(REQUEST) Advanced Coupons

add_action( 'woocommerce_before_cart', 'custom_coupon_messages' );
add_action( 'woocommerce_before_checkout_form', 'custom_coupon_messages' );
function custom_coupon_messages() {
    global $woocommerce;
    //Set coupon codes.
    $coupon_code = 'Your-Coupon-here';
    //Set coupon objects.
    $coupon_test = new WC_Coupon( 'Your-Coupon-here' );
    //Get the cart subtotal. Should return as a Double.
    $cart_subtotal = WC()->cart->subtotal;
    //If coupon test is passed add coupon.
    if ( $coupon_test->is_valid() && $woocommerce->cart->has_discount( $coupon_code ) ) {
        //Filter the coupon success message to display a custom message.
        add_filter( 'woocommerce_coupon_message', 'filter_woocommerce_coupon_message', 10, 3 );
        function filter_woocommerce_coupon_message( $msg, $msg_code, $instance ) {
            //Set a custom coupon message.
            $msg_code = 'case self::WC_COUPON_SUCCESS';
            $msg = __( 'Your message here!', 'your-theme-text-domain' );
            return $msg;
            return $msg_code;
            //Or return nothing (no message will be displayed - comment out the above/uncomment below).
            // return '';
        };
        //Print the above notice to screen.
        wc_print_notices();
    }
    elseif ( $cart_subtotal > 499 ) {
        //Print a notice (the blue boxed one)
        wc_print_notice( 'Spend $500 to qualify for the BIGLY YUGE discount!!!', 'notice' );
    }
}