package gw.lang.enhancements

uses gw.api.util.MultiCurrencySummation
uses gw.pl.currency.MonetaryAmount

/**
 * Adds multi-currency summation enhancements.
 */
@ReadOnly
enhancement PCIterableMonetaryAmountSumEnhancement<T> : java.lang.Iterable<T> {
  /**
   * Sums up the values of the target of the mapper argument converting
   *   monetary amounts of currencies different than the specified currency.
   */
  function sumDifferentCurriences(currency : Currency, mapper(elt:T) : MonetaryAmount) : MonetaryAmount {
    // sum up like currencies    
    var summation = new MultiCurrencySummation()
    for (elt in this) {
      summation.add(mapper(elt))
    }
    // sum up like currency summations converted to currency
    return summation.sum(currency)
  }
}