Get product IDS that are in sale for woocommerce product query

Hello,

I am trying to display the discounted products on my sale page, the sale page is simply a filter on the woocommerce_product_query hook.

Woocommerce has a function which returns all the product ID’s that are on sale. I’ve tried to loop through all the products with the advanced_woo_discount_rules_get_product_discount_price_from_custom_price filter (see bottom), but that results in a 500 error.

function bd_change_product_query( $q ){
	if($_GET['filter'] == 'sale'){
		$id_s = wc_get_product_ids_on_sale();
		
		$q->set( 'post__in', (array) $id_s );
	}

}
add_action( 'woocommerce_product_query', 'bd_change_product_query' );

Looping through all products:

$args     = array( 'post_type' => 'product', 'posts_per_page' => -1 );
$products = get_posts( $args ); 
foreach($products as $p){

$discounted_price = apply_filters('advanced_woo_discount_rules_get_product_discount_price_from_custom_price', false, $product, 1, 0, 'all', true);
$wooco_discounted_price = $product->get_sale_price();

if ($discounted_price !== false) {
    if ($discounted_price['discounted_price']  > 0) { 
        // woo discount rule, here I want to push the ID to a array
    } elseif ($wooco_discounted_price > 0) {
        // woocommerce discount
    }
}
}