Wordpress Watermark system (use Regenerate Thumbnail after apply)

watermarked.php

<?php

// 
// Source: https://wordpress.org/support/article/debugging-in-wordpress/
// 

function register_watermarked_size() {
      add_theme_support( 'post-thumbnails' );
      add_image_size( 'watermarked', 550, 550, true ); 
}
    
add_action( 'init', 'register_watermarked_size' );


function save_watermarked_image( $image_resource, $original_image_path ) {

      $image_data = pathinfo( $original_image_path );
    
      $new_filename = $image_data['filename'] . '-watermarked.' . $image_data['extension'];
    
      $watermarked_image_path = str_replace($image_data['basename'], $new_filename, $original_image_path);
    
      if ( ! $image_resource->writeImage( $watermarked_image_path ) )
        return $image_data['basename'];
    
      unlink( $original_image_path );
    
      return $new_filename;
    
}


function watermark_image( $filename, $upload_dir ) {

      $original_image_path = trailingslashit( $upload_dir['path'] ) . $filename;
    
      $image_resource = new Imagick( $original_image_path );
      // $image_resource->blurImage( 20, 10 );
    
      $watermark_resource = new Imagick( URL_ASSETS . '/img/waterh.png' );
      $watermark_resource->scaleImage(300, 300, true);
      // $image_resource->compositeImage( $watermark_resource, Imagick::COMPOSITE_DEFAULT, 100, 250 );

      $image_resource = $image_resource->textureImage($watermark_resource);
    
      return save_watermarked_image( $image_resource, $original_image_path );
    
}


function generate_watermarked_image( $meta ) {

      $time = substr( $meta['file'], 0, 7); // Extract the date in form "2015/04"
      $upload_dir = wp_upload_dir( $time );

      $filename = $meta['sizes']['watermarked']['file'];
      $meta['sizes']['watermarked']['file'] = watermark_image( $filename, $upload_dir );

      return $meta;

}
add_filter( 'wp_generate_attachment_metadata', 'generate_watermarked_image' );