Add nonce & timestamp to block

Sources/Blockchain/Models/Block.swift

@@ -10,12 +10,27 @@ import Foundation
 import CryptoSwift
 
 class Block {
-    var hash: String!
+    var hash: String
-    var data: String!
+    var data: String
-    var previousHash: String!
+    var previousHash: String
-    var index: Int!
+    var index: Int
+    var nonce: Int
+    var timestamp: Int
+    
+    init(hash: String = "", data: String = "", previousHash: String = "", index: Int = 0, nonce: Int = 0, timestamp: Int = 0) {
+        self.data = data
+        self.previousHash = previousHash
+        self.index = index
+        self.nonce = nonce
+        self.timestamp = timestamp
+        self.hash = hash
+    }
     
     func generateHash() -> String {
         return data.sha256()
     }
+    
+    func generateTimestamp() -> Int {
+        return Int(Date().timeIntervalSince1970)
+    }
 }

Sources/Blockchain/Models/Blockchain.swift

@@ -16,6 +16,8 @@ class Blockchain {
         genesisBlock.data = data
         genesisBlock.previousHash = "0000"
         genesisBlock.index = 0
+        genesisBlock.nonce = 0
+        genesisBlock.timestamp = genesisBlock.generateTimestamp()
         genesisBlock.hash = genesisBlock.generateHash()
         chain.append(genesisBlock)
         print("Genesis block created -- hash: \(genesisBlock.hash ?? "")")
@@ -26,6 +28,8 @@ class Blockchain {
         newBlock.data = data
         newBlock.previousHash = chain[chain.count-1].hash
         newBlock.index = chain.count
+        newBlock.nonce = 0
+        newBlock.timestamp = newBlock.generateTimestamp()
         newBlock.hash = newBlock.generateHash()
         chain.append(newBlock)