Updated MenuItem and User, and completed AuthService, MenuService, OrderService and ConsoleMenu.

src/main/java/dev/service/AuthService.java

@@ -1,23 +1,75 @@
 package dev.service;
 
+import dev.database.DatabaseConnection;
 import dev.model.User;
 
+import java.security.MessageDigest;
+import java.sql.*;
+import java.util.Base64;
+
 public class AuthService {
 
+    private String hashPassword(String password) {
+        try {
+            MessageDigest digest = MessageDigest.getInstance("SHA-256");
+            byte[] hash = digest.digest(password.getBytes("UTF-8"));
+            return Base64.getEncoder().encodeToString(hash);
+        } catch (Exception e) {
+            throw new RuntimeException("Hashing failed", e);
+        }
+    }
+
     public boolean register(String username, String password, String email) {
 
-        // TODO:
-        // Validate and register user
+        if (username == null || username.trim().isEmpty() || password == null || password.isEmpty()) {
+            System.out.println("Username and password cannot be empty.");
+            return false;
+        }
 
-        return false;
+        String sql = "INSERT INTO users (username, password, email) VALUES (?, ?, ?)";
+        try (Connection conn = DatabaseConnection.getConnection();
+             PreparedStatement pstmt = conn.prepareStatement(sql)) {
+
+            pstmt.setString(1, username);
+            pstmt.setString(2, hashPassword(password));
+            if (email == null || email.trim().isEmpty()) {
+                pstmt.setNull(3, Types.VARCHAR);
+            } else {
+                pstmt.setString(3, email);
+            }
+
+            pstmt.executeUpdate();
+            return true;
+        } catch (SQLException e) {
+            System.out.println("Registration failed (Username might already exist): " + e.getMessage());
+            return false;
+        }
     }
 
     public User login(String username, String password) {
 
-        // TODO:
-        // Authenticate user
+        String sql = "SELECT * FROM users WHERE username = ? AND password = ?";
+        try (Connection conn = DatabaseConnection.getConnection();
+             PreparedStatement pstmt = conn.prepareStatement(sql)) {
 
+            pstmt.setString(1, username);
+            pstmt.setString(2, hashPassword(password));
+
+            try (ResultSet rs = pstmt.executeQuery()) {
+                if (rs.next()) {
+                    return new User(
+                            rs.getInt("id"),
+                            rs.getString("username"),
+                            rs.getString("password"),
+                            rs.getString("email")
+                    );
+                }
+            }
+        } catch (SQLException e) {
+            System.out.println("Login error: " + e.getMessage());
+        }
         return null;
+
     }
 
 }