watchtower/wtwire/init: borrow LN init msg for WT init

watchtower/wtwire/init.go

@@ -0,0 +1,30 @@
+package wtwire
+
+import "github.com/lightningnetwork/lnd/lnwire"
+
+// Init is the first message sent over the watchtower wire protocol, and
+// specifies features and level of requiredness maintained by the sending node.
+// The watchtower Init message is identical to the LN Init message, except it
+// uses a different message type to ensure the two are not conflated.
+type Init struct {
+	*lnwire.Init
+}
+
+// NewInitMessage generates a new Init message from raw global and local feature
+// vectors.
+func NewInitMessage(gf, lf *lnwire.RawFeatureVector) *Init {
+	return &Init{
+		Init: lnwire.NewInitMessage(gf, lf),
+	}
+}
+
+// MsgType returns the integer uniquely identifying this message type on the
+// wire.
+//
+// This is part of the wtwire.Message interface.
+func (msg *Init) MsgType() MessageType {
+	return MsgInit
+}
+
+// A compile-time constraint to ensure Init implements the Message interface.
+var _ Message = (*Init)(nil)