import { PerformanceIssueEvent, PerformanceIssuesOptions } from '../types/issues';
/** Default threshold for Long Tasks detector (ms). */
export declare const DEFAULT_LONG_TASK_THRESHOLD_MS = 100;
/** Default threshold for Long Animation Frames detector (ms). */
export declare const DEFAULT_LOAF_THRESHOLD_MS = 300;
/**
 * Hard lower bound for custom detector thresholds (in ms).
 * Prevents near-zero values that would generate noisy, low-value issue reports.
 */
export declare const MIN_REPORTABLE_ISSUE_THRESHOLD_MS = 50;
/**
 * Performance issues monitor.
 *
 * Observes browser Performance API entries and Web Vitals metrics,
 * validates them against configured thresholds and filtering rules,
 * and emits structured {@link PerformanceIssueEvent} payloads.
 *
 * Supported detectors:
 * - **Long Tasks** — cross-origin / iframe tasks with identifiable container
 * - **Long Animation Frames** — frames with at least one identifiable script
 * - **Web Vitals** — poor-rated Core Web Vitals (LCP, FCP, TTFB, INP, CLS)
 */
export declare class PerformanceIssuesMonitor {
    /**
     * Initializes enabled detectors based on the provided options.
     *
     * @param options - detector configuration (longTasks, longAnimationFrames, webVitals)
     * @param onIssue - callback invoked for each detected performance issue
     */
    init(options: PerformanceIssuesOptions, onIssue: (event: PerformanceIssueEvent) => void): void;
    /**
     * Creates a PerformanceObserver for the given entry type.
     * Returns null if the browser does not support the entry type or the observer fails.
     *
     * @param type - performance entry type (e.g. "longtask", "long-animation-frame")
     * @param onEntry - callback invoked for each observed entry
     */
    private observe;
    /**
     * Subscribes to Core Web Vitals via the web-vitals library.
     * Emits one issue per poor-rated metric; each metric name is reported at most once.
     *
     * @param onIssue - callback invoked for each poor metric
     * @param webVitalsOptions
     */
    private observeWebVitals;
}