# ✅ auth.py (Updated with persistent login tracking)
import sqlite3
import hashlib
import os
import tempfile

# Persistent DB and login state file
DB_PATH = os.path.join(tempfile.gettempdir(), "users.db")
LOGIN_STATE_FILE = os.path.join(tempfile.gettempdir(), "last_login.txt")

def get_connection():
    conn = sqlite3.connect(DB_PATH)
    conn.execute("""
        CREATE TABLE IF NOT EXISTS users (
            username TEXT PRIMARY KEY,
            password TEXT
        )
    """)
    return conn

def hash_password(password):
    return hashlib.sha256(password.encode()).hexdigest()

def signup_user(username, password):
    conn = get_connection()
    try:
        conn.execute("INSERT INTO users VALUES (?, ?)", (username, hash_password(password)))
        conn.commit()
        return True
    except sqlite3.IntegrityError:
        return False
    finally:
        conn.close()

def login_user(username, password):
    conn = get_connection()
    hashed = hash_password(password)
    result = conn.execute("SELECT * FROM users WHERE username=? AND password=?", (username, hashed)).fetchone()
    conn.close()
    return result is not None

def save_login(username):
    with open(LOGIN_STATE_FILE, "w") as f:
        f.write(username)

def load_login():
    if os.path.exists(LOGIN_STATE_FILE):
        with open(LOGIN_STATE_FILE, "r") as f:
            return f.read().strip()
    return None

def logout_user():
    if os.path.exists(LOGIN_STATE_FILE):
        os.remove(LOGIN_STATE_FILE)