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

auth_bp = Blueprint('auth', __name__, url_prefix='/auth')


@auth_bp.route('/register', methods=['GET', 'POST'])
def register():
    """User registration."""
    if current_user.is_authenticated:
        return redirect(url_for('main.index'))
    
    if request.method == 'POST':
        username = request.form.get('username')
        email = request.form.get('email')
        password = request.form.get('password')
        confirm_password = request.form.get('confirm_password')
        
        # Validation
        if not all([username, email, password, confirm_password]):
            flash('All fields are required.', 'danger')
            return render_template('auth/register.html')
        
        if password != confirm_password:
            flash('Passwords do not match.', 'danger')
            return render_template('auth/register.html')
        
        if len(password) < 6:
            flash('Password must be at least 6 characters long.', 'danger')
            return render_template('auth/register.html')
        
        # Check if user already exists
        if User.query.filter_by(username=username).first():
            flash('Username already exists.', 'danger')
            return render_template('auth/register.html')
        
        if User.query.filter_by(email=email).first():
            flash('Email already registered.', 'danger')
            return render_template('auth/register.html')
        
        # Create new user
        user = User(username=username, email=email)
        user.set_password(password)
        
        db.session.add(user)
        db.session.commit()
        
        flash('Registration successful! Please log in.', 'success')
        return redirect(url_for('auth.login'))
    
    return render_template('auth/register.html')


@auth_bp.route('/login', methods=['GET', 'POST'])
def login():
    """User login."""
    if current_user.is_authenticated:
        return redirect(url_for('main.index'))
    
    if request.method == 'POST':
        username = request.form.get('username')
        password = request.form.get('password')
        remember = request.form.get('remember', False)
        
        if not username or not password:
            flash('Please provide both username and password.', 'danger')
            return render_template('auth/login.html')
        
        user = User.query.filter_by(username=username).first()
        
        if user and user.check_password(password):
            login_user(user, remember=bool(remember))
            next_page = request.args.get('next')
            flash(f'Welcome back, {user.username}!', 'success')
            return redirect(next_page) if next_page else redirect(url_for('main.index'))
        else:
            flash('Invalid username or password.', 'danger')
    
    return render_template('auth/login.html')


@auth_bp.route('/logout')
@login_required
def logout():
    """User logout."""
    logout_user()
    flash('You have been logged out.', 'info')
    return redirect(url_for('auth.login'))


@auth_bp.route('/profile')
@login_required
def profile():
    """User profile page."""
    set_count = current_user.sets.count()
    instruction_count = current_user.instructions.count()
    
    return render_template('auth/profile.html',
                         set_count=set_count,
                         instruction_count=instruction_count)