import type { ModelMessage } from "ai";
import { type AuthorizationChallenge } from "#harness/authorization.js";
import type { HarnessSessionBase, SessionStateMap } from "#harness/types.js";
import type { UnstampedMessageStreamEvent } from "#protocol/message.js";
import type { SessionProjection } from "#protocol/session-projection.js";
import { type TurnState } from "./state.js";
import type { SessionView } from "./view.js";
/** What a transition returns. Nothing else changes session state. */
export interface Transition {
    readonly turn: TurnState;
    readonly events: readonly UnstampedMessageStreamEvent[];
    /** Messages the transition commits to the end of history. */
    readonly commit?: readonly ModelMessage[];
    /** The transition empties history, as `clear` does. */
    readonly clearsHistory?: true;
    /** Every sign-in the session waits on once the transition applies; `[]` withdraws them all. */
    readonly signIns?: readonly AuthorizationChallenge[];
}
/** Publishes one event; `messages` is the conversation hooks see with it. */
export type Publish = (event: UnstampedMessageStreamEvent, messages?: readonly ModelMessage[]) => Promise<void>;
export declare function sessionView(projection: SessionProjection, state: SessionStateMap | undefined): SessionView;
/**
 * Publishes a transition's events, then saves what it changed. A transition that changes history
 * needs a session restored with it.
 */
export declare function applyTransition<T extends HarnessSessionBase>(session: T, transition: Transition, publish: Publish, messages?: readonly ModelMessage[]): Promise<T>;
/** Drops the private records whose owner the projection shows closed. */
export declare function dropClosedRecords<T extends HarnessSessionBase>(session: T, projection: SessionProjection): T;