import { Logger } from '../utils/Logger';
import YahooFinanceFXProvider from '../FXService/providers/YahooFXProvider';
import OpenExchangeProvider from '../FXService/providers/OpenExchangeProvider';
import { FXService } from '../FXService/FXService';
import CoinMarketCapProvider from '../FXService/providers/CoinMarketCapProvider';
/**
 * Create and return a new FXProvider.
 * @param provider {string} Allowed values are 'yahoo' and 'openexhangerates'. OpenExchangeRates requires the API key to
 * be specifies in the OPENEXCHANGERATE_KEY environment variable.
 * @param logger {Logger} An existing logger object.
 * @constructor
 */
export declare function FXProviderFactory(provider: string, logger: Logger): YahooFinanceFXProvider | OpenExchangeProvider | CoinMarketCapProvider;
/**
 * Generate an return an FXService provider with sane defaults. If no arguments are specified, Yahoo Finance is used
 * as the sole provider using a SimpleRateCalculator instance.
 *
 * The returned FXService has a default refresh interval of 10 minutes. By default, no currency pairs are set, so a
 * recommended pattern is to set them directly after receiving the FXService, i.e.
 *
 * ```
 *   const service = SimpleFXServiceFactory().addCurrencyePair({ from: 'USD', to: 'EUR'});
 * ```
 *
 * @param provider {string} Either 'yahoo', 'openexchangerates' or 'coinmarketcap'. For OER, the OPENEXCHANGE_KEY envar must be set
 * @param logger {Logger} If not specified a new ConsoleLogger will be created
 * @param refreshInterval {number} the period (in ms) to poll the underlying API for new prices
 */
export declare function SimpleFXServiceFactory(provider?: string, logger?: Logger, refreshInterval?: number): FXService;