from flask import Flask, render_template, redirect, url_for, request
from flask_sqlalchemy import SQLAlchemy
from flask_login import LoginManager, UserMixin, login_user, login_required, logout_user
from werkzeug.security import generate_password_hash, check_password_hash

app = Flask(__name__)
app.config['SECRET_KEY'] = 'your-secret-key-here'
app.config['SQLALCHEMY_DATABASE_URI'] = 'sqlite:///instance/users.db'
app.config['SQLALCHEMY_TRACK_MODIFICATIONS'] = False

db = SQLAlchemy(app)
login_manager = LoginManager(app)
login_manager.login_view = 'login'

class User(UserMixin, db.Model):
    id = db.Column(db.Integer, primary_key=True)
    email = db.Column(db.String(100), unique=True)
    password = db.Column(db.String(100))

@login_manager.user_loader
def load_user(user_id):
    return User.query.get(int(user_id))

@app.route('/')
def home():
    return redirect(url_for('login'))

@app.route('/login', methods=['GET', 'POST'])
def login():
    if request.method == 'POST':
        email = request.form.get('email')
        password = request.form.get('password')
        user = User.query.filter_by(email=email).first()
        
        if user and check_password_hash(user.password, password):
            login_user(user)
            return redirect(url_for('dashboard'))
        
        return 'Invalid credentials'
    return render_template('login.html')

@app.route('/register', methods=['GET', 'POST'])
def register():
    if request.method == 'POST':
        email = request.form.get('email')
        password = generate_password_hash(request.form.get('password'))
        
        if User.query.filter_by(email=email).first():
            return 'Email already registered'
            
        new_user = User(email=email, password=password)
        db.session.add(new_user)
        db.session.commit()
        
        return redirect(url_for('login'))
    return render_template('register.html')

@app.route('/dashboard')
@login_required
def dashboard():
    return render_template('dashboard.html')

@app.route('/logout')
@login_required
def logout():
    logout_user()
    return redirect(url_for('login'))