Add fees to the WooCommerce cart, based on the state chosen for shipping

woocommerce-fees-by-state.php

<?php
/**
 * Plugin Name: WooCommerce - Fees by State
 * Plugin URI:  https://filament-studios.com/
 * Description: Add Fees to the cart based off the shipping state
 * Version:     1.0
 * Author:      Filament Studios
 * Author URI:  https://filament-studios.com
 * License:     GPL-2.0+
 */

if ( ! defined( 'ABSPATH' ) ) {
	exit;
}

function fs_per_state_fees() {
	global $woocommerce;

	$packages = $woocommerce->shipping->packages;
	$state_fees = array(
		'CA' => array( // Start of CA fees
			'amount'     => 2,
			'is_taxable' => false,
			'name'       => __( 'CA Fee', 'woo-psf' ),
		), // End of CA Fees
		'AZ' => array( // Start of AZ fees
			'amount'     => 3.25,
			'is_taxable' => true,
			'name'       => __( 'AZ Fee', 'woo-psf' ),
		), // End of AZ fees
	);

	foreach ( $packages as $package ) {
		$state = ! empty( $package['destination']['state'] ) ? strtoupper( $package['destination']['state'] ) : false;

		if ( ! empty( $state ) && array_key_exists( $state, $state_fees ) ) {

			$fee        = $state_fees[ $state ]['amount'];
			$is_taxable = $state_fees[ $state ]['is_taxable'];
			$name       = $state_fees[ $state ]['name'];

			if ( ! empty( $fee ) ) {
				$woocommerce->cart->add_fee( $name, $fee, $is_taxable, '' );
			}

		}
	}

}
add_action( 'woocommerce_cart_calculate_fees', 'fs_per_state_fees' );