/**
 * In-memory nonce cache for anti-replay.
 * TTL defines how long a nonce is considered "seen".
 */
export class NonceCache {
    cache = new Map();
    ttlMs;
    constructor(ttlMs = 3600000) {
        this.ttlMs = ttlMs;
    }
    /**
     * Returns true if nonce is valid (not seen within TTL). Records nonce on success.
     */
    isValid(nonce, timestamp) {
        const now = Date.now();
        const cached = this.cache.get(nonce);
        if (cached !== undefined) {
            if (now - cached < this.ttlMs) {
                return false;
            }
            this.cache.delete(nonce);
        }
        this.cache.set(nonce, timestamp);
        this.cleanup(now);
        return true;
    }
    cleanup(now) {
        for (const [n, ts] of this.cache.entries()) {
            if (now - ts >= this.ttlMs) {
                this.cache.delete(n);
            }
        }
    }
    clear() {
        this.cache.clear();
    }
}