import json #json.load(), json.dump()
import time #time.sleep()
import csv #csv.reader(), csv.writer()
import sys #sys.exit()
import os #os.path.isfile()
import configparser #configparser.ConfigParser()
import string #string.ascii_letters


def start():
    user_input = input_checker("""1: Login
2: Register
Please choose one of the above options: """,(1,2))

    option_selector((login,register),(1,2),user_input)()

def input_checker(question, valid_inputs):
    user_input = input(question)

    while 1:
        while [i for i in valid_inputs if type(i) == int]:
            try:
                user_input = int(user_input)
                break
            except ValueError:
                user_input = input("Please enter a valid number: ")
        try:
            if not [x for x in user_input if x not in valid_inputs]:
                break
            user_input = input("Please enter a valid input: ")
        except TypeError:
            if user_input in valid_inputs:
                break
            user_input = input("Please enter a valid input: ")

    return user_input

def option_selector(options,numbers,user_input):
    option_dict = dict(zip(numbers, options))
    return option_dict[user_input]

def register():
    name = input_checker("Please enter your name: ",tuple(string.ascii_letters)).title()

    age = input_checker("Please enter your age (you must be 11-18 years old): ",tuple(range(11,19)))

    year_group = input_checker("Please enter your year group (7-13): ",tuple(range(7,14)))

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

    with open("users.csv") as u:
        users = u.read()
        while username in users:
            username += "1"

    print("Welcome {}, your username is: {}".format(name,username))

    password = input("Please create a password: ")

    user_details = (name,age,year_group,username,password)

    with open("users.csv","a") as u:
        writer = csv.writer(u)
        writer.writerow(user_details)

    print("You will now be prompted to login.")

    time.sleep(0.5)

    login()

def login():
    given_username = input("Please enter your username: ").title()

    given_password = input("Please enter your password: ")

    config.read("config.ini")

    admin_password = config["quiz_settings"]["admin_password"]

    if given_username == "Teacher":
        if given_password == admin_password:
            admin()
        else:
            print("Incorrect password.")
            login()

    with open("users.csv") as user_file:
        reader = csv.reader(user_file)
        user_check = tuple(filter(lambda x: x and given_username == x[3],[row for row in reader]))

    if not user_check:
        user_input = input_checker("""The username you entered doesn't exist.
1: Try again
2: Register
Please choose one of the above options to continue: """,[1,2])
        option_selector((login,register),(1,2),user_input)()

    else:
        user_details = user_check[0]
        password = user_details[4]

        if given_password == password:
            print("Welcome, " + given_username)

            with open("username.json","w") as u:
                json.dump(given_username, u)

            menu()

        else:
            print("Incorrect password.")
            login()

def menu():
    with open("username.json") as u:
        username = json.load(u)

    subject,subjects,chosen_difficulty,difficulties = quiz_selector()

    with open("user_results.csv") as u:
        reader = csv.reader(u)
        user_check = [row for row in reader if row and row[0] == username]

    if len(user_check) == len(subjects) * len(difficulties):
        print("You have taken every quiz. You will now be logged out.")
        time.sleep(1)
        start()

    for result in user_check:
        if [subject,chosen_difficulty] == result[1:3]:
            print("You have already taken this quiz.")
            time.sleep(0.5)
            menu()

    quiz_file = subject.lower() + ".csv"

    score = quiz(quiz_file, chosen_difficulty)

    percentage = int(round((score/5) * 100))

    percentage_map = {0: 'E', 20: 'D', 40: 'C', 60: 'B', 80: 'A', 100: 'A*'}

    grade = percentage_map[percentage]

    print("""Your final score is: {}/5.
Your percentage is: {}%.
Your grade is: {}.""".format(str(score),str(percentage),grade))

    user_result = (username,subject,chosen_difficulty,str(score),grade)

    with open("user_results.csv","a") as u:
        writer = csv.writer(u)
        writer.writerow(user_result)

    user_input = input_checker("""1: Take another quiz
2: Logout
Please choose one of the above options to continue: """,(1,2))

    option_selector((menu,start),(1,2),user_input)()

def quiz_selector():
    config.read("config.ini")

    subjects = tuple(config["quiz_settings"]["subjects"].split(","))

    subject_index = []

    for i, topic in enumerate(subjects, start=1):
        print((i),": " + topic)
        subject_index.append(i)

    chosen_subject = input_checker("Please choose one of the above subjects: ",subject_index)

    subject = subjects[(subject_index.index(chosen_subject))]

    difficulty = input_checker("""1: Easy
2: Medium
3: Hard
Please choose one of the above difficulties: """,(1,2,3))

    difficulties = ("easy","medium","hard")

    chosen_difficulty = difficulties[difficulty - 1]

    return subject,subjects,chosen_difficulty,difficulties

def quiz(quiz_file,difficulty):
    with open(quiz_file) as q:
        reader = csv.reader(q)
        questions = [line for line in reader]

    difficulty_map = {"easy" : (0,5),
                      "medium" : (5,10),
                      "hard" : (10,15)}

    question_reader = difficulty_map[difficulty]

    quiz_questions = questions[(question_reader[0]):(question_reader[1])]

    score = 0

    for line in quiz_questions:
        x, question = line[0:2]

        answers = tuple(filter(lambda a: a != x and a != question, line))

        valid_answers = []

        print(question)

        for i, answer in enumerate(answers,start=1):
            print((i),": " + answer)
            valid_answers.append(i)

        user_answer = input_checker("Please choose one of the above answers: ",valid_answers)

        correct_answer = line[int(x)]

        correct_input = valid_answers[answers.index(correct_answer)]

        if user_answer == correct_input:
            print("Correct!")
            score += 1

        else:
            print("Sorry, the correct answer was: {}".format(str(correct_answer)))

    return score

def admin():
    user_input = input_checker("""1: Check a user's results
2: Check the results for a quiz
3: Logout
Please choose one of the above options to continue: """,(1,2,3))

    option_selector((user_report,quiz_report,start),(1,2,3),user_input)()

def user_report():
    username = input("Please enter their username: ").title()

    with open("user_results.csv") as u:
        reader = csv.reader(u)
        user_result = [row for row in reader if row and username == row[0]]

    if not user_result:
        print("This user hasn't completed any quizzes.")
        admin()

    for result in user_result:
        print("""Subject: {}
Difficulty: {}
Score: {}
Grade: {}\n""".format(result[1],result[2].title(),result[3],result[4]))

    admin()

def quiz_report():
    subject,subjects,difficulty,difficulties = quiz_selector()

    with open("user_results.csv") as u:
        reader = csv.reader(u)
        user_result = [row for row in reader if row and [subject,difficulty] == row[1:3]]

    if not user_result:
        print("No-one has taken this quiz.")
        admin()

    total_score = 0

    for result in user_result:
        total_score += int(result[3])

    avg_score = round(total_score/len(user_result),1)

    print("The average score for this quiz is {}.".format(str(avg_score)))

    scores = sorted(user_result,key=lambda score: int(score[3]),reverse=True)

    highest_user = scores[0]

    with open("users.csv") as u:
        with open("users.csv") as user_file:
            reader = csv.reader(user_file)
            user = tuple(filter(lambda x: x and highest_user[0] == x[3],[line for line in reader]))

    user_details = user[0]

    print("""The highest score was {}, achieved by {}. The details of this user are:
Name: {}
Age: {}
Year Group: {}""".format(highest_user[3],highest_user[0],user_details[0],user_details[1],user_details[2]))

    admin()

config = configparser.ConfigParser()

for x in ("users.csv","user_results.csv"):
    if not os.path.isfile(x):
        open(x,"w").close()

if not os.path.isfile("config.ini"):
    config["quiz_settings"] = {"subjects": "Maths,Business","admin_password": "admin456"}
    with open("config.ini","w") as config_file:
        config.write(config_file)

start()