/**
 * Web Vitals Manager
 *
 * Extends LazyFeature to handle lazy-loading the web-vitals script.
 * Captures Core Web Vitals (LCP, CLS, FCP, INP, TTFB) and sends them
 * as batched $web_vitals events.
 *
 * Event structure:
 * - event: "$web_vitals"
 * - properties:
 *   - $web_vitals_LCP_value: number
 *   - $web_vitals_LCP_event: { name, value, delta, rating, ... }
 *   - $pathname: string
 *   - $current_url: string
 *
 * @see docs/patterns/tracker-feature-lifecycle.md
 */
import { VTiltConfig, CapturePerformanceConfig, SupportedWebVitalsMetric } from "../../types";
import { LazyFeature } from "../../feature";
import type { VTilt } from "../../vtilt";
import { WebVitalsCallbacks } from "../../utils/globals";
export declare class WebVitalsManager extends LazyFeature<CapturePerformanceConfig, WebVitalsCallbacks> {
    readonly name = "WebVitals";
    readonly scriptName = "web-vitals";
    private _buffer;
    private _flushTimer;
    static extractConfig(config: VTiltConfig): CapturePerformanceConfig;
    constructor(instance: VTilt, config?: CapturePerformanceConfig);
    get isEnabled(): boolean;
    /**
     * Web Vitals checks if callbacks are already registered (from full bundle)
     * before trying to lazy-load the script.
     */
    startIfEnabled(): void;
    stop(): void;
    onConfigUpdate(config: VTiltConfig): void;
    protected _createLoaded(): WebVitalsCallbacks;
    protected _onLoaded(loaded: WebVitalsCallbacks): void;
    get allowedMetrics(): SupportedWebVitalsMetric[];
    get flushTimeoutMs(): number;
    get maxAllowedValue(): number;
    private _createEmptyBuffer;
    private _getWebVitalsCallbacks;
    private _startCapturing;
    private _getCurrentUrl;
    private _getCurrentPathname;
    private _addToBuffer;
    private _cleanAttribution;
    private _getWindowId;
    private _scheduleFlush;
    private _flush;
}