Wordpress front-end media upload

Front-end-upload.php

<form action="<?php echo esc_url( admin_url('admin-post.php') ); ?>" method="post" enctype="multipart/form-data">
    <!-- Security field -->
    <?php wp_nonce_field( 'media_upload', 'media_upload_nonce' ); ?>
    
    <label for="file_upload">Select File:</label>
    <input type="file" name="file_upload" id="file_upload" required />
    <input type="hidden" name="action" value="frontend_media_upload">
    <input type="submit" name="submit" value="Upload Media" />
</form>
<?php

function handle_frontend_media_upload() {
    // Verify nonce for security
    if ( ! isset( $_POST['media_upload_nonce'] ) || ! wp_verify_nonce( $_POST['media_upload_nonce'], 'media_upload' ) ) {
        wp_die( 'Security check failed.' );
    }

    // Check if file was uploaded
    if ( empty( $_FILES['file_upload'] ) ) {
        wp_die( 'No file selected.' );
    }

    // Required WordPress files for media handling
    require_once( ABSPATH . 'wp-admin/includes/file.php' );
    require_once( ABSPATH . 'wp-admin/includes/image.php' );
    require_once( ABSPATH . 'wp-admin/includes/media.php' );

    // Handle the upload using the built-in WordPress function
    $upload = wp_handle_upload( $_FILES['file_upload'], array( 'test_form' => false ) );

    if ( ! empty( $upload['error'] ) ) {
        wp_die( $upload['error'] );
    }

    // Insert the uploaded file into the media library
    $attachment_id = wp_insert_attachment(
        array(
            'guid'           => $upload['url'],
            'post_mime_type' => $upload['type'],
            'post_title'     => basename( $upload['file'] ),
            'post_content'   => '',
            'post_status'    => 'publish',
        ),
        $upload['file']
    );

    if ( is_wp_error( $attachment_id ) || ! $attachment_id ) {
        wp_die( 'Error adding file to media library.' );
    }

    // Generate metadata and image sizes (essential for images)
    wp_update_attachment_metadata(
        $attachment_id,
        wp_generate_attachment_metadata( $attachment_id, $upload['file'] )
    );

    // Redirect the user after successful upload
    wp_safe_redirect( home_url( '/curriculum-vitae/' ) ); // Redirect back to the front page
    exit;
}

// Hook the function to the 'admin_post_' action specified in the form
add_action( 'admin_post_frontend_media_upload', 'handle_frontend_media_upload' );
add_action( 'admin_post_nopriv_frontend_media_upload', 'handle_frontend_media_upload' ); // For logged out users

?>