package ledger

type Deltas []Delta

func (deltas Deltas) Like(like ...Like) Deltas {
	result := make(Deltas, 0, len(deltas))
	for i := range deltas {
		if likes(like).all(deltas[i]) {
			result = append(result, deltas[i])
		}
	}
	return result
}

func (deltas Deltas) Balances() (Balances, error) {
	result := make(Balances)
	for _, delta := range deltas {
		if _, ok := result[delta.Name]; !ok {
			result[delta.Name] = make(Balance)
		}
		if _, ok := result[delta.Name][delta.Currency]; !ok {
			result[delta.Name][delta.Currency] = 0
		}
		result[delta.Name][delta.Currency] += delta.Value
	}

	return result, nil
}