import type { CooldownOption } from "./types.js";
/** Parse a duration string like `'500ms'`, `'30s'`, `'1m'`, `'2h'` to milliseconds. */
export declare function parseDuration(value: string): number;
/**
 * Per-logical-id sticky+reset state. Disabled by default — a {@link CooldownState}
 * is only constructed when `createRouter`'s `cooldown` option is set.
 *
 * It tracks an absolute index into the FULL (unfiltered) candidate array. After
 * the router switches away from the primary, that survivor stays sticky so the
 * next request skips the known-down primary; once `modelResetInterval` ms have
 * elapsed since the switch, the next request re-probes the primary.
 *
 * The `now` clock is injectable so tests can advance time deterministically.
 */
export declare class CooldownState {
    private activeFullIndex;
    private lastReset;
    private readonly cfg;
    private readonly now;
    private lastValidNow;
    constructor(cfg: {
        modelResetInterval: number;
    }, now?: () => number);
    /** Reset to the primary if the sticky window has elapsed. Call once per selection. */
    checkAndReset(): void;
    /** The full-array index the next request should start probing from. */
    current(): number;
    /**
     * Commit a survivor. Starting the reset window only when leaving the primary
     * means a healthy primary keeps serving and the interval is measured from the
     * last real switch away from it.
     */
    advanceTo(fullIndex: number): void;
    private clockNow;
}
/** Normalize the `cooldown` option to a concrete config, or `undefined` when off. */
export declare function resolveCooldown(opt?: CooldownOption): {
    modelResetInterval: number;
} | undefined;