import hashlib
import time
from typing import List

class Block:
    def __init__(self, index: int, previous_hash: str, timestamp: int, transactions: List[dict]):
        self.index = index
        self.previous_hash = previous_hash
        self.timestamp = timestamp
        self.transactions = transactions
        self.hash = self.calculate_hash()

    def calculate_hash(self):
        block_string = f"{self.index}{self.previous_hash}{self.timestamp}{self.transactions}"
        return hashlib.sha256(block_string.encode()).hexdigest()

class Blockchain:
    def __init__(self):
        self.chain = [self.create_genesis_block()]

    def create_genesis_block(self):
        return Block(0, "0", int(time.time()), [{"sender": "genesis", "receiver": "network", "amount": 0}])

    def get_latest_block(self):
        return self.chain[-1]

    def add_block(self, transactions: List[dict]):
        latest_block = self.get_latest_block()
        new_block = Block(latest_block.index + 1, latest_block.hash, int(time.time()), transactions)
        self.chain.append(new_block)

    def is_chain_valid(self):
        for i in range(1, len(self.chain)):
            current_block = self.chain[i]
            previous_block = self.chain[i-1]
            print(f"current_block.hash : {current_block.hash} , current_block.calculate_hash : {current_block.calculate_hash()}")
            print(f"current_block.previous_hash : {current_block.previous_hash} , previous_block.hash : {previous_block.hash}")
            if current_block.hash != current_block.calculate_hash():
                return False
            if current_block.previous_hash != previous_block.hash:
                return False
        return True

# ブロックチェーンの初期化
my_blockchain = Blockchain()

# 取引の例
transactions1 = [
    {"sender": "Alice", "receiver": "Bob", "amount": 50},
    {"sender": "Bob", "receiver": "Charlie", "amount": 30}
]
my_blockchain.add_block(transactions1)

transactions2 = [
    {"sender": "Alice", "receiver": "Charlie", "amount": 20},
    {"sender": "Charlie", "receiver": "Bob", "amount": 10}
]
my_blockchain.add_block(transactions2)

# ブロックチェーンの内容を表示
for block in my_blockchain.chain:
    print(f"Index: {block.index}")
    print(f"Previous Hash: {block.previous_hash}")
    print(f"Timestamp: {block.timestamp}")
    print(f"Transactions: {block.transactions}")
    print(f"Hash: {block.hash}")
    print("-" * 30)

# ブロックチェーンの有効性を検証
print("Is blockchain valid?", my_blockchain.is_chain_valid())

import hashlib
import time

class Block:
    def __init__(self, index, previous_hash, timestamp, data, nonce=0):
        self.index = index
        self.previous_hash = previous_hash
        self.timestamp = timestamp
        self.data = data
        self.nonce = nonce
        self.hash = self.calculate_hash()

    def calculate_hash(self):
        value = (str(self.index) + str(self.previous_hash) + str(self.timestamp) +
                 str(self.data) + str(self.nonce)).encode()
        return hashlib.sha256(value).hexdigest()

    def mine_block(self, difficulty):
        target = '0' * difficulty
        while self.hash[:difficulty] != target:
            self.nonce += 1
            self.hash = self.calculate_hash()
        print(f"Block mined: {self.hash}")

class Blockchain:
    def __init__(self):
        self.chain = [self.create_genesis_block()]
        self.difficulty = 5  # 難易度

    def create_genesis_block(self):
        return Block(0, "0", time.time(), "Genesis Block")

    def get_latest_block(self):
        return self.chain[-1]

    def add_block(self, new_block):
        new_block.previous_hash = self.get_latest_block().hash
        new_block.mine_block(self.difficulty)
        self.chain.append(new_block)

# ブロックチェーンの初期化
blockchain = Blockchain()

# 新しいブロックを追加
print("Mining block 1...")
new_block = Block(1, "", time.time(), "Block 1 Data")
blockchain.add_block(new_block)

print("Mining block 2...")
new_block = Block(2, "", time.time(), "Block 2 Data")
blockchain.add_block(new_block)

print("Mining block 3...")
new_block = Block(3, "", time.time(), "Block 3 Data")
blockchain.add_block(new_block)