[#11] accounting: Implement ServiceExecutor on Neo:Morph client

Signed-off-by: Leonard Lyubich <leonard@nspcc.ru>

pkg/services/accounting/morph/executor.go

@@ -0,0 +1,54 @@
+package accounting
+
+import (
+	"context"
+
+	"github.com/nspcc-dev/neofs-api-go/v2/accounting"
+	"github.com/nspcc-dev/neofs-node/pkg/morph/client/balance"
+	accountingSvc "github.com/nspcc-dev/neofs-node/pkg/services/accounting"
+	"github.com/pkg/errors"
+)
+
+type morphExecutor struct {
+	// TODO: use client wrapper
+	client *balance.Client
+}
+
+func NewExecutor(client *balance.Client) accountingSvc.ServiceExecutor {
+	return &morphExecutor{
+		client: client,
+	}
+}
+
+func (s *morphExecutor) Balance(ctx context.Context, body *accounting.BalanceRequestBody) (*accounting.BalanceResponseBody, error) {
+	id := body.GetOwnerID()
+
+	idBytes, err := id.StableMarshal(nil)
+	if err != nil {
+		return nil, errors.Wrap(err, "could not marshal wallet owner ID")
+	}
+
+	argsBalance := balance.GetBalanceOfArgs{}
+	argsBalance.SetWallet(idBytes)
+
+	vBalance, err := s.client.BalanceOf(argsBalance)
+	if err != nil {
+		return nil, errors.Wrap(err, "could not call BalanceOf method")
+	}
+
+	argsDecimals := balance.DecimalsArgs{}
+
+	vDecimals, err := s.client.Decimals(argsDecimals)
+	if err != nil {
+		return nil, errors.Wrap(err, "could not call decimals method")
+	}
+
+	dec := new(accounting.Decimal)
+	dec.SetValue(vBalance.Amount())
+	dec.SetPrecision(uint32(vDecimals.Decimals()))
+
+	res := new(accounting.BalanceResponseBody)
+	res.SetBalance(dec)
+
+	return res, nil
+}