import streamlit as st
from utils import init_supabase

def get_user_by_username(username):
    """Get user from database by username"""
    supabase = init_supabase()
    if not supabase:
        return None
    
    try:
        # First try the function
        response = supabase.rpc('get_user_by_username', {'username_param': username}).execute()
        if response.data:
            return response.data[0]
        
        # Fallback: query the table directly
        response = supabase.table('users').select('*').eq('username', username).execute()
        if response.data:
            return response.data[0]
        
        return None
    except Exception as e:
        st.error(f"Database error: {str(e)}")
        return None

def show_login_page():
    """Show a simple custom login page"""
    st.title("🎭 Cura Learning Debate Class")
    st.markdown("### Welcome to Debate Class!")
    st.markdown("Please log in to access your course materials.")
    
    # Simple login form
    with st.form("login_form"):
        username = st.text_input("Username")
        password = st.text_input("Password", type="password")
        submit_button = st.form_submit_button("Login")
        
        if submit_button:
            if check_credentials(username, password):
                st.session_state.authenticated = True
                st.session_state.username = username
                st.session_state.name = get_user_name(username)
                st.success(f'Welcome {st.session_state.name}!')
                st.rerun()
            else:
                st.error('Invalid username or password')

def check_credentials(username, password):
    """Check if username and password are valid"""
    if not username or not password:
        return False
    
    # Get user from database
    user = get_user_by_username(username)
    
    if user:
        # Get the password from the database (plain text for now)
        stored_password = user.get('password')
        
        if stored_password:
            # Compare passwords directly (plain text)
            return password == stored_password
    
    return False

def get_user_name(username):
    """Get the display name for a username"""
    user = get_user_by_username(username)
    if user:
        return user.get('full_name', username)
    return username

def handle_logout():
    """Handle logout functionality"""
    if st.button("Logout"):
        st.session_state.authenticated = False
        st.session_state.username = None
        st.session_state.name = None
        st.rerun()

def is_authenticated():
    """Check if user is authenticated"""
    return st.session_state.get('authenticated', False)