From a796f2b61d8e795fa519e72b6544117c06dfa32d Mon Sep 17 00:00:00 2001
From: Evgenii Stratonikov <evgeniy@nspcc.ru>
Date: Thu, 13 Aug 2020 10:48:33 +0300
Subject: [PATCH] names: implement FromID

Allow to convert interop id to it's name.
---
 pkg/core/interop/interopnames/convert.go      | 13 ++++
 pkg/core/interop/interopnames/convert_test.go | 21 ++++++
 pkg/core/interop/interopnames/names.go        | 65 +++++++++++++++++++
 3 files changed, 99 insertions(+)
 create mode 100644 pkg/core/interop/interopnames/convert_test.go

diff --git a/pkg/core/interop/interopnames/convert.go b/pkg/core/interop/interopnames/convert.go
index cacd44985..54aa0f09c 100644
--- a/pkg/core/interop/interopnames/convert.go
+++ b/pkg/core/interop/interopnames/convert.go
@@ -3,10 +3,23 @@ package interopnames
 import (
 	"crypto/sha256"
 	"encoding/binary"
+	"errors"
 )
 
+var errNotFound = errors.New("interop not found")
+
 // ToID returns an identificator of the method based on its name.
 func ToID(name []byte) uint32 {
 	h := sha256.Sum256(name)
 	return binary.LittleEndian.Uint32(h[:4])
 }
+
+// FromID returns interop name from its id.
+func FromID(id uint32) (string, error) {
+	for i := range names {
+		if id == ToID([]byte(names[i])) {
+			return names[i], nil
+		}
+	}
+	return "", errNotFound
+}
diff --git a/pkg/core/interop/interopnames/convert_test.go b/pkg/core/interop/interopnames/convert_test.go
new file mode 100644
index 000000000..1ec2c1f21
--- /dev/null
+++ b/pkg/core/interop/interopnames/convert_test.go
@@ -0,0 +1,21 @@
+package interopnames
+
+import (
+	"errors"
+	"testing"
+
+	"github.com/stretchr/testify/require"
+)
+
+func TestFromID(t *testing.T) {
+	t.Run("Valid", func(t *testing.T) {
+		id := ToID([]byte(names[0]))
+		name, err := FromID(id)
+		require.NoError(t, err)
+		require.Equal(t, names[0], name)
+	})
+	t.Run("Invalid", func(t *testing.T) {
+		_, err := FromID(0x42424242)
+		require.True(t, errors.Is(err, errNotFound))
+	})
+}
diff --git a/pkg/core/interop/interopnames/names.go b/pkg/core/interop/interopnames/names.go
index ecf033a7a..01f36cdf1 100644
--- a/pkg/core/interop/interopnames/names.go
+++ b/pkg/core/interop/interopnames/names.go
@@ -65,3 +65,68 @@ const (
 	NeoNativeCall                            = "Neo.Native.Call"
 	NeoNativeDeploy                          = "Neo.Native.Deploy"
 )
+
+var names = []string{
+	SystemBinaryBase64Decode,
+	SystemBinaryBase64Encode,
+	SystemBinaryDeserialize,
+	SystemBinarySerialize,
+	SystemBlockchainGetBlock,
+	SystemBlockchainGetContract,
+	SystemBlockchainGetHeight,
+	SystemBlockchainGetTransaction,
+	SystemBlockchainGetTransactionFromBlock,
+	SystemBlockchainGetTransactionHeight,
+	SystemCallbackCreate,
+	SystemCallbackCreateFromMethod,
+	SystemCallbackCreateFromSyscall,
+	SystemCallbackInvoke,
+	SystemContractCall,
+	SystemContractCallEx,
+	SystemContractCreate,
+	SystemContractCreateStandardAccount,
+	SystemContractDestroy,
+	SystemContractIsStandard,
+	SystemContractGetCallFlags,
+	SystemContractUpdate,
+	SystemEnumeratorConcat,
+	SystemEnumeratorCreate,
+	SystemEnumeratorNext,
+	SystemEnumeratorValue,
+	SystemIteratorConcat,
+	SystemIteratorCreate,
+	SystemIteratorKey,
+	SystemIteratorKeys,
+	SystemIteratorValues,
+	SystemJSONDeserialize,
+	SystemJSONSerialize,
+	SystemRuntimeCheckWitness,
+	SystemRuntimeGasLeft,
+	SystemRuntimeGetCallingScriptHash,
+	SystemRuntimeGetEntryScriptHash,
+	SystemRuntimeGetExecutingScriptHash,
+	SystemRuntimeGetInvocationCounter,
+	SystemRuntimeGetNotifications,
+	SystemRuntimeGetScriptContainer,
+	SystemRuntimeGetTime,
+	SystemRuntimeGetTrigger,
+	SystemRuntimeLog,
+	SystemRuntimeNotify,
+	SystemRuntimePlatform,
+	SystemStorageDelete,
+	SystemStorageFind,
+	SystemStorageGet,
+	SystemStorageGetContext,
+	SystemStorageGetReadOnlyContext,
+	SystemStoragePut,
+	SystemStoragePutEx,
+	SystemStorageAsReadOnly,
+	NeoCryptoVerifyWithECDsaSecp256r1,
+	NeoCryptoVerifyWithECDsaSecp256k1,
+	NeoCryptoCheckMultisigWithECDsaSecp256r1,
+	NeoCryptoCheckMultisigWithECDsaSecp256k1,
+	NeoCryptoSHA256,
+	NeoCryptoRIPEMD160,
+	NeoNativeCall,
+	NeoNativeDeploy,
+}