def mine_block(self):
response = {
'block': False,
'wallet': self.hosting_node_id is not None,
}
# Check wallet address. We can't mine without wallet address.
if not self.hosting_node_id:
response['message'] = 'Create or restore wallet'
return response
# Check chain sync with other peer nodes
if self.resolve_conflicts:
print('Blockchain has OLDER STATE. Need update node blockchain!')
response['message'] = 'Blockchain has OLDER STATE. Update it!'
return response
# Check signatures opened transactions before adding to block
for tx in self.__open_transactions:
message = tx.sender + tx.recipient + str(tx.amount)
if not Wallet.check_signature(tx.public_key, message,
tx.signature):
response[
'message'] = f'Transaction to {tx.recipient} has bad signature'
return response
# Reward transaction for miners
reward_transaction = Transaction(
sender='MINING_REWARD_BOT',
public_key='MINING_REWARD_BOT_PUBLIC_KEY',
signature='MINING_REWARD_BOT_SIGNATURE',
recipient=self.hosting_node_id,
amount=MINING_REWARD)
# Add reward transaction
self.__open_transactions.append(reward_transaction)
# IMPORTANT: Proof of Work should NOT INCLUDE REWARD TRANSACTION
nonce = self.proof_of_work()
# Create block
block = Block(index=len(self.__chain),
previous_hash=hash_block(self.__chain[-1]),
transactions=self.__open_transactions[:],
nonce=nonce)
# Convert Block Object to dictionary
block_dict = self.block_as_dict(block)
# Broadcast new block to other nodes
result = self.broadcast_to_other_nodes(block_dict)
if result['ok']:
# Add block to blockchain and save updated blockchain
self.__chain.append(block)
self.save_blockchain()
# Clear open transactions and save updated
self.__open_transactions.clear()
self.save_open_transactions()
response['block'] = block_dict
response['message'] = f'Block successfuly added to blockchain'
else:
response['message'] = '\n'.join(result['errors'])
return response
