/**
 * src/engine/background.ts — background delegation run registry (node-only).
 *
 * A run id is returned IMMEDIATELY (synchronous register); the actual child
 * work runs in the background via an executor promise. `getDelegationRun`
 * reads the current state; `awaitDelegationRun` waits for settlement with a
 * BOUNDED timeout (never blocks forever). State is hash-only (result output
 * is never stored raw on the state; only a status + the settled ChildResult
 * which lives with the caller).
 *
 * Zero @earendil-works/* imports.
 */
import type { ChildResult } from "../core/types.js";
import { type DelegationRunMode } from "./runs.js";
/** Background run status set (subset of DelegationRunStatus). */
export type BackgroundRunStatus = "queued" | "running" | "complete" | "failed" | "aborted";
/** Registry-visible snapshot of a background run (body-free metadata only). */
export interface BackgroundRunState {
    runId: string;
    agent: string;
    mode: DelegationRunMode;
    source: string;
    status: BackgroundRunStatus;
    startedAtMs: number;
    endedAtMs?: number;
    taskHash?: string;
    outputHash?: string;
    exitCode?: number;
    errorMessage?: string;
}
export declare const DEFAULT_AWAIT_TIMEOUT_MS = 300000;
/** Bounded background run registry. */
export declare class BackgroundRunRegistry {
    private readonly entries;
    private readonly now;
    constructor(now?: () => number);
    /**
     * Register a background run and immediately return its run id. The executor
     * runs in the background; its resolution updates the state. Never throws.
     */
    register(input: {
        agent: string;
        mode: DelegationRunMode;
        source: string;
        executor: Promise<ChildResult>;
        runId?: string;
        taskHash?: string;
    }): string;
    /** Read the current body-free state of a background run. */
    getDelegationRun(runId: string): BackgroundRunState | undefined;
    /**
     * Await settlement of a background run with a BOUNDED timeout. Resolves with
     * the current state on success, or with the state marked failed + a timeout
     * error message when the timeout elapses first.
     */
    awaitDelegationRun(runId: string, timeoutMs?: number): Promise<BackgroundRunState>;
    /** All registered background runs (body-free states). */
    list(): BackgroundRunState[];
    /** Number of registered background runs. */
    get size(): number;
    clear(): void;
}