Transactions

BasicBlockChain/BasicBlockChain.csproj

@@ -50,6 +50,7 @@
     <Compile Include="BlockChain.cs" />
     <Compile Include="Program.cs" />
     <Compile Include="Properties\AssemblyInfo.cs" />
+    <Compile Include="Transaction.cs" />
   </ItemGroup>
   <ItemGroup>
     <None Include="App.config" />

BasicBlockChain/Block.cs

@@ -1,4 +1,5 @@
 using System;
+using System.Collections.Generic;
 using System.Security.Cryptography;
 using System.Text;
 
@@ -9,25 +10,38 @@ namespace BasicBlockChain
         public int Index { get; set; }
         public DateTime Date { get; set; }
         public string PreviousHash { get; set; }
-        public string Data { get; set; }
+        public List<Transaction> Transactions { get; } = new List<Transaction>();
         public string Hash { get; set; }
         public int Nonce { get; set; }
 
-        public Block(DateTime date, Block previousBlock, string data)
+        public Block(DateTime date, Block previousBlock, IList<Transaction> transactions)
         {
             Index = (previousBlock?.Index ?? -1) + 1;
             Date = date;
             PreviousHash = previousBlock?.Hash;
-            Data = data;
+            if (transactions != null) { Transactions.AddRange(transactions); }
             Nonce = 0;
             Hash = CalculateHash();
         }
 
-        public string CalculateHash()
+        private string GetData()
         {
-            SHA256 sha256 = SHA256.Create();
+            VAR.Json.JsonWriter jsonWriter = new VAR.Json.JsonWriter(1);
+            return jsonWriter.Write(Transactions);
+        }
 
-            byte[] dataBytes = Encoding.UTF8.GetBytes(string.Format("{0}-{1}-{2}-{3}", Date, PreviousHash, Data, Nonce));
+        public string CalculateHash(string data = null, SHA256 sha256 = null)
+        {
+            if (sha256 == null) { sha256 = SHA256.Create(); }
+            if (data == null)
+            {
+                data = GetData();
+            }
+            byte[] dataBytes = Encoding.UTF8.GetBytes(string.Format("{0}-{1}-{2}-{3}",
+                Date,
+                PreviousHash,
+                data,
+                Nonce));
             byte[] hashBytes = sha256.ComputeHash(dataBytes);
 
             string hash = Convert.ToBase64String(hashBytes);
@@ -36,11 +50,13 @@ namespace BasicBlockChain
 
         public void Mine(int difficulty)
         {
+            SHA256 sha256 = SHA256.Create();
             var leadingZeros = new string('0', difficulty);
+            string data = GetData();
             while (Hash.Substring(0, difficulty) != leadingZeros)
             {
                 Nonce++;
-                Hash = CalculateHash();
+                Hash = CalculateHash(data, sha256);
             }
         }
     }

BasicBlockChain/BlockChain.cs

@@ -11,16 +11,16 @@ namespace BasicBlockChain
 
         public BlockChain(DateTime? genesisDate = null, int difficulty = 2)
         {
-            Block genesisBlock = new Block(genesisDate ?? DateTime.UtcNow, null, "{}");
+            Block genesisBlock = new Block(genesisDate ?? DateTime.UtcNow, null, null);
             genesisBlock.Mine(difficulty);
             Difficulty = difficulty;
             Chain.Add(genesisBlock);
         }
 
-        public void AddData(DateTime date, string data)
+        public void AddBlock(DateTime date, IList<Transaction> transactions)
         {
             Block lastBlock = Chain.Last();
-            Block newBlock = new Block(date, lastBlock, data);
+            Block newBlock = new Block(date, lastBlock, transactions);
             newBlock.Mine(Difficulty);
             Chain.Add(newBlock);
         }
@@ -40,5 +40,30 @@ namespace BasicBlockChain
             }
             return true;
         }
+
+        public long GetMicroCoinBalance(string receiver)
+        {
+            long microCoinBalance = 0;
+
+            for (int i = 0; i < Chain.Count; i++)
+            {
+                for (int j = 0; j < Chain[i].Transactions.Count; j++)
+                {
+                    var transaction = Chain[i].Transactions[j];
+
+                    if (transaction.Sender == receiver)
+                    {
+                        microCoinBalance -= transaction.MicroCoinAmount;
+                    }
+
+                    if (transaction.Receiver == receiver)
+                    {
+                        microCoinBalance += transaction.MicroCoinAmount;
+                    }
+                }
+            }
+
+            return microCoinBalance;
+        }
     }
 }

BasicBlockChain/Program.cs

@@ -1,4 +1,5 @@
 using System;
+using System.Collections.Generic;
 
 namespace BasicBlockChain
 {
@@ -13,9 +14,9 @@ namespace BasicBlockChain
             Console.WriteLine("#### Mining BlockChain with sample data");
             var startTime = DateTime.UtcNow;
             BlockChain nullCoin = new BlockChain(genesisDate: new DateTime(2000, 1, 1), difficulty: 2);
-            nullCoin.AddData(new DateTime(2000, 1, 2), "{ sender: VAR, receiver: NAM, amount: 10.00}");
+            nullCoin.AddBlock(new DateTime(2000, 1, 2), new List<Transaction> { new Transaction("VAR", "NAM", 10_000_000) });
-            nullCoin.AddData(new DateTime(2000, 1, 3), "{ sender: NAM, receiver: VAR, amount: 5.00}");
+            nullCoin.AddBlock(new DateTime(2000, 1, 3), new List<Transaction> { new Transaction("NAM", "VAR", 5_000_000) });
-            nullCoin.AddData(new DateTime(2000, 1, 4), "{ sender: NAM, receiver: VAR, amount: 5.00}");
+            nullCoin.AddBlock(new DateTime(2000, 1, 4), new List<Transaction> { new Transaction("NAM", "VAR", 5_000_000) });
             Console.WriteLine(jsonWriter.Write(nullCoin));
             var endTime = DateTime.UtcNow;
             Console.WriteLine($"Duration: {endTime - startTime}");
@@ -23,14 +24,21 @@ namespace BasicBlockChain
             // Verify
             Console.WriteLine("BlockChain is Valid? {0}", nullCoin.Verify() ? "True" : "False");
 
+            // Show balance
+            Console.WriteLine("Balance of \"{0}\": {1}", "VAR", nullCoin.GetMicroCoinBalance("VAR"));
+            Console.WriteLine("Balance of \"{0}\": {1}", "NAM", nullCoin.GetMicroCoinBalance("NAM"));
+
             // Tamper with the data
             Console.WriteLine();
             Console.WriteLine("#### Tampering with the data");
-            nullCoin.Chain[1].Data = "{ sender: VAR, receiver: NAM, amount: 1000.00}";
+            nullCoin.Chain[1].Transactions.Clear();
+            nullCoin.Chain[1].Transactions.Add(new Transaction("VAR", "NAM", 1000_000_000));
             Console.WriteLine(jsonWriter.Write(nullCoin));
 
             // Verify
             Console.WriteLine("BlockChain is Valid? {0}", nullCoin.Verify() ? "True" : "False");
+            Console.WriteLine("Balance of \"{0}\": {1}", "VAR", nullCoin.GetMicroCoinBalance("VAR"));
+            Console.WriteLine("Balance of \"{0}\": {1}", "NAM", nullCoin.GetMicroCoinBalance("NAM"));
 
             Console.Read();
         }

BasicBlockChain/Transaction.cs

@@ -0,0 +1,16 @@
+namespace BasicBlockChain
+{
+    public class Transaction
+    {
+        public string Sender { get; set; }
+        public string Receiver { get; set; }
+        public long MicroCoinAmount { get; set; }
+
+        public Transaction(string sender, string receiver, long microCoinAmount)
+        {
+            Sender = sender;
+            Receiver = receiver;
+            MicroCoinAmount = microCoinAmount;
+        }
+    }
+}