dynamic-discount-coupon.php

<?php

class pisol_example_of_dynamic_coupon{
	function __construct(){
		add_action('woocommerce_before_calculate_totals', array($this,'applyDiscountCode'));
		add_filter('woocommerce_get_shop_coupon_data', array($this, 'addDiscountCouponData'),10,3);
	}

	function applyDiscountCode(WC_Cart $cart){
		if($this->userSelectedLocalPickup()){
        	$cart->applied_coupons[] = "pisol-discount";
		}
    }

	function addDiscountCouponData($false, $data, $coupon){
        if(!function_exists('WC') || !isset(WC()->cart) || strpos($data,'pisol-discount') === false ) return $false;

		if($this->userSelectedLocalPickup()){
			$coupon->set_discount_type('fixed_cart');
			$coupon->set_amount(10);
			return $coupon;
		}
			
		WC()->cart->remove_coupon( $data );
		return $false;
	}

	function userSelectedLocalPickup(){
        $chosen_methods = WC()->session->get( 'chosen_shipping_methods' );
        $chosen_shipping_no_ajax = $chosen_methods[0];
        if ( 0 === strpos( $chosen_shipping_no_ajax, 'local_pickup' ) ) {
            return true;
        }
        return false;
    }
	
}

new pisol_example_of_dynamic_coupon();