multi: add asset specifier field to CommitmentConstraints struct

This commit replaces the asset ID and asset group public key fields in
the `CommitmentConstraints` struct with an asset specifier field.

tapdb/assets_store.go

@@ -803,14 +803,14 @@ func (a *AssetStore) constraintsToDbFilter(
 				query.MinAnchorHeight,
 			)
 		}
-		if query.AssetID != nil {
-			assetID := query.AssetID[:]
-			assetFilter.AssetIDFilter = assetID
-		}
-		if query.GroupKey != nil {
-			groupKey := query.GroupKey.SerializeCompressed()
-			assetFilter.KeyGroupFilter = groupKey
-		}
+
+		// Add asset ID bytes and group key bytes to the filter. These
+		// byte arrays are empty if the asset ID or group key is not
+		// specified in the query.
+		assetIDBytes, groupKeyBytes := query.AssetSpecifier.AsBytes()
+		assetFilter.AssetIDFilter = assetIDBytes
+		assetFilter.KeyGroupFilter = groupKeyBytes
+
 		// TODO(roasbeef): only want to allow asset ID or other and not
 		// both?
 

tapdb/assets_store_test.go

@@ -280,7 +280,6 @@ func TestImportAssetProof(t *testing.T) {
 
 	// Add a random asset and corresponding proof into the database.
 	testAsset, testProof := dbHandle.AddRandomAssetProof(t)
-	assetID := testAsset.ID()
 	initialBlob := testProof.Blob
 
 	// We should now be able to retrieve the set of all assets inserted on
@@ -313,11 +312,8 @@ func TestImportAssetProof(t *testing.T) {
 	// We should also be able to fetch the created asset above based on
 	// either the asset ID, or key group via the main coin selection
 	// routine.
-	var assetConstraints tapfreighter.CommitmentConstraints
-	if testAsset.GroupKey != nil {
-		assetConstraints.GroupKey = &testAsset.GroupKey.GroupPubKey
-	} else {
-		assetConstraints.AssetID = &assetID
+	assetConstraints := tapfreighter.CommitmentConstraints{
+		AssetSpecifier: testAsset.Specifier(),
 	}
 	selectedAssets, err := assetStore.ListEligibleCoins(
 		ctxb, assetConstraints,
@@ -659,16 +655,20 @@ func (a *assetGenerator) genAssets(t *testing.T, assetStore *AssetStore,
 	}
 }
 
-func (a *assetGenerator) bindAssetID(i int, op wire.OutPoint) *asset.ID {
+func (a *assetGenerator) assetSpecifierAssetID(i int,
+	op wire.OutPoint) asset.Specifier {
+
 	gen := a.assetGens[i]
 	gen.FirstPrevOut = op
 
 	id := gen.ID()
 
-	return &id
+	return asset.NewSpecifierFromId(id)
 }
 
-func (a *assetGenerator) bindGroupKey(i int, op wire.OutPoint) *btcec.PublicKey {
+func (a *assetGenerator) assetSpecifierGroupKey(i int,
+	op wire.OutPoint) asset.Specifier {
+
 	gen := a.assetGens[i]
 	gen.FirstPrevOut = op
 	genTweak := gen.ID()
@@ -677,8 +677,9 @@ func (a *assetGenerator) bindGroupKey(i int, op wire.OutPoint) *btcec.PublicKey
 
 	internalPriv := input.TweakPrivKey(&groupPriv, genTweak[:])
 	tweakedPriv := txscript.TweakTaprootPrivKey(*internalPriv, nil)
+	groupPubKey := tweakedPriv.PubKey()
 
-	return tweakedPriv.PubKey()
+	return asset.NewSpecifierFromGroupKey(*groupPubKey)
 }
 
 // TestFetchAllAssets tests that the different AssetQueryFilters work as
@@ -1000,7 +1001,7 @@ func TestSelectCommitment(t *testing.T) {
 				},
 			},
 			constraints: tapfreighter.CommitmentConstraints{
-				AssetID: assetGen.bindAssetID(
+				AssetSpecifier: assetGen.assetSpecifierAssetID(
 					0, assetGen.anchorPoints[0],
 				),
 				MinAmt: 2,
@@ -1022,7 +1023,7 @@ func TestSelectCommitment(t *testing.T) {
 				},
 			},
 			constraints: tapfreighter.CommitmentConstraints{
-				AssetID: assetGen.bindAssetID(
+				AssetSpecifier: assetGen.assetSpecifierAssetID(
 					0, assetGen.anchorPoints[0],
 				),
 				MinAmt: 10,
@@ -1043,7 +1044,7 @@ func TestSelectCommitment(t *testing.T) {
 				},
 			},
 			constraints: tapfreighter.CommitmentConstraints{
-				AssetID: assetGen.bindAssetID(
+				AssetSpecifier: assetGen.assetSpecifierAssetID(
 					1, assetGen.anchorPoints[1],
 				),
 				MinAmt: 10,
@@ -1074,7 +1075,7 @@ func TestSelectCommitment(t *testing.T) {
 				},
 			},
 			constraints: tapfreighter.CommitmentConstraints{
-				GroupKey: assetGen.bindGroupKey(
+				AssetSpecifier: assetGen.assetSpecifierGroupKey(
 					0, assetGen.anchorPoints[0],
 				),
 				MinAmt: 1,
@@ -1104,7 +1105,7 @@ func TestSelectCommitment(t *testing.T) {
 				},
 			},
 			constraints: tapfreighter.CommitmentConstraints{
-				AssetID: assetGen.bindAssetID(
+				AssetSpecifier: assetGen.assetSpecifierAssetID(
 					0, assetGen.anchorPoints[0],
 				),
 				MinAmt: 2,
@@ -1146,7 +1147,7 @@ func TestSelectCommitment(t *testing.T) {
 				},
 			},
 			constraints: tapfreighter.CommitmentConstraints{
-				GroupKey: assetGen.bindGroupKey(
+				AssetSpecifier: assetGen.assetSpecifierGroupKey(
 					0, assetGen.anchorPoints[0],
 				),
 				MinAmt: 1,

tapfreighter/coin_select.go

@@ -52,9 +52,8 @@ func (s *CoinSelect) SelectCoins(ctx context.Context,
 	}
 
 	listConstraints := CommitmentConstraints{
-		GroupKey: constraints.GroupKey,
-		AssetID:  constraints.AssetID,
-		MinAmt:   1,
+		AssetSpecifier: constraints.AssetSpecifier,
+		MinAmt:         1,
 	}
 	eligibleCommitments, err := s.coinLister.ListEligibleCoins(
 		ctx, listConstraints,

tapfreighter/interface.go

@@ -5,7 +5,6 @@ import (
 	"fmt"
 	"time"
 
-	"github.com/btcsuite/btcd/btcec/v2"
 	"github.com/btcsuite/btcd/btcutil"
 	"github.com/btcsuite/btcd/btcutil/psbt"
 	"github.com/btcsuite/btcd/chaincfg/chainhash"
@@ -28,13 +27,8 @@ import (
 //
 // NOTE: Only the GroupKey or the AssetID should be set.
 type CommitmentConstraints struct {
-	// GroupKey is the required group key. This is an optional field, if
-	// set then the asset returned may have a distinct asset ID to the one
-	// specified below.
-	GroupKey *btcec.PublicKey
-
-	// AssetID is the asset ID that needs to be satisfied.
-	AssetID *asset.ID
+	// AssetSpecifier specifies the asset.
+	AssetSpecifier asset.Specifier
 
 	// MinAmt is the minimum amount that an asset commitment needs to hold
 	// to satisfy the constraints.
@@ -47,13 +41,8 @@ type CommitmentConstraints struct {
 
 // String returns the string representation of the commitment constraints.
 func (c *CommitmentConstraints) String() string {
-	var groupKeyBytes, assetIDBytes []byte
-	if c.GroupKey != nil {
-		groupKeyBytes = c.GroupKey.SerializeCompressed()
-	}
-	if c.AssetID != nil {
-		assetIDBytes = c.AssetID[:]
-	}
+	assetIDBytes, groupKeyBytes := c.AssetSpecifier.AsBytes()
+
 	return fmt.Sprintf("group_key=%x, asset_id=%x, min_amt=%d",
 		groupKeyBytes, assetIDBytes, c.MinAmt)
 }

tapfreighter/wallet.go

@@ -362,20 +362,11 @@ func (f *AssetWallet) FundPacket(ctx context.Context,
 		return nil, address.ErrMismatchedHRP
 	}
 
-	// Extract the asset ID and group key from the funding descriptor.
-	assetId := fundDesc.AssetSpecifier.UnwrapIdToPtr()
-	if assetId == nil {
-		return nil, fmt.Errorf("unable to unwrap asset ID")
-	}
-
-	groupKey := fundDesc.AssetSpecifier.UnwrapGroupKeyToPtr()
-
 	// We need to find a commitment that has enough assets to satisfy this
 	// send request. We'll map the address to a set of constraints, so we
 	// can use that to do Taproot asset coin selection.
 	constraints := CommitmentConstraints{
-		GroupKey:            groupKey,
-		AssetID:             assetId,
+		AssetSpecifier:      fundDesc.AssetSpecifier,
 		MinAmt:              fundDesc.Amount,
 		Bip86ScriptKeysOnly: true,
 	}
@@ -410,15 +401,12 @@ func (f *AssetWallet) FundBurn(ctx context.Context,
 		return nil, err
 	}
 
-	groupKey := fundDesc.AssetSpecifier.UnwrapGroupKeyToPtr()
-
 	// We need to find a commitment that has enough assets to satisfy this
 	// send request. We'll map the address to a set of constraints, so we
 	// can use that to do Taproot asset coin selection.
 	constraints := CommitmentConstraints{
-		GroupKey: groupKey,
-		AssetID:  assetId,
-		MinAmt:   fundDesc.Amount,
+		AssetSpecifier: fundDesc.AssetSpecifier,
+		MinAmt:         fundDesc.Amount,
 	}
 	selectedCommitments, err := f.cfg.CoinSelector.SelectCoins(
 		ctx, constraints, PreferMaxAmount, commitment.TapCommitmentV2,