<?php
/**
 * Cached system status for the Powerups sidebar.
 *
 * @package AdminPowerups
 */

namespace SmartWP\AdminPowerups\Support;

use SmartWP\AdminPowerups\Admin\Sidebar;
use SmartWP\AdminPowerups\Plugin;

defined( 'ABSPATH' ) || exit;

/**
 * Everything in the sidebar "System" card (versions, order storage, power-ups on, background
 * jobs), checked once and kept in a transient. The card's refresh button re-checks it all.
 *
 * @since 1.0.0
 */
final class SystemStatus {

	const TRANSIENT = 'apwc_system_status';
	const TTL       = 12 * HOUR_IN_SECONDS;

	/**
	 * Per-request copy.
	 *
	 * @var array<string, mixed>|null
	 */
	private static $cache = null;

	/**
	 * Clear the cache when something shown in the card changes.
	 *
	 * @since 1.0.0
	 * @return void
	 */
	public static function register() {
		add_action( 'apwc_module_toggled', array( __CLASS__, 'flush' ) );
	}

	/**
	 * The status: cached, or checked now when asked, missing, or from another plugin version.
	 *
	 * @since 1.0.0
	 * @param bool $fresh Check now and update the cache.
	 * @return array{facts: array<string, string>, jobs: array<string, mixed>, checked_at: int, version: string}
	 */
	public static function get( $fresh = false ) {
		if ( ! $fresh ) {
			if ( null !== self::$cache ) {
				return self::$cache;
			}
			$cached = get_transient( self::TRANSIENT );
			if ( is_array( $cached ) && ( $cached['version'] ?? '' ) === APWC_VERSION && isset( $cached['facts'], $cached['jobs'] ) ) {
				self::$cache = $cached;
				return $cached;
			}
		}

		Health::flush();
		self::$cache = array(
			'facts'      => Sidebar::system_info( Plugin::instance()->registry() ),
			'jobs'       => Health::check(),
			'checked_at' => time(),
			'version'    => APWC_VERSION,
		);
		set_transient( self::TRANSIENT, self::$cache, self::TTL );
		return self::$cache;
	}

	/**
	 * "Checked 5 minutes ago".
	 *
	 * @since 1.0.0
	 * @param array<string, mixed> $status Result of get().
	 * @return string
	 */
	public static function checked_text( array $status ) {
		$at = (int) ( $status['checked_at'] ?? 0 );
		if ( ! $at || time() - $at < MINUTE_IN_SECONDS ) {
			return __( 'Checked just now', 'admin-powerups-for-woocommerce' );
		}
		/* translators: %s: time since, e.g. "5 minutes". */
		return sprintf( __( 'Checked %s ago', 'admin-powerups-for-woocommerce' ), human_time_diff( $at ) );
	}

	/**
	 * Forget the cached status.
	 *
	 * @since 1.0.0
	 * @return void
	 */
	public static function flush() {
		self::$cache = null;
		delete_transient( self::TRANSIENT );
	}
}