<?php
/**
 * Connector runtime state.
 *
 * @package Rahkar\WP
 */

declare( strict_types = 1 );

namespace Rahkar\WP\Modules\HubConnector;

defined( 'ABSPATH' ) || exit;

/**
 * What the connector has learned from the hub: clock offset, back-off, the last
 * answer, and a stop reason that needs the admin's attention.
 *
 * One non-autoloaded option, read only by the flush job and the settings screen.
 */
final class State {

	public const OPTION = 'rahkar_wp_hub_state';

	/** Sending normally. */
	public const OK = 'ok';

	/** The hub refused the key; a person has to reconnect. */
	public const AUTH_FAILED = 'auth_failed';

	/** The site address changed since pairing (likely a staging copy). */
	public const SITE_MISMATCH = 'site_mismatch';

	/** The hub no longer serves this plugin's contract version. */
	public const UPGRADE_REQUIRED = 'upgrade_required';

	/** The subscription is paused; sending resumes on its own. */
	public const PAUSED = 'paused';

	/**
	 * Stored values.
	 *
	 * @var array<string, mixed>
	 */
	private array $data;

	/**
	 * Load.
	 */
	public function __construct() {
		$stored     = get_option( self::OPTION );
		$this->data = is_array( $stored ) ? $stored : [];
	}

	/**
	 * Read a value.
	 *
	 * @param string $key      Key.
	 * @param mixed  $fallback Value when absent.
	 */
	public function get( string $key, mixed $fallback = null ): mixed {
		return $this->data[ $key ] ?? $fallback;
	}

	/**
	 * Change values and persist.
	 *
	 * @param array<string, mixed> $values Values to merge.
	 */
	public function update( array $values ): void {
		$this->data = array_merge( $this->data, $values );

		update_option( self::OPTION, $this->data, false );
	}

	/**
	 * Current status, one of the constants above.
	 */
	public function status(): string {
		return (string) $this->get( 'status', self::OK );
	}

	/**
	 * Seconds to add to `time()` so signatures match the hub's clock.
	 */
	public function clockOffset(): int {
		return (int) $this->get( 'clock_offset', 0 );
	}

	/**
	 * Unix time before which nothing should be sent, or zero.
	 */
	public function waitUntil(): int {
		return (int) $this->get( 'wait_until', 0 );
	}

	/**
	 * Smallest gap between two sends the hub asked for, in seconds.
	 */
	public function minInterval(): int {
		return max( 0, (int) $this->get( 'min_interval', 0 ) );
	}

	/**
	 * Forget everything.
	 */
	public static function reset(): void {
		delete_option( self::OPTION );
	}
}