Programmatically creates CommerceOrder on D8

gistfile1.txt

  // {
  //   "mail": "testrest@test.com",
  //   "uid": 1,
  //   "store_id": 1,
  //   "order_items": [
  //	   {"title": "restTitle1", "quantity": 2, "unit_price": {"number": "23.45", "currency_code": "CNY"}, "total_price": {"number": "46.9", "currency_code": "CNY"}},
  //	   {"title": "restTitle2", "quantity": 3, "unit_price": {"number": "10.01", "currency_code": "CNY"}, "total_price": {"number": "30.03", "currency_code": "CNY"}},
  //	   {"title": "restTitle3", "quantity": 4, "unit_price": {"number": "0.2", "currency_code": "CNY"}, "total_price": {"number": "0.8", "currency_code": "CNY"}}
  //	 ]
  // }
  
  /** Command to test
  * curl -X POST -H "Authorization: Basic dGVzdDp0ZXN0" -H "Content-Type: application/json" -H "Cache-Control: no-cache" -d '{
  * "mail": "testrest@test.com",
  * "uid": 1,
  * "store_id": 1,
  * "field_de_business_id": 43,
  * "field_de_store_id": 75,
  * "placed": 1420070400,
  * "order_items": [
  * 	{"title": "restTitle1", "quantity": 2, "unit_price": {"number": "23.45", "currency_code": "CNY"}, "total_price": {"number": "46.9", "currency_code": "CNY"}},
  * 	{"title": "restTitle2", "quantity": 3, "unit_price": {"number": "10.01", "currency_code": "CNY"}, "total_price": {"number": "30.03", "currency_code": "CNY"}},
  * 	{"title": "restTitle3", "quantity": 4, "unit_price": {"number": "0.2", "currency_code": "CNY"}, "total_price": {"number": "0.8", "currency_code": "CNY"}}
  *	]
  * }' "http://insready.com:8080/custom/entity/commerce_order"
  */
  
  public function post($body, $request) {

    $order_data = [
      'type' => 'default',
      'mail' => $body['mail'],
      'uid' => [$body['uid']],
      'store_id' => [$body['store_id']],
    ];
    if (!empty($body['custom_placed_date']) && !empty($body['placed'])) {
      $order_data['placed'] = $body['placed']->getTimestamp();
    }
    $order = Order::create($order_data);
    $order->save();

    foreach ($body['order_items'] as $item) {
      $item['order_id'] = intval($order->id());
      $item['type'] = 'default';
      $order_item = OrderItem::create($item);
      $order_item->save();
      $order->addItem($order_item);
    }
    
    $order->save();

    return new ResourceResponse("{'order_id': " . $order->id() ."}");
  }