import { Context, Session } from 'koishi';
export interface FetchImageResult {
    buffer: Buffer;
    source: string;
    sourceType: 'data-uri' | 'base64' | 'local' | 'bot-file' | 'url';
}
export interface FetchOptions {
    maxFileSize?: number;
    groupFileRetryDelay?: number;
    groupFileRetryCount?: number;
    privateFileRetryDelay?: number;
    privateFileRetryCount?: number;
    logger?: any;
    debug?: boolean;
}
/**
 * Fetch image from various sources
 */
export declare function fetchImage(ctx: Context, session: Session, segment: any, options?: FetchOptions | number): Promise<FetchImageResult | null>;
/**
 * Fetch from URL
 */
declare function fetchFromURL(url: string, logger?: any, debug?: boolean): Promise<Buffer | null>;
declare const _default: {
    fetchImage: typeof fetchImage;
    fetchFromURL: typeof fetchFromURL;
};
export default _default;