Migrate images form a Magic Fields to ACF (inside a wordpress loop)

gistfile1.php

<?php

$photo_name = get_field("cover");

if ($photo_name != "") {
    
    $ff         = '/Users/mosne/Sites/Dropbox/mosne.local/wp-content/files_mf/' . $photo_name;
    $handle     = fopen($ff, "r");
    $ffcontents = fread($handle, filesize($ff));
    $attachment = wp_upload_bits($photo_name, null, $ffcontents);
    
    $filetype = wp_check_filetype(basename($attachment['file']), null);
    
    $postinfo = array(
        'post_mime_type' => $filetype['type'],
        'post_title' => $post->post_title . ' ' . "cover",
        'post_content' => '',
        'post_status' => 'inherit'
    );
    echo $filename = $attachment['file'];
    echo $attach_id = wp_insert_attachment($postinfo, $filename, $post->ID);
    
    if (!function_exists('wp_generate_attachment_data'))
        require_once(ABSPATH . "wp-admin" . '/includes/image.php');
    $attach_data = wp_generate_attachment_metadata($attach_id, $filename);
    wp_update_attachment_metadata($attach_id, $attach_data);
    
    update_post_meta($post->ID, "_cover_new", "field_53aed7e7a7ff5");
    update_post_meta($post->ID, "cover_new", $attach_id);
    update_field("field_53aed7e7a7ff5", $attach_id, $post->ID);
}
?>