import statistics as s #To create maths qs. like mean, median etc.. and allows me to write statistic as s to decrease typing time
import random #random letters to add to a name (to make it unique), also random questions
import string
import sys #system/ sys.end to end the program
import time
import json

def adlogin():#This is the function responsible for the login of the admin
    print("Please enter the administrator's username")

def stlogin():#This is the function responsible for the login of students
    print ("you have chosen to login")

    with open("file.txt") as read:

        username = input("Username:")

    try:
        data = json.load(read)

    except ValueError:
        print("no users registered. Sign up!!!")

    try:
        data = json.load(read)

    except json.decoder.JSONDecodeError as je:
        print('invalid json: %s' % je)
        print ("no users registered. Sign up!!!")
        time.sleep(1)
        entrance()


    data = json.load(read)
    inputted_user = input("username")
    if inputted_user in open('file.txt').read():
        if type(inputted_user) == str:
            account = json.loads(inputted_user)
            inputted_password = input(" Password: ")
            if inputted_password == account["password"]:
                print("logged in")
            else:
                print("incorrect login")
        else:
         print("incorrect login")
    else:
        print("incorrect login")



def signup():
    print ("you have chosen to sign up.")

    name = input("Please enter your name.\n {Name}: ")

    nameforinfo = name

    age = input("Please enter your age:\n[This program is optimised for those 11-17]\n{age}: ")

    while int(age) < 10 or int(age) > 18:# loop created until a valid age entered.
       age = input("What is your age?\n{age}:  ")

    username = (name[0:3] + age)

    while username in open('userinfo.txt').read():#checking the availability of username
        username += random.choice(string.ascii_letters)

    print ("your username is " + username)

    password = input("Make a password (longer than 5 letters).\n{password}:")

    while len(password) < 3:
        print("password is too short")
        password = input("Make a password (longer than 5 letters).\n{password}:")
    userinfo = open("userinfo.txt", 'w')
    userinfo.write("User's Info\n")
    userinfo.close()
    with open("userinfo.txt", 'w') as w:

        w.write(
            json.dumps(
                {
                      "user": {
                                    "username": username,
                                    "name": nameforinfo,
                                    "age" : age,
                                    "password": password
                            }
                 }
            )
        )
    entrance()

def close():#This is the function which quits the program.
    closebinary =input("Are you sure you want to quit? {yes} {no}\n{yes/no}: ")
    if closebinary == "yes":
        print("See you next time")
        time.sleep(2)
        sys.exit
    elif closebinary == "no":
        print("Glad you're staying with us.")
        time.sleep(2)
        entrance()
    else:
        invalid_answer()

def invalid_answer():
    print("Thats not a valid answer.\nI'll prompt you to the start.")
    time.sleep(2)
    entrance()

def entrance():
    print("Hello and welcome to this quiz")


    answer = input("{1} Student Login\n{2}Admin Login:\n{3}Signup\n{4}Exit\n{#}: ")
    if answer == "1":
        stlogin()
    elif answer == "2" :
        adlogin()
    elif answer == "3" :
        signup()
    elif answer == "4" :
        close()
    else:
        invalid_answer()
        entrance()


entrance()