/**
 * Normalize an `allowedFormats` value (array or undefined) to lowercase, trimmed, non-empty tokens.
 */
export declare function normalizeAllowedFormats(formats: string[] | undefined | null): string[];
/**
 * Parse a native `accept` attribute value (comma-separated) into normalized tokens.
 */
export declare function parseAcceptTokens(accept: string | undefined | null): string[];
/**
 * Return `true` when a file matches one of the normalized allowed-format tokens.
 * Supports plain extensions (`'pdf'`, `'.pdf'`), exact MIME types (`'application/pdf'`),
 * and wildcards (`'image/*'`).
 */
export declare function matchesAllowedFormat(token: string, fileExtension: string, fileMimeType: string): boolean;
/**
 * Check whether a `File` matches any of the allowed formats.
 * An empty list is treated as "accept everything".
 */
export declare function isFileAllowed(file: File, allowedFormats: string[]): boolean;
/**
 * Build a `accept=""` string from allowed formats, falling back to an explicit accept when provided.
 */
export declare function resolveAcceptAttribute(explicitAccept: string | undefined, allowedFormats: string[] | undefined): string;
/** Human-readable token for the "Format: …" help line. */
export declare function formatTokenForDisplay(token: string): string;
/**
 * Produce the "Format: PDF, JPG, …" list used under the drop zone.
 * Falls back to `accept` tokens when `allowedFormats` is empty.
 */
export declare function getSupportedFormatsText(allowedFormats: string[] | undefined, accept: string | undefined): string;