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

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

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