import * as moment from 'moment';

export interface IExchangeRate {
  id: string;
  value: number;
  startDate: Date;
  endDate: Date;
  baseCurrencyId: string;
  quoteCurrencyId: string;
}

export interface IExchangeRateProperties {
  id: boolean;
  value: boolean;
  startDate: boolean;
  endDate: boolean;
  baseCurrencyId: boolean;
  quoteCurrencyId: boolean;
}

export interface IExchangeRatesInfo {
  baseCurrencyId: string;
  quoteCurrencyId: string;
  startPeriod: Date;
  endPeriod: Date;
  frequency: string;
}

export function invertExchangeRate(exchangeRate: IExchangeRate) {
  const newId = createExchangeRateId(exchangeRate.quoteCurrencyId, exchangeRate.baseCurrencyId,
    exchangeRate.startDate, exchangeRate.endDate);
  return {
    id: newId,
    value: 1.0 / exchangeRate.value,
    startDate: exchangeRate.startDate,
    endDate: exchangeRate.endDate,
    baseCurrencyId: exchangeRate.quoteCurrencyId,
    quoteCurrencyId: exchangeRate.baseCurrencyId,
  };
}

export function createExchangeRateId(baseCurrencyId: string, quoteCurrencyId: string,
                                     startPeriod: Date, endPeriod: Date): string {
  let startPeriodString = '';
  if (startPeriod) {
    startPeriodString = startPeriod.getTime().toString();
  }
  let endPeriodString = '';
  if (endPeriod) {
    endPeriodString = endPeriod.getTime().toString();
  }
  return `${quoteCurrencyId}.${baseCurrencyId}.${startPeriodString}.${endPeriodString}`;
}

export function parseExchangeRate(exchangeRate: IExchangeRate) {
  return {
    startDate: moment(exchangeRate.startDate).toDate(),
    endDate: moment(exchangeRate.endDate).toDate(),
    value: +exchangeRate.value,
    id: exchangeRate.id,
    baseCurrencyId: exchangeRate.baseCurrencyId,
    quoteCurrencyId: exchangeRate.quoteCurrencyId,
  };
}