tapchannel: properly create ContractResolution in createAndSignSweepVpackets

With all the prior commits in place, we can now create the new contract
resolution that includes the 1st and 2nd level packets, and the
information that we'll need to re-sign the second level packets later.

Author: Roasbeef

tapchannel/aux_sweeper.go

@@ -1679,25 +1679,71 @@ func (a *AuxSweeper) resolveContract(
 	log.Infof("Sweeping %v asset outputs: %v", len(assetOutputs),
 		limitSpewer.Sdump(assetOutputs))
 
-	// With the sweep desc constructed above, we'll create vPackets for
-	// each of the local assets, then sign them all.
-	sPkts := a.createAndSignSweepVpackets(
-		assetOutputs, req.SignDesc, sweepDesc,
-	)
+	tapSweepDesc, err := sweepDesc.Unpack()
+	if err != nil {
+		return lfn.Err[tlv.Blob](err)
+	}
+
+	// With the sweep desc constructed above, we'll create vPackets for each
+	// of the local assets, then sign them all.
+	firstLevelPkts, err := a.createAndSignSweepVpackets(
+		lfn.Ok(tapSweepDesc.firstLevel), assetOutputs, req,
+	).Unpack()
+	if err != nil {
+		return lfn.Err[tlv.Blob](err)
+	}
+
+	// We can't yet make the second level proof as we don't know exactly
+	// what the final txid of the sweep transaction will be. So we'll use a
+	// blank proof in place.
+	//
+	// TODO(roasbeef): need to set internal key? already known
+	var proof proof.Proof
+
+	// We'll make a place holder for the second level output based on the
+	// assetID+value tuple.
+	secondLevelInputs := []*cmsg.AssetOutput{cmsg.NewAssetOutput(
+		assetOutputs[0].AssetID.Val, assetOutputs[0].Amount.Val, proof,
+	)}
+
+	// Unlike the first level packets, we can't yet sign the second level
+	// packets yet, as we don't know what the sweeping transaction will look
+	// like. So we'll just create them.
+	secondLevelPkts, err := lfn.MapOption(
+		func(desc tapscriptSweepDesc) lfn.Result[[]*tappsbt.VPacket] {
+			return a.createSweepVpackets(
+				secondLevelInputs, lfn.Ok(desc), req,
+			)
+		},
+	)(tapSweepDesc.secondLevel).UnwrapOr(
+		lfn.Ok[[]*tappsbt.VPacket](nil),
+	).Unpack()
+	if err != nil {
+		return lfn.Err[tlv.Blob](err)
+	}
 
 	// With the vPackets fully generated and signed above, we'll serialize
 	// it into a resolution blob to return.
-	return lfn.AndThen(
-		sPkts, func(vPkts []*tappsbt.VPacket) lfn.Result[tlv.Blob] {
-			res := cmsg.NewContractResolution(vPkts)
+	secondLevelSigDesc := lfn.MapOption(
+		func(d tapscriptSweepDesc) cmsg.TapscriptSigDesc {
+			return cmsg.NewTapscriptSigDesc(
+				d.scriptTree.TapTweak(), d.ctrlBlockBytes,
+			)
+		},
+	)(tapSweepDesc.secondLevel)
 
-			var b bytes.Buffer
-			if err := res.Encode(&b); err != nil {
-				return lfn.Err[returnType](err)
-			}
+	res := cmsg.NewContractResolution(
+		firstLevelPkts, secondLevelPkts, secondLevelSigDesc,
+	)
+
+	var b bytes.Buffer
+	if err := res.Encode(&b); err != nil {
+		return lfn.Err[tlv.Blob](err)
+	}
+
+	return lfn.Ok(b.Bytes())
+}
 
-			return lfn.Ok(b.Bytes())
-		},
 // preimageDesc is a helper struct that contains the preimage and the witness
 // index that the preimage should be placed within the witness stack. This is
 // useful as in an earlier step, we've already pre-signed the witness, but will