wp_insert_post multi upload Images

I want to upload multiple images with wp_insert_post but only the last image of multiple uploads insert there other images uploaded but didn’t attach there…

Here is code

<form action="#" method="post" enctype="multipart/form-data">
   <input type="file" name="agp_gallery[]" id="agp_image_files" style="width:90%; margin-left:5px;" multiple>
</form>

Here is function multiupload

if ( $_FILES ) {
    $files = $_FILES['agp_gallery'];
    foreach ($files['name'] as $key => $value) {
       if ($files['name'][$key]) {
          $file = array(
            'name' => $files['name'][$key],
            'type' => $files['type'][$key],
            'tmp_name' => $files['tmp_name'][$key],
            'error' => $files['error'][$key],
            'size' => $files['size'][$key]
          );
     
          $_FILES = array("agp_gallery" => $file);
     
          foreach ($_FILES as $file => $array) {
        
              agp_process_wooimage($file, $post_id, $result['caption']);
          }
       }
    }
 }
    

Here is main function

function agp_process_wooimage($file, $post_id, $caption){
    
  if ($_FILES[$file]['error'] !== UPLOAD_ERR_OK) __return_false();
 
  require_once(ABSPATH . "wp-admin" . '/includes/image.php');
  require_once(ABSPATH . "wp-admin" . '/includes/file.php');
  require_once(ABSPATH . "wp-admin" . '/includes/media.php');
 
  $attachment_id = media_handle_upload($file, $post_id);
 
  update_post_meta($post_id, '_product_image_gallery', $attachment_id);

  $attachment_data = array(
    'ID' => $attachment_id,
    'post_excerpt' => $caption
  );
  
  wp_update_post($attachment_data);

  return $attachment_id;

}   

I get this above code from here:-

http://madebyraygun.com/blog/2012/upload-and-attach-multiple-images-from-the-wordpress-front-end/

and all code here:

http://wp.tutsplus.com/tutorials/allow-users-to-submit-images-your-site/