'''
Handles all Login/Sign Up logic - calling on database module where needed
'''
import os
import ast
import hashlib
from passman.functions import getUserInput, quit
from passman.database import checkUserCredentials, addUser, \
        setDBUsername, pullDatabase, checkConnection
from passman.JSON import setOfflineUsername

############################################################
# Login Functions
############################################################

def handleLogin():
    '''
    Handles main menu login/signup functionality
    '''
    prompt = "Do you want to log in or start a new account?\n"\
            + "(Enter the number of your choice)\n\n" \
            + "(1) Log In\n"\
            + "(2) Start New Account\n"
    option = getUserInput(prompt)
    if option == "1":
        loginUser()

    elif option == "2":
        signUpUser()

    else:
        print("Please enter a valid option\n")
        handleLogin() # back to the beginning

def loginUser(username=""):
    '''
    Handles login for online database
    '''
    isCommandLine = username

    username = username if username else getUserInput("Please enter your username")

    if not checkConnection("test"):
        handleOfflineLogin(username)

    pw  = getUserInput("Please enter your password", True)
    inc = 0
    while not checkUserCredentials(pw, username) and inc < 2:
        print("Sorry, that doesn't match our records")
        pw   = getUserInput("Please enter your password", True)
        inc += 1

    if inc >= 2: # three strikes; you're out
        quit()

    setDBUsername(pw, username)
    pullDatabase()
    return True

def signUpUser():
    '''
    Handles sign up for new users
    '''
    if not checkConnection("test"):
        print("Sorry - cannot create user without internet connection")
        quit()

    username = getUserInput("Please enter your username")
    pw       = getUserInput("Please enter your password", True)

    if addUser(username, pw):
        setDBUsername(pw, username)
        pullDatabase()
        return True
    else:
        print("Sorry, that username is already taken")
        signUpUser()

def getOfflineUsername(username=""):
    '''
    Checks if a user has a local database saved. Reprompts for new 
    username if none is found.
    '''
    if username:
        file_path = os.path.expanduser("~/.passman/{}.json".format(username))
    else:
        username = getUserInput("Please enter your username")
        file_path = os.path.expanduser("~/.passman/{}.json".format(username))

    while (not os.path.isfile(file_path)) or (file_path == ".json"):
        print("Sorry, that doesn't match our records")
        username = getUserInput("Please enter your username")
        file_path = os.path.expanduser("~/.passman/{}.json".format(username))

    return username

def getOfflinePassword(data):
    '''
    Checks a password against that stored in the local database
    '''
    pw       = getUserInput("Please enter your password", True)
    key      = hashlib.sha256(pw.encode()).digest()
    hashedpw = hashlib.sha512(pw.encode('utf-8')).hexdigest()
    inc      = 0

    while hashedpw != data['password'] and inc < 2:
        print("Wrong password")
        pw       = getUserInput("Please enter your password", True)
        key      = hashlib.sha256(pw.encode()).digest()
        hashedpw = hashlib.sha512(pw.encode('utf-8')).hexdigest()
        inc     += 1
    if inc >= 2: # three strikes; you're out
        quit()

    return key

def handleOfflineLogin(username=""):
    '''
    Logs in users to local database in lieu of internet connection
    '''
    print("NOTE: No connection")
    print("Continuing in offline mode. \nYou can retrieve any service data, " \
            +"but you will not be \nable to edit or upload data\n\n")

    username  = getOfflineUsername(username)
    file_path = os.path.expanduser("~/.passman/{}.json".format(username))
    dir_path  = os.path.expanduser("~/.passman")

    if not os.path.isdir(dir_path):
        print("Sorry, no local users found")
        quit()

    with open(file_path) as data_file:
        data = data_file.read()

    if data:
        data = ast.literal_eval(data) # from string to dict
    else:
        print("Sorry, cannot get data")
        quit()

    key = getOfflinePassword(data)

    setOfflineUsername(username, key)
    return True
