[#21] Add neofs unbind event

Signed-off-by: Alex Vanin <alexey@nspcc.ru>

pkg/morph/event/neofs/unbind.go

@@ -0,0 +1,69 @@
+package neofs
+
+import (
+	"crypto/elliptic"
+
+	"github.com/nspcc-dev/neo-go/pkg/crypto/keys"
+	"github.com/nspcc-dev/neo-go/pkg/smartcontract"
+	"github.com/nspcc-dev/neo-go/pkg/util"
+	"github.com/nspcc-dev/neofs-node/pkg/morph/client"
+	"github.com/nspcc-dev/neofs-node/pkg/morph/event"
+	"github.com/pkg/errors"
+)
+
+type Unbind struct {
+	user util.Uint160
+	keys []*keys.PublicKey
+}
+
+// MorphEvent implements Neo:Morph Event interface.
+func (Unbind) MorphEvent() {}
+
+func (u Unbind) Keys() []*keys.PublicKey { return u.keys }
+
+func (u Unbind) User() util.Uint160 { return u.user }
+
+func ParseUnbind(params []smartcontract.Parameter) (event.Event, error) {
+	var (
+		ev  Unbind
+		err error
+	)
+
+	if ln := len(params); ln != 2 {
+		return nil, event.WrongNumberOfParameters(2, ln)
+	}
+
+	// parse user
+	user, err := client.BytesFromStackParameter(params[0])
+	if err != nil {
+		return nil, errors.Wrap(err, "could not get bind user")
+	}
+
+	ev.user, err = util.Uint160DecodeBytesBE(user)
+	if err != nil {
+		return nil, errors.Wrap(err, "could not convert unbind user to uint160")
+	}
+
+	// parse keys
+	unbindKeys, err := client.ArrayFromStackParameter(params[1])
+	if err != nil {
+		return nil, errors.Wrap(err, "could not get unbind keys")
+	}
+
+	ev.keys = make([]*keys.PublicKey, 0, len(unbindKeys))
+	for i := range unbindKeys {
+		rawKey, err := client.BytesFromStackParameter(unbindKeys[i])
+		if err != nil {
+			return nil, errors.Wrap(err, "could not get unbind public key")
+		}
+
+		key, err := keys.NewPublicKeyFromBytes(rawKey, elliptic.P256())
+		if err != nil {
+			return nil, errors.Wrap(err, "could not parse unbind public key")
+		}
+
+		ev.keys = append(ev.keys, key)
+	}
+
+	return ev, nil
+}