Create blockchain_gui.py

Author: rogers-cyber

130-Blockchain-implementation/blockchain_gui.py

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+import hashlib
+import json
+import os
+import time
+import uuid
+from dataclasses import dataclass, asdict
+from typing import List
+import tkinter as tk
+from tkinter import messagebox
+
+import ttkbootstrap as tb
+from ttkbootstrap.constants import *
+from ttkbootstrap.scrolled import ScrolledText
+
+# ---------------- CONFIG ---------------- #
+CHAIN_FILE = "blockchain.json"
+DIFFICULTY = 4
+MINING_REWARD = 50
+
+# ---------------- DATA STRUCTURES ---------------- #
+@dataclass
+class Transaction:
+    sender: str
+    recipient: str
+    amount: float
+    timestamp: float
+
+@dataclass
+class Block:
+    index: int
+    timestamp: float
+    transactions: List[Transaction]
+    previous_hash: str
+    nonce: int = 0
+    hash: str = ""
+
+    def compute_hash(self):
+        data = {
+            "index": self.index,
+            "timestamp": self.timestamp,
+            "transactions": [asdict(tx) for tx in self.transactions],
+            "previous_hash": self.previous_hash,
+            "nonce": self.nonce,
+        }
+        return hashlib.sha256(json.dumps(data, sort_keys=True).encode()).hexdigest()
+
+# ---------------- BLOCKCHAIN ---------------- #
+class Blockchain:
+    def __init__(self):
+        self.chain: List[Block] = []
+        self.pending: List[Transaction] = []
+        self.load()
+
+    def create_genesis(self):
+        block = Block(0, time.time(), [], "0")
+        block.hash = block.compute_hash()
+        self.chain.append(block)
+        self.save()
+
+    def load(self):
+        if not os.path.exists(CHAIN_FILE):
+            self.create_genesis()
+            return
+        with open(CHAIN_FILE, "r") as f:
+            data = json.load(f)
+            self.chain = [self.dict_to_block(b) for b in data]
+
+    def save(self):
+        with open(CHAIN_FILE, "w") as f:
+            json.dump([self.block_to_dict(b) for b in self.chain], f, indent=2)
+
+    def add_transaction(self, sender, recipient, amount):
+        self.pending.append(Transaction(sender, recipient, amount, time.time()))
+
+    def mine(self, miner):
+        if not self.pending:
+            return None
+
+        self.pending.append(Transaction("SYSTEM", miner, MINING_REWARD, time.time()))
+
+        block = Block(
+            index=len(self.chain),
+            timestamp=time.time(),
+            transactions=self.pending.copy(),
+            previous_hash=self.chain[-1].hash,
+        )
+
+        while True:
+            block.hash = block.compute_hash()
+            if block.hash.startswith("0" * DIFFICULTY):
+                break
+            block.nonce += 1
+
+        self.chain.append(block)
+        self.pending.clear()
+        self.save()
+        return block
+
+    def is_valid(self):
+        for i in range(1, len(self.chain)):
+            c, p = self.chain[i], self.chain[i - 1]
+            if c.hash != c.compute_hash():
+                return False
+            if c.previous_hash != p.hash:
+                return False
+        return True
+
+    def balance(self, addr):
+        bal = 0
+        for b in self.chain:
+            for t in b.transactions:
+                if t.sender == addr:
+                    bal -= t.amount
+                if t.recipient == addr:
+                    bal += t.amount
+        return bal
+
+    def block_to_dict(self, b):
+        return {
+            "index": b.index,
+            "timestamp": b.timestamp,
+            "transactions": [asdict(t) for t in b.transactions],
+            "previous_hash": b.previous_hash,
+            "nonce": b.nonce,
+            "hash": b.hash,
+        }
+
+    def dict_to_block(self, d):
+        txs = [Transaction(**t) for t in d["transactions"]]
+        return Block(d["index"], d["timestamp"], txs, d["previous_hash"], d["nonce"], d["hash"])
+
+# ---------------- GUI ---------------- #
+class BlockchainGUI:
+    def __init__(self, app):
+        self.app = app
+        self.chain = Blockchain()
+        self.wallet = uuid.uuid4().hex
+
+        self.build_ui()
+        self.refresh()
+
+    def build_ui(self):
+        self.app.title("🔗 Blockchain GUI")
+        self.app.geometry("1000x700")
+
+        top = tb.Frame(self.app, padding=15)
+        top.pack(fill=X)
+
+        tb.Label(top, text="🔗 Blockchain Explorer", font=("Segoe UI", 18, "bold")).pack(anchor=W)
+        self.balance_lbl = tb.Label(top, text="")
+        self.balance_lbl.pack(anchor=W, pady=5)
+        tb.Label(top, text=f"👛 Wallet: {self.wallet}", font=("Segoe UI", 9)).pack(anchor=W)
+
+        form = tb.Labelframe(self.app, text="Create Transaction", padding=10)
+        form.pack(fill=X, padx=15, pady=10)
+
+        self.to_var = tk.StringVar()
+        self.amount_var = tk.DoubleVar()
+
+        tb.Entry(form, textvariable=self.to_var).pack(fill=X, pady=5)
+        tb.Entry(form, textvariable=self.amount_var).pack(fill=X, pady=5)
+
+        tb.Button(form, text="Send Transaction", bootstyle=SUCCESS, command=self.send_tx).pack()
+
+        actions = tb.Frame(self.app, padding=10)
+        actions.pack(fill=X)
+
+        tb.Button(actions, text="⛏ Mine Block", bootstyle=WARNING, command=self.mine).pack(side=LEFT, padx=5)
+        tb.Button(actions, text="✔ Validate Chain", bootstyle=INFO, command=self.validate).pack(side=LEFT)
+
+        view = tb.Labelframe(self.app, text="Blockchain", padding=10)
+        view.pack(fill=BOTH, expand=True, padx=15, pady=10)
+
+        self.text = ScrolledText(view)
+        self.text.pack(fill=BOTH, expand=True)
+        self.text.text.configure(state="disabled")
+
+    def refresh(self):
+        self.balance_lbl.config(text=f"💰 Balance: {self.chain.balance(self.wallet)}")
+        self.text.text.configure(state="normal")
+        self.text.text.delete("1.0", END)
+        for block in self.chain.chain:
+            self.text.text.insert(END, json.dumps(self.chain.block_to_dict(block), indent=2))
+            self.text.text.insert(END, "\n\n")
+        self.text.text.configure(state="disabled")
+
+    def send_tx(self):
+        if not self.to_var.get() or self.amount_var.get() <= 0:
+            messagebox.showerror("Error", "Invalid transaction")
+            return
+        self.chain.add_transaction(self.wallet, self.to_var.get(), self.amount_var.get())
+        messagebox.showinfo("Success", "Transaction added")
+
+    def mine(self):
+        block = self.chain.mine(self.wallet)
+        if not block:
+            messagebox.showwarning("Mine", "No transactions")
+        else:
+            messagebox.showinfo("Mine", f"Block #{block.index} mined!")
+            self.refresh()
+
+    def validate(self):
+        ok = self.chain.is_valid()
+        messagebox.showinfo("Validation", "Blockchain is valid ✔" if ok else "Blockchain corrupted ❌")
+
+# ---------------- RUN ---------------- #
+if __name__ == "__main__":
+    app = tb.Window(themename="darkly")
+    BlockchainGUI(app)
+    app.mainloop()