Implement Omni parser for Bitcoin

bchain/coins/bch/bcashparser.go

@@ -166,7 +166,7 @@ func (p *BCashParser) outputScriptToAddresses(script []byte) ([]string, bool, er
 		// do not return unknown script type error as error
 		if err.Error() == "unknown script type" {
 			// try OP_RETURN script
-			or := btc.TryParseOPReturn(script)
+			or := p.TryParseOPReturn(script)
 			if or != "" {
 				return []string{or}, false, nil
 			}

bchain/coins/btc/bitcoinparser.go

@@ -105,7 +105,7 @@ func (p *BitcoinParser) addressToOutputScript(address string) ([]byte, error) {
 }
 
 // TryParseOPReturn tries to process OP_RETURN script and return its string representation
-func TryParseOPReturn(script []byte) string {
+func (p *BitcoinParser) TryParseOPReturn(script []byte) string {
 	if len(script) > 1 && script[0] == txscript.OP_RETURN {
 		// trying 2 variants of OP_RETURN data
 		// 1) OP_RETURN OP_PUSHDATA1 <datalen> <data>
@@ -124,8 +124,12 @@ func TryParseOPReturn(script []byte) string {
 			data = script[2:]
 		}
 		if l == len(data) {
+			var ed string
 
-			// TODO try parse OMNI
+			ed = p.tryOmniParser(data)
+			if ed != "" {
+				return ed
+			}
 
 			isASCII := true
 			for _, c := range data {
@@ -134,7 +138,6 @@ func TryParseOPReturn(script []byte) string {
 					break
 				}
 			}
-			var ed string
 			if isASCII {
 				ed = "(" + string(data) + ")"
 			} else {
@@ -146,6 +149,39 @@ func TryParseOPReturn(script []byte) string {
 	return ""
 }
 
+var omniCurrencyMap = map[uint32]string{
+	1:  "Omni",
+	2:  "Test Omni",
+	31: "TetherUS",
+}
+
+// try to parse Omni transaction from script to human-readable string
+func (p *BitcoinParser) tryOmniParser(data []byte) string {
+
+	// Currently only simple send transaction is supported, see
+	// https://github.com/OmniLayer/spec#transfer-coins-simple-send
+	if len(data) != 20 && data[0] != 111 {
+		return ""
+	}
+	// omni (4) <tx_version> (2) <tx_type> (2)
+	omni_header := []byte{111, 109, 110, 105, 0, 0, 0, 0}
+	if bytes.Compare(data[0:8], omni_header) != 0 {
+		return ""
+	}
+
+	currency_id := binary.BigEndian.Uint32(data[8:12])
+	currency, ok := omniCurrencyMap[currency_id]
+	if !ok {
+		return ""
+	}
+	amount := new(big.Int)
+	amount.SetBytes(data[12:])
+	amount_str := p.AmountToDecimalString(amount)
+
+	ed := "OMNI Simple Send " + amount_str + " " + currency + " (#" + strconv.Itoa(int(currency_id)) + ")"
+	return ed
+}
+
 // outputScriptToAddresses converts ScriptPubKey to addresses with a flag that the addresses are searchable
 func (p *BitcoinParser) outputScriptToAddresses(script []byte) ([]string, bool, error) {
 	sc, addresses, _, err := txscript.ExtractPkScriptAddrs(script, p.Params)
@@ -160,7 +196,7 @@ func (p *BitcoinParser) outputScriptToAddresses(script []byte) ([]string, bool,
 	if sc == txscript.PubKeyHashTy || sc == txscript.WitnessV0PubKeyHashTy || sc == txscript.ScriptHashTy || sc == txscript.WitnessV0ScriptHashTy {
 		s = true
 	} else if len(rv) == 0 {
-		or := TryParseOPReturn(script)
+		or := p.TryParseOPReturn(script)
 		if or != "" {
 			rv = []string{or}
 		}

bchain/coins/btc/bitcoinparser_test.go

@@ -215,8 +215,27 @@ func TestGetAddressesFromAddrDesc(t *testing.T) {
 			want2:   false,
 			wantErr: false,
 		},
-
-		// TODO test case for omni
+		{
+			name:    "OP_RETURN omni simple send tether",
+			args:    args{script: "6a146f6d6e69000000000000001f00000709bb647351"},
+			want:    []string{"OMNI Simple Send 77383.80022609 TetherUS (#31)"},
+			want2:   false,
+			wantErr: false,
+		},
+		{
+			name:    "OP_RETURN omni simple send not supported coin",
+			args:    args{script: "6a146f6d6e69000000000000000300000709bb647351"},
+			want:    []string{"OP_RETURN 6f6d6e69000000000000000300000709bb647351"},
+			want2:   false,
+			wantErr: false,
+		},
+		{
+			name:    "OP_RETURN omni not supported version",
+			args:    args{script: "6a146f6d6e69010000000000000300000709bb647351"},
+			want:    []string{"OP_RETURN 6f6d6e69010000000000000300000709bb647351"},
+			want2:   false,
+			wantErr: false,
+		},
 	}
 
 	parser := NewBitcoinParser(GetChainParams("main"), &Configuration{})