import os
import re

username_and_password = {}
wrong_time = 0
while True:
    print("\nWelcome to system!")
    # press 1 to login,2 to register
    print("1.login\n2.register")
    # scan a number from keyboards
    input_number = input("Enter a number\n")
    if input_number == "1":
        input_username = input("Enter a username\n")
        input_password = input("Enter a password\n")
        # check if the username and password are in the dictionary
        if input_username in username_and_password:
            if input_password == username_and_password[input_username]:
                print("Login successfully!")
                exit()
            else:
                print("Wrong password!")
                wrong_time += 1
                if wrong_time == 3:
                    print("Too many wrong password!")
                    exit()
        else:
            print("Wrong username!")
    elif input_number == "2":
        input_username = input("Enter a username\n")
        input_password = input("Enter a password\n")
        # check if the username is in the dictionary  it is duplicate
        if input_username in username_and_password:
            print("The username is duplicate!")
        else:
            error_message = False
            sensitive_words = ["傻", "蠢", "笨", "呆", "愚"]
            # check if the username contains sensitive words
            for word in sensitive_words:
                if word in input_username:
                    print("The username contains blacklist words!")
                    # replace \u50bb\u8822\u7b28\u5446\u611a in input_username with *
                    input_username = re.sub('\u50bb', "*", input_username)
                    input_username = re.sub('\u8822', "*", input_username)
                    input_username = re.sub('\u7b28', "*", input_username)
                    input_username = re.sub('\u5446', "*", input_username)
                    input_username = re.sub('\u611a', "*", input_username)

                    print("The username is changed to:", input_username)
                    error_message = True
                    break
            # check password length
            if len(input_password) < 6:
                print("The password is too short!")
                error_message = True
            # check if the password contain alphabet and number
            if not re.search("[a-zA-Z]", input_password):
                print("The password must contain alphabet!")
                error_message = True
            if not re.search("[0-9]", input_password):
                print("The password must contain number!")
                error_message = True
            if error_message:
                print("Register failed!")
            else:
                # add the username and password to the dictionary
                username_and_password[input_username] = input_password
                print("Register successfully!")
                # back to menu
                continue

    else:
        print("Wrong number!")  # if the input is not 1 or 2, it will print wrong number
    os.system("pause")
    os.system("cls")
    # clear the screen