integratio

import java.util.*;

public class UserLoginSystem {
    private Map<String, String> users; // Map to store username-password pairs

    public UserLoginSystem() {
        this.users = new HashMap<>();
    }

    // Method to register a new user
    public void registerUser(String username, String password) {
        users.put(username, password);
    }

    // Method to authenticate a user
    public boolean authenticateUser(String username, String password) {
        return users.containsKey(username) && users.get(username).equals(password);
    }
}

public class MusicRecommendationSystem {
    private UserLoginSystem userLoginSystem; // User login system reference
    private Map<String, List<String>> userPreferences; // Map to store user preferences

    public MusicRecommendationSystem() {
        this.userLoginSystem = new UserLoginSystem();
        this.userPreferences = new HashMap<>();
    }

    // Method to add user preferences
    public void addUserPreferences(String username, List<String> preferences) {
        userPreferences.put(username, preferences);
    }

    // Method to recommend songs based on user preferences
    public List<String> recommendSongs(String username, Map<String, List<String>> musicCatalog) {
        List<String> userPreferences = this.userPreferences.get(username);
        if (userPreferences == null || userPreferences.isEmpty()) {
            System.out.println("User has no preferences.");
            return new ArrayList<>();
        }

        Map<String, Integer> songScores = new HashMap<>(); // Map to store song scores

        // Iterate over user preferences and music catalog to calculate song scores
        for (String preference : userPreferences) {
            for (Map.Entry<String, List<String>> entry : musicCatalog.entrySet()) {
                String song = entry.getKey();
                List<String> genres = entry.getValue();
                if (genres.contains(preference)) {
                    songScores.put(song, songScores.getOrDefault(song, 0) + 1);
                }
            }
        }

        // Sort songs by score in descending order
        List<Map.Entry<String, Integer>> sortedSongs = new ArrayList<>(songScores.entrySet());
        sortedSongs.sort((a, b) -> b.getValue().compareTo(a.getValue()));

        // Extract song names from sorted entries
        List<String> recommendedSongs = new ArrayList<>();
        for (Map.Entry<String, Integer> entry : sortedSongs) {
            recommendedSongs.add(entry.getKey());
        }

        return recommendedSongs;
    }

    // Method to register a new user
    public void registerUser(String username, String password) {
        userLoginSystem.registerUser(username, password);
    }

    // Method to authenticate a user
    public boolean authenticateUser(String username, String password) {
        return userLoginSystem.authenticateUser(username, password);
    }

    public static void main(String[] args) {
        MusicRecommendationSystem recommendationSystem = new MusicRecommendationSystem();

        // Register users
        recommendationSystem.registerUser("User1", "password1");
        recommendationSystem.registerUser("User2", "password2");
        recommendationSystem.registerUser("User3", "password3");

        // Sample music catalog (song, genres)
        Map<String, List<String>> musicCatalog = new HashMap<>();
        musicCatalog.put("Song1", Arrays.asList("Rock", "Pop"));
        musicCatalog.put("Song2", Arrays.asList("Pop", "Hip Hop"));
        musicCatalog.put("Song3", Arrays.asList("Jazz", "Blues"));
        musicCatalog.put("Song4", Arrays.asList("Rock", "Metal"));
        // Add more songs to the catalog as needed

        // Sample user preferences
        recommendationSystem.addUserPreferences("User1", Arrays.asList("Rock", "Pop"));
        recommendationSystem.addUserPreferences("User2", Arrays.asList("Pop", "Hip Hop"));
        recommendationSystem.addUserPreferences("User3", Arrays.asList("Jazz", "Blues"));
        // Add more users with preferences as needed

        // Authenticate users and recommend songs
        String username = "User1";
        String password = "password1";
        if (recommendationSystem.authenticateUser(username, password)) {
            List<String> recommendedSongs = recommendationSystem.recommendSongs(username, musicCatalog);
            System.out.println("Recommended songs for " + username + ": " + recommendedSongs);
        } else {
            System.out.println("Authentication failed for " + username);
        }
    }
}