WooCommerce cart discount on second item with coupon code - php

Question

I am trying to implement a rule to make discounts on products depending on the quantity of products and with a coupon code, taking into account the following points:
With the application of a code the second item has a discount of 40%, the discount must be applied to the item of lesser value, if 4 products are purchased, the discount must be applied to the 2 items of lesser value and so on.
Try this code but it only applies to the second item and doesn't take into account if there are more than 4 items
add_filter( 'woocommerce_coupon_get_discount_amount',
'filter_wc_coupon_get_discount_amount', 10, 5 );
function filter_wc_coupon_get_discount_amount( $discount_amount,
$discounting_amount, $cart_item, $single, $coupon ) {
// Define below your existing coupon code
$coupon_code = 'coupon_code';
// Only for a defined coupon code
if( strtolower( $coupon_code ) !== $coupon->get_code() )
return $discount_amount;
$items_prices = [];
$items_count = 0;
// Loop through cart items
foreach( WC()->cart->get_cart() as $key => $item ){
// Get the cart item price (the product price)
if ( wc_prices_include_tax() ) {
$price = wc_get_price_including_tax( $item['data'] );
} else {
$price = wc_get_price_excluding_tax( $item['data'] );
}
if ( $price > 0 ){
$items_prices[$key] = $price;
$items_count += $item['quantity'];
}
}
// Only when there is more than one item in cart
if ( $items_count > 1 ) {
asort($items_prices); // Sorting prices from lowest to highest
$item_keys = array_keys($items_prices);
$item_key = reset($item_keys); // Get current cart item key
// Targeting only the current cart item that has the lowest price
if ( $cart_item['key'] == $item_key ) {
return $discount_amount; // return discount
}
} else {
return 0;
}
}