra_meta(
+				EE_Ticket::META_KEY_TICKET_RESERVATIONS,
+				__LINE__ . ') ' . __METHOD__ . '()'
+			);
+			if ($quantity > 0) {
+				EED_Ticket_Sales_Monitor::instance()->_reserve_ticket($ticket, $quantity);
+			} else {
+				EED_Ticket_Sales_Monitor::instance()->_release_reserved_ticket($ticket, $quantity);
+			}
+		}
+	}
+
+
+	/**
+	 * releases reserved ticket(s) based on quantity passed
+	 *
+	 * @param  EE_Ticket $ticket
+	 * @param  int       $quantity
+	 * @return void
+	 * @throws EE_Error
+	 */
+	public static function ticket_removed_from_cart(EE_Ticket $ticket, $quantity = 1)
+	{
+		$ticket->add_extra_meta(
+			EE_Ticket::META_KEY_TICKET_RESERVATIONS,
+			__LINE__ . ') ' . __METHOD__ . '()'
+		);
+		EED_Ticket_Sales_Monitor::instance()->_release_reserved_ticket($ticket, $quantity);
+	}
+
+
+
+	/********************************** POST_NOTICES  **********************************/
+
+
+	/**
+	 * @return void
+	 * @throws EE_Error
+	 * @throws InvalidArgumentException
+	 * @throws ReflectionException
+	 * @throws InvalidDataTypeException
+	 * @throws InvalidInterfaceException
+	 */
+	public static function post_notices()
+	{
+		EED_Ticket_Sales_Monitor::instance()->_post_notices();
+	}
+
+
+	/**
+	 * @return void
+	 * @throws EE_Error
+	 * @throws InvalidArgumentException
+	 * @throws ReflectionException
+	 * @throws InvalidDataTypeException
+	 * @throws InvalidInterfaceException
+	 */
+	protected function _post_notices()
+	{
+		if (self::debug) {
+			echo self::$nl . self::$nl . __LINE__ . ') ' . __METHOD__ . '() ';
+		}
+		$refresh_msg = '';
+		$none_added_msg = '';
+		if (defined('DOING_AJAX') && DOING_AJAX) {
+			$refresh_msg = __(
+				'Please refresh the page to view updated ticket quantities.',
+				'event_espresso'
+			);
+			$none_added_msg = __('No tickets were added for the event.', 'event_espresso');
+		}
+		if (! empty($this->sold_out_tickets)) {
+			EE_Error::add_attention(
+				sprintf(
+					apply_filters(
+						'FHEE__EED_Ticket_Sales_Monitor___post_notices__sold_out_tickets_notice',
+						__(
+							'We\'re sorry...%1$sThe following items have sold out since you first viewed this page, and can no longer be registered for:%1$s%1$s%2$s%1$s%1$sPlease note that availability can change at any time due to cancellations, so please check back again later if registration for this event(s) is important to you.%1$s%1$s%3$s%1$s%4$s%1$s',
+							'event_espresso'
+						)
+					),
+					'<br />',
+					implode('<br />', $this->sold_out_tickets),
+					$none_added_msg,
+					$refresh_msg
+				)
+			);
+			// alter code flow in the Ticket Selector for better UX
+			add_filter('FHEE__EED_Ticket_Selector__process_ticket_selections__tckts_slctd', '__return_true');
+			add_filter('FHEE__EED_Ticket_Selector__process_ticket_selections__success', '__return_false');
+			$this->sold_out_tickets = array();
+			// and reset the cart
+			EED_Ticket_Sales_Monitor::session_cart_reset(EE_Registry::instance()->SSN);
+		}
+		if (! empty($this->decremented_tickets)) {
+			EE_Error::add_attention(
+				sprintf(
+					apply_filters(
+						'FHEE__EED_Ticket_Sales_Monitor___ticket_quantity_decremented__notice',
+						__(
+							'We\'re sorry...%1$sDue to sales that have occurred since you first viewed the last page, the following items have had their quantities adjusted to match the current available amount:%1$s%1$s%2$s%1$s%1$sPlease note that availability can change at any time due to cancellations, so please check back again later if registration for this event(s) is important to you.%1$s%1$s%3$s%1$s%4$s%1$s',
+							'event_espresso'
+						)
+					),
+					'<br />',
+					implode('<br />', $this->decremented_tickets),
+					$none_added_msg,
+					$refresh_msg
+				)
+			);
+			$this->decremented_tickets = array();
+		}
+	}
+
+
+
+	/********************************** RELEASE_ALL_RESERVED_TICKETS_FOR_TRANSACTION  **********************************/
+
+
+	/**
+	 * releases reserved tickets for all registrations of an EE_Transaction
+	 * by default, will NOT release tickets for finalized transactions
+	 *
+	 * @param    EE_Transaction $transaction
+	 * @return int
+	 * @throws EE_Error
+	 * @throws InvalidSessionDataException
+	 */
+	protected function _release_all_reserved_tickets_for_transaction(EE_Transaction $transaction)
+	{
+		if (self::debug) {
+			echo self::$nl . self::$nl . __LINE__ . ') ' . __METHOD__ . '() ';
+			echo self::$nl . ' . transaction->ID: ' . $transaction->ID();
+			echo self::$nl . ' . TXN status_ID: ' . $transaction->status_ID();
+		}
+		// check if 'finalize_registration' step has been completed...
+		$finalized = $transaction->reg_step_completed('finalize_registration');
+		if (self::debug) {
+			// DEBUG LOG
+			EEH_Debug_Tools::log(
+				__CLASS__,
+				__FUNCTION__,
+				__LINE__,
+				array('finalized' => $finalized),
+				false,
+				'EE_Transaction: ' . $transaction->ID()
+			);
+		}
+		// how many tickets were released
+		$count = 0;
+		if (self::debug) {
+			echo self::$nl . ' . . . TXN finalized: ' . $finalized;
+		}
+		$release_tickets_with_TXN_status = array(
+			EEM_Transaction::failed_status_code,
+			EEM_Transaction::abandoned_status_code,
+			EEM_Transaction::incomplete_status_code,
+		);
+		$events = array();
+		// if the session is getting cleared BEFORE the TXN has been finalized or the transaction is not completed
+		if (! $finalized || in_array($transaction->status_ID(), $release_tickets_with_TXN_status, true)) {
+			// cancel any reserved tickets for registrations that were not approved
+			$registrations = $transaction->registrations();
+			if (self::debug) {
+				echo self::$nl . ' . . . # registrations: ' . count($registrations);
+				$reg = reset($registrations);
+				$ticket = $reg->ticket();
+				if ($ticket instanceof EE_Ticket) {
+					$ticket->add_extra_meta(
+						EE_Ticket::META_KEY_TICKET_RESERVATIONS,
+						__LINE__ . ') Release All Tickets TXN:' . $transaction->ID()
+					);
+				}
+			}
+			if (! empty($registrations)) {
+				foreach ($registrations as $registration) {
+					if ($registration instanceof EE_Registration
+						&& $this->_release_reserved_ticket_for_registration($registration, $transaction)
+					) {
+						$count++;
+						$events[ $registration->event_ID() ] = $registration->event();
+					}
+				}
+			}
+		}
+		if ($events !== array()) {
+			foreach ($events as $event) {
+				/** @var EE_Event $event */
+				$event->perform_sold_out_status_check();
+			}
+		}
+		return $count;
+	}
+
+
+	/**
+	 * releases reserved tickets for an EE_Registration
+	 * by default, will NOT release tickets for APPROVED registrations
+	 *
+	 * @param EE_Registration $registration
+	 * @param EE_Transaction  $transaction
+	 * @return int
+	 * @throws EE_Error
+	 */
+	protected function _release_reserved_ticket_for_registration(
+		EE_Registration $registration,
+		EE_Transaction $transaction
+	) {
+		$STS_ID = $transaction->status_ID();
+		if (self::debug) {
+			echo self::$nl . self::$nl . __LINE__ . ') ' . __METHOD__ . '() ';
+			echo self::$nl . ' . . registration->ID: ' . $registration->ID();
+			echo self::$nl . ' . . registration->status_ID: ' . $registration->status_ID();
+			echo self::$nl . ' . . transaction->status_ID(): ' . $STS_ID;
+		}
+		if (// release Tickets for Failed Transactions and Abandoned Transactions
+			$STS_ID === EEM_Transaction::failed_status_code
+			|| $STS_ID === EEM_Transaction::abandoned_status_code
+			|| (
+				// also release Tickets for Incomplete Transactions, but ONLY if the Registrations are NOT Approved
+				$STS_ID === EEM_Transaction::incomplete_status_code
+				&& $registration->status_ID() !== EEM_Registration::status_id_approved
+			)
+		) {
+			if (self::debug) {
+				echo self::$nl . self::$nl . ' . . RELEASE RESERVED TICKET';
+				$rsrvd = $registration->get_extra_meta(EE_Registration::HAS_RESERVED_TICKET_KEY, true);
+				echo self::$nl . ' . . . registration HAS_RESERVED_TICKET_KEY: ';
+				var_dump($rsrvd);
+			}
+			$registration->release_reserved_ticket(true, 'TicketSalesMonitor:' . __LINE__);
+			return 1;
+		}
+		return 0;
+	}
+
+
+
+	/********************************** SESSION_CART_RESET  **********************************/
+
+
+	/**
+	 * callback hooked into 'AHEE__EE_Session__reset_cart__before_reset'
+	 *
+	 * @param EE_Session $session
+	 * @return void
+	 * @throws EE_Error
+	 * @throws InvalidArgumentException
+	 * @throws ReflectionException
+	 * @throws InvalidDataTypeException
+	 * @throws InvalidInterfaceException
+	 */
+	public static function session_cart_reset(EE_Session $session)
+	{
+		// don't release tickets if checkout was already reset
+		if (did_action('AHEE__EE_Session__reset_checkout__before_reset')) {
+			return;
+		}
+		if (self::debug) {
+			echo self::$nl . self::$nl . __LINE__ . ') ' . __METHOD__ . '() ';
+		}
+		// first check of the session has a valid Checkout object
+		$checkout = $session->checkout();
+		if ($checkout instanceof EE_Checkout) {
+			// and use that to clear ticket reservations because it will update the associated registration meta data
+			EED_Ticket_Sales_Monitor::instance()->_session_checkout_reset($checkout);
+			return;
+		}
+		$cart = $session->cart();
+		if ($cart instanceof EE_Cart) {
+			if (self::debug) {
+				echo self::$nl . self::$nl . ' cart instance of EE_Cart: ';
+			}
+			EED_Ticket_Sales_Monitor::instance()->_session_cart_reset($cart, $session);
+		} else {
+			if (self::debug) {
+				echo self::$nl . self::$nl . ' invalid EE_Cart: ';
+				var_export($cart, true);
+			}
+		}
+	}
+
+
+	/**
+	 * releases reserved tickets in the EE_Cart
+	 *
+	 * @param EE_Cart $cart
+	 * @return void
+	 * @throws EE_Error
+	 * @throws InvalidArgumentException
+	 * @throws ReflectionException
+	 * @throws InvalidDataTypeException
+	 * @throws InvalidInterfaceException
+	 */
+	protected function _session_cart_reset(EE_Cart $cart, EE_Session $session)
+	{
+		if (self::debug) {
+			echo self::$nl . self::$nl . __LINE__ . ') ' . __METHOD__ . '() ';
+		}
+		$ticket_line_items = $cart->get_tickets();
+		if (empty($ticket_line_items)) {
+			return;
+		}
+		if (self::debug) {
+			echo '<br /> . ticket_line_item count: ' . count($ticket_line_items);
+		}
+		foreach ($ticket_line_items as $ticket_line_item) {
+			if (self::debug) {
+				echo self::$nl . ' . ticket_line_item->ID(): ' . $ticket_line_item->ID();
+			}
+			if ($ticket_line_item instanceof EE_Line_Item && $ticket_line_item->OBJ_type() === 'Ticket') {
+				if (self::debug) {
+					echo self::$nl . ' . . ticket_line_item->OBJ_ID(): ' . $ticket_line_item->OBJ_ID();
+				}
+				$ticket = EEM_Ticket::instance()->get_one_by_ID($ticket_line_item->OBJ_ID());
+				if ($ticket instanceof EE_Ticket) {
+					if (self::debug) {
+						echo self::$nl . ' . . ticket->ID(): ' . $ticket->ID();
+						echo self::$nl . ' . . ticket_line_item->quantity(): ' . $ticket_line_item->quantity();
+					}
+					$ticket->add_extra_meta(
+						EE_Ticket::META_KEY_TICKET_RESERVATIONS,
+						__LINE__ . ') ' . __METHOD__ . '() SID = ' . $session->id()
+					);
+					$this->_release_reserved_ticket($ticket, $ticket_line_item->quantity());
+				}
+			}
+		}
+		if (self::debug) {
+			echo self::$nl . self::$nl . ' RESET COMPLETED ';
+		}
+	}
+
+
+
+	/********************************** SESSION_CHECKOUT_RESET  **********************************/
+
+
+	/**
+	 * callback hooked into 'AHEE__EE_Session__reset_checkout__before_reset'
+	 *
+	 * @param EE_Session $session
+	 * @return void
+	 * @throws EE_Error
+	 * @throws InvalidSessionDataException
+	 */
+	public static function session_checkout_reset(EE_Session $session)
+	{
+		// don't release tickets if cart was already reset
+		if (did_action('AHEE__EE_Session__reset_cart__before_reset')) {
+			return;
+		}
+		$checkout = $session->checkout();
+		if ($checkout instanceof EE_Checkout) {
+			EED_Ticket_Sales_Monitor::instance()->_session_checkout_reset($checkout);
+		}
+	}
+
+
+	/**
+	 * releases reserved tickets for the EE_Checkout->transaction
+	 *
+	 * @param EE_Checkout $checkout
+	 * @return void
+	 * @throws EE_Error
+	 * @throws InvalidSessionDataException
+	 */
+	protected function _session_checkout_reset(EE_Checkout $checkout)
+	{
+		if (self::debug) {
+			echo self::$nl . self::$nl . __LINE__ . ') ' . __METHOD__ . '() ';
+		}
+		// we want to release the each registration's reserved tickets if the session was cleared, but not if this is a revisit
+		if ($checkout->revisit || ! $checkout->transaction instanceof EE_Transaction) {
+			return;
+		}
+		$this->_release_all_reserved_tickets_for_transaction($checkout->transaction);
+	}
+
+
+
+	/********************************** SESSION_EXPIRED_RESET  **********************************/
+
+
+	/**
+	 * @param    EE_Session $session
+	 * @return    void
+	 */
+	public static function session_expired_reset(EE_Session $session)
+	{
+	}
+
+
+
+	/********************************** PROCESS_ABANDONED_TRANSACTIONS  **********************************/
+
+
+	/**
+	 * releases reserved tickets for all registrations of an ABANDONED EE_Transaction
+	 * by default, will NOT release tickets for free transactions, or any that have received a payment
+	 *
+	 * @param EE_Transaction $transaction
+	 * @return void
+	 * @throws EE_Error
+	 * @throws InvalidSessionDataException
+	 */
+	public static function process_abandoned_transactions(EE_Transaction $transaction)
+	{
+		// is this TXN free or has any money been paid towards this TXN? If so, then leave it alone
+		if ($transaction->is_free() || $transaction->paid() > 0) {
+			if (self::debug) {
+				// DEBUG LOG
+				EEH_Debug_Tools::log(
+					__CLASS__,
+					__FUNCTION__,
+					__LINE__,
+					array($transaction),
+					false,
+					'EE_Transaction: ' . $transaction->ID()
+				);
+			}
+			return;
+		}
+		// have their been any successful payments made ?
+		$payments = $transaction->payments();
+		foreach ($payments as $payment) {
+			if ($payment instanceof EE_Payment && $payment->status() === EEM_Payment::status_id_approved) {
+				if (self::debug) {
+					// DEBUG LOG
+					EEH_Debug_Tools::log(
+						__CLASS__,
+						__FUNCTION__,
+						__LINE__,
+						array($payment),
+						false,
+						'EE_Transaction: ' . $transaction->ID()
+					);
+				}
+				return;
+			}
+		}
+		// since you haven't even attempted to pay for your ticket...
+		EED_Ticket_Sales_Monitor::instance()->_release_all_reserved_tickets_for_transaction($transaction);
+	}
+
+
+
+	/********************************** PROCESS_FAILED_TRANSACTIONS  **********************************/
+
+
+	/**
+	 * releases reserved tickets for absolutely ALL registrations of a FAILED EE_Transaction
+	 *
+	 * @param EE_Transaction $transaction
+	 * @return void
+	 * @throws EE_Error
+	 * @throws InvalidSessionDataException
+	 */
+	public static function process_failed_transactions(EE_Transaction $transaction)
+	{
+		// since you haven't even attempted to pay for your ticket...
+		EED_Ticket_Sales_Monitor::instance()->_release_all_reserved_tickets_for_transaction($transaction);
+	}
+
+
+
+	/********************************** RESET RESERVATION COUNTS  *********************************/
+
+
+	/**
+	 * Resets the ticket and datetime reserved counts.
+	 *
+	 * For all the tickets with reservations, recalculates what their actual reserved counts should be based
+	 * on the valid transactions.
+	 *
+	 * @return int number of tickets whose reservations were released.
+	 * @throws EE_Error
+	 * @throws DomainException
+	 * @throws InvalidDataTypeException
+	 * @throws InvalidInterfaceException
+	 * @throws InvalidArgumentException
+	 * @throws UnexpectedEntityException
+	 * @throws ReflectionException
+	 */
+	public static function reset_reservation_counts()
+	{
+		/** @var EE_Line_Item[] $valid_reserved_tickets */
+		$valid_reserved_tickets = array();
+		/** @var EE_Transaction[] $transactions_in_progress */
+		$transactions_in_progress = EEM_Transaction::instance()->get_transactions_in_progress();
+		foreach ($transactions_in_progress as $transaction) {
+			// if this TXN has been fully completed, then skip it
+			if ($transaction->reg_step_completed('finalize_registration')) {
+				continue;
+			}
+			$total_line_item = $transaction->total_line_item();
+			// $transaction_in_progress->line
+			if (! $total_line_item instanceof EE_Line_Item) {
+				throw new DomainException(
+					esc_html__(
+						'Transaction does not have a valid Total Line Item associated with it.',
+						'event_espresso'
+					)
+				);
+			}
+			$valid_reserved_tickets += EED_Ticket_Sales_Monitor::get_ticket_line_items_for_grand_total(
+				$total_line_item
+			);
+		}
+		$total_line_items = EEM_Line_Item::instance()->get_total_line_items_for_active_carts();
+		foreach ($total_line_items as $total_line_item) {
+			$valid_reserved_tickets += EED_Ticket_Sales_Monitor::get_ticket_line_items_for_grand_total(
+				$total_line_item
+			);
+		}
+		$tickets_with_reservations = EEM_Ticket::instance()->get_tickets_with_reservations();
+		return EED_Ticket_Sales_Monitor::release_reservations_for_tickets(
+			$tickets_with_reservations,
+			$valid_reserved_tickets,
+			__FUNCTION__
+		);
+	}
+
+
+	/**
+	 * @param EE_Line_Item $total_line_item
+	 * @return EE_Line_Item[]
+	 */
+	private static function get_ticket_line_items_for_grand_total(EE_Line_Item $total_line_item)
+	{
+		/** @var EE_Line_Item[] $valid_reserved_tickets */
+		$valid_reserved_tickets = array();
+		$ticket_line_items = EEH_Line_Item::get_ticket_line_items($total_line_item);
+		foreach ($ticket_line_items as $ticket_line_item) {
+			if ($ticket_line_item instanceof EE_Line_Item) {
+				$valid_reserved_tickets[$ticket_line_item->ID()] = $ticket_line_item;
+			}
+		}
+		return $valid_reserved_tickets;
+	}
+
+
+	/**
+	 * @param EE_Ticket[]    $tickets_with_reservations
+	 * @param EE_Line_Item[] $valid_reserved_ticket_line_items
+	 * @return int
+	 * @throws UnexpectedEntityException
+	 * @throws DomainException
+	 * @throws EE_Error
+	 */
+	private static function release_reservations_for_tickets(
+		array $tickets_with_reservations,
+		array $valid_reserved_ticket_line_items = array(),
+		$source
+	) {
+		if (self::debug) {
+			echo self::$nl . self::$nl . __LINE__ . ') ' . __METHOD__ . '()';
+		}
+		$total_tickets_released = 0;
+		$sold_out_events = array();
+		foreach ($tickets_with_reservations as $ticket_with_reservations) {
+			if (! $ticket_with_reservations instanceof EE_Ticket) {
+				continue;
+			}
+			$reserved_qty = $ticket_with_reservations->reserved();
+			if (self::debug) {
+				echo self::$nl . ' . $ticket_with_reservations->ID(): ' . $ticket_with_reservations->ID();
+				echo self::$nl . ' . $reserved_qty: ' . $reserved_qty;
+			}
+			foreach ($valid_reserved_ticket_line_items as $valid_reserved_ticket_line_item) {
+				if ($valid_reserved_ticket_line_item instanceof EE_Line_Item
+					&& $valid_reserved_ticket_line_item->OBJ_ID() === $ticket_with_reservations->ID()
+				) {
+					if (self::debug) {
+						echo self::$nl . ' . $valid_reserved_ticket_line_item->quantity(): '
+							 . $valid_reserved_ticket_line_item->quantity();
+					}
+					$reserved_qty -= $valid_reserved_ticket_line_item->quantity();
+				}
+			}
+			if ($reserved_qty > 0) {
+				$ticket_with_reservations->add_extra_meta(
+					EE_Ticket::META_KEY_TICKET_RESERVATIONS,
+					__LINE__ . ') ' . $source . '()'
+				);
+				$ticket_with_reservations->decreaseReserved($reserved_qty, true, 'TicketSalesMonitor:' . __LINE__);
+				$ticket_with_reservations->save();
+				$total_tickets_released += $reserved_qty;
+				$event = $ticket_with_reservations->get_related_event();
+				// track sold out events
+				if ($event instanceof EE_Event && $event->is_sold_out()) {
+					$sold_out_events[] = $event;
+				}
+			}
+		}
+		if (self::debug) {
+			echo self::$nl . ' . $total_tickets_released: ' . $total_tickets_released;
+		}
+		// double check whether sold out events should remain sold out after releasing tickets
+		if ($sold_out_events !== array()) {
+			foreach ($sold_out_events as $sold_out_event) {
+				/** @var EE_Event $sold_out_event */
+				$sold_out_event->perform_sold_out_status_check();
+			}
+		}
+		return $total_tickets_released;
+	}
+
+
+
+	/********************************** SHUTDOWN  **********************************/
+
+
+	/**
+	 * @param int $timestamp
+	 * @return false|int
+	 * @throws EE_Error
+	 * @throws InvalidArgumentException
+	 * @throws InvalidDataTypeException
+	 * @throws InvalidInterfaceException
+	 */
+	public static function clear_expired_line_items_with_no_transaction($timestamp = 0)
+	{
+		/** @type WPDB $wpdb */
+		global $wpdb;
+		if (! absint($timestamp)) {
+			/** @var EventEspresso\core\domain\values\session\SessionLifespan $session_lifespan */
+			$session_lifespan = LoaderFactory::getLoader()->getShared(
+				'EventEspresso\core\domain\values\session\SessionLifespan'
+			);
+			$timestamp = $session_lifespan->expiration();
+		}
+		return $wpdb->query(
+			$wpdb->prepare(
+				'DELETE FROM ' . EEM_Line_Item::instance()->table() . '
                 WHERE TXN_ID = 0 AND LIN_timestamp <= %s',
-                // use GMT time because that's what LIN_timestamps are in
-                date('Y-m-d H:i:s', $timestamp)
-            )
-        );
-    }
+				// use GMT time because that's what LIN_timestamps are in
+				date('Y-m-d H:i:s', $timestamp)
+			)
+		);
+	}
 }