[#815] morph/event/netmap: Add addPeer notary notification support

Signed-off-by: Pavel Karpy <carpawell@nspcc.ru>

pkg/morph/event/netmap/add_peer.go

@@ -19,14 +19,16 @@ func (s AddPeer) Node() []byte {
 	return s.node
 }
 
+const expectedItemNumAddPeer = 1
+
 func ParseAddPeer(prms []stackitem.Item) (event.Event, error) {
 	var (
 		ev  AddPeer
 		err error
 	)
 
-	if ln := len(prms); ln != 1 {
-		return nil, event.WrongNumberOfParameters(1, ln)
+	if ln := len(prms); ln != expectedItemNumAddPeer {
+		return nil, event.WrongNumberOfParameters(expectedItemNumAddPeer, ln)
 	}
 
 	ev.node, err = client.BytesFromStackItem(prms[0])

pkg/morph/event/netmap/add_peer_notary.go

@@ -0,0 +1,47 @@
+package netmap
+
+import (
+	"github.com/nspcc-dev/neo-go/pkg/vm/opcode"
+	"github.com/nspcc-dev/neofs-node/pkg/morph/event"
+)
+
+func (s *AddPeer) setNode(v []byte) {
+	if v != nil {
+		s.node = v
+	}
+}
+
+const (
+	// AddPeerNotaryEvent is method name for netmap `addPeer` operation
+	// in `Netmap` contract. Is used as identificator for notary
+	// peer addition requests.
+	AddPeerNotaryEvent = "addPeer"
+)
+
+// ParseAddPeerNotary from NotaryEvent into netmap event structure.
+func ParseAddPeerNotary(ne event.NotaryEvent) (event.Event, error) {
+	var (
+		ev        AddPeer
+		currentOp opcode.Opcode
+	)
+
+	fieldNum := 0
+
+	for _, op := range ne.Params() {
+		currentOp = op.Code()
+
+		switch {
+		case opcode.PUSHDATA1 <= currentOp && currentOp <= opcode.PUSHDATA4:
+			if fieldNum == expectedItemNumAddPeer {
+				return nil, event.UnexpectedArgNumErr(AddPeerNotaryEvent)
+			}
+
+			ev.setNode(op.Param())
+			fieldNum++
+		default:
+			return nil, event.UnexpectedOpcode(AddPeerNotaryEvent, currentOp)
+		}
+	}
+
+	return ev, nil
+}