✨ Enhance blockchain

SwiftChainCore/Models/Transaction.swift

@@ -0,0 +1,96 @@
+//
+//  File.swift
+//
+//
+//  Created by Victor BODINAUD on 31/03/2021.
+//
+
+import Foundation
+
+public class Transaction: Codable {
+    public let sender: String
+    public let receiver: String
+    public let amount: Int
+    public let type: String
+    public var signature: Data?
+    public var senderPublicKey: Data?
+
+    public init(sender: String, receiver: String, amount: Int, type: String) {
+        self.sender = sender
+        self.receiver = receiver
+        self.amount = amount
+        self.type = type
+    }
+
+    // Pour encoder/décoder les Data optionnels
+    enum CodingKeys: String, CodingKey {
+        case sender, receiver, amount, type, signature, senderPublicKey
+    }
+
+    func messageToSign() -> Data {
+        return "\(sender)\(receiver)\(amount)\(type)".data(using: .utf8)!
+    }
+
+    func isSignatureValid() -> Bool {
+        guard let signature = signature,
+              let publicKeyData = senderPublicKey
+        else {
+            return false
+        }
+
+        if type == "MINING_REWARD" {
+            return true
+        }
+
+        return Wallet.verifySignature(
+            for: self,
+            signature: signature,
+            publicKeyData: publicKeyData
+        )
+    }
+
+    func isValid() -> Bool {
+        // Vérifications de base
+        if amount <= 0 {
+            print("Transaction: Amount must be positive")
+            return false
+        }
+
+        if sender.isEmpty || receiver.isEmpty {
+            print("Transaction: Invalid addresses")
+            return false
+        }
+
+        // Vérification du type
+        if !["TRANSFER", "MINING_REWARD"].contains(type) {
+            print("Transaction: Invalid type")
+            return false
+        }
+
+        // Vérifications spécifiques selon le type
+        if type == "MINING_REWARD" {
+            if sender != "SYSTEM" {
+                print("Transaction: Mining reward must come from SYSTEM")
+                return false
+            }
+            if amount != 50 { // La récompense doit être exactement 50
+                print("Transaction: Invalid mining reward amount")
+                return false
+            }
+            return true // Pas besoin de vérifier la signature pour les récompenses
+        }
+
+        // Pour les transactions normales
+        if !isSignatureValid() {
+            print("Transaction: Invalid signature")
+            return false
+        }
+
+        if sender == receiver {
+            print("Transaction: Sender cannot be receiver")
+            return false
+        }
+
+        return true
+    }
+}