import { TypedConfigOptions } from './types.js';
import { OptionsSync } from 'cosmiconfig';
import 'class-transformer';
import 'class-validator';

interface FileLoaderOptions extends Partial<OptionsSync> {
    /**
     * basename of config file, defaults to `.env`.
     *
     * In other words, `.env.yaml`, `.env.yml`, `.env.json`, `.env.toml`, `.env.js`
     * will be searched by default.
     */
    basename?: string;
    /**
     * Use given file directly, instead of recursively searching in directory tree.
     */
    absolutePath?: string;
    /**
     * The directory to search from, defaults to `process.cwd()`. See: https://github.com/davidtheclark/cosmiconfig#explorersearch
     */
    searchFrom?: string;
    /**
     * If "true", ignore environment variable substitution.
     * Default: true
     */
    ignoreEnvironmentVariableSubstitution?: boolean;
    /**
     * If "true", disallow undefined environment variables.
     * Default: true
     */
    disallowUndefinedEnvironmentVariables?: boolean;
}
/**
 * File loader loads configuration with `cosmiconfig` from file system.
 *
 * It is designed to be easy to use by default:
 *  1. Searching for configuration file starts at `process.cwd()`, and continues
 *     to search up the directory tree until it finds some acceptable configuration.
 *  2. Various extensions are supported, such as `.json`, `.yaml`, `.toml`, `.js` and `.cjs`.
 *  3. Configuration base name defaults to .env (so the full name is `.env.json` or `.env.yaml`),
 *     separate file for each environment is also supported. For example, if current `NODE_ENV` is
 *     development, `.env.development.json` has higher priority over `.env.json`.
 *
 * @see https://github.com/davidtheclark/cosmiconfig
 * @param options cosmiconfig initialize options. See: https://github.com/davidtheclark/cosmiconfig#cosmiconfigoptions
 */
declare const fileLoader: (options?: FileLoaderOptions) => (() => Record<string, any>);

interface DotenvLoaderOptions {
    /**
     * If set, use the separator to parse environment variables to objects.
     *
     * @example
     *
     * ```bash
     * app__port=8080
     * db__host=127.0.0.1
     * db__port=3000
     * ```
     *
     * if `separator` is set to `__`, environment variables above will be parsed as:
     *
     * ```json
     * {
     *     "app": {
     *         "port": 8080
     *     },
     *     "db": {
     *         "host": "127.0.0.1",
     *         "port": 3000
     *     }
     * }
     * ```
     */
    separator?: string;
    /**
     * If "true", environment files (`.env`) will be ignored.
     */
    ignoreEnvFile?: boolean;
    /**
     * If "true", predefined environment variables will not be validated.
     */
    ignoreEnvVars?: boolean;
    /**
     * Path to the environment file(s) to be loaded.
     */
    envFilePath?: string | string[];
    /**
     * A boolean value indicating the use of expanded variables.
     * If .env contains expanded variables, they'll only be parsed if
     * this property is set to true.
     *
     * Internally, dotenv-expand is used to expand variables.
     */
    expandVariables?: boolean;
}
/**
 * Dotenv loader loads configuration with `dotenv`.
 *
 */
declare const dotenvLoader: (options?: DotenvLoaderOptions) => () => Record<string, any>;

declare class TypedConfig<T extends object> {
    init(options: TypedConfigOptions<T>): Promise<T>;
    private processConfig;
    private getRawConfigAsync;
    private validateWithClassValidator;
    private getConfigErrorMessage;
    private formatValidationError;
}
declare function defineConfig<T extends object>(options: TypedConfigOptions<T>): Promise<T>;

export { DotenvLoaderOptions, FileLoaderOptions, TypedConfig, defineConfig, dotenvLoader, fileLoader };