export type FileContent = string | Uint8Array;
export type GetFileContentFn = (filepath: string) => Promise<FileContent> | FileContent;
export interface IPreviewControllerOptions {
    baseUrl: string;
    getFileContent: GetFileContentFn;
    indexFiles?: string[];
}
export declare function normalizeFilepath(filepath: string): string;
export declare function joinFilepath(filepath: string, addition: string): string;
export declare function getExtension(filepath: string): string;
export declare class PreviewController {
    private baseUrl;
    private indexFiles;
    private getFileContent;
    private initPromise;
    constructor(options: IPreviewControllerOptions);
    private getIndexAtPath;
    private handleWorkerRequest;
    private getRelayUrl;
    private _initPreview;
    /**
     * Initialize a preview and return the url at which the preview is being served
     **/
    initPreview(): Promise<string>;
    destroy(): void;
}