<?php
    session_start();
    require '../../../assets/utils/db_auth.php';
    require '../../../assets/utils/classes/OrderManager.php';

    $order = new OrderManager($pdo2, $company_id);

    $id = (int)($data['id'] ?? 0);

    if ($id > 0) {
        $result = $order->getOrderById($id);
        if (!$result) {
            http_response_code(404);
            $answer['message'] = 'Order not found.';
            exit(json_encode($answer));
        }
        $answer['output'] = $result;

        // Check if an active invoice already exists for this order
        $sth = $pdo2->prepare(
            "SELECT COUNT(*) FROM td_invoice
             WHERE company_id = :company_id
               AND order_id   = :order_id
               AND doc_type   = 'invoice'
               AND status    != 4"
        );
        $sth->execute([':company_id' => $company_id, ':order_id' => $id]);
        $answer['has_active_invoice'] = (int)$sth->fetchColumn() > 0;

        // Calculate returnable items — order items minus already confirmed returns
        $order_items = $result['items'] ?? '[]';

        // Aggregate returned qty per item_id from confirmed returns
        $sth = $pdo2->prepare(
            "SELECT items FROM td_return
             WHERE company_id = :company_id
               AND order_id   = :order_id
               AND status     = 1"
        );
        $sth->execute([':company_id' => $company_id, ':order_id' => $id]);
        $returned_qty = [];

        foreach ($sth->fetchAll(PDO::FETCH_COLUMN) as $items_json) {
            $items = json_decode($items_json, true) ?: [];
            foreach ($items as $item) {
                $item_id = (int)($item['item_id'] ?? -1);
                if ($item_id < 0) continue;
                $returned_qty[$item_id] = ($returned_qty[$item_id] ?? 0) + (float)$item['quantity'];
            }
        }

        $returnable = [];
        foreach ($order_items as $i => $item) {
            $already_returned = $returned_qty[$i] ?? 0;
            $remaining        = (float)$item['quantity'] - $already_returned;
            if ($remaining > 0) {
                $stock_out_warehouse_id = (int)($item['warehouse_id'] ?? 0);
                $stock_out_id           = (int)($item['stock_out_id'] ?? 0);

                if ($stock_out_warehouse_id > 0 && $stock_out_id > 0) {
                    $table = 'td_stock_' . $stock_out_warehouse_id;
                    $sth = $pdo2->prepare(
                        "SELECT id, status, zone, aisle, rack, lot_number, serial_number
                         FROM `{$table}`
                         WHERE company_id = :company_id
                           AND id         = :id
                           AND type       = 'out'
                         LIMIT 1"
                    );
                    $sth->execute([
                        ':company_id' => $company_id,
                        ':id'         => $stock_out_id,
                    ]);
                    $stock_out = $sth->fetch(PDO::FETCH_ASSOC);

                    if ($stock_out) {
                        $item['zone']              = $stock_out['zone']          ?? ($item['zone'] ?? '');
                        $item['aisle']             = $stock_out['aisle']         ?? ($item['aisle'] ?? '');
                        $item['rack']              = $stock_out['rack']          ?? ($item['rack'] ?? '');
                        $item['lot_number']        = $stock_out['lot_number']    ?? ($item['lot_number'] ?? '');
                        $item['serial_number']     = $stock_out['serial_number'] ?? ($item['serial_number'] ?? '');
                        $item['stock_out_status']  = (int)$stock_out['status'];
                    }
                }

                $returnable[] = array_merge($item, [
                    'item_id'                => $i,
                    'original_qty'           => (float)$item['quantity'],
                    'returned_qty'           => $already_returned,
                    'returnable_qty'         => $remaining,
                    'stock_out_warehouse_id' => $stock_out_warehouse_id,
                    'stock_out_status'       => (int)($item['stock_out_status'] ?? 0),
                ]);
            }
        }

        $answer['returnable_items'] = $returnable;
    } else {
        $answer['output'] = $order->getOrderList();
    }

    $answer['success'] = 1;
    exit(json_encode($answer));
?>