first commit. application working

backend/src/main/java/com/weighttracker/service/UserService.java

@@ -0,0 +1,53 @@
+
+package com.weighttracker.service;
+
+import com.weighttracker.model.User;
+import com.weighttracker.repository.UserRepository;
+import org.springframework.beans.factory.annotation.Autowired;
+import org.springframework.security.core.userdetails.UsernameNotFoundException;
+import org.springframework.security.crypto.password.PasswordEncoder;
+import org.springframework.stereotype.Service;
+import org.springframework.transaction.annotation.Transactional;
+
+import java.util.List;
+
+@Service
+public class UserService {
+
+    @Autowired
+    private UserRepository userRepository;
+
+    public User findByUsername(String username) {
+        return userRepository.findByUsername(username)
+                .orElseThrow(() -> new UsernameNotFoundException("Usuario no encontrado: " + username));
+    }
+
+    public List<User> findAll() {
+        return userRepository.findAll();
+    }
+
+    @Autowired
+    private PasswordEncoder passwordEncoder;
+
+    public void save(User user) {
+        if (user.getPassword() != null && !user.getPassword().startsWith("$2a$")) {
+            user.setPassword(passwordEncoder.encode(user.getPassword()));
+        }
+        userRepository.save(user);
+    }
+
+    public User findById(Long id) {
+        return userRepository.findById(id).orElseThrow();
+    }
+
+    @Autowired
+    private WeightService weightService;
+
+    @Transactional
+    public void deleteById(Long id) {
+        User user = userRepository.findById(id).orElseThrow();
+        weightService.deleteByUser(user);
+        userRepository.deleteById(id);
+    }
+
+}

backend/src/main/java/com/weighttracker/service/WeightService.java

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+package com.weighttracker.service;
+
+import com.weighttracker.model.User;
+import com.weighttracker.model.WeightRecord;
+import com.weighttracker.repository.WeightRecordRepository;
+import org.springframework.stereotype.Service;
+
+import java.time.LocalDateTime;
+import java.util.List;
+
+@Service
+public class WeightService {
+    private final WeightRecordRepository repo;
+
+    public WeightService(WeightRecordRepository r) {
+        this.repo = r;
+    }
+
+    public WeightRecord save(WeightRecord w) {
+        return repo.save(w);
+    }
+
+    public List<WeightRecord> last10(User u) {
+        return repo.findTop10ByUserOrderByDateDesc(u);
+    }
+
+    public List<WeightRecord> findByUser(User u) {
+        return repo.findByUserOrderByDateDesc(u);
+    }
+
+    public List<WeightRecord> recordsAfter(User u, LocalDateTime d) {
+        return repo.findByUserAndDateAfterOrderByDateAsc(u, d);
+    }
+
+    public WeightRecord findById(Long id) {
+        return repo.findById(id).orElseThrow();
+    }
+
+    public void deleteById(Long id) {
+        repo.deleteById(id);
+    }
+
+    public List<WeightRecord> recordsBetween(User user, LocalDateTime start, LocalDateTime end) {
+        return repo.findByUserAndDateBetweenOrderByDateAsc(user, start, end);
+    }
+
+    public void deleteByUser(User user) {
+        repo.deleteAllByUser(user);
+    }
+
+}