<?php

// Ensure the file is not accessed directly.
if ( ! defined( 'ABSPATH' ) ) {
	exit;
}

use Disco\App\Disco;

if ( ! function_exists( 'disco_add_free_shipping_rate' ) ) {

	/**
	 * Add free shipping rate to the package. If any campaign matches, then apply free shipping.
     *
	 * @param array $rates Array of rates found for the package.
	 * @return array
	 */
	function disco_add_free_shipping_rate( $rates ) {
		$is_free_shipping = ( new Disco )->apply_free_shipping( WC()->cart );

		if ( ! $is_free_shipping ) {
			return $rates;
		}

		foreach ( $rates as $rate_id => $rate ) {
			if ( 'free_shipping' === $rate->method_id ) {
				return $rates;
			}
		}

		// If free shipping is not available, override rates with free shipping
		// TODO: Add Label from campaign
		$free_shipping_rate           = new WC_Shipping_Rate( 'disco_free_shipping', __( 'Free Shipping', 'disco' ), 0, array(), 'disco_free_shipping' );
		$rates['disco_free_shipping'] = $free_shipping_rate;

		return $rates;
	}

	add_filter( 'woocommerce_package_rates', 'disco_add_free_shipping_rate', 100, 1 );
}

if ( ! function_exists( 'disco_refresh_shipping_cache_on_cart_checkout' ) ) {

	/**
	 * Force WooCommerce to recalculate shipping rates on the cart and checkout pages.
	 *
	 * Disco adds/removes the disco_free_shipping rate through the
	 * woocommerce_package_rates filter based on the current campaign state, but
	 * WooCommerce caches the calculated package rates in the customer session
	 * keyed by a hash of the cart contents only - campaign state is NOT part of
	 * that hash. So when a campaign is activated or deactivated, an existing
	 * session keeps serving the stale cached rates: a lingering disco_free_shipping
	 * rate after deactivation, or a chosen shipping method that no longer exists,
	 * which makes the shipping options appear hidden or broken until the cart
	 * contents change.
	 *
	 * Clearing this session's cached package rates whenever the cart or checkout
	 * page is viewed forces a fresh calculation that reflects the current campaign
	 * state, for this customer only (no global cache flush).
	 *
	 * @return void
	 */
	function disco_refresh_shipping_cache_on_cart_checkout() {
		if ( is_admin() || ! function_exists( 'is_cart' ) || ! function_exists( 'WC' ) ) {
			return;
		}

		if ( ! is_cart() && ! is_checkout() ) {
			return;
		}

		$session = WC()->session;
		$cart    = WC()->cart;

		if ( ! $session instanceof WC_Session || ! $cart instanceof WC_Cart ) {
			return;
		}

		// Invalidate the cached rates for every shipping package in this session.
		// The package keys match the keys WooCommerce uses when it stores rates
		// under 'shipping_for_package_{key}', so setting them to false makes
		// WC_Shipping::calculate_shipping_for_package() recalculate instead of
		// returning the stale cached rates.
		foreach ( array_keys( $cart->get_shipping_packages() ) as $package_key ) {
			$session->set( 'shipping_for_package_' . $package_key, false );
		}

		$cart->calculate_shipping();
	}

	add_action( 'template_redirect', 'disco_refresh_shipping_cache_on_cart_checkout' );
}