class Node:
"""The node which runs the local blockchain instance.
Attributes:
:id: The id of the node.
:blockchain: The blockchain which is run by this node.
"""
def __init__(self):
# self.id = str(uuid4())
self.wallet = Wallet()
self.wallet.create_keys()
self.blockchain = Blockchain(self.wallet.public_key)
def get_transaction_value(self):
""" Returns the input of the user (a new transaction amount) as a float. """
# Get the user input, transform it from a string to a float and store it in user_input
tx_recipient = input('Enter the recipient of the transaction: ')
tx_amount = float(input('Your transaction amount please: '))
return tx_recipient, tx_amount
def get_loan_request(self):
'''Returns the inputs of the user for the loan request'''
tx_amount = float(input('Enter the loan amount: '))
tx_length = float(input('Enter your desired loan term: '))
tx_apr = float(input('Enter your desired apr: '))
return tx_amount, tx_length, tx_apr
def get_user_choice(self):
"""Prompts the user for its choice and return it."""
user_input = input('Your choice: ')
return user_input
def print_blockchain_elements(self):
""" Output all blocks of the blockchain. """
# Output the blockchain list to the console
for block in self.blockchain.chain:
print('Outputting Block')
print(block)
else:
print('-' * 20)
def listen_for_input(self):
"""Starts the node and waits for user input."""
waiting_for_input = True
# A while loop for the user input interface
# It's a loop that exits once waiting_for_input becomes False or when break is called
while waiting_for_input:
print('Please choose')
print('1: Add a new transaction value')
print('2: Mine a new block')
print('3: Output the blockchain blocks')
print('4: Check transaction validity')
print('5: Create wallet')
print('6: Load wallet')
print('7: Save keys')
print('8: Request Loan')
print('q: Quit')
user_choice = self.get_user_choice()
if user_choice == '1':
tx_data = self.get_transaction_value()
recipient, amount = tx_data
# Add the transaction amount to the blockchain
signature = self.wallet.sign_transaction(self.wallet.public_key, recipient, amount)
if self.blockchain.add_transaction(recipient, self.wallet.public_key, signature, amount=amount):
print('Added transaction!')
else:
print('Transaction failed!')
print(self.blockchain.get_open_transactions())
elif user_choice == '2':
if not self.blockchain.mine_block():
print('Mining failed. Got no wallet?')
elif user_choice == '3':
self.print_blockchain_elements()
elif user_choice == '4':
if Verification.verify_transactions(self.blockchain.get_open_transactions(), self.blockchain.get_balance):
print('All transactions are valid')
else:
print('There are invalid transactions')
elif user_choice == '5':
self.wallet.create_keys()
self.blockchain = Blockchain(self.wallet.public_key)
elif user_choice == '6':
self.wallet.load_keys()
self.blockchain = Blockchain(self.wallet.public_key)
elif user_choice == '7':
self.wallet.save_keys()
elif user_choice == '8':
first_time = self.blockchain.first_time_borrow()
loan_data = self.get_loan_request()
tx_amount, tx_length, tx_apr = loan_data
credit_score = self.blockchain.check_credit_score(first_time)
self.blockchain.accept_loan(credit_score,tx_amount,tx_length, tx_apr)
print('Loan request successful')
print(self.blockchain.get_open_transactions())
elif user_choice == 'q':
# This will lead to the loop to exist because it's running condition becomes False
waiting_for_input = False
else:
print('Input was invalid, please pick a value from the list!')
if not Verification.verify_chain(self.blockchain.chain):
self.print_blockchain_elements()
print('Invalid blockchain!')
# Break out of the loop
break
print('Balance of {}: {:6.2f}'.format(self.wallet.public_key, self.blockchain.get_balance()))
else:
print('User left!')
print('Done!')
