import json

admin = False

def firstMenu():
    print("Pick an option")
    menu = [
        "Login",
        "New User",
        "List of users"
    ]

    for n in range(len(menu)):
        print("{} {}".format(n+1, menu[n]))

    given = int(input())

    if given == 1:
        login()
    elif given == 2:
        addAccount()
    elif given == 3:
        listAccounts()
    else:
        print("sorry didn't understand")

def login():
    username = input("username: ")
    password = input("password: ")
    if authenticate(username,password):
        print("you exist")
        main()
    else:
        print ("Sorry, no account matches: Make an account!")
        addAccount()

def userFileExists(username):
    print()

def listAccounts():
   accounts =loadAccount()
   for account in accounts:
       print ("{username}".format(**account))
       main()

def authenticate(whichName,theirPassword):
    theUsers = loadAccount()
    for person in theUsers:
        if (person['username']== whichName):
            if (person['password'] == theirPassword):
                return True

def loadAccount():
    with open('users.json') as f:
        theUsers = json.loads(f.read())
        return theUsers

def addAccount():
    stuff = {}
    stuff['username'] = input("username: ")
    stuff['password'] = input("password: ")
    original = loadAccount()
    original.append(stuff)
    with open('users.json','w')as f:
        f.write(json.dumps(original))
    main()

def main():
    firstMenu()

main()