Setup minimum order amount

/**
 * Set a minimum order amount for checkout
 */
if (!function_exists('tzn_wc_minimum_order_amount')) {
    add_action( 'woocommerce_checkout_process', 'tzn_wc_minimum_order_amount' );
    function tzn_wc_minimum_order_amount() {
        $minimum = 35;
		$total_cart = tzn_priceToFloat(WC()->cart->get_cart_subtotal());
        if ( $total_cart < $minimum ) {
            wc_add_notice(sprintf( 'Der Mindestbestellwert beträgt %s' , $minimum.get_woocommerce_currency_symbol()), 'error');
        }
    }
}
// show alert minimum amount mini cart and cart
if (!function_exists('tzn_custom_woocommerce_after_cart_totals')) {
    add_action('woocommerce_cart_totals_after_order_total', 'tzn_custom_woocommerce_after_cart_totals', 8);
    
    function tzn_custom_woocommerce_after_cart_totals() {
        $minimum = 35;
		$total_cart = tzn_priceToFloat(WC()->cart->get_cart_subtotal());
        if ( $total_cart < $minimum ) {
            echo '<p class="inner-container notification-minimum-amount"><img src="' . get_stylesheet_directory_uri() . '/assets/images/ionic-ios-information-circle.svg" alt=""/>' . sprintf(__("Der Mindestbestellwert beträgt %s", 'tzn'), $minimum.get_woocommerce_currency_symbol()) . '</p>';
        }
    }
}
function tzn_priceToFloat($s){
    $s = str_replace(',', '.', $s);
    $s = preg_replace("/[^0-9\.]/", "", $s);
    $s = str_replace('.', '',substr($s, 0, -3)) . substr($s, -3);
    return $s;
}