<?php

namespace StoreSuit;

defined( 'ABSPATH' ) || exit;
// phpcs:disable WordPress.Security.EscapeOutput.ExceptionNotEscaped -- Messages are returned as JSON by Admin::ajax() and shown with textContent; HTML output escapes them where printed.
/** Operational stages are derived from the existing order, never a second order ledger. */
final class OrderFlow {
    // Four steps (0.62.12, owner item 40): an order handed to the carrier is completed; delivery is a confirmation, not a step.
    public const STAGES = array(
        'new'       => 'New',
        'preparing' => 'Preparing',
        'ready'     => 'Ready to ship',
        'done'      => 'Completed',
        'closed'    => 'Cancelled / returned',
    );

    /**
     * A sale at the register leaves with the customer at the counter: nothing to pick, pack or ship (0.61.1). A POS return is
     * not a sale. Any till's sale counts (Orders::store_sale(), Almira audit SAT-2); one with a shipping line was sold in the
     * store and is sent to the customer, so it keeps the shipping flow.
     */
    public static function counter( \WC_Order $order ) : bool {
        return Orders::store_sale( $order ) && !$order->get_shipping_methods();
    }

    public static function read( \WC_Order $order ) : array {
        $all = (array) (( $order->get_meta( '_storesuit_fulfilment' ) ?: array() ));
        $totals = array(
            'quantity' => 0.0,
            'picked'   => 0.0,
            'packed'   => 0.0,
            'shipped'  => 0.0,
        );
        foreach ( $order->get_items() as $id => $item ) {
            $qty = max( 0, (float) $item->get_quantity() - abs( $order->get_qty_refunded_for_item( $id ) ) );
            $totals['quantity'] += $qty;
            foreach ( array('picked', 'packed', 'shipped') as $key ) {
                $totals[$key] += min( $qty, max( 0, (float) ($all[$id][$key] ?? 0) ) );
            }
        }
        $has = $totals['quantity'] > 0;
        $shipped = $has && $totals['shipped'] >= $totals['quantity'];
        $delivered = (array) (( $order->get_meta( '_storesuit_delivery_confirmed' ) ?: array() ));
        $shipments = (array) (( $order->get_meta( '_storesuit_shipments' ) ?: array() ));
        $handover = $shipped && count( $shipments ) > 0;
        foreach ( $shipments as $s ) {
            if ( ($s['mode'] ?? '') !== 'handover' ) {
                $handover = false;
                break;
            }
        }
        if ( SaleStatus::quote( $order ) ) {
            $stage = SaleStatus::QUOTE_STAGE;
        } elseif ( $order->has_status( array(
            'cancelled',
            'failed',
            'refunded',
            'checkout-draft',
            'trash'
        ) ) ) {
            $stage = 'closed';
        } elseif ( self::counter( $order ) ) {
            $stage = 'done';
        } elseif ( $shipped ) {
            $stage = 'done';
        } elseif ( $order->has_status( 'completed' ) || Orders::shipped_status( $order ) ) {
            $stage = 'done';
        } elseif ( $has && $totals['packed'] >= $totals['quantity'] ) {
            $stage = 'ready';
        } elseif ( $order->get_meta( '_storesuit_preparation_started' ) || $totals['picked'] > 0 || $totals['packed'] > 0 || $totals['shipped'] > 0 ) {
            $stage = 'preparing';
        } else {
            $stage = 'new';
        }
        $returns = 0;
        foreach ( (array) (( $order->get_meta( '_storesuit_returns' ) ?: array() )) as $r ) {
            if ( in_array( $r['status'] ?? '', array('requested', 'approved'), true ) ) {
                ++$returns;
            }
        }
        $withdrawal = Operations::pending_withdrawal( $order );
        if ( $withdrawal ) {
            ++$returns;
        }
        $abandoned = Orders::abandoned_checkout( $order );
        $open = ( $stage !== 'closed' && $stage !== SaleStatus::QUOTE_STAGE && !$abandoned ? Orders::outstanding( $order ) : 0.0 );
        $next = 'view';
        $next_label = 'Review order';
        if ( $stage === SaleStatus::QUOTE_STAGE ) {
            $next_label = 'Review quote';
        } elseif ( $withdrawal ) {
            $next = 'view';
            $next_label = 'Review customer return request';
        } elseif ( $returns ) {
            $next = 'returns';
            $next_label = 'Manage return';
        } elseif ( $stage === 'new' && $order->has_status( 'pending' ) ) {
            $next = 'checkout';
            $next_label = ( $abandoned ? 'Checkout not completed' : 'Waiting for the customer\'s payment' );
        } elseif ( $stage === 'new' && $has ) {
            $next = 'start';
            $next_label = 'Start preparing';
        } elseif ( $stage === 'preparing' ) {
            $next = 'ready';
            $next_label = 'Mark as ready';
        } elseif ( $stage === 'ready' ) {
            $next = 'prepare';
            $next_label = ( $order->get_meta( '_storesuit_delivery' ) === 'pickup' ? 'Record in-person handover' : 'Record delivery' );
        } elseif ( $open > 0 ) {
            $next = 'payment';
            $next_label = 'Track payment';
            // The free build's cash on delivery is paid when its delivery is confirmed (ORD-2, OD-3).
            if ( $stage === 'done' && $shipped && !$delivered && !$handover && Orders::cod_paid_on_delivery( $order ) ) {
                $next = 'delivered';
                $next_label = 'Confirm delivery';
            }
        }
        $stage_label = ( $stage === 'ready' && $order->get_meta( '_storesuit_delivery' ) === 'pickup' ? 'Ready for pickup' : (( $stage === SaleStatus::QUOTE_STAGE ? 'Quote' : self::STAGES[$stage] )) );
        // Handed to the carrier while money is open (ORD-3, P1-04): the stage stays 'done' (owner item 40; the index counts it so),
        // only its name says that the payment is still open.
        if ( $stage === 'done' && $open > 0 && !self::counter( $order ) ) {
            $stage_label = ( !$shipped ? 'Completed · payment open' : (( $handover ? 'Handed over · payment open' : (( Orders::is_cod( $order ) ? 'Shipped · collect on delivery' : 'Shipped · payment open' )) )) );
        }
        return array(
            'stage'                => $stage,
            'label'                => I18n::t( $stage_label ),
            'next'                 => $next,
            'next_label'           => I18n::t( $next_label ),
            'totals'               => $totals,
            'open_returns'         => $returns,
            'withdrawal_requested' => $withdrawal,
            'delivery_confirmed'   => ( $delivered ?: null ),
            'partial_shipment'     => $totals['shipped'] > 0 && !$shipped,
            'counter'              => self::counter( $order ),
        );
    }

    /**
     * The same step for several orders at once (0.58): each order is checked and moved as on its own, in its own
     * transaction; one that cannot take the step is skipped with the reason and holds no other back. Each order's key comes
     * from the request's key, so sending the same request again moves nothing twice.
     */
    public static function bulk( array $data ) : array {
        Store::require_cap( 'storesuit_fulfil' );
        $operation = Store::text( $data, 'operation' );
        if ( !in_array( $operation, array('start', 'ready', 'ship'), true ) ) {
            throw new \InvalidArgumentException(I18n::t( 'Choose a valid order step.' ));
        }
        if ( empty( $data['confirmed'] ) ) {
            throw new \InvalidArgumentException(I18n::t( 'Review and confirm the action.' ));
        }
        $key = Store::text( $data, 'request_key' );
        if ( !preg_match( '/^[a-zA-Z0-9_-]{16,80}$/', $key ) ) {
            throw new \InvalidArgumentException(I18n::t( 'The action key is missing.' ));
        }
        $ids = array_values( array_unique( array_filter( array_map( 'absint', ( is_array( $data['ids'] ?? null ) ? $data['ids'] : array() ) ) ) ) );
        if ( !$ids || count( $ids ) > 100 ) {
            throw new \InvalidArgumentException(I18n::t( 'Select between 1 and 100 orders.' ));
        }
        // Shipping several orders (ORD-3, P3-07): one carrier and an optional expected date for all, no tracking number; checked once
        // before any order moves. Unpaid prepaid orders go only when the request says so.
        $shipment = array();
        if ( $operation === 'ship' ) {
            $shipment = array(
                'carrier'           => Store::text( $data, 'carrier' ),
                'carrier_other'     => Store::text( $data, 'carrier_other' ),
                'expected_delivery' => Store::text( $data, 'expected_delivery' ),
                'ship_unpaid'       => ( empty( $data['ship_unpaid'] ) ? 0 : 1 ),
            );
            if ( $shipment['carrier'] === '' || $shipment['carrier'] === 'other' && $shipment['carrier_other'] === '' ) {
                throw new \InvalidArgumentException(I18n::t( 'Enter the carrier or courier name.' ));
            }
            Shipping::details( $shipment );
            // The carrier and the date are valid, or nothing is shipped.
        }
        $done = array();
        $skipped = array();
        $skip = static function ( int $id, $order, string $why ) use(&$skipped) {
            $skipped[] = array(
                'id'     => $id,
                'number' => ( $order instanceof \WC_Order ? (string) $order->get_order_number() : (string) $id ),
                'reason' => $why,
            );
        };
        foreach ( $ids as $id ) {
            $order_key = substr( hash( 'sha256', $key . ':' . $id ), 0, 40 );
            // A plain read first: only an order that can take the step (or already took it with this key) enters advance() and
            // its locks, so orders already further on never hold the store's money lock or flush the cache (review 0.58 M8).
            $order = wc_get_order( $id );
            if ( !$order instanceof \WC_Order || $order->get_type() !== 'shop_order' ) {
                $skip( $id, null, I18n::t( 'Order not found.' ) );
                continue;
            }
            $history = (array) (( $order->get_meta( ( $operation === 'ship' ? '_storesuit_fulfil_keys' : '_storesuit_flow_keys' ) ) ?: array() ));
            $taken = ( $operation === 'ship' ? in_array( $order_key, $history, true ) : isset( $history[$order_key] ) );
            $why = ( $taken ? '' : self::bulk_refusal( $order, $operation, $shipment ) );
            if ( $why !== '' ) {
                $skip( $id, $order, $why );
                continue;
            }
            try {
                // Each order in its own transaction, under its own lock, as the order screen's Ship order (Operations::ship_order()).
                if ( $operation === 'ship' ) {
                    Operations::fulfil( $id, array_merge( $shipment, array(
                        'stage'       => 'ship_order',
                        'request_key' => $order_key,
                    ) ) );
                } else {
                    self::advance( $id, array(
                        'operation'   => $operation,
                        'confirmed'   => 1,
                        'request_key' => $order_key,
                    ) );
                }
                $done[] = $id;
            } catch ( \Throwable $e ) {
                $skip( $id, wc_get_order( $id ), $e->getMessage() );
            }
        }
        if ( $done ) {
            Store::audit(
                'order',
                0,
                'flow_bulk_' . $operation,
                array(
                    'done'    => count( $done ),
                    'skipped' => count( $skipped ),
                )
            );
        }
        return array(
            'operation' => $operation,
            'done'      => $done,
            'skipped'   => $skipped,
        );
    }

    /** Why an order cannot take a bulk step, read without locks ('' when it can); advance() checks the same under its locks. */
    private static function bulk_refusal( \WC_Order $order, string $operation, array $shipment = array() ) : string {
        $flow = self::read( $order );
        if ( $operation === 'start' ) {
            return ( $flow['stage'] !== 'new' || $order->has_status( 'pending' ) || $flow['totals']['quantity'] <= 0 || $flow['open_returns'] ? I18n::t( 'The order is no longer eligible to start preparation or has an open return. Refresh the view.' ) : '' );
        }
        if ( $operation === 'ship' ) {
            if ( $flow['stage'] !== 'ready' || $flow['totals']['quantity'] <= 0 ) {
                return I18n::t( 'The order is not ready to ship. Refresh the view.' );
            }
            if ( (( $order->get_meta( '_storesuit_delivery' ) ?: 'shipping' )) === 'pickup' ) {
                return I18n::t( 'Use the in-person handover step for a store-pickup order.' );
            }
            if ( $flow['open_returns'] ) {
                return I18n::t( 'Resolve the open return request first.' );
            }
            if ( empty( $shipment['ship_unpaid'] ) && Orders::unpaid_prepaid( $order ) ) {
                return I18n::format( 'Payment not received yet (%s open). Ship it from the order, or tick the option to ship unpaid orders too.', Orders::money_text( Orders::outstanding( $order ), $order->get_currency() ) );
            }
            return '';
        }
        return ( $flow['stage'] !== 'preparing' || $flow['totals']['quantity'] <= 0 || $flow['open_returns'] ? I18n::t( 'The order cannot be marked ready or has an open return. Refresh the view.' ) : '' );
    }

    public static function advance( int $id, array $data ) : array {
        Store::require_cap( 'storesuit_fulfil' );
        $action = Store::text( $data, 'operation' );
        if ( !in_array( $action, array('start', 'ready', 'delivered'), true ) ) {
            throw new \InvalidArgumentException(I18n::t( 'Choose a valid order step.' ));
        }
        if ( empty( $data['confirmed'] ) ) {
            throw new \InvalidArgumentException(I18n::t( 'Review and confirm the action.' ));
        }
        return Store::atomic( static function () use($id, $data, $action) {
            return Store::lock( 'order-' . $id, static function () use($id, $data, $action) {
                $o = Orders::fresh( $id );
                $key = Store::text( $data, 'request_key' );
                if ( !preg_match( '/^[a-zA-Z0-9_-]{16,80}$/', $key ) ) {
                    throw new \InvalidArgumentException(I18n::t( 'The action key is missing.' ));
                }
                $history = (array) (( $o->get_meta( '_storesuit_flow_keys' ) ?: array() ));
                if ( isset( $history[$key] ) ) {
                    if ( $history[$key] !== $action ) {
                        throw new \InvalidArgumentException(I18n::t( 'This action key was used for another step.' ));
                    }
                    return Orders::summary( $o );
                }
                $flow = self::read( $o );
                $reference = '';
                if ( $action === 'start' ) {
                    if ( $flow['stage'] !== 'new' || $o->has_status( 'pending' ) || $flow['totals']['quantity'] <= 0 || $flow['open_returns'] ) {
                        throw new \InvalidArgumentException(I18n::t( 'The order is no longer eligible to start preparation or has an open return. Refresh the view.' ));
                    }
                    $o->update_meta_data( '_storesuit_preparation_started', array(
                        'at'    => gmdate( 'c' ),
                        'actor' => get_current_user_id(),
                    ) );
                } elseif ( $action === 'ready' ) {
                    if ( $flow['stage'] !== 'preparing' || $flow['totals']['quantity'] <= 0 || $flow['open_returns'] ) {
                        throw new \InvalidArgumentException(I18n::t( 'The order cannot be marked ready or has an open return. Refresh the view.' ));
                    }
                    $all = (array) (( $o->get_meta( '_storesuit_fulfilment' ) ?: array() ));
                    foreach ( $o->get_items() as $item_id => $item ) {
                        $qty = max( 0, (float) $item->get_quantity() - abs( $o->get_qty_refunded_for_item( $item_id ) ) );
                        $line = $all[$item_id] ?? array(
                            'picked'  => 0,
                            'packed'  => 0,
                            'shipped' => 0,
                        );
                        $line['picked'] = $qty;
                        $line['packed'] = $qty;
                        $line['shipped'] = min( $qty, max( 0, (float) ($line['shipped'] ?? 0) ) );
                        $all[$item_id] = $line;
                    }
                    $o->update_meta_data( '_storesuit_fulfilment', $all );
                    $o->update_meta_data( '_storesuit_ready_confirmed', array(
                        'at'    => gmdate( 'c' ),
                        'actor' => get_current_user_id(),
                    ) );
                } else {
                    $reference = Store::text( $data, 'reference' );
                    $all_shipped = $flow['totals']['quantity'] > 0 && $flow['totals']['shipped'] >= $flow['totals']['quantity'];
                    if ( !$all_shipped || !empty( $flow['delivery_confirmed'] ) || $reference === '' ) {
                        throw new \InvalidArgumentException(I18n::t( 'Ship all products first and enter the recipient or delivery confirmation reference.' ));
                    }
                    if ( $flow['open_returns'] ) {
                        throw new \InvalidArgumentException(I18n::t( 'Resolve the open return request first.' ));
                    }
                    $o->update_meta_data( '_storesuit_delivery_confirmed', array(
                        'at'        => gmdate( 'c' ),
                        'actor'     => get_current_user_id(),
                        'reference' => $reference,
                    ) );
                }
                $history[$key] = $action;
                $o->update_meta_data( '_storesuit_flow_keys', $history );
                $o->save();
                // Delivered and nothing left to pay (the free build's cash on delivery is paid by this confirmation, ORD-2): the order is
                // complete, as shipping a paid order completes it (Operations::ship_order()).
                if ( $action === 'delivered' && !$o->has_status( 'completed' ) && Orders::outstanding( $o ) <= 0 && Operations::all_shipped( $o ) && !Operations::return_open( $o ) ) {
                    $o->update_status( 'completed', I18n::t( 'StoreRuler: delivery confirmed and nothing is left to pay; the order is complete.' ) );
                }
                Store::audit(
                    'order',
                    $id,
                    'flow_' . $action,
                    array(
                        'reference' => Store::text( $data, 'reference' ),
                    )
                );
                return Orders::summary( $o );
            } );
        } );
    }

}