add_action( 'wp_loaded', 'auto_add_auctions_to_cart', 10 );

function auto_add_auctions_to_cart() {
	if ( ! is_admin() && is_user_logged_in() ) {
		$user_id = get_current_user_id();
		$args    = array(
			'post_type'          => 'product',
			'posts_per_page'     => '-1',
			'order'              => 'ASC',
			'orderby'            => 'meta_value',
			'meta_key'           => '_auction_dates_to',
			'meta_query'         => array(
				array(
					'key'   => '_auction_closed',
					'value' => 2,
				),
				array(
					'key'   => '_auction_current_bider',
					'value' => $user_id,
				),
				array(
					'key'     => '_auction_payed',
					'compare' => 'NOT EXISTS',
				),
			),
			'show_past_auctions' => true,
			'auction_arhive'     => true,
			'fields'                 => 'ids',
			'no_found_rows'          => true,
			'update_post_meta_cache' => false,
			'update_post_term_cache' => false,
		);

		$winningloop = new WP_Query( $args );

		$posts_ids = $winningloop->posts;
		if ( is_array( $posts_ids ) ) {

			foreach ( $posts_ids as $posts_id ) {
				$found = false;
				//check if product already in cart
				if ( sizeof( WC()->cart->get_cart() ) > 0 ) {
					foreach ( WC()->cart->get_cart() as $cart_item_key => $values ) {
						$_product = $values['data'];
						if ( $_product->get_id() == $posts_id ) {
							$found = true;
						}
					}
					// if product not found, add it
					if ( ! $found ) {
						WC()->cart->add_to_cart( $posts_id );
					}
				} else {
					// if no products in cart, add it
					WC()->cart->add_to_cart( $posts_id );
				}
			}
		}
	}
}