Rename WordPress media file name when doing upload

functions.php

<?php
/**
 * Rename file name while doing upload.
 *
 * @param string $filename The name of the file being uploaded
 *
 * @return  string    The sanitized string
 */
function my_custom_file_name( $filename ) {
    $info = pathinfo( $filename );
    $ext  = empty( $info['extension'] ) ? '' : '.' . $info['extension'];
    $name = basename( $filename, $ext );

    if ( isset( $_REQUEST['post_id'] ) && is_numeric( $_REQUEST['post_id'] ) ) {
        $postObj  = get_post( $_REQUEST['post_id'] );
        $postSlug = sanitize_title( $postObj->post_title );
    }

    if ( isset( $postSlug ) && ! empty( $postSlug ) && $postSlug != 'rascunho-automatico' ) {
        $finalFileName = $postSlug;
    } // File name will be the same as the post slug.
    else {
        $finalFileName = sanitize_title( $name );
    } // File name will be the same as the image file name, but sanitized.

    return $finalFileName . $ext;
}

add_filter( 'sanitize_file_name', 'my_custom_file_name', 100 );