feat(ledger): String method for Voter

ledger/common/gov.go

@@ -15,10 +15,12 @@
 package common
 
 import (
+	"fmt"
 	"math/big"
 
 	"github.com/blinklabs-io/gouroboros/cbor"
 	"github.com/blinklabs-io/plutigo/data"
+	"github.com/btcsuite/btcd/btcutil/bech32"
 )
 
 // VotingProcedures is a convenience type to avoid needing to duplicate the full type definition everywhere
@@ -38,6 +40,69 @@ type Voter struct {
 	Hash [28]byte
 }
 
+func encodeCip129Voter(
+	prefix string,
+	keyType uint8,
+	credentialType uint8,
+	hash []byte,
+) string {
+	// Header packs the 4-bit key type (per CIP-129) in the high nibble and the credential semantics in the low nibble.
+	// Since CIP-129 reserves values 0 and 1,we offset the existing credential constants (0 = key hash, 1 = script hash) by 2
+	// so the output nibble matches the spec's 0x2/0x3 tags.
+	header := byte((keyType << 4) | ((credentialType + 2) & 0x0f))
+	data := make([]byte, 1+len(hash))
+	data[0] = header
+	copy(data[1:], hash)
+	convData, err := bech32.ConvertBits(data, 8, 5, true)
+	if err != nil {
+		panic(fmt.Sprintf("unexpected error converting voter data to base32: %s", err))
+	}
+	encoded, err := bech32.Encode(prefix, convData)
+	if err != nil {
+		panic(fmt.Sprintf("unexpected error encoding voter data as bech32: %s", err))
+	}
+	return encoded
+}
+
+// Generates bech32-encoded identifier for the voter credential.
+func (v Voter) String() string {
+	switch v.Type {
+	case VoterTypeConstitutionalCommitteeHotKeyHash:
+		return encodeCip129Voter(
+			"cc_hot",
+			VoterTypeConstitutionalCommitteeHotKeyHash,
+			CredentialTypeAddrKeyHash,
+			v.Hash[:],
+		)
+	case VoterTypeConstitutionalCommitteeHotScriptHash:
+		return encodeCip129Voter(
+			"cc_hot",
+			VoterTypeConstitutionalCommitteeHotKeyHash,
+			CredentialTypeScriptHash,
+			v.Hash[:],
+		)
+	case VoterTypeDRepKeyHash:
+		return encodeCip129Voter(
+			"drep",
+			VoterTypeDRepKeyHash,
+			CredentialTypeAddrKeyHash,
+			v.Hash[:],
+		)
+	case VoterTypeDRepScriptHash:
+		return encodeCip129Voter(
+			"drep",
+			VoterTypeDRepKeyHash,
+			CredentialTypeScriptHash,
+			v.Hash[:],
+		)
+	case VoterTypeStakingPoolKeyHash:
+		poolId := PoolId(v.Hash)
+		return poolId.String()
+	default:
+		panic(fmt.Sprintf("unknown voter type: %d", v.Type))
+	}
+}
+
 func (v Voter) ToPlutusData() data.PlutusData {
 	switch v.Type {
 	case VoterTypeConstitutionalCommitteeHotScriptHash:

ledger/common/gov_test.go

@@ -168,6 +168,68 @@ func TestVoterToPlutusData(t *testing.T) {
 	}
 }
 
+func TestVoterString(t *testing.T) {
+	var zeroHash [28]byte
+	var sequentialHash [28]byte
+	for i := range sequentialHash {
+		sequentialHash[i] = byte(i)
+	}
+	testCases := []struct {
+		name  string
+		voter Voter
+		want  string
+	}{
+		{
+			name: "CIP129CcHotKeyHash",
+			voter: Voter{
+				Type: VoterTypeConstitutionalCommitteeHotKeyHash,
+				Hash: zeroHash,
+			},
+			want: "cc_hot1qgqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqvcdjk7",
+		},
+		{
+			name: "CIP129CcHotScriptHash",
+			voter: Voter{
+				Type: VoterTypeConstitutionalCommitteeHotScriptHash,
+				Hash: zeroHash,
+			},
+			want: "cc_hot1qvqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqv2arke",
+		},
+		{
+			name: "CIP129DRepKeyHash",
+			voter: Voter{
+				Type: VoterTypeDRepKeyHash,
+				Hash: zeroHash,
+			},
+			want: "drep1ygqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqq7vlc9n",
+		},
+		{
+			name: "CIP129DRepScriptHash",
+			voter: Voter{
+				Type: VoterTypeDRepScriptHash,
+				Hash: zeroHash,
+			},
+			want: "drep1yvqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqq770f95",
+		},
+		{
+			name: "StakingPoolKeyHash",
+			voter: Voter{
+				Type: VoterTypeStakingPoolKeyHash,
+				Hash: sequentialHash,
+			},
+			want: "pool1qqqsyqcyq5rqwzqfpg9scrgwpugpzysnzs23v9ccrydpk35lkuk",
+		},
+	}
+	for _, tc := range testCases {
+		t.Run(tc.name, func(t *testing.T) {
+			assert.Equal(t, tc.want, tc.voter.String())
+		})
+	}
+	assert.Panics(t, func() {
+		_ = Voter{Type: 99}.String()
+	})
+}
+
 // Tests the ToPlutusData method for Vote types
 func TestVoteToPlutusData(t *testing.T) {
 	testCases := []struct {