import type { UsageEntry } from './usage-store.js';
/**
 * Reading a cached usage entry as CURRENT capacity rather than as history.
 *
 * The snapshot is a cache, and utilization only climbs while a window is open.
 * The moment a window resets, the stored number is not merely old, it is wrong:
 * it reports "spent" about a limit that has already lifted. Acting on that moves
 * a session off a model it could still be using, and announces a limit that no
 * longer exists.
 *
 * Every stored number carries the time its window resets, so this needs no
 * guess about staleness: a number past its own reset is simply expired.
 */
export interface UsableCapacity {
    /** Per-model utilization, with expired windows left out entirely. */
    models: Record<string, number | null>;
    /** Whether an account-wide window is at its limit and still closed. */
    accountWideOut: boolean;
}
/**
 * The parts of a usage entry this actually reads.
 *
 * Declared structurally rather than as the whole stored entry, so a caller
 * holding the same windows in a different shape does not have to assert its
 * way in. A cast there would keep compiling if the windows were ever dropped,
 * and `accountWideOut` would quietly become false: an account reported as
 * usable when every window on it is spent.
 */
export type CapacityWindows = Pick<UsageEntry, 'fiveHour' | 'sevenDay' | 'fiveHourReset' | 'sevenDayReset'> & Partial<Pick<UsageEntry, 'models'>>;
/**
 * How much headroom an account has left, as a fraction 0..1 (1 = untouched,
 * 0 = spent), on its BINDING account-wide window: the tighter of the 5-hour and
 * weekly limits. Higher means less used.
 *
 * This is the "how heavily has this account been used overall" metric the
 * least-used ordering sorts by. It is deliberately account-wide, not per-model:
 * which MODEL to run is the planner's job, while this answers which ACCOUNT has
 * the most room to give. An account with no usage read yet counts as fully open
 * (1), so a brand-new or just-reset account is treated as least-used, which is
 * exactly what it is.
 */
export declare function remainingRoom(entry: CapacityWindows | undefined, now: number): number;
/** What an account can still be asked to do, according to `entry`, right now. */
export declare function usableCapacity(entry: CapacityWindows | undefined, now: number): UsableCapacity;