From 5fb307526aaabbcbaee4bfc0f5388b0020832592 Mon Sep 17 00:00:00 2001
From: Andrei Kuzmiankov <ender2016@gmail.com>
Date: Thu, 22 Oct 2020 17:42:47 -0700
Subject: [PATCH] feat: Added getTransactionHash to transaction

---
 transaction.go        | 23 +++++++++++++++++++++++
 transaction_test.go   |  4 ++++
 utilities_for_test.go |  7 +++++++
 3 files changed, 34 insertions(+)

diff --git a/transaction.go b/transaction.go
index e5d80f56d..79cfb38cb 100644
--- a/transaction.go
+++ b/transaction.go
@@ -2,6 +2,8 @@ package hedera
 
 import (
 	"bytes"
+	"crypto/sha512"
+	"encoding/hex"
 	"time"
 
 	protobuf "github.com/golang/protobuf/proto"
@@ -63,6 +65,27 @@ func TransactionFromBytes(bytes []byte) Transaction {
 	return tx
 }
 
+func (transaction *Transaction) getTransactionHash() map[AccountID][]byte {
+	hash := sha512.New384()
+	bytes, err := protobuf.Marshal(transaction.pbBody)
+	if err != nil {
+		// This should be unreachable
+		// From the documentation this appears to only be possible if there are missing proto types
+		panic(err)
+	}
+	hash.Write(bytes)
+
+	byteHash :=  hex.EncodeToString(hash.Sum(nil))
+
+	transactionHash := make(map[AccountID][]byte)
+
+	for _, node := range transaction.nodeIDs {
+		transactionHash[node] = []byte(byteHash)
+	}
+
+	return transactionHash
+}
+
 func (transaction *Transaction) initFee(client *Client) {
 	if client != nil && transaction.pbBody.TransactionFee == 0 {
 		transaction.SetMaxTransactionFee(client.maxTransactionFee)
diff --git a/transaction_test.go b/transaction_test.go
index 9167e9259..fc9913427 100644
--- a/transaction_test.go
+++ b/transaction_test.go
@@ -11,6 +11,10 @@ func TestTransactionSerializationDeserialization(t *testing.T) {
 
 	assert.NoError(t, err)
 
+	_ = transaction.getTransactionHash()
+
+	assert.NoError(t, err)
+
 	txBytes, err := transaction.MarshalBinary()
 
 	assert.NoError(t, err)
diff --git a/utilities_for_test.go b/utilities_for_test.go
index 0bcec408b..7ea3494fa 100644
--- a/utilities_for_test.go
+++ b/utilities_for_test.go
@@ -44,11 +44,18 @@ func newMockTransaction() (Transaction, error) {
 		return Transaction{}, err
 	}
 
+	nodeIDs := make([]AccountID, 1)
+	nodeIDs[0], err = AccountIDFromString("0.0.4")
+	if err != nil {
+		return Transaction{}, err
+	}
+
 	tx, err := NewCryptoTransferTransaction().
 		AddSender(AccountID{Account: 2}, HbarFromTinybar(100)).
 		AddRecipient(AccountID{Account: 3}, HbarFromTinybar(100)).
 		SetMaxTransactionFee(HbarFrom(1, HbarUnits.Hbar)).
 		SetTransactionID(testTransactionID).
+		SetNodeAccountIDs(nodeIDs).
 		FreezeWith(client)
 
 	if err != nil {