add BrandService and enhance UserService with additional user retrieval methods

api/src/main/java/fr/gameovergne/api/service/app/BrandService.java

@@ -0,0 +1,56 @@
+package fr.gameovergne.api.service.app;
+
+import fr.gameovergne.api.model.app.Brand;
+import fr.gameovergne.api.repository.app.BrandRepository;
+import jakarta.transaction.Transactional;
+import org.springframework.beans.factory.annotation.Autowired;
+import org.springframework.stereotype.Service;
+
+import java.util.List;
+import java.util.Optional;
+
+@Service
+public class BrandService {
+
+    private final BrandRepository brandRepository;
+
+    @Autowired
+    public BrandService(BrandRepository brandRepository) {
+        this.brandRepository = brandRepository;
+    }
+
+    @Transactional
+    public void saveBrand(Brand brand) {
+        if (brand.getId() == null) {
+            brandRepository.save(brand);
+        }
+    }
+
+    public List<Brand> getAllBrands() {
+        return brandRepository.findAll();
+    }
+
+    public Optional<Brand> getBrandById(Long id) {
+        return brandRepository.findById(id);
+    }
+
+    public Optional<Brand> getBrandByName(String name) {
+        return brandRepository.findByName(name);
+    }
+
+    @Transactional
+    public Optional<Brand> updateBrand(Brand brand) {
+        return brandRepository.findById(brand.getId()).map(existingBrand -> {
+            existingBrand.setName(brand.getName());
+            existingBrand.setPlatforms(brand.getPlatforms());
+            return brandRepository.save(existingBrand);
+        });
+    }
+
+    @Transactional
+    public Optional<Brand> deleteBrandById(Long id) {
+        Optional<Brand> brand = brandRepository.findById(id);
+        brand.ifPresent(brandRepository::delete);
+        return brand;
+    }
+}

api/src/main/java/fr/gameovergne/api/service/user/UserService.java

@@ -26,19 +26,25 @@ public class UserService {
         }
     }
 
+    public List<User> getAllUsers() {
+        return userRepository.findAll();
+    }
+
     public Optional<User> getUserById(Long id) {
         return userRepository.findById(id);
     }
 
-    public List<User> getAllUsers() {
-        return userRepository.findAll();
+    public Optional<User> getUserByUsername(String username) {
+        return userRepository.findByUsername(username);
+    }
+
+    public Optional<User> getUserByEmail(String email) {
+        return userRepository.findByEmail(email);
     }
 
     @Transactional
     public Optional<User> updateUser(User user) {
         return userRepository.findById(user.getId()).map(existingUser -> {
-            existingUser.setFirstName(user.getFirstName());
-            existingUser.setLastName(user.getLastName());
             existingUser.setEmail(user.getEmail());
             existingUser.setUsername(user.getUsername());
             existingUser.setPassword(user.getPassword());