protofsm: add daemon events for spend+conf registration

protofsm/daemon_events.go

@@ -2,6 +2,7 @@ package protofsm
 
 import (
 	"github.com/btcsuite/btcd/btcec/v2"
+	"github.com/btcsuite/btcd/chaincfg/chainhash"
 	"github.com/btcsuite/btcd/wire"
 	"github.com/lightningnetwork/lnd/fn"
 	"github.com/lightningnetwork/lnd/lnwire"
@@ -21,7 +22,8 @@ type DaemonEventSet []DaemonEvent
 // DaemonEvents is a special type constraint that enumerates all the possible
 // types of daemon events.
 type DaemonEvents interface {
-	SendMsgEvent[any] | BroadcastTxn
+	SendMsgEvent[any] | BroadcastTxn | RegisterSpend[any] |
+		RegisterConf[any]
 }
 
 // SendPredicate is a function that returns true if the target message should
@@ -64,3 +66,53 @@ type BroadcastTxn struct {
 
 // daemonSealed indicates that this struct is a DaemonEvent instance.
 func (b *BroadcastTxn) daemonSealed() {}
+
+// RegisterSpend is used to request that a certain event is sent into the state
+// machien once the specified outpoint has been spent.
+type RegisterSpend[Event any] struct {
+	// OutPoint is the outpoint on chain to watch.
+	OutPoint wire.OutPoint
+
+	// PkScript is the script that we expect to be spent along with the
+	// outpoint.
+	PkScript []byte
+
+	// HeightHint is a value used to give the chain scanner a hint on how
+	// far back it needs to start its search.
+	HeightHint uint32
+
+	// PostSpendEvent is an event that's sent back to the requester once a
+	// transaction spending the outpoint has been confirmed in the main
+	// chain.
+	PostSpendEvent fn.Option[Event]
+}
+
+// daemonSealed indicates that this struct is a DaemonEvent instance.
+func (r *RegisterSpend[E]) daemonSealed() {}
+
+// RegisterConf is used to request that a certain event is sent into the state
+// machien once the specified outpoint has been spent.
+type RegisterConf[Event any] struct {
+	// Txid is the txid of the txn we want to watch the chain for.
+	Txid chainhash.Hash
+
+	// PkScript is the script that we expect to be created along with the
+	// outpoint.
+	PkScript []byte
+
+	// HeightHint is a value used to give the chain scanner a hint on how
+	// far back it needs to start its search.
+	HeightHint uint32
+
+	// NumConfs is the number of confirmations that the spending
+	// transaction needs to dispatch an event.
+	NumConfs fn.Option[uint32]
+
+	// PostConfEvent is an event that's sent back to the requester once the
+	// transaction specified above has confirmed in the chain with
+	// sufficient depth.
+	PostConfEvent fn.Option[Event]
+}
+
+// daemonSealed indicates that this struct is a DaemonEvent instance.
+func (r *RegisterConf[E]) daemonSealed() {}