/// <reference types="node" />
import { IModuleOptions, Module } from "../../container";
import { Observable } from "../../container/RxJS";
import { ErrorChain } from "../error";
/** Assets files may be cached when read. */
export interface IAssetsCache {
    [key: string]: Buffer | string;
}
/** Assets error class. */
export declare class AssetsError extends ErrorChain {
    constructor(name: string, value: string, cause?: Error);
}
/** Assets file read options. */
export interface IAssetsReadOptions {
    encoding?: string;
    cache?: boolean;
}
/** Assets read only files module. */
export declare class Assets extends Module {
    /** Default module name. */
    static readonly moduleName: string;
    /** Environment variable names. */
    static readonly ENV: {
        PATH: string;
    };
    /** Error names. */
    static readonly ERROR: {
        DEPENDENCY: string;
    } & {
        READ_FILE: string;
        JSON_PARSE: string;
    };
    protected readonly path: string;
    protected readonly cache: IAssetsCache;
    constructor(options: IModuleOptions);
    /** Returns true if target file is cached. */
    isCached(target: string, encoding?: string): boolean;
    readFile(target: string, options?: {
        cache?: boolean;
    }): Observable<Buffer>;
    readFile(target: string, options: IAssetsReadOptions): Observable<string>;
    /** Read asset file contents and parse JSON object. */
    readJson<T>(target: string, options?: IAssetsReadOptions): Observable<T>;
    protected readonly envPath: string;
    protected read<T extends string | Buffer>(target: string, options?: IAssetsReadOptions): Observable<T>;
}