API problem?

Question

PHP

Krch, I wrote a bot in VK that responds to a message, but the problem is that it can respond to one message several times, how can I fix it? Code below

if (!isset($_REQUEST))
  {
    return;
  }
$data = json_decode(file_get_contents('php://input'));

  switch ($data->type) 
  {
    case 'confirmation':

    echo $cal_string;

    header("HTTP/1.1 200 OK");

    break;
   
    case'message_new':
 
    $text = $data->object->text;
    $user_id = $data->object->from_id;
    $user_info = json_decode(file_get_contents("https://api.vk.com/method/users.get?user_ids={$user_id}&access_token={$key}&v=5.101"));
    $user_name = $user_info->response[0]->first_name;

        $params = array(
        'message' => "Привет, $user_name!",
        'access_token' => $key,
        'user_id' => $user_id,
        'v' => '5.101',
        'random_id' =>  rand()
        );

        $get_params = http_build_query($params);

        file_get_contents('https://api.vk.com/method/messages.send?'. $get_params);

    echo 'ok';

    header("HTTP/1.1 200");
    
    break;

Answer 1

Extra:

if (!isset($_REQUEST))
{
  return;
}

after:

<?php
$data = json_decode(file_get_contents('php://input'), true);
switch ($data['type']) 
{
  case 'confirmation': 
  {
    echo $cal_string;
    break;
  }
  case'message_new':
  {
    echo 'ok';
    fastcgi_finish_request();
    $text = $data['object']['text'];
    $user_id = $data['object']['from_id'];
    $user_info = json_decode(file_get_contents("https://api.vk.com/method/users.get?user_ids={$user_id}&access_token={$key}&v=5.101"));
    $user_name = $user_info['response'][0]['first_name'];
    $params = [
      'message' => urlencode("Привет, $user_name!"),
      'access_token' => $key,
      'user_id' => $user_id,
      'v' => '5.101',
    ];
    $get_params = http_build_query($params);
    file_get_contents('https://api.vk.com/method/messages.send?'. $get_params);
    break;
  }
}
?>