wordpress remove gift product on cart total change - php

Question

using the code found on Internet, works perfectly, but it needs to be updated with extra function.
now: if total sum gets 100+ free gift is added. if user removes some products and total gets lower than 100, free gift still stays there
should be: if user removes products and total gets lower than 100, free gift is removed
function aapc_add_product_to_cart() {
global $woocommerce;
$cart_total = 100;
if ( $woocommerce->cart->total >= $cart_total ) {
if ( ! is_admin() ) {
$free_product_id = 6663; // Product Id of the free product which will get added to cart
$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() == $free_product_id )
$found = true;
}
// if product not found, add it
if ( ! $found )
WC()->cart->add_to_cart( $free_product_id );
} else {
// if no products in cart, add it
WC()->cart->add_to_cart( $free_product_id );
}
}
}
}
add_action( 'template_redirect', 'aapc_add_product_to_cart' );

Answer 1

this works
add_action( 'woocommerce_before_calculate_totals', 'add_or_remove_cart_items', 10, 1 );
function add_or_remove_cart_items( $cart ) {
if ( is_admin() && ! defined( 'DOING_AJAX' ) )
return;
// ONLY for logged users (and avoiding the hook repetition)
if ( ! is_user_logged_in() && did_action( 'woocommerce_before_calculate_totals' ) >= 2 )
return;
$threshold_amount = 99.9; // The threshold amount for cart total
$free_product_id = 6663; // ID of the free product
$cart_items_total = 0; // Initializing
// Loop through cart items
foreach ( $cart->get_cart() as $cart_item_key => $cart_item ){
// Check if the free product is in cart
if ( $cart_item['data']->get_id() == $free_product_id ) {
$free_item_key = $cart_item_key;
}
// Get cart subtotal incl. tax from items (with discounts if any)
$cart_items_total += $cart_item['line_total'] + $cart_item['line_tax'];
}
// If Cart total is up to the defined amount and if the free products is not in cart, we add it.
if ( $cart_items_total >= $threshold_amount && ! isset($free_item_key) ) {
$cart->add_to_cart( $free_product_id );
}
// If cart total is below the defined amount and free product is in cart, we remove it.
elseif ( $cart_items_total remove_cart_item( $free_item_key );
}
}