/** True when a background refresh was spawned within the debounce window. */
export declare function isRefreshSpawnDebounced(accountsDirPath: string): boolean;
/** Record that a background refresh is being spawned now (best-effort). */
export declare function markRefreshSpawned(accountsDirPath: string): void;
interface UsageWindow {
    utilization: number;
    resets_at?: string;
}
export interface UsagePayload {
    five_hour: UsageWindow;
    seven_day: UsageWindow;
    seven_day_opus?: UsageWindow | null;
    seven_day_sonnet?: UsageWindow | null;
}
export interface UsageCache {
    fetchedAt: number;
    /** Email of the account whose token produced this snapshot. Different
     *  accounts have completely independent quotas, so a cache from account
     *  A must never be displayed while account B is active. */
    account?: string;
    payload?: UsagePayload;
    rateLimitedUntil?: number;
}
/**
 * Parse the Retry-After header value into seconds. Defaults to 300s only when
 * the header is missing/unparseable — `Retry-After: 0` is valid (retry now).
 */
export declare function parseRetryAfter(header: string | string[] | undefined): number;
/** Type predicate for `UsagePayload` — validates both mandatory window fields. */
export declare function isUsagePayloadShaped(v: unknown): v is UsagePayload;
/**
 * Read the legacy global cache file. Kept for back-compat — new callers
 * should prefer `readUsageCacheForAccount(dir, email)` which checks the
 * per-account file first.
 */
export declare function readUsageCache(accountsDirPath: string): UsageCache | null;
/**
 * Read the per-account cache for the given email. Falls back to the
 * legacy global cache ONLY when (a) the per-account file doesn't exist
 * AND (b) the legacy file's `account` field matches the requested
 * email — preserves cached numbers across the v3.7 upgrade without
 * leaking another account's cache.
 */
export declare function readUsageCacheForAccount(accountsDirPath: string, email: string): UsageCache | null;
export declare function writeUsageCache(accountsDirPath: string, cache: UsageCache): void;
/**
 * Returns true if the cache is missing, missing a payload, older than
 * STATUSLINE_REFRESH_AFTER_MS, or belongs to a different account than the
 * one currently active. Always false while a recorded rate-limit back-off
 * is still in effect, since refreshing into a 429 makes nothing better.
 */
export declare function isUsageCacheStale(cache: UsageCache | null, currentAccount?: string): boolean;
/**
 * Returns the cache only if it belongs to the given account. Used by display
 * code (statusline, status) to avoid showing numbers from a different
 * account's quota.
 */
export declare function readUsageCacheFor(accountsDirPath: string, account: string): UsageCache | null;
/**
 * Decision helper for the "pre-fetch on switch" path: returns
 * true when the target account's cache is missing or stale, false when it
 * is fresh enough that an immediate refresh would be wasted. Kept as a
 * pure predicate so switcher.ts can call it without pulling in the
 * spawn/IO side effects.
 */
export declare function shouldTriggerUsageRefreshAfterSwitch(accountsDirPath: string, email: string): boolean;
export {};