Combo RTL

functions.php

/**
 * Applies a combo discount when specific products are in the cart.
 *
 * This function checks if two or more products with the specified product IDs are in the cart.
 * If both products are present, a discount is applied as a negative fee.
 *
 * @param WC_Cart $cart The WooCommerce cart instance.
 */
function apply_discount_on_combo( $cart ) {
    if ( is_admin() && ! defined( 'DOING_AJAX' ) ) {
        return;
    }

    $product_id1 = 360894; // epp
    $product_id2 = 360773; // oap

		$product_id3 = 3037; // mycotoxin

		$product_id4 = 357953; // Glyphosate

		$product_id5 = 3171; // Environmental Mycotoxin Panel
		$product_id6 = 359895; // Fungal Count Dx


		$oap_epp_discount_amount = 60;
		$tox_complete_discount_amount = 150;
		$tox_complete_plus_discount_amount = 229;
		$emma_combo_discount_amount = 119;

    // Check if both products are in the cart
    $product1_in_cart = false;
    $product2_in_cart = false;
		$product3_in_cart = false;
		$product4_in_cart = false;
		$product5_in_cart = false;
		$product6_in_cart = false;

    foreach ( $cart->get_cart() as $cart_item ) {
        if ( $cart_item['product_id'] == $product_id1 ) {
            $product1_in_cart = true;
        }
        if ( $cart_item['product_id'] == $product_id2 ) {
            $product2_in_cart = true;
        }
				if ( $cart_item['product_id'] == $product_id3 ) {
            $product3_in_cart = true;
        }
				if ( $cart_item['product_id'] == $product_id4 ) {
            $product4_in_cart = true;
        }
				if ( $cart_item['product_id'] == $product_id5 ) {
            $product5_in_cart = true;
        }
				if ( $cart_item['product_id'] == $product_id6 ) {
            $product6_in_cart = true;
        }
    }


		// Apply the discount if 4 products are in the cart
    if ( $product1_in_cart && $product2_in_cart && $product3_in_cart && $product4_in_cart ) {
        $cart->add_fee( 'RTL Tox Complete Plus Panel Discount', -$tox_complete_plus_discount_amount );
    }

		// Apply the discount if 3 products are in the cart
    elseif ( $product1_in_cart && $product2_in_cart && $product3_in_cart ) {
        $cart->add_fee( 'RTL Tox Complete Panel Discount', -$tox_complete_discount_amount );
    }

		// Apply the discount if both products are in the cart
    elseif ( $product1_in_cart && $product2_in_cart ) {
        $cart->add_fee( 'OAP+EPP Combo Discount', -$oap_epp_discount_amount );
    }

		// Apply the discount if both products are in the cart
    elseif ( $product5_in_cart && $product6_in_cart ) {
        $cart->add_fee( 'EMMA Combo Discount', -$emma_combo_discount_amount );
    }
}
add_action( 'woocommerce_cart_calculate_fees', 'apply_discount_on_combo', 10, 1 );