import type { AwbConfig } from './rest.js';
export declare const MAX_INLINE_TEXT_BYTES: number;
export declare const MAX_ATTACHMENTS_PER_TURN = 20;
export interface RawChatAttachment {
    id?: string;
    attachment_id?: string;
    filename?: string;
    file_name?: string;
    mime_type?: string;
    file_mimetype?: string;
    size_bytes?: number;
    file_size?: number;
    download_url?: string;
    thumbnail_url?: string;
}
export type PreparedAttachmentKind = 'image_base64' | 'text_inline' | 'materialized_file' | 'metadata_only';
export interface PreparedAttachment {
    id: string;
    filename: string;
    mime_type: string;
    size_bytes: number;
    download_url: string;
    kind: PreparedAttachmentKind;
    image_base64?: string;
    text_content?: string;
    local_path?: string;
    note?: string;
}
export interface PrepareOptions {
    fetchImages: boolean;
    materialize?: boolean;
}
export declare function prepareChatAttachments(config: AwbConfig, roomId: string, rawList: RawChatAttachment[] | undefined, options: PrepareOptions): Promise<PreparedAttachment[]>;
export declare function approxBase64Bytes(base64: string | undefined): number;
export declare function renderAttachmentBlock(attachments: PreparedAttachment[], heading?: string): string[];