app.py

from flask import Flask, render_template, request, redirect, url_for, session
import mysql.connector
from werkzeug.security import generate_password_hash, check_password_hash

app = Flask(__name__)
app.secret_key = 'secret_key'

# Database connection
def get_db_connection():
    conn = mysql.connector.connect(
        host='localhost',
        user='root',
        password='root',
        database='userauth'
    )
    return conn

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

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

        conn = get_db_connection()
        cursor = conn.cursor(dictionary=True)
        cursor.execute('SELECT * FROM users WHERE username = %s', (username,))
        user = cursor.fetchone()
        conn.close()

        if user and check_password_hash(user['password'], password):
            session['user_id'] = user['id']
            session['username'] = user['username']
            return redirect(url_for('dashboard'))
        else:
            return 'Incorrect username or password'

    return render_template('login.html')

@app.route('/signup', methods=['GET', 'POST'])
def signup():
    if request.method == 'POST':
        username = request.form['username']
        password = request.form['password']
        hashed_password = generate_password_hash(password)

        conn = get_db_connection()
        cursor = conn.cursor()
        cursor.execute('INSERT INTO users (username, password) VALUES (%s, %s)', (username, hashed_password))
        conn.commit()
        conn.close()

        return redirect(url_for('login'))

    return render_template('signup.html')

@app.route('/dashboard')
def dashboard():
    if 'user_id' not in session:
        return redirect(url_for('login'))

    return f"Welcome {session['username']}!"

@app.route('/logout')
def logout():
    session.pop('user_id', None)
    session.pop('username', None)
    return redirect(url_for('home'))

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