/**
 * Event Buffer
 *
 * Buffers events until fresh remote config is resolved. Ensures every
 * event respects current project config.
 *
 * Ready condition:
 *  - _configReady: fresh /api/d response applied (or fetch failed)
 *
 * When config IS ready, queued events are filtered against the resolved
 * analytics toggles (capture_pageview, capture_pageleave, etc.) and
 * dropped if disabled — mirroring the server-side $config_pending filter.
 *
 * Events that flush before config is ready (safety timeout, page unload)
 * are tagged with $config_pending for server-side filtering.
 */
import type { TrackingEvent, VTiltConfig } from "../types";
export interface BufferedEvent {
    name: string;
    url: string;
    event: TrackingEvent;
}
export interface EventBufferHost {
    sendRequest(url: string, event: TrackingEvent): void;
    requestQueue: {
        flush(): void;
    };
    getConfig(): VTiltConfig;
}
export declare class EventBuffer {
    private _host;
    private readonly _queue;
    private _ready;
    private _configReady;
    private _safetyTimer;
    constructor(host: EventBufferHost);
    /**
     * Push an event into the buffer.
     * If ready, processes inline (pass-through). Otherwise queues.
     */
    push(item: BufferedEvent): void;
    /** Signal that fresh remote config has been loaded (or fetch failed). */
    markConfigReady(): void;
    /**
     * Force-flush all buffered events (page unload / safety timeout).
     * Tags events with $config_pending when config hasn't loaded.
     */
    forceFlush(): void;
    private _checkReady;
    private _tryFlush;
    private _flush;
    private _process;
    /**
     * Check whether the event should be dropped based on resolved config.
     * Mirrors the server-side checkProjectConfigFilter logic.
     */
    private _isDisabledByConfig;
    private _tagConfigPending;
    private _clearSafetyTimer;
}