import { IRateLimitResult } from '../../../shared/types';
/**
 * Pure, time-injected implementations of the three rate limit algorithms for
 * the in-memory store. Result parity contract: for the same inputs these
 * functions produce exactly what the Lua scripts + the Redis adapter's
 * parse helpers produce — including rounding and the `retryAfter`
 * 0 -> undefined mapping. `now` is always epoch milliseconds.
 */
export interface IFixedWindowEntry {
    kind: 'fixed';
    /** Window start, epoch seconds. */
    window: number;
    count: number;
    /** Epoch ms after which the entry is dead (sweep/lazy-expiry boundary). */
    expiresAt: number;
}
export interface ISlidingWindowEntry {
    kind: 'sliding';
    /** Epoch ms of each allowed request, oldest first. */
    timestamps: number[];
    expiresAt: number;
}
export interface ITokenBucketEntry {
    kind: 'bucket';
    tokens: number;
    /** Epoch ms of the last refill computation. */
    lastRefill: number;
    expiresAt: number;
}
export type IMemoryRateLimitEntry = IFixedWindowEntry | ISlidingWindowEntry | ITokenBucketEntry;
/**
 * True when the entry has outlived its retention window and must be treated
 * as absent (the in-memory equivalent of Redis key expiry).
 */
export declare function isEntryExpired(entry: IMemoryRateLimitEntry, now: number): boolean;
/**
 * Fixed window: counter per aligned window. Lua parity: the counter keeps
 * incrementing on rejects (INCR runs unconditionally).
 */
export declare function applyFixedWindow(entry: IMemoryRateLimitEntry | undefined, now: number, points: number, duration: number): {
    entry: IFixedWindowEntry;
    result: IRateLimitResult;
};
/**
 * Sliding window log. Lua parity: entries with score <= now - duration are
 * pruned (inclusive boundary), rejected requests are NOT recorded, and the
 * expiry is refreshed only on allow (PEXPIRE lives in the allow branch).
 */
export declare function applySlidingWindow(entry: IMemoryRateLimitEntry | undefined, now: number, points: number, duration: number): {
    entry: ISlidingWindowEntry;
    result: IRateLimitResult;
};
/**
 * Token bucket. Lua parity: state is persisted on BOTH branches (reject still
 * stores the refilled tokens and stamps lastRefill), `current` is the floored
 * pre-consume token count, and retention mirrors
 * PEXPIRE ceil(capacity / refillRate * 1000) + 1000.
 */
export declare function applyTokenBucket(entry: IMemoryRateLimitEntry | undefined, now: number, capacity: number, refillRate: number, consume?: number): {
    entry: ITokenBucketEntry;
    result: IRateLimitResult;
};
/**
 * Peek parity with RedisRateLimitStoreAdapter.peek: fixed window uses strict
 * `<` for allowed, sliding window resets at floor(now/1000) + duration, and
 * token bucket reports `current` as capacity - remaining.
 */
export declare function peekFixedWindow(entry: IMemoryRateLimitEntry | undefined, now: number, points: number, duration: number): IRateLimitResult;
export declare function peekSlidingWindow(entry: IMemoryRateLimitEntry | undefined, now: number, points: number, duration: number): IRateLimitResult;
export declare function peekTokenBucket(entry: IMemoryRateLimitEntry | undefined, now: number, capacity: number, refillRate: number): IRateLimitResult;
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