import type { DexieCloudDB } from '../db/DexieCloudDB';
import { BlobRef } from './blobResolve';
/**
 * Deduplicates in-flight blob downloads.
 *
 * Both the blob-resolve middleware and the eager blob downloader may
 * try to fetch the same blob concurrently. This tracker ensures each
 * unique blob ref is only downloaded once — subsequent requests for
 * the same ref piggyback on the existing promise.
 *
 * Instantiate once per DexieCloudDB.
 */
export declare class BlobDownloadTracker {
    private inFlight;
    private db;
    constructor(db: DexieCloudDB);
    /**
     * Download a blob, deduplicating concurrent requests for the same ref.
     *
     * @param blobRef - The BlobRef to download
     * @param dbUrl - Base URL for the database (e.g., 'https://mydb.dexie.cloud')
     */
    download(blobRef: BlobRef, dbUrl: string): Promise<Uint8Array>;
}
/**
 * Download blob data from server via proxy endpoint.
 * Uses auth header for authentication (same as sync).
 * When accessToken is null, the request is made without Authorization header —
 * this allows downloading blobs from public realms (rlm-public) for
 * unauthenticated users.
 *
 * @param blobRef - The BlobRef to download
 * @param dbUrl - Base URL for the database (e.g., 'https://mydb.dexie.cloud')
 * @param accessToken - Access token for authentication, or null for anonymous access
 */
export declare function downloadBlob(blobRef: BlobRef, dbUrl: string, accessToken: string | null): Promise<Uint8Array>;