✨ Enhance blockchain

SwiftChainCore/Models/Block.swift

@@ -0,0 +1,116 @@
+//
+//  Block.swift
+//  Blockchain
+//
+//  Created by Victor BODINAUD on 27/02/2020.
+//  Copyright © 2020 Victor BODINAUD. All rights reserved.
+//
+
+internal import CryptoSwift
+import Foundation
+
+public class Block: Codable {
+    var hash: String
+    var transactions: [Transaction]
+    var previousHash: String
+    var index: Int
+    var nonce: Int
+    var timestamp: Int
+    var difficulty: Int
+    var miner: String?
+
+    enum CodingKeys: String, CodingKey {
+        case hash, transactions, previousHash, index, nonce, timestamp, difficulty, miner
+    }
+
+    init(hash: String = "", transactions: [Transaction] = [], previousHash: String = "",
+         index: Int = 0, nonce: Int = 0, timestamp: Int = 0, difficulty: Int = 4)
+    {
+        self.hash = hash
+        self.transactions = transactions
+        self.previousHash = previousHash
+        self.index = index
+        self.nonce = nonce
+        self.timestamp = timestamp
+        self.difficulty = difficulty
+    }
+
+    func mineBlock() -> Double {
+        let startTime = Date()
+        let target = String(repeating: "0", count: difficulty)
+
+        print("Mining block \(index) with difficulty \(difficulty)...")
+
+        repeat {
+            nonce += 1
+            hash = generateHash()
+        } while !hash.hasPrefix(target)
+
+        let timeElapsed = Date().timeIntervalSince(startTime)
+        print("Block mined! Nonce: \(nonce), Hash: \(hash)")
+
+        return timeElapsed
+    }
+
+    func isValid() -> Bool {
+        // Vérification de base du hash
+        let target = String(repeating: "0", count: difficulty)
+        if hash != generateHash() || !hash.hasPrefix(target) {
+            print("Block \(index): Invalid hash")
+            return false
+        }
+
+        // Vérifier l'index
+        if index < 0 {
+            print("Block: Invalid index")
+            return false
+        }
+
+        // Vérifier le timestamp
+        let currentTime = Int(Date().timeIntervalSince1970)
+        if timestamp > currentTime + 7200 || timestamp < 1701388800 { // 2h dans le futur max
+            print("Block: Invalid timestamp")
+            return false
+        }
+
+        // Vérifier les transactions
+        for transaction in transactions {
+            if !transaction.isValid() {
+                print("Block: Invalid transaction found")
+                return false
+            }
+
+            // Vérifier qu'il n'y a qu'une seule récompense de minage
+            if transaction.type == "MINING_REWARD" {
+                if transactions.filter({ $0.type == "MINING_REWARD" }).count > 1 {
+                    print("Block: Multiple mining rewards found")
+                    return false
+                }
+            }
+        }
+
+        return true
+    }
+
+    func generateHash() -> String {
+        let txData = transactions.map {
+            "\($0.sender)\($0.receiver)\($0.amount)\($0.type)"
+        }.joined()
+
+        return "\(previousHash)\(txData)\(String(timestamp))\(String(index))\(String(nonce))".sha256()
+    }
+}
+
+// Structure pour suivre la progression du mining
+struct MiningProgress {
+    let hashesChecked: Int
+    let hashRate: Double
+    let elapsedTime: TimeInterval
+    let estimatedTimeRemaining: TimeInterval?
+}
+
+// Erreurs possibles pendant le mining
+enum MiningError: Error {
+    case cancelled
+    case failed(String)
+}