/**
 * Preview Worker - Fast-path local preview generation
 *
 * Watches ~/Lia-Hub/shared/outputs/ and generates:
 * - Thumbnails (for images)
 * - Metadata extraction (dimensions, page count, text snippets)
 * - Preview JSON for instant gallery display
 *
 * NO LLM involvement - pure local, deterministic processing.
 * Targets sub-second response for most assets.
 *
 * Uses chokidar for reliable cross-platform file watching with:
 * - awaitWriteFinish to handle half-written files
 * - Ignore patterns to avoid loops (*.asset.json, thumbs, etc.)
 */
import { AssetManifest, AssetPreview } from './assets.js';
export interface PreviewWorkerOptions {
    /** Directories to watch */
    watchDirs?: string[];
    /** Max concurrent preview jobs */
    concurrency?: number;
    /** Callback when asset is discovered */
    onAsset?: (manifest: AssetManifest) => void;
    /** Callback when preview is ready */
    onPreview?: (preview: AssetPreview) => void;
    /** Enable verbose logging */
    verbose?: boolean;
}
export declare class PreviewWorker {
    private watcher;
    private queue;
    private processing;
    private debounceTimers;
    private concurrency;
    private options;
    private running;
    private rootDir;
    constructor(options?: PreviewWorkerOptions);
    /**
     * Start watching directories
     */
    start(): void;
    /**
     * Handle file add/change with debouncing
     */
    private handleFile;
    /**
     * Stop watching
     */
    stop(): void;
    /**
     * Add file to processing queue
     */
    private enqueue;
    /**
     * Process queue with concurrency limit
     */
    private processQueue;
    /**
     * Process a single file - generate manifest and preview
     */
    private processFile;
    /**
     * Generate preview for an asset
     */
    private generatePreview;
    /**
     * Get image dimensions using sips (macOS) or file command
     */
    private getImageInfo;
    /**
     * Generate thumbnail as base64 data URL
     * Uses sips on macOS for fast resizing
     */
    private generateImageThumbnail;
    /**
     * Get PDF info using pdfinfo or mdls
     */
    private getPdfInfo;
    /**
     * Get text snippet from file
     */
    private getTextSnippet;
    /**
     * Extract group ID from file path
     * e.g., ~/Lia-Hub/shared/outputs/run_abc123/file.png -> run_abc123
     */
    private extractGroupId;
    private log;
}
export interface AssetRegistry {
    assets: Map<string, AssetManifest>;
    previews: Map<string, AssetPreview>;
    byGroup: Map<string, Set<string>>;
}
export declare function getAssetRegistry(): AssetRegistry;
export declare function registerAsset(manifest: AssetManifest): void;
export declare function registerPreview(preview: AssetPreview): void;
export declare function getAsset(assetId: string): AssetManifest | undefined;
export declare function getPreview(assetId: string): AssetPreview | undefined;
export declare function getAssetsByGroup(groupId: string): AssetManifest[];
export declare function getAllAssets(): AssetManifest[];
export declare function startPreviewWorker(options?: PreviewWorkerOptions): PreviewWorker;
export declare function stopPreviewWorker(): void;