CLI Chat App Template

import hashlib

class User:
def __init__(self, username, password_hash, profile):
self.username = username
self.password_hash = password_hash
self.profile = profile
self.friends = []
self.direct_messages = []

class Message:
def __init__(self, sender, receiver, content):
self.sender = sender
self.receiver = receiver
self.content = content

users = {}
messages = []

def generate_password_hash(password):
hash_object = hashlib.sha256(password.encode())
return hash_object.hexdigest()

def create_account():
new_user = User("", "", "")
new_user.username = input("Enter your desired username: ")

if new_user.username in users:
print("Username already exists. Please choose another username.")
return

new_user.password_hash = generate_password_hash(input("Enter your password: "))
new_user.profile = input("Create your profile: ")

users[new_user.username] = new_user
print("Account created successfully!")

def authenticate_user(username, password):
if username in users:
entered_password_hash = generate_password_hash(password)
if entered_password_hash == users[username].password_hash:
print("Authentication successful!")
else :
print("Authentication failed. Incorrect password.")
else :
print("User not found.")

def delete_account(username):
if username in users:
del users[username]
print("Account deleted successfully!")
else :
print("User not found.")

def encrypt_message(message, key):
encrypted_message = ""
for char in message:
if char.isalpha():
encrypted_message += chr((ord(char) + key - ord('A')) % 26 + ord('A'))
else :
encrypted_message += char
return encrypted_message

def secure_send_message(sender, receiver, content):
new_message = Message(sender, receiver, content)
messages.append(new_message)

if receiver in users:
encrypted_content = encrypt_message(content, 3) # Example Caesar cipher with key 3
users[receiver].direct_messages.append(encrypted_content)

def rotate_password(username):
if username in users:
new_password = input("Enter your new password: ")
users[username].password_hash = generate_password_hash(new_password)
print("Password rotated successfully!")
else :
print("User not found.")

def display_messages(username):
if username in users:
print(f"Displaying messages for {
    username
}:")
for message in messages:
if message.receiver == username or message.sender == username:
print(f" {
    message.sender
} -> {
    message.receiver
}: {
    message.content
}")
else :
print("User not found.")

def display_direct_messages(username):
if username in users:
print(f"Displaying direct messages for {
    username
}:")
for encrypted_message in users[username].direct_messages:
decrypted_message = encrypt_message(encrypted_message, -3) # Decrypt with key -3
print(f" {
    username
} received: {
    decrypted_message
}")
else :
print("User not found.")

def main():
choice = None

while choice != 0:
print("\n--- Secure Messaging Tool ---")
print("1. Create Account")
print("2. Authenticate User")
print("3. Delete Account")
print("4. Send Message")
print("5. Rotate Password")
print("6. Display Messages")
print("7. Display Direct Messages")
print("0. Exit")

choice = int(input("Enter your choice: "))

if choice == 1:
create_account()
elif choice == 2:
username = input("Enter your username: ")
password = input("Enter your password: ")
authenticate_user(username, password)
elif choice == 3:
username = input("Enter your username to delete your account: ")
delete_account(username)
elif choice == 4:
sender = input("Enter sender username: ")
receiver = input("Enter receiver username: ")
content = input("Enter message content: ")
secure_send_message(sender, receiver, content)
elif choice == 5:
username = input("Enter your username: ")
rotate_password(username)
elif choice == 6:
username = input("Enter username to display messages: ")
display_messages(username)
elif choice == 7:
username = input("Enter your username: ")
display_direct_messages(username)
elif choice == 0:
print("Exiting program.")
else :
print("Invalid choice. Try again.")

if __name__ == "__main__":
main()