WooCommerce: Filter gateways by product ID

functions.php

<?php

// Filter gateways by product ID

add_filter('woocommerce_available_payment_gateways', 'cg_filter_gateways', 1);
function cg_filter_gateways($gateways) {
	global $woocommerce;
	$authorized_products = array(1,2,5);
	$gateways_to_unset = array('paypal', 'cielo');
	$unset_gateways = true;
	
	foreach ($woocommerce->cart->cart_contents as $key => $values ) {
		// Store product id's in array
		if(in_array($values['product_id'], $authorized_products)){
			$unset = false;
		}
	}
	
	if($unset) {
		foreach($gateways_to_unset as $gw) {
		  unset($gateways[$gw]);
		}
	}

	return $gateways;
}