/**
 * The primitives every mailbox transition shares (WFT-84):
 * the rejection vocabulary, the transition result shape, non-terminal
 * narrowing, identity-field carry-over, and retry backoff.
 *
 * Extracted so `mailbox-transitions.ts` and
 * `mailbox-transitions-recovery.ts` can both use them without
 * importing each other — a runtime cycle this repository forbids outright.
 *
 * @module core/mailbox-transition-helpers
 */
import { computeRetryBackoffMs } from './application-primitive-timing.ts';
import type { ApplicationCommandAccepted, ApplicationCommandAvailable, ApplicationCommandCancelling, ApplicationCommandClaimed, ApplicationCommandRecord, ApplicationCommandTerminalRecord } from './mailbox-types.ts';
export { computeRetryBackoffMs };
/**
 * Why a proposed transition is illegal. Stable and low-cardinality, so callers
 * can map each reason onto a discriminated result without string matching.
 */
export type MailboxTransitionRejection = 'stale-attempt' | 'not-leased' | 'not-waiting' | 'not-due' | 'deadline-exceeded' | 'already-terminal';
/**
 * The outcome of a proposed transition: the record to persist, or why the edge
 * is illegal.
 */
export type MailboxTransition<TNext> = {
    readonly ok: true;
    readonly next: TNext;
} | {
    readonly ok: false;
    readonly reason: MailboxTransitionRejection;
};
export declare function rejectedTransition<TNext>(reason: MailboxTransitionRejection): MailboxTransition<TNext>;
export declare function succeededTransition<TNext>(next: TNext): MailboxTransition<TNext>;
/**
 * Narrow a record to the four non-terminal states.
 *
 * `isApplicationCommandTerminalState` narrows the `state` string but not the
 * record it came from, so every transition below needs this to stay cast-free.
 */
export declare function isTerminalCommandRecord(record: ApplicationCommandRecord): record is ApplicationCommandTerminalRecord;
export declare function nonTerminalCommandRecord(record: ApplicationCommandRecord): ApplicationCommandAccepted | ApplicationCommandAvailable | ApplicationCommandClaimed | ApplicationCommandCancelling | null;
/** Strip the state-specific fields so a transition rebuilds a record from identity alone. */
export declare function applicationCommandIdentityFields(record: ApplicationCommandRecord): {
    readonly recordVersion: 1;
    readonly namespace: string;
    readonly resourceId: string;
    readonly commandId: string;
    readonly sequence: number;
    readonly idempotencyKey: string | undefined;
    readonly caller: string;
    readonly target: string;
    readonly kind: string;
    readonly payload: import("./mailbox-types.ts").ApplicationCommandPayload;
    readonly payloadDigest: string;
    readonly payloadMediaType: string | undefined;
    readonly payloadSchema: string | undefined;
    readonly causation: Readonly<{
        correlationId?: string | undefined;
        causationId?: string | undefined;
        traceparent?: string | undefined;
    }> | undefined;
    readonly acceptedAt: number;
    readonly absoluteDeadlineAt: number;
    readonly maxAttempts: number;
    readonly visibilityTimeoutMs: number;
    readonly generation: number;
    readonly attempt: number;
    readonly retryCount: number;
    readonly firstClaimedAt: number | undefined;
    readonly availableAt: number;
};