AuthenticationController.java

package controllers;

import interfaces.IAuthenticationService;
import models.User;
import java.util.HashMap;
import java.util.Map;

// This class handles the logic for Registration and Login
public class AuthenticationController implements IAuthenticationService {
    
    // Simulating a Database using a Map (Email -> User Object)
    private Map<String, User> usersDatabase = new HashMap<>();

    @Override
    public User registerUser(String studentId, String email, String password, String fullName) {
        // 1. Check if email already exists
        if(usersDatabase.containsKey(email)) {
            System.out.println("Error: Email already exists.");
            return null;
        }

        // 2. Encrypt Password (Simple simulation)
        String encryptedPass = "HASHED_" + password; 

        // 3. Create new User object
        User newUser = new User(studentId, email, encryptedPass, fullName);
        
        // 4. Save to our "Database"
        usersDatabase.put(email, newUser);
        System.out.println("Success: User registered successfully!");
        
        return newUser;
    }

    @Override
    public User login(String email, String password) {
        // 1. Find user by email
        User user = usersDatabase.get(email);
        
        // 2. Validate password
        if (user != null && user.getPasswordHash().equals("HASHED_" + password)) {
            System.out.println("Login Successful! Welcome " + user.getFullName());
            return user;
        } else {
            System.out.println("Error: Invalid Email or Password.");
            return null;
        }
    }
}