<?php
/**
 * High-Performance Order Storage (HPOS) sync state.
 *
 * @package Keepwatch
 */

namespace Keepwatch\WooCommerce;

use Keepwatch\Checks\Check;
use Keepwatch\Checks\Result;

defined( 'ABSPATH' ) || exit;

/**
 * When compatibility mode keeps the old (posts) and new (HPOS) order tables in sync, orders waiting to be
 * synced mean the two copies differ; switching storage at that point can hide orders. Read-only.
 */
final class OrderStorageCheck implements Check {

	private const ORDER_UTIL   = 'Automattic\\WooCommerce\\Utilities\\OrderUtil';
	private const SYNCHRONIZER = 'Automattic\\WooCommerce\\Internal\\DataStores\\Orders\\DataSynchronizer';

	/**
	 * {@inheritDoc}
	 */
	public function group(): string {
		return 'woocommerce';
	}

	/**
	 * {@inheritDoc}
	 */
	public function run(): array {
		if ( ! is_callable( array( self::ORDER_UTIL, 'custom_orders_table_usage_is_enabled' ) ) ) {
			return array();
		}

		return self::evaluate(
			(bool) call_user_func( array( self::ORDER_UTIL, 'custom_orders_table_usage_is_enabled' ) ),
			'yes' === get_option( 'woocommerce_custom_orders_table_data_sync_enabled', 'no' ),
			$this->pending()
		);
	}

	/**
	 * Pure evaluation.
	 *
	 * @param bool     $hpos    Whether HPOS is the authoritative order storage.
	 * @param bool     $sync    Whether compatibility mode (sync) is on.
	 * @param int|null $pending Orders waiting to be synced; null if unknown.
	 * @return Result[]
	 */
	public static function evaluate( bool $hpos, bool $sync, ?int $pending ): array {
		$url = admin_url( 'admin.php?page=wc-settings&tab=advanced&section=features' );

		if ( $sync && null !== $pending && $pending > 0 ) {
			return array(
				new Result(
					'woocommerce.hpos',
					Result::RECOMMENDED,
					/* translators: %d: number of orders */
					sprintf( _n( '%d order is waiting to be synced between order tables', '%d orders are waiting to be synced between order tables', $pending, 'keepwatch' ), $pending ),
					__( 'Compatibility mode is on but the two order storages are not in sync yet. Do not switch order storage until the sync has finished.', 'keepwatch' ),
					$url,
					__( 'Order storage settings', 'keepwatch' )
				),
			);
		}

		return array(
			new Result(
				'woocommerce.hpos',
				Result::GOOD,
				$hpos
					? __( 'Orders use High-Performance Order Storage', 'keepwatch' )
					: __( 'Orders use the WordPress posts storage', 'keepwatch' )
			),
		);
	}

	/**
	 * Orders pending sync, via WooCommerce's own synchronizer when available.
	 */
	private function pending(): ?int {
		if ( ! function_exists( 'wc_get_container' ) ) {
			return null;
		}
		try {
			$synchronizer = wc_get_container()->get( self::SYNCHRONIZER );
			if ( is_object( $synchronizer ) && is_callable( array( $synchronizer, 'get_current_orders_pending_sync_count' ) ) ) {
				return (int) call_user_func( array( $synchronizer, 'get_current_orders_pending_sync_count' ) );
			}
		} catch ( \Throwable $e ) {
			return null;
		}
		return null;
	}
}