Woocommerce 使用FORM数据格式将订单详细信息发送到外部API

我正在尝试将订单详细信息从woocommerce发送到外部API。 它可以很好地处理原始json，但是我很难发送文件格式，比如上传图片 我做了一些研究，它说需要使用表单数据，我已经将API更改为表单数据类型 但是它不能很好地与代码配合使用

/* after an order has been processed, we will use the  'woocommerce_thankyou' hook, to add our function, to send the data */
add_action('woocommerce_thankyou', 'wdm_send_order_to_ext'); 
function wdm_send_order_to_ext( $order_id ){
    // get order object and order details
    $order = new WC_Order( $order_id ); 
    $email = $order->billing_email;
    $phone = $order->billing_phone;
    $shipping_type = $order->get_shipping_method();
    $shipping_cost = $order->get_total_shipping();

    // set the address fields
    $user_id = $order->user_id;
    $address_fields = array('country',
        'title',
        'first_name',
        'last_name',
        'company',
        'address_1',
        'address_2',
        'address_3',
        'address_4',
        'city',
        'state',
        'postcode');

    $address = array();
    if(is_array($address_fields)){
        foreach($address_fields as $field){
            $address['billing_'.$field] = get_user_meta( $user_id, 'billing_'.$field, true );
            $address['shipping_'.$field] = get_user_meta( $user_id, 'shipping_'.$field, true );
        }
    }
    
    // get coupon information (if applicable)
    $cps = array();
    $cps = $order->get_items( 'coupon' );
    
    $coupon = array();
    foreach($cps as $cp){
            // get coupon titles (and additional details if accepted by the API)
            $coupon[] = $cp['name'];
    }
    
    // get product details
    $items = $order->get_items();
    
    $item_name = array();
    $item_qty = array();
    $item_price = array();
    $item_sku = array();
        
    foreach( $items as $key => $item){
        $item_name[] = $item['name'];
        $item_qty[] = $item['qty'];
        $item_price[] = $item['line_total'];
        
        $item_id = $item['product_id'];
        $product = new WC_Product($item_id);
        $item_sku[] = $product->get_sku();
    }
    
    /* for online payments, send across the transaction ID/key. If the payment is handled offline, you could send across the order key instead */
    $transaction_key = get_post_meta( $order_id, '_transaction_id', true );
    $transaction_key = empty($transaction_key) ? $_GET['key'] : $transaction_key;   
    
    // set the username and password
    $api_username = 'testuser';
    $api_password = 'testpass';

    // to test out the API, set $api_mode as ‘sandbox’
    $api_mode = 'sandbox';
    if($api_mode == 'sandbox'){
        // sandbox URL example
        $endpoint = "http://sandbox.example.com/"; 
    }
    else{
        // production URL example
        $endpoint = "http://example.com/"; 
    }

        // setup the data which has to be sent
    $data = array(
            'apiuser' => $api_username,
            'apipass' => $api_password,
            'customer_email' => $email,
            'customer_phone' => $phone,
            'bill_firstname' => $address['billing_first_name'],
            'bill_surname' => $address['billing_last_name'],
            'bill_address1' => $address['billing_address_1'],
            'bill_address2' => $address['billing_address_2'],
            'bill_city' => $address['billing_city'],
            'bill_state' => $address['billing_state'],
            'bill_zip' => $address['billing_postcode'],
            'ship_firstname' => $address['shipping_first_name'],
            'ship_surname' => $address['shipping_last_name'],
            'ship_address1' => $address['shipping_address_1'],
            'ship_address2' => $address['shipping_address_2'],
            'ship_city' => $address['shipping_city'],
            'ship_state' => $address['shipping_state'],
            'ship_zip' => $address['shipping_postcode'],
            'shipping_type' => $shipping_type,
            'shipping_cost' => $shipping_cost,
            'item_sku' => implode(',', $item_sku), 
            'item_price' => implode(',', $item_price), 
            'quantity' => implode(',', $item_qty), 
            'transaction_key' => $transaction_key,
            'coupon_code' => implode( ",", $coupon )
        );

            // send API request via cURL
        $ch = curl_init();

        /* set the complete URL, to process the order on the external system. Let’s consider http://example.com/buyitem.php is the URL, which invokes the API */
        curl_setopt($ch, CURLOPT_URL, $endpoint."buyitem.php");
        curl_setopt($ch, CURLOPT_POST, 1);
        curl_setopt($ch, CURLOPT_POSTFIELDS, http_build_query($data));
        curl_setopt($ch, CURLOPT_RETURNTRANSFER, true);
    
        $response = curl_exec ($ch);
    
        curl_close ($ch);
        
        // the handle response    
        if (strpos($response,'ERROR') !== false) {
                print_r($response);
        } else {
                // success
        }
 }

因此，我认为需要对代码进行一些调整

——使用Guzzle之类的东西向API发送请求。