import { Pool } from 'pg';
export interface TenantQuota {
    tenantId: string;
    totalRequestsThisMonth: number;
    quotaLimit: number;
    billingCycleResetDate: Date;
}
export declare class PostgresQuotaLimiter {
    private pool;
    private inMemoryQuotas;
    private pendingIncrements;
    private flushIntervalMs;
    private flushTimer;
    private isFlushing;
    constructor(pool: Pool, flushIntervalMs?: number);
    /**
     * Start the background flush timer
     */
    start(): void;
    /**
     * Stop the background flush timer and flush any remaining increments
     */
    stop(): Promise<void>;
    /**
     * Synchronously validate a tenant's request against in-memory limits.
     * If a cache miss occurs, initializes with default limits and lazily loads from Postgres in the background.
     */
    checkQuota(tenantId: string, defaultLimit?: number): {
        allowed: boolean;
        reason?: string;
    };
    /**
     * Lazily loads tenant quota details from PostgreSQL in the background.
     * Merges loaded DB counts with any in-memory increments that accumulated in the meantime.
     */
    private lazyLoadTenantQuota;
    /**
     * Queue increments in memory to await bulk batch flush
     */
    private enqueueIncrement;
    /**
     * Performs an atomic database bulk UPSERT of all pending in-memory increments.
     * If a database error occurs, pending increments are safely rolled back and merged
     * into the in-memory map to try again in the next batch flush cycle.
     */
    flushPendingIncrements(): Promise<void>;
    /**
     * Helper to calculate the 1st of the next calendar month at midnight UTC
     */
    private calculateNextResetDate;
    /**
     * For test harness only: directly seed an in-memory quota entry
     */
    seedQuotaForTest(tenantId: string, quota: TenantQuota): void;
    /**
     * For test harness only: check in-memory status
     */
    getInMemoryQuota(tenantId: string): TenantQuota | undefined;
}
//# sourceMappingURL=PostgresQuotaLimiter.d.ts.map