pages/monolithic.py

import streamlit as st
from utils.code_examples import monolithic_example
from utils.quiz import monolithic_quiz

st.title("Monolithic Architecture")

st.write("""
Monolithic architecture is a traditional unified model for designing software programs.
In this architecture, all components of the application are interconnected and interdependent,
forming a single, indivisible unit.
""")

st.subheader("Characteristics of Monolithic Architecture")
st.write("""
1. **Single Codebase**: The entire application is contained within a single codebase.
2. **Shared Database**: All modules typically share a single database.
3. **Tightly Coupled**: Components are interconnected and interdependent.
4. **Single Deployment Unit**: The entire application is deployed as a single unit.
""")

st.subheader("Advantages and Disadvantages")
col1, col2 = st.columns(2)

with col1:
    st.markdown("**Advantages**")
    st.write("""
    - Simple to develop
    - Easy to deploy
    - Good performance (no network latency between components)
    """)

with col2:
    st.markdown("**Disadvantages**")
    st.write("""
    - Can become complex as the application grows
    - Difficult to scale individual components
    - Technology stack is shared across the entire application
    - Changes can affect the entire system
    """)

st.subheader("Example of a Monolithic Architecture")

st.write("Here's a simplified example of a monolithic e-commerce application with a product recommendation system:")

# Create tabs for Python and Java examples
python_tab, java_tab = st.tabs(["Python", "Java"])

with python_tab:
    st.code(monolithic_example, language="python")

with java_tab:
    java_monolithic_example = """
import java.util.*;

class EcommerceApp {
    private Map<String, User> users = new HashMap<>();
    private Map<Integer, Product> products = new HashMap<>();
    private Map<Integer, Order> orders = new HashMap<>();
    private Map<Integer, Payment> payments = new HashMap<>();
    private Map<String, List<String>> userPreferences = new HashMap<>();

    public void registerUser(String username, String password) {
        users.put(username, new User(username, password));
        userPreferences.put(username, new ArrayList<>());
    }

    public void addProduct(int productId, String name, double price, String category) {
        products.put(productId, new Product(productId, name, price, category));
    }

    public Integer createOrder(String user, int productId, int quantity) {
        if (users.containsKey(user) && products.containsKey(productId)) {
            int orderId = orders.size() + 1;
            orders.put(orderId, new Order(orderId, user, productId, quantity));
            userPreferences.get(user).add(products.get(productId).getCategory());
            return orderId;
        }
        return null;
    }

    public boolean processPayment(int orderId, String paymentMethod) {
        if (orders.containsKey(orderId)) {
            payments.put(orderId, new Payment(paymentMethod, "completed"));
            return true;
        }
        return false;
    }

    public List<Product> recommendProducts(String user, int numRecommendations) {
        if (!userPreferences.containsKey(user) || userPreferences.get(user).isEmpty()) {
            return new ArrayList<>(products.values()).subList(0, Math.min(numRecommendations, products.size()));
        }

        List<String> userCategories = userPreferences.get(user);
        String mostCommonCategory = getMostCommonCategory(userCategories);

        List<Product> recommendedProducts = products.values().stream()
                .filter(p -> p.getCategory().equals(mostCommonCategory))
                .limit(numRecommendations)
                .collect(ArrayList::new, ArrayList::add, ArrayList::addAll);

        if (recommendedProducts.size() < numRecommendations) {
            List<Product> otherProducts = products.values().stream()
                    .filter(p -> !p.getCategory().equals(mostCommonCategory))
                    .limit(numRecommendations - recommendedProducts.size())
                    .collect(ArrayList::new, ArrayList::add, ArrayList::addAll);
            recommendedProducts.addAll(otherProducts);
        }

        return recommendedProducts;
    }

    private String getMostCommonCategory(List<String> categories) {
        return categories.stream()
                .collect(java.util.stream.Collectors.groupingBy(c -> c, java.util.stream.Collectors.counting()))
                .entrySet().stream()
                .max(Map.Entry.comparingByValue())
                .map(Map.Entry::getKey)
                .orElse(null);
    }
}

// Helper classes (User, Product, Order, Payment) are omitted for brevity
"""
    st.code(java_monolithic_example, language="java")

st.write("""
In this example, all the main functionalities of the e-commerce application 
(user management, product management, order processing, payment handling, and product recommendations) 
are contained within a single application. They share the same data structures and are 
tightly coupled.
""")

st.subheader("Interactive Exercise: Exploring the Monolithic Architecture")

st.write("Let's modify the monolithic application to enhance the product recommendation system.")

new_feature = st.text_area("Add a new method to the EcommerceApp class to implement a more advanced product recommendation system:", 
                           height=200)

if new_feature:
    updated_code = monolithic_example.replace("def recommend_products(self, user, num_recommendations=3):", new_feature)
    st.code(updated_code, language="python")
    st.write("""
    Now that you've enhanced the product recommendation system, consider the following:
    1. How does this new feature interact with the existing components of the application?
    2. What challenges might you face if you want to scale just the recommendation system?
    3. How would you handle updates or maintenance for this feature in a monolithic architecture?
    """)

st.markdown("---")

st.subheader("Quiz: Monolithic Architecture Concepts")
monolithic_quiz()