Code Editor for app.py

import streamlit as st
import streamlit_authenticator as stauth
import yaml
from yaml.loader import SafeLoader
from sqlalchemy import create_engine, Column, Integer, String, Boolean, ForeignKey
from sqlalchemy.orm import Session, relationship, DeclarativeBase
import stripe
import random

# Set your Stripe API key
stripe.api_key = "your_stripe_api_key"  # Replace with your actual Stripe API key

# Database setup
class Base(DeclarativeBase):
    pass

class User(Base):
    __tablename__ = 'users'
    id = Column(Integer, primary_key=True)
    username = Column(String, unique=True)
    password = Column(String)
    email = Column(String, unique=True)
    is_premium = Column(Boolean, default=False)
    questions = relationship("Question", back_populates="user")

class Question(Base):
    __tablename__ = 'questions'
    id = Column(Integer, primary_key=True)
    user_id = Column(Integer, ForeignKey('users.id'))
    question = Column(String)
    answer = Column(String)
    user = relationship("User", back_populates="questions")

# Create SQLite database and tables
engine = create_engine('sqlite:///quiz_platform.db')
Base.metadata.create_all(engine)

# Initialize session state
if 'authenticated' not in st.session_state:
    st.session_state.authenticated = False
if 'username' not in st.session_state:
    st.session_state.username = None

def main():
    st.title("Quiz Platform")
    
    # Sidebar for navigation
    menu = st.sidebar.selectbox(
        "Menu",
        ["Login", "Register", "Dashboard", "Add Questions", "Take Quiz", "Upgrade to Premium"]
    )
    
    if menu == "Login":
        show_login_page()
    elif menu == "Register":
        show_register_page()
    elif not st.session_state.authenticated:
        st.warning("Please login first!")
        show_login_page()
    elif menu == "Dashboard":
        show_dashboard()
    elif menu == "Add Questions":
        show_add_questions()
    elif menu == "Take Quiz":
        show_quiz()
    elif menu == "Upgrade to Premium":
        show_upgrade_page()

def show_login_page():
    st.header("Login")
    username = st.text_input("Username")
    password = st.text_input("Password", type="password")
    
    if st.button("Login"):
        with Session(engine) as session:
            user = session.query(User).filter_by(username=username).first()
            if user and stauth.Hasher([password]).verify(user.password)[0]:
                st.session_state.authenticated = True
                st.session_state.username = username
                st.success("Login successful!")
                st.rerun()
            else:
                st.error("Invalid username or password")

def show_register_page():
    st.header("Register")
    username = st.text_input("Username")
    email = st.text_input("Email")
    password = st.text_input("Password", type="password")
    
    if st.button("Register"):
        hashed_password = stauth.Hasher([password]).generate()[0]
        with Session(engine) as session:
            new_user = User(
                username=username,
                email=email,
                password=hashed_password,
                is_premium=False
            )
            session.add(new_user)
            try:
                session.commit()
                st.success("Registration successful! Please login.")
            except:
                session.rollback()
                st.error("Username or email already exists!")

def show_dashboard():
    st.header("Dashboard")
    with Session(engine) as session:
        user = session.query(User).filter_by(username=st.session_state.username).first()
        st.write(f"Welcome, {user.username}!")
        st.write(f"Premium Status: {'Premium' if user.is_premium else 'Basic'}")
        
        question_count = session.query(Question).filter_by(user_id=user.id).count()
        st.write(f"Total Questions Added: {question_count}")

def show_add_questions():
    st.header("Add Questions")
    question = st.text_input("Question")
    answer = st.text_input("Answer")
    
    if st.button("Add Question"):
        with Session(engine) as session:
            user = session.query(User).filter_by(username=st.session_state.username).first()
            new_question = Question(
                user_id=user.id,
                question=question,
                answer=answer
            )
            session.add(new_question)
            session.commit()
            st.success("Question added successfully!")

def show_quiz():
    st.header("Take Quiz")
    with Session(engine) as session:
        user = session.query(User).filter_by(username=st.session_state.username).first()
        questions = session.query(Question).filter_by(user_id=user.id).all()
        
        if not questions:
            st.warning("No questions available. Please add some questions first!")
            return
        
        if 'current_question' not in st.session_state:
            st.session_state.current_question = random.choice(questions)
        
        st.write(st.session_state.current_question.question)
        user_answer = st.text_input("Your Answer")
        
        col1, col2 = st.columns(2)
        with col1:
            if st.button("Check Answer"):
                if user_answer.lower() == st.session_state.current_question.answer.lower():
                    st.success("Correct!")
                else:
                    st.error(f"Wrong! The correct answer is: {st.session_state.current_question.answer}")
        
        with col2:
            if st.button("Next Question"):
                st.session_state.current_question = random.choice(questions)
                st.rerun()

def show_upgrade_page():
    st.header("Upgrade to Premium")
    st.write("Get unlimited questions and advanced features!")
    
    amount = 999  # $9.99
    if st.button("Upgrade Now - $9.99"):
        try:
            checkout_session = stripe.checkout.Session.create(
                payment_method_types=['card'],
                line_items=[{
                    'price_data': {
                        'currency': 'usd',
                        'unit_amount': amount,
                        'product_data': {
                            'name': 'Premium Subscription',
                        },
                    },
                    'quantity': 1,
                }],
                mode='payment',
                success_url='http://localhost:8501/success',
                cancel_url='http://localhost:8501/cancel',
            )
            st.write("Redirecting to payment...")
            st.markdown(f"<script>window.location.href = '{checkout_session.url}';</script>", unsafe_allow_html=True)
        except Exception as e:
            st.error(f"Error processing payment: {str(e)}")

if __name__ == "__main__":
    main()