import { BaseCheckpointSaver } from "@langchain/langgraph";
import { OnModuleDestroy } from "@nestjs/common";
import { ConfigService } from "@nestjs/config";
import { BaseConfigInterface } from "../../../config/interfaces/base.config.interface";
/** Default number of days an operator approval may stay pending. */
export declare const OPERATOR_DEFAULT_APPROVAL_TTL_DAYS = 7;
/**
 * OperatorCheckpointerService - Durable checkpoint storage for the operator agent.
 *
 * Lazily constructs and caches a LangGraph checkpoint saver:
 * - `RedisSaver` (from `@langchain/langgraph-checkpoint-redis`) when a Redis
 *   connection is configured, using the same `redis` config block the
 *   QueueModule reads from ConfigService.
 * - `MemorySaver` fallback when no Redis config is present (tests).
 *
 * Checkpoints expire after `(operator.approvalTtlDays ?? 7) + 1` days, one day
 * past the approval expiry so a pending approval never outlives its checkpoint.
 */
export declare class OperatorCheckpointerService implements OnModuleDestroy {
    private readonly configService;
    private readonly logger;
    private saverPromise?;
    constructor(configService: ConfigService<BaseConfigInterface>);
    /** Lazily constructs and caches the saver; MemorySaver fallback when redis config is absent (tests). */
    getSaver(): Promise<BaseCheckpointSaver>;
    /** Closes the Redis connection on shutdown; never throws. */
    onModuleDestroy(): Promise<void>;
    private createSaver;
    /**
     * Probes the Redis server for the module commands RedisSaver depends on,
     * using a short-lived ioredis client (already a dependency of this package —
     * the node-redis `redis` package used by the saver is not resolvable from
     * here under pnpm's strict isolation).
     *
     * `COMMAND INFO <name>` replies with a single-element array whose element is
     * nil (`[null]`) when the command is unknown, and a populated array when it
     * exists. It is preferred over `MODULE LIST` because on Redis 8+ the JSON
     * and search commands are built into core (no module entry), while
     * COMMAND INFO reports them uniformly on redis-stack, module-loaded Redis,
     * and Redis 8+.
     *
     * Connection failures reject and propagate to the caller, exactly like a
     * `RedisSaver.fromUrl` failure: getSaver() clears the cached promise so the
     * next call retries.
     */
    private probeMissingRedisCommands;
    /**
     * RedisSaver.fromUrl creates its node-redis client without an "error"
     * listener, so a socket error after startup would crash the process. The
     * client is a TypeScript-private but runtime-reachable field; attach a
     * logging handler when it is reachable, and degrade silently when a future
     * library version hides it.
     */
    private attachSaverErrorHandler;
    private buildRedisUrl;
}
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