import { type RotationStrategy } from '../usage/rotation-plan.js';
import { type AccountModelUsage } from '../usage/model-preference.js';
/**
 * Where rotation will actually send this session, in words.
 *
 * The table says what every account HAS. This says what happens next, which is
 * the question the numbers are being read to answer and the one thing no other
 * tool can show: it needs the usage, the policy and the ledger together, and
 * only ccx has all three.
 *
 * Kept out of the renderer so that stays a pure function of what it is given,
 * and out of the planner so the planner keeps answering one question.
 */
export interface NextUpInput {
    /** Candidates in the order rotation would try them, already filtered. */
    candidates: AccountModelUsage[];
    /** The account running now, so "staying put" can be said as staying put. */
    current: string | null;
    modelInUse: string | null;
    preference: readonly string[];
    strategy: RotationStrategy;
    spentThisRun?: ReadonlySet<string>;
}
export declare function describeNextUp(input: NextUpInput): string | null;