"""
Authentication Blueprint
Handles user registration, login, and logout
"""

from flask import Blueprint, render_template, redirect, url_for, request, flash
from flask_login import login_user, logout_user, login_required, current_user
from models import db, User
import logging

logger = logging.getLogger(__name__)

auth_bp = Blueprint('auth', __name__)


@auth_bp.route('/register', methods=['GET', 'POST'])
def register():
    """User registration page."""
    logger.info("--- AUTH/REGISTER: Accesso alla pagina di registrazione.")
    if current_user.is_authenticated:
        return redirect(url_for('chat.chat_interface'))

    if request.method == 'POST':
        logger.info("--- AUTH/REGISTER: Ricevuto POST per la registrazione.")
        username = request.form.get('username', '').strip()
        email = request.form.get('email', '').strip()
        password = request.form.get('password', '')
        password_confirm = request.form.get('password_confirm', '')

        # Validation
        errors = []

        if not username or len(username) < 3:
            errors.append('Username must be at least 3 characters long.')

        if not email or '@' not in email:
            errors.append('Please enter a valid email address.')

        if not password or len(password) < 6:
            errors.append('Password must be at least 6 characters long.')

        if password != password_confirm:
            errors.append('Passwords do not match.')

        # Check if user already exists
        try:
            logger.info(f"--- AUTH/REGISTER: Controllo se l'utente '{username}' esiste...")
            if User.query.filter_by(username=username).first():
                errors.append('Username already exists.')
                logger.warning(f"--- AUTH/REGISTER: L'utente '{username}' esiste già.")

            logger.info(f"--- AUTH/REGISTER: Controllo se l'email '{email}' esiste...")
            if User.query.filter_by(email=email).first():
                errors.append('Email already registered.')
                logger.warning(f"--- AUTH/REGISTER: L'email '{email}' esiste già.")
        
        except Exception as e:
            logger.error(f"--- AUTH/REGISTER: ERRORE DB durante il controllo utente: {e}", exc_info=True)
            flash('An error occurred checking user data. Please try again.', 'danger')
            return render_template('register.html', username=username, email=email)

        if errors:
            for error in errors:
                flash(error, 'danger')
            return render_template('register.html', username=username, email=email)

        # Create new user
        try:
            logger.info(f"--- AUTH/REGISTER: Creazione nuovo utente: {username}")
            user = User(username=username, email=email)
            user.set_password(password)

            db.session.add(user)
            db.session.commit()

            logger.info(f"--- AUTH/REGISTER: Utente {username} salvato nel DB.")
            flash('Registration successful! Please log in.', 'success')
            return redirect(url_for('auth.login'))

        except Exception as e:
            db.session.rollback()
            logger.error(f"Error during registration: {e}", exc_info=True)
            flash('An error occurred during registration. Please try again.', 'danger')

    return render_template('register.html')


@auth_bp.route('/login', methods=['GET', 'POST'])
def login():
    """User login page."""
    logger.info(f"--- AUTH/LOGIN: Accesso alla pagina di login (Metodo: {request.method}).")
    if current_user.is_authenticated:
        logger.info("--- AUTH/LOGIN: Utente già autenticato, redirect alla chat.")
        return redirect(url_for('chat.chat_interface'))

    if request.method == 'POST':
        logger.info("--- AUTH/LOGIN: Ricevuto POST per il login.")
        username = request.form.get('username', '').strip()
        password = request.form.get('password', '')
        remember = request.form.get('remember', False) == 'on'

        if not username or not password:
            logger.warning("--- AUTH/LOGIN: Username o password vuoti.")
            flash('Please enter both username and password.', 'warning')
            return render_template('login.html', username=username)

        # Find user
        user = None
        try:
            logger.info(f"--- AUTH/LOGIN: Ricerca utente '{username}' nel DB...")
            user = User.query.filter_by(username=username).first()
        except Exception as e:
            logger.error(f"--- AUTH/LOGIN: ERRORE DB durante la ricerca utente: {e}", exc_info=True)
            flash('An error occurred during login. Please try again.', 'danger')
            return render_template('login.html', username=username)

        if user:
            logger.info(f"--- AUTH/LOGIN: Utente '{username}' trovato. Controllo password...")
            if user.check_password(password):
                logger.info(f"--- AUTH/LOGIN: Password CORRETTA. Chiamata a login_user() per '{username}'.")
                
                # Chiamata a Flask-Login
                login_user(user, remember=remember)
                # AGGIUNGI QUESTA RIGA QUI
                from flask import session
                logger.info(f"--- AUTH/LOGIN: login_user() completata. _user_id nella sessione: {session.get('_user_id')}")
                logger.info(f"--- AUTH/LOGIN: Funzione login_user() completata. Reindirizzamento alla chat...")
                
                # Redirect alla chat (o alla pagina 'next')
                next_page = request.args.get('next')
                if next_page and next_page.startswith('/'):
                    return redirect(next_page)
                return redirect(url_for('chat.chat_interface'))
            else:
                logger.warning(f"--- AUTH/LOGIN: Password ERRATA per l'utente '{username}'.")
                flash('Invalid username or password.', 'danger')
                return render_template('login.html', username=username)
        else:
            logger.warning(f"--- AUTH/LOGIN: Utente '{username}' NON TROVATO nel DB.")
            flash('Invalid username or password.', 'danger')
            return render_template('login.html', username=username)

    return render_template('login.html')


@auth_bp.route('/logout')
@login_required
def logout():
    """User logout."""
    username = current_user.username
    logout_user()
    logger.info(f"--- AUTH/LOGOUT: Utente {username} disconnesso.")
    flash('You have been logged out successfully.', 'info')
    return redirect(url_for('auth.login'))