Update project structure and build process

libwallet/newop/money.go

@@ -0,0 +1,86 @@
+package newop
+
+import (
+	"fmt"
+	"log"
+
+	"github.com/btcsuite/btcutil"
+	"github.com/shopspring/decimal"
+)
+
+// MonetaryAmount holds an amount of money in a certain currency
+type MonetaryAmount struct {
+	Value    decimal.Decimal
+	Currency string
+}
+
+func NewMonetaryAmountFromSatoshis(value int64) *MonetaryAmount {
+	v := decimal.NewFromInt(value).Div(decimal.NewFromInt(100_000_000))
+	return &MonetaryAmount{
+		Value:    v,
+		Currency: "BTC",
+	}
+}
+
+func NewMonetaryAmountFromFiat(value string, currency string) *MonetaryAmount {
+	v, err := decimal.NewFromString(value)
+	if err != nil {
+		log.Printf("could not initialize monetary amount: %v", err)
+		return nil
+	}
+	return &MonetaryAmount{
+		Value:    v,
+		Currency: currency,
+	}
+}
+
+func (m *MonetaryAmount) ValueAsString() string {
+	return m.Value.String()
+}
+
+func (m *MonetaryAmount) String() string {
+	return fmt.Sprintf("%v %v", m.Value, m.Currency) // TODO(newop): this is just a stub implementation
+}
+
+func (m *MonetaryAmount) toBtc(window *ExchangeRateWindow) btcutil.Amount {
+	rate := window.Rate(m.Currency)
+	v := m.Value.Div(decimal.NewFromFloat(rate)).Mul(decimal.NewFromInt(100_000_000))
+	v = v.RoundBank(0)
+	return btcutil.Amount(v.IntPart())
+}
+
+func (m *MonetaryAmount) add(n *MonetaryAmount) *MonetaryAmount {
+	if m.Currency != n.Currency {
+		panic("currencies do not match") // TODO(newop): replace panic and bubble up errors?
+	}
+	return &MonetaryAmount{
+		Value:    m.Value.Add(n.Value),
+		Currency: m.Currency,
+	}
+}
+
+func (m *MonetaryAmount) toBitcoinAmount(window *ExchangeRateWindow, primaryCurrency string) *BitcoinAmount {
+	return &BitcoinAmount{
+		InSat:             int64(m.toBtc(window)),
+		InInputCurrency:   m,
+		InPrimaryCurrency: window.convert(m, primaryCurrency),
+	}
+}
+
+type BitcoinAmount struct {
+	InSat             int64
+	InPrimaryCurrency *MonetaryAmount
+	InInputCurrency   *MonetaryAmount
+}
+
+func (a *BitcoinAmount) toBtc() btcutil.Amount {
+	return btcutil.Amount(a.InSat)
+}
+
+func (a *BitcoinAmount) add(b *BitcoinAmount) *BitcoinAmount {
+	return &BitcoinAmount{
+		InSat:             a.InSat + b.InSat,
+		InInputCurrency:   a.InInputCurrency.add(b.InInputCurrency),
+		InPrimaryCurrency: a.InPrimaryCurrency.add(b.InPrimaryCurrency),
+	}
+}