import { Contributor, LanguageMap } from './types';
/**
 * Normalize a language value to a plain string.
 * - string[] → first element or undefined
 * - Record → first value or undefined
 * - string → as-is
 */
export declare function normalizeLanguage(lang: string | string[] | undefined): string | undefined;
/**
 * Normalize a title/subtitle to a plain string.
 * - LanguageMap object → first value
 * - string → as-is
 */
export declare function normalizeTitle(title: LanguageMap | undefined): string | undefined;
/**
 * Normalize a publisher to a plain string.
 * - Contributor object → name field
 * - LanguageMap object → first value
 * - string → as-is
 */
export declare function normalizePublisher(pub: Contributor | LanguageMap | undefined): string | undefined;
/**
 * Normalize contributors to always be an array of Contributor objects.
 * - string → [{ name: str }]
 * - string[] → [{ name: str }, ...]
 * - Contributor → [contributor]
 * - Contributor[] → as-is
 */
export declare function normalizeContributors(contrib: Contributor | Contributor[] | string | string[] | undefined): Contributor[] | undefined;
/**
 * Normalize subject/keywords to always be an array of strings.
 * - string → [str]
 * - string[] → as-is
 */
export declare function normalizeSubjects(subject: string | string[] | undefined): string[] | undefined;
//# sourceMappingURL=metadata.d.ts.map