import { Nullable } from '../../../../shared/dist/esm/index';
import { BaseError } from '../common/error';
export type FileTypeSpecifier = UniqueFileTypeSpecifier | `.${string}`;
export declare enum UniqueFileTypeSpecifier {
    AnyAudio = "audio/*",
    AnyVideo = "video/*",
    AnyImage = "image/*"
}
/**
 * Validate if file has the allowed type. While we could also test for MIME types
 * not in UniqueFileTypeSpecifier, this function is meant to be equivalent to the
 * 'accept' attribute, which only allows for extensions or UniqueFileTypeSpecifier
 * values.
 * @param file
 * @param allowedTypes The file must have one of these types
 * @returns True if valid, Error object if not
 */
export declare function validateFileType(file: File, allowedTypes: FileTypeSpecifier[]): true | Error;
/**
 * Resolve file extension (with leading dot)
 */
export declare function resolveFileExtension(fileName: string): Nullable<FileTypeSpecifier>;
/**
 * Check if string is a FileTypeSpecifier
 */
export declare function isFileTypeSpecifier(type: string): type is FileTypeSpecifier;
/**
 * Create a human readable file size string from the numeric size in bytes
 */
export declare function prettyFileSize(sizeInBytes: number): string;
/**
 * Generate an ID that uniquely identifies a specific file. The same file
 * will always have the same ID.
 */
export declare function generateFileId(file: File): string;
export declare class MissingFileExtensionError extends BaseError {
    static defaultMessage: string;
}
export declare class ForbiddenFileTypeError extends BaseError {
    static defaultMessage: string;
}