/**
 * Run state machine: admitted → leased → running → terminal.
 *
 * Every transition is recorded through the storage adapter. Claims are CAS on
 * the attempt's lease_generation; a stale claim is rejected. Retries keep the
 * run_id and mint a new attempt_id with a fresh lease_generation counter.
 */
import type { ClaimAttemptInput, ClaimResult, ExecutionRunStatus, RunExecutionStore } from "./storage.js";
import type { TerminalRunStatus } from "./types.js";
export type { ClaimResult };
/** The only legal edges of the state machine. */
export declare const LEGAL_TRANSITIONS: Record<ExecutionRunStatus, ExecutionRunStatus[]>;
export type TransitionFailure = "NO_SUCH_RUN" | "NO_SUCH_ATTEMPT" | "INVALID_TRANSITION" | "ATTEMPT_TERMINAL" | "RUN_TERMINAL" | "RUN_CANCELLED";
export type TransitionResult = {
    ok: true;
} | {
    ok: false;
    reason: TransitionFailure;
};
export interface RunStateMachine {
    /** CAS-claim an attempt: expectedLeaseGeneration must match. */
    claim(input: ClaimAttemptInput): Promise<ClaimResult>;
    /** admitted → leased (claim recorded as a transition). */
    lease(input: ClaimAttemptInput): Promise<ClaimResult>;
    /** leased → running. */
    start(runId: string, attemptId: string): Promise<TransitionResult>;
    /** running → terminal; finalizes the run row. */
    terminate(input: {
        runId: string;
        attemptId: string;
        status: TerminalRunStatus;
    }): Promise<TransitionResult>;
    /** Cancel a run: fences the current generation and moves it to terminal. */
    cancel(runId: string): Promise<TransitionResult>;
    transition(runId: string, from: ExecutionRunStatus, to: ExecutionRunStatus, attemptId?: string | null): Promise<TransitionResult>;
    getStatus(runId: string): Promise<ExecutionRunStatus | null>;
}
export declare function createRunStateMachine(store: RunExecutionStore): RunStateMachine;