import type { ImageContentBlock, DocumentContentBlock } from '../../types';
export declare function formatDate(date: Date): string;
export declare function convertBufferToBase64(buffer: ArrayBuffer, format: ImageContentBlock['format']): string;
export declare function getAttachmentFormat(file: File): string;
export declare function getValidDocumentName(file: File): string;
export declare const documentFileTypes: Set<string>;
export declare const imageFileTypes: Set<string>;
export declare const validFileTypes: Set<string>;
export declare function isDocumentFormat(format: string): format is DocumentContentBlock['format'];
export declare function isImageFormat(format: string): format is ImageContentBlock['format'];
export declare function attachmentsValidator({ files, maxAttachments, maxAttachmentSize, }: {
    files: File[];
    maxAttachments: number;
    maxAttachmentSize: number;
}): Promise<{
    acceptedFiles: File[];
    rejectedFiles: File[];
    hasMaxAttachmentSizeError: boolean;
    hasMaxAttachmentsError: boolean;
    hasUnsupportedFileError: boolean;
}>;