/**
 * Content Engagement Tracking
 *
 * Tracks how users engage with content: scroll depth, time on page, copy events, session lifecycle.
 * Philosophy: Understand what content resonates without being invasive.
 *
 * @packageDocumentation
 */
import type { AnalyticsClient } from './client.js';
interface SessionTrackerOptions {
    /** Emit session_start event on initialization (default: true) */
    emitSessionStart?: boolean;
}
/**
 * Creates a session lifecycle tracker with accurate active time measurement.
 *
 * Tracks cumulative active time by pausing when the tab is hidden and resuming
 * when visible. Reports session_end with activeTimeSeconds on page unload.
 *
 * Philosophy: Wall clock time doesn't reflect engagement. Active time does.
 */
export declare function createSessionTracker(client: AnalyticsClient, options?: SessionTrackerOptions): () => void;
interface ScrollTrackerOptions {
    thresholds?: number[];
    throttleMs?: number;
}
/**
 * Creates a scroll depth tracker that reports when users reach depth milestones.
 * Uses IntersectionObserver for performance.
 */
export declare function createScrollTracker(client: AnalyticsClient, options?: ScrollTrackerOptions): () => void;
interface TimeTrackerOptions {
    /** Intervals in seconds to report (default: [30, 60, 120, 300]) */
    intervals?: number[];
    /** Track active time only (pauses when tab hidden) */
    activeOnly?: boolean;
}
/**
 * Creates a time-on-page tracker that reports engagement duration.
 * Pauses when tab is hidden if activeOnly is true.
 */
export declare function createTimeTracker(client: AnalyticsClient, options?: TimeTrackerOptions): () => void;
/**
 * Creates a tracker for text copy events.
 */
export declare function createCopyTracker(client: AnalyticsClient): () => void;
/**
 * Creates a tracker for internal content link clicks.
 * Useful for understanding content navigation patterns.
 */
export declare function createLinkTracker(client: AnalyticsClient, options?: {
    /** Selector for content area (default: 'main') */
    contentSelector?: string;
    /** Only track internal links (default: true) */
    internalOnly?: boolean;
}): () => void;
export interface EngagementTrackerOptions {
    scroll?: ScrollTrackerOptions | false;
    time?: TimeTrackerOptions | false;
    copy?: boolean;
    links?: {
        contentSelector?: string;
        internalOnly?: boolean;
    } | false;
}
/**
 * Creates a combined engagement tracker with all content metrics.
 */
export declare function createEngagementTracker(client: AnalyticsClient, options?: EngagementTrackerOptions): () => void;
export {};