import type { OutputEvent } from '../../../agent/types.js';
import type { CompletionWriter } from './shared.js';
import { PlainTurnHooks } from './turn-handler.plain-hooks.js';
export interface TurnTtfbState {
    readonly startedAt: number;
    received: boolean;
    waitingLineEmitted: boolean;
    plainHooks?: PlainTurnHooks;
}
export declare function createTurnTtfbState(startedAt: number): TurnTtfbState;
export declare function ttfbRendererOptions(state: TurnTtfbState): {
    turnStartedAt?: number;
};
export declare function observeFirstContent(state: TurnTtfbState, event: OutputEvent, streamingStarted: boolean): boolean;
export declare function emitPlainTtfbWaiting(completionWriter: CompletionWriter | undefined, stdout?: NodeJS.WriteStream, state?: TurnTtfbState): void;
export declare function eraseWaitingLineIfNeeded(state: TurnTtfbState, stdout?: NodeJS.WriteStream): void;