import re
import datetime
import sys

def mainMenu():
    print("Welcome - Please select from the following selections below:\n Press 1 to Login\n Press 2 to Create an Account")
    selection = int(input(""))

    if selection == 1:
        login()# Since the user already has an account, this will take them to login.
    else:
        registerAccount() #This will take the user to register

def menu():
    print("\nWelcome",login_info[0],"to the main menu - select from the options below:\n\nPress 1 to change password \n\nPress 2 to view user details \n\nPress 3 to list all users \n\nPress 4 to check your password strength")
    selection = int(input(""))

    if selection == 1:
        changePassword()
    if selection == 2:
        userInformation()


def registerAccount():
    global password, username

    username = input("Please input your desired username")
    while True:
        password = input("Please input your desired password")
        if len(password) < 6: #This loop to make sure the user inputs a valid password.
            print("\nYou must enter a password with a minimum of 6 characters\n")
        elif len(password) > 12:
            print("\nPassword is too long!")
        else:
            break
    registerUserInformation()

def registerUserInformation():
    global fullName, emailAddress, dateofBirth
    fullName = input("Please enter your full name")
    print("\nPlease enter a valid email address")
    while True:
        emailAddress = input("")
        addressToVerify = emailAddress.lower() #Turns the email to all lower case before verifying address
        match = re.match('^[_a-z0-9-]+(\.[_a-z0-9-]+)*@[a-z0-9-]+(\.[a-z0-9-]+)*(\.[a-z]{2,4})$', addressToVerify)

        if match == None:
            print("ERROR! The e-mail you have entered is NOT valid, please try again:")
        else:
            break
    print("\nPlease enter your date of birthday (DD/MM/YYYY) *Include the /'s!:")

    while True:
        dateofBirth = input("Enter the date in format 'dd/mm/yy' : ")
        day,month,year = dateofBirth.split('/')
        isValidDate = True
        try:
            datetime.datetime(int(year),int(month),int(day))
        except ValueError :
            isValidDate = False
        if(isValidDate) :
            print ("Account created! Logging in...")
            break
        else :
            print ("Please enter the date in the correct formart:")
    storingInformation()

def storingInformation(): #!IMPORTANT! This is done after the account/user information so that if the program closes that information will NOT be stored!!
    file = open("Accounts.txt","a") #This ensures that all information will be collected and then stored in this function.
    file.write(username)
    file.write(" ")
    file.write(password)
    file.write("\n")
    file.close()

    file = open("UserInformation.txt","a")
    file.write(fullName)
    file.write(" ")
    file.write(emailAddress)
    file.write(" ")
    file.write(dateofBirth)
    file.write("\n")
    file.close()
    print("\nAccount Created! You are now able to log in\n")
    mainMenu()

def login():
    count = 0
    while True:
        global login_info, userloc
        username = input("Please enter your username")
        password = input("Please enter your password")
        userloc = -1
        count += 1
        if count == 3:
            print("You have exceeded the maximum amount of login attempts. Exiting...")
            break
        with open('Accounts.txt') as inputFile:
            login_info = [ line.strip().split() for line in inputFile]
            print(login_info)
        for pos, line in enumerate(login_info): # Read the lines
            #login_data = line.strip().split() # Split on the space, and store the results in a list of two strings
            if username == line[0] and password == line[1]:
                print("\nCorrect credentials! You are now logging in...")
                userloc = pos
                menu()
                return True
        else:
            print("Incorrect credentials.")

def changePassword():
    print("Are you sure you want to change your password?\nPress 1 for Yes \nPress 2 for No")
    selection = int(input())
    if selection == 1:
        print("Please enter your new password")
        newPass = input("")
        login_info[userloc][1] = newPass
        with open("Accounts.txt", 'w') as of:
            for pair in login_info:
                of.write(pair[0] + " " + pair[1] + "\n")
    else:
        menu()

def userInformation():
    print(login_info[0], ",here is your registered information:\n")
    for line in open("UserInformation.txt","r").readlines():
        user_info = line.split()
    print("Your name is:",user_info[0])
    print("Your e-mail is:",user_info[1])
    print("Your date of birth is:",user_info[2])
    print("\n Press 1 to return to the main menu")
    selection = int(input())
    if selection == True:
        menu()

def passCheck():
    pass
mainMenu()