import { ServiceNowInstance } from "../ServiceNowInstance.js";
import { AggregateQuery } from "../aggregate/AggregateQuery.js";
import { HealthCheckOptions, HealthCheckResult } from './HealthModels.js';
/**
 * InstanceHealth provides a consolidated health check for a ServiceNow instance.
 * Checks version info, cluster status, stuck jobs, semaphores, and operational counts.
 * Each sub-check is isolated — a failure in one does not affect others.
 */
export declare class InstanceHealth {
    private static readonly SYS_PROPERTIES_TABLE;
    private static readonly SYS_CLUSTER_STATE_TABLE;
    private static readonly SYS_TRIGGER_TABLE;
    private static readonly SYS_SEMAPHORE_TABLE;
    private _logger;
    private _tableAPI;
    private _aggregateQuery;
    private _instance;
    constructor(instance: ServiceNowInstance, aggregateQuery?: AggregateQuery);
    /**
     * Run a consolidated health check on the instance.
     * Each sub-check is wrapped in try/catch — failures return null for that check
     * without affecting the overall result.
     *
     * @param options Options to control which checks are run
     * @returns HealthCheckResult with all collected information and a summary
     */
    checkHealth(options?: HealthCheckOptions): Promise<HealthCheckResult>;
    /**
     * Get instance version information from sys_properties.
     * @private
     */
    private _getVersionInfo;
    /**
     * Get cluster node status from sys_cluster_state.
     * @private
     */
    private _getClusterStatus;
    /**
     * Get stuck jobs from sys_trigger (state=0 and next_action overdue).
     * @private
     */
    private _getStuckJobs;
    /**
     * Get count of active semaphores from sys_semaphore.
     * @private
     */
    private _getActiveSemaphores;
    /**
     * Get operational counts using AggregateQuery.
     * @private
     */
    private _getOperationalCounts;
    /**
     * Build a human-readable summary string from the health check results.
     * @private
     */
    private _buildSummary;
}