/**
 * @copyright Sister Software
 * @license AGPL-3.0
 * @author Teffen Ellis, et al.
 *
 *   Download + manifest plumbing for the `mailwoman corpus fetch <source>` family — one download-with-retry and
 *   one MANIFEST.json idiom instead of the per-script clones the 2026-07-09 dedupe survey counted
 *   (6× `downloadToFile`, 2× `isTransientStatus`, 9× manifest writes).
 */
/**
 * The option base every `mailwoman corpus fetch <source>` module extends.
 */
export interface BaseFetchOptions {
    /**
     * Destination root for downloaded source data. Each source writes its own subdirectory.
     */
    outRoot: string;
}
/**
 * The per-run result every fetch module returns; the command maps `failed > 0` to exit code 1.
 */
export interface FetchSummary {
    fetched: number;
    skipped: number;
    failed: number;
    failedCodes: string[];
}
/**
 * A status worth retrying: rate limiting or a server-side failure.
 */
export declare function isTransientStatus(status: number): boolean;
export interface DownloadOptions {
    url: string;
    dest: string;
    /**
     * Per-attempt timeout. Default 10 minutes — these are multi-GB government dumps.
     */
    timeoutMs?: number;
    /**
     * Extra attempts after the first, taken only on transient statuses or network errors. Default 0.
     */
    retries?: number;
    /**
     * Delay between attempts. Default 5s.
     */
    retryDelayMs?: number;
    headers?: Record<string, string>;
    report?: (line: string) => void;
}
/**
 * Download `url` to `dest` with per-attempt timeout and transient-status retry. Throws on a non-transient HTTP status
 * or once retries are exhausted. Returns the byte count written.
 */
export declare function downloadToFile(options: DownloadOptions): Promise<{
    bytes: number;
}>;
/**
 * Read a MANIFEST.json; `null` when missing or corrupt (callers re-fetch from scratch).
 */
export declare function readManifest<T>(path: string): Promise<T | null>;
/**
 * Load manifest entries into a map so untouched keys survive a partial re-fetch.
 */
export declare function loadManifestEntries<T>(path: string, key: (entry: T) => string): Promise<Map<string, T>>;
/**
 * Write a MANIFEST.json in the house shape: pretty-printed, trailing newline.
 */
export declare function writeManifest(path: string, manifest: unknown): Promise<void>;
//# sourceMappingURL=download.d.ts.map