from functools import wraps

from flask import Flask, render_template, redirect, request, url_for, session, flash
from flask_sqlalchemy import SQLAlchemy
from werkzeug.security import generate_password_hash, check_password_hash

app = Flask(__name__)

app.config['SQLALCHEMY_DATABASE_URI'] = 'sqlite:///accounts.db'
app.config['SQLALCHEMY_TRACK_MODIFICATIONS'] = False
app.secret_key = 'super_secret_session_encryption_key' 
db = SQLAlchemy(app)

class User(db.Model):
    id = db.Column(db.Integer, primary_key=True)
    username = db.Column(db.String(80), unique=True, nullable=False)
    email = db.Column(db.String(120), unique=True, nullable=False)
    password_hash = db.Column(db.String(128), nullable=False)

with app.app_context():
    db.create_all()


def login_required(view_func):
    @wraps(view_func)
    def wrapped(*args, **kwargs):
        if 'user_id' not in session:
            flash('Please sign in to view that page.')
            return redirect(url_for('signin'))
        return view_func(*args, **kwargs)
    return wrapped


@app.route('/submit-form', methods=['POST'])
def handle_submission():
    form_username = request.form.get('username')
    form_email = request.form.get('email')
    form_password = request.form.get('password')
    
    if User.query.filter_by(username=form_username).first():
        return "<h3>Username taken!</h3>", 400
    if User.query.filter_by(email=form_email).first():
        return "<h3>Email already registered!</h3>", 400
    
    hashed_password = generate_password_hash(form_password)
    
    new_user = User(username=form_username, email=form_email, password_hash=hashed_password)
    db.session.add(new_user)
    db.session.commit()
    
    return redirect(url_for('success'))


@app.route('/users')
@login_required
def view_users():
    all_users = User.query.all()

    html_output = "<h2>Registered Accounts</h2><table border='1' cellpadding='10'>"
    html_output += "<tr><th>ID</th><th>Username</th><th>Email</th></tr>"

    for user in all_users:
        html_output += f"<tr><td>{user.id}</td><td>{user.username}</td><td>{user.email}</td></tr>"

    html_output += "</table>"

    if not all_users:
        return "<h3>No accounts found in the database yet.</h3>"

    return html_output


@app.route('/')
def home():
    return render_template('index.html')

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

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

@app.route('/signin', methods=['GET', 'POST'])
def signin():
    if request.method == 'POST':
        form_username = request.form.get('username')
        form_password = request.form.get('password')

        user = User.query.filter_by(username=form_username).first()

        if user is None or not check_password_hash(user.password_hash, form_password):
            flash('Incorrect username or password.')
            return render_template('signin.html'), 401

        session['user_id'] = user.id
        session['username'] = user.username
        return redirect(url_for('home'))

    return render_template('signin.html')


@app.route('/logout')
def logout():
    session.clear()
    return redirect(url_for('home'))

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

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

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

if __name__ == '__main__':
    app.run(debug=True)