<?php
/**
 * Facts payment and shipping rules check.
 *
 * @package AdminPowerups
 */

namespace SmartWP\AdminPowerups\Modules\CheckoutRules;

use WC_Order;
use WC_Product;

defined( 'ABSPATH' ) || exit;

/**
 * Builds the context a rule is checked against, from the cart, a shipping package or an order
 * (the "pay for order" page). Keys match Rules::fields().
 *
 * @since 1.0.0
 */
final class Context {

	/**
	 * Context from product lines, an address and a user.
	 *
	 * @since 1.0.0
	 * @param array<int, array<string, mixed>> $lines   [ [ product => WC_Product, quantity => int ] ].
	 * @param float                            $total   Items total after discounts, incl. tax.
	 * @param string                           $country Country code.
	 * @param string                           $state   State code.
	 * @param int                              $user_id User ID (0 = guest).
	 * @param string[]                         $chosen  Chosen shipping rate IDs (e.g. flat_rate:3).
	 * @return array<string, mixed>
	 */
	public static function build( array $lines, $total, $country, $state, $user_id, array $chosen = array() ) {
		$categories = array();
		$types      = array();
		$classes    = array();
		$quantity   = 0;
		foreach ( $lines as $line ) {
			$product = $line['product'] ?? null;
			if ( ! $product instanceof WC_Product ) {
				continue;
			}
			$quantity += (int) ( $line['quantity'] ?? 1 );
			$parent    = $product->get_parent_id() ? $product->get_parent_id() : $product->get_id();
			foreach ( wc_get_product_term_ids( $parent, 'product_cat' ) as $cat ) {
				// A product in "Hoodies" is also in its parents ("Clothing").
				$categories = array_merge( $categories, array( (int) $cat ), array_map( 'intval', get_ancestors( $cat, 'product_cat', 'taxonomy' ) ) );
			}
			$types[] = self::parent_type( $product );
			if ( $product->is_virtual() ) {
				$types[] = 'virtual';
			}
			if ( $product->is_downloadable() ) {
				$types[] = 'downloadable';
			}
			if ( $product->get_shipping_class_id() ) {
				$classes[] = (int) $product->get_shipping_class_id();
			}
		}

		$methods = array();
		foreach ( $chosen as $rate ) {
			$methods[] = (string) $rate;
			$methods[] = strtok( (string) $rate, ':' ); // The type too: "flat_rate".
		}

		$roles = self::roles( (int) $user_id );

		$context = array(
			'cart_total'      => (float) $total,
			'quantity'        => $quantity,
			'category'        => array_values( array_unique( $categories ) ),
			'product_type'    => array_values( array_unique( $types ) ),
			'shipping_class'  => array_values( array_unique( $classes ) ),
			'shipping_method' => array_values( array_unique( array_filter( $methods ) ) ),
			'country'         => $country ? array( (string) $country ) : array(),
			'state'           => $country && $state ? array( $country . ':' . $state ) : array(),
			'user_role'       => $roles,
		);

		/**
		 * Filter the facts payment and shipping rules are checked against.
		 *
		 * @since 1.0.0
		 * @param array<string, mixed>            $context Context.
		 * @param array<int, array<string, mixed>> $lines   Product lines.
		 */
		return (array) apply_filters( 'apwc_checkout_rules_context', $context, $lines );
	}

	/**
	 * A user's roles on this site. Guests, and logged-in users with no role here (e.g. a network
	 * user who isn't a member of this site on multisite), count as "guest": an empty list would
	 * slip past "is any of" deny rules.
	 *
	 * @since 1.0.0
	 * @param int $user_id User ID (0 = guest).
	 * @return string[]
	 */
	public static function roles( $user_id ) {
		$user  = $user_id > 0 ? get_userdata( $user_id ) : null;
		$roles = $user ? array_values( array_filter( array_map( 'strval', (array) $user->roles ) ) ) : array();
		return $roles ? $roles : array( 'guest' );
	}

	/**
	 * Product type rules check: the parent's for a variation ("variable"), without loading the
	 * parent (that would cost a query per cart request). Variation types from other plugins
	 * (e.g. subscription variations) ask WooCommerce for the parent's type instead.
	 *
	 * @param WC_Product $product Product or variation.
	 * @return string
	 */
	private static function parent_type( WC_Product $product ) {
		if ( ! $product->get_parent_id() ) {
			return $product->get_type();
		}
		if ( 'variation' === $product->get_type() ) {
			return 'variable';
		}
		$type = \WC_Product_Factory::get_product_type( $product->get_parent_id() );
		return is_string( $type ) && '' !== $type ? $type : $product->get_type();
	}

	/**
	 * The shopper's address: shipping when set, else billing.
	 *
	 * @since 1.0.0
	 * @return array{0: string, 1: string}
	 */
	private static function customer_place() {
		$customer = function_exists( 'WC' ) ? WC()->customer : null;
		if ( ! $customer ) {
			return array( '', '' );
		}
		$country = $customer->get_shipping_country() ? $customer->get_shipping_country() : $customer->get_billing_country();
		$state   = $customer->get_shipping_country() ? $customer->get_shipping_state() : $customer->get_billing_state();
		return array( (string) $country, (string) $state );
	}

	/**
	 * Context from the cart.
	 *
	 * @since 1.0.0
	 * @return array<string, mixed>|null Null without a cart.
	 */
	public static function from_cart() {
		$cart = function_exists( 'WC' ) ? WC()->cart : null;
		if ( ! $cart ) {
			return null;
		}
		$lines = array();
		foreach ( $cart->get_cart() as $item ) {
			$lines[] = array(
				'product'  => $item['data'] ?? null,
				'quantity' => (int) ( $item['quantity'] ?? 1 ),
			);
		}
		list( $country, $state ) = self::customer_place();
		return self::build( $lines, (float) $cart->get_cart_contents_total() + (float) $cart->get_cart_contents_tax(), $country, $state, get_current_user_id(), self::chosen_rates( $cart ) );
	}

	/**
	 * Chosen shipping rates of the cart's real packages. The session can hold more (the classic
	 * checkout copies every posted `shipping_method[i]` into it), so only a choice for a package
	 * WooCommerce calculated, that the package offers, counts. A cart that doesn't ship has none.
	 *
	 * @since 1.0.0
	 * @param \WC_Cart $cart Cart.
	 * @return string[]
	 */
	private static function chosen_rates( $cart ) {
		if ( ! WC()->session || ! $cart->needs_shipping() ) {
			return array();
		}
		$chosen = (array) WC()->session->get( 'chosen_shipping_methods', array() );
		$rates  = array();
		foreach ( WC()->shipping()->get_packages() as $index => $package ) {
			$rate = $chosen[ $index ] ?? null;
			if ( is_string( $rate ) && '' !== $rate && is_array( $package['rates'] ?? null ) && isset( $package['rates'][ $rate ] ) ) {
				$rates[] = $rate;
			}
		}
		return $rates;
	}

	/**
	 * Context from a shipping package.
	 *
	 * @since 1.0.0
	 * @param array<string, mixed> $package Package.
	 * @return array<string, mixed>
	 */
	public static function from_package( array $package ) {
		$lines = array();
		$total = 0.0;
		foreach ( (array) ( $package['contents'] ?? array() ) as $item ) {
			$lines[] = array(
				'product'  => $item['data'] ?? null,
				'quantity' => (int) ( $item['quantity'] ?? 1 ),
			);
			$total  += (float) ( $item['line_total'] ?? 0 ) + (float) ( $item['line_tax'] ?? 0 );
		}
		$dest = (array) ( $package['destination'] ?? array() );
		$user = (int) ( $package['user']['ID'] ?? get_current_user_id() );
		return self::build( $lines, $total, (string) ( $dest['country'] ?? '' ), (string) ( $dest['state'] ?? '' ), $user );
	}

	/**
	 * Context from an order (pay for order page).
	 *
	 * @since 1.0.0
	 * @param WC_Order $order Order.
	 * @return array<string, mixed>
	 */
	public static function from_order( WC_Order $order ) {
		$lines = array();
		foreach ( $order->get_items() as $item ) {
			if ( $item instanceof \WC_Order_Item_Product ) {
				$lines[] = array(
					'product'  => $item->get_product(),
					'quantity' => $item->get_quantity(),
				);
			}
		}
		$country = $order->get_shipping_country() ? $order->get_shipping_country() : $order->get_billing_country();
		$state   = $order->get_shipping_country() ? $order->get_shipping_state() : $order->get_billing_state();
		$chosen  = array();
		foreach ( $order->get_shipping_methods() as $shipping ) {
			$chosen[] = $shipping->get_method_id() . ':' . $shipping->get_instance_id();
		}
		$total = (float) $order->get_subtotal() - (float) $order->get_discount_total() + (float) $order->get_cart_tax();
		return self::build( $lines, $total, $country, $state, (int) $order->get_customer_id(), $chosen );
	}
}