import random
import re
import os

TERMS = {
    "ALGORITHM": "A set of instructions to solve a problem",
    "MALWARE": "Software designed to cause harm to a system",
    "PHISHING": "Fraudulent attempt to obtain sensitive information",
    "SQL": "Language used to communicate with databases",
    "ENCRYPTION": "Process of converting data to prevent unauthorized access",
    "SERVER": "A computer that provides data to other computers",
    "TESTING": "Checking code to ensure it meets requirements without errors"
}

def auth():
    choice = input("Enter 'r' to register or 'l' to login: ").lower()
    if choice == 'r':
        name = input("Enter full name: ")
        while True:
            user = input("Choose username (4-8 characters): ")
            if 4 <= len(user) <= 8: break
            print("Username must be between 4 and 8 characters.")
        while True:
            pwd = input("Choose password (requires uppercase, lowercase, and a number): ")
            if re.search(r'[A-Z]', pwd) and re.search(r'[a-z]', pwd) and re.search(r'\d', pwd): break
            print("Password does not meet complexity requirements.")
        
        with open("students.txt", "a") as f: 
            f.write(f"{user},{pwd},{name}\n")
        return user
    else:
        u, p = input("Username: "), input("Password: ")
        try:
            with open("students.txt", "r") as f:
                if any(line.strip().startswith(f"{u},{p},") for line in f): return u
        except FileNotFoundError: pass
        print("Login failed or user does not exist."); return None

def quiz(user):
    keyword, correct_def = random.choice(list(TERMS.items()))
    options = [correct_def] + random.sample([v for k, v in TERMS.items() if k != keyword], min(3, len(TERMS)-1))
    random.shuffle(options)
    
    print(f"\nKeyword: {keyword}")
    for i, opt in enumerate(options, 1): 
        print(f"{i}. {opt}")
    
    score = 0
    for attempt, points in [(1, 3), (2, 1)]:
        try:
            ans = int(input(f"Attempt {attempt} - Choose 1-{len(options)}: "))
            if options[ans-1] == correct_def:
                print("Correct!")
                score = points
                break
            print("Incorrect!")
        except (ValueError, IndexError): 
            print("Invalid choice.")
    else:
        print(f"The correct definition was: {correct_def}")
        
    with open("scores.txt", "a") as f: 
        f.write(f"{user},{score}\n")

def main():
    user = None
    while not user: 
        user = auth()
        
    while True:
        action = input("\nChoose: [1] Try Quiz [2] View Scores [3] Quit: ")
        if action == '1': 
            quiz(user)
        elif action == '2':
            try:
                with open("scores.txt", "r") as f:
                    scores = [l.strip().split(',')[1] for l in f if l.startswith(f"{user},")]
                    print("Your previous scores:" if scores else "No scores yet.")
                    for s in scores: print(f"- {s} points")
            except FileNotFoundError: 
                print("No scores yet.")
        elif action == '3': 
            break

if __name__ == "__main__": 
    main()