import { CurrencyEnum } from './types/currency.enum';
import { CurrencyRates } from './types/currency-converter-api-response';
export declare class CurrencyConversion {
    /**
     * Formats the given date into the `YYYY-MM-DD` format.
     *
     * @param date - The date object to format.
     * @returns The formatted date string in `YYYY-MM-DD` format.
     *
     * @example
     * const currencyConversion = new CurrencyConversion();
     * const formattedDate = currencyConversion.formatDate(new Date());
     * console.log(formattedDate); // Output: "2024-09-09" (depends on the current date)
     */
    private static formatDate;
    /**
     * Attempts to fetch currency rates from the primary and fallback APIs.
     *
     * @param url - The API URL to fetch data from.
     * @returns A promise that resolves to the fetched currency rates.
     */
    private static fetchRates;
    /**
     * Fetches currency rates for a given currency from the API. Optionally, you can pass a specific date for historical rates.
     *
     * @param currency - The base currency you want to fetch rates for (e.g., `CurrencyEnum.USD`).
     * @param date - (Optional) A specific date to fetch historical rates. If omitted, the latest rates will be fetched.
     * @returns A promise that resolves to the currency rates.
     *
     * @example
     * const currencyConversion = new CurrencyConversion();
     * const rates = await currencyConversion.getCurrencyRates(CurrencyEnum.USD);
     * console.log(rates); // Output: { "eur": 0.92, "gbp": 0.80, "inr": 73.25, ... }
     *
     * // Fetching historical rates
     * const historicalRates = await currencyConversion.getCurrencyRates(CurrencyEnum.USD, '2024-09-01');
     * console.log(historicalRates); // Output: { "eur": 0.90, "gbp": 0.78, "inr": 72.50, ... }
     */
    static getCurrencyRates(currency: CurrencyEnum, date?: string): Promise<CurrencyRates>;
    /**
     * Converts a given amount from one currency to another based on real-time or historical exchange rates.
     *
     * @param from - The base currency to convert from (e.g., `CurrencyEnum.USD`).
     * @param to - The target currency to convert to (e.g., `CurrencyEnum.EUR`).
     * @param amount - The amount of base currency to convert.
     * @param date - (Optional) A specific date to fetch historical rates. If omitted, the latest rates will be used.
     * @returns A promise that resolves to the converted amount as a string with two decimal places.
     *
     * @example
     * const currencyConversion = new CurrencyConversion();
     * const convertedAmount = await currencyConversion.convert(CurrencyEnum.USD, CurrencyEnum.EUR, 100);
     * console.log(convertedAmount); // Output: "92.00" (depending on the exchange rate)
     *
     * // Converting with historical rates
     * const historicalConversion = await currencyConversion.convert(CurrencyEnum.USD, CurrencyEnum.EUR, 100, '2024-09-01');
     * console.log(historicalConversion); // Output: "90.00" (depending on the historical rate)
     */
    static convert(from: CurrencyEnum, to: CurrencyEnum, amount: number, date?: string): Promise<string>;
}