fix validation bugs

backend/src/main/java/com/petshop/backend/controller/AuthController.java

@@ -309,17 +309,18 @@ public class AuthController {
     public ResponseEntity<Resource> getAvatarFile() {
         User user = authHelper.getAuthenticatedUser();
 
-        if (!avatarStorageService.hasAvatar(user)) {
-            return ResponseEntity.notFound().build();
+        if (avatarStorageService.hasAvatar(user)) {
+            try {
+                Resource resource = avatarStorageService.loadAvatarResource(user);
+                MediaType mediaType = avatarStorageService.resolveMediaType(user);
+                return ResponseEntity.ok().contentType(mediaType).body(resource);
+            } catch (IllegalArgumentException ignored) {
+            }
         }
 
-        try {
-            Resource resource = avatarStorageService.loadAvatarResource(user);
-            MediaType mediaType = avatarStorageService.resolveMediaType(user);
-            return ResponseEntity.ok().contentType(mediaType).body(resource);
-        } catch (IllegalArgumentException ex) {
-            return ResponseEntity.notFound().build();
-        }
+        return ResponseEntity.ok()
+                .contentType(MediaType.valueOf("image/svg+xml"))
+                .body(avatarStorageService.loadDefaultAvatarResource());
     }
 
     @DeleteMapping("/me/avatar")

backend/src/main/java/com/petshop/backend/controller/UserAvatarController.java

@@ -7,6 +7,7 @@ import com.petshop.backend.repository.UserRepository;
 import com.petshop.backend.service.AvatarStorageService;
 import com.petshop.backend.util.ImageValidationUtil;
 import org.springframework.core.io.Resource;
+import org.springframework.http.MediaType;
 import org.springframework.http.ResponseEntity;
 import org.springframework.security.access.prepost.PreAuthorize;
 import org.springframework.web.bind.annotation.DeleteMapping;
@@ -42,18 +43,23 @@ public class UserAvatarController {
     @PreAuthorize("isAuthenticated()")
     public ResponseEntity<Resource> getUserAvatarFile(@PathVariable Long userId) {
         User user = userRepository.findById(userId).orElse(null);
-        if (user == null || !avatarStorageService.hasAvatar(user)) {
+        if (user == null) {
             return ResponseEntity.notFound().build();
         }
 
-        try {
-            Resource resource = avatarStorageService.loadAvatarResource(user);
-            return ResponseEntity.ok()
-                    .contentType(avatarStorageService.resolveMediaType(user))
-                    .body(resource);
-        } catch (IllegalArgumentException ex) {
-            return ResponseEntity.notFound().build();
+        if (avatarStorageService.hasAvatar(user)) {
+            try {
+                Resource resource = avatarStorageService.loadAvatarResource(user);
+                return ResponseEntity.ok()
+                        .contentType(avatarStorageService.resolveMediaType(user))
+                        .body(resource);
+            } catch (IllegalArgumentException ignored) {
+            }
         }
+
+        return ResponseEntity.ok()
+                .contentType(MediaType.valueOf("image/svg+xml"))
+                .body(avatarStorageService.loadDefaultAvatarResource());
     }
 
     @PostMapping("/{userId}/avatar")

backend/src/main/java/com/petshop/backend/service/AppointmentService.java

@@ -143,7 +143,7 @@ public class AppointmentService {
         appointment.setEmployee(employee);
         appointment.setAppointmentDate(request.getAppointmentDate());
         appointment.setAppointmentTime(request.getAppointmentTime());
-        appointment.setAppointmentStatus(request.getAppointmentStatus());
+        appointment.setAppointmentStatus("Scheduled");
         appointment.setPet(pet);
 
         appointment = appointmentRepository.save(appointment);
@@ -304,11 +304,9 @@ public class AppointmentService {
     }
 
     private void validateAppointmentRequest(AppointmentRequest request) {
-        if ("Booked".equalsIgnoreCase(request.getAppointmentStatus())) {
-            LocalDateTime appointmentDateTime = LocalDateTime.of(request.getAppointmentDate(), request.getAppointmentTime());
-            if (appointmentDateTime.isBefore(LocalDateTime.now())) {
-                throw new BusinessException("Booked appointments must be scheduled in the future");
-            }
+        LocalDateTime appointmentDateTime = LocalDateTime.of(request.getAppointmentDate(), request.getAppointmentTime());
+        if (appointmentDateTime.isBefore(LocalDateTime.now())) {
+            throw new BusinessException("Appointments must be scheduled in the future");
         }
     }
 

backend/src/main/java/com/petshop/backend/service/AvatarStorageService.java

@@ -13,6 +13,7 @@ import org.springframework.web.multipart.MultipartFile;
 
 import jakarta.annotation.PostConstruct;
 import java.io.IOException;
+import java.io.InputStream;
 import java.nio.file.Files;
 import java.nio.file.Path;
 import java.nio.file.Paths;
@@ -54,7 +55,11 @@ public class AvatarStorageService {
     public Resource loadAvatarResource(User user) {
         String filename = extractFilename(user.getAvatarUrl());
         if (blobService.isEnabled()) {
-            return new ByteArrayResource(blobService.download(BLOB_CONTAINER, filename));
+            try {
+                return new ByteArrayResource(blobService.download(BLOB_CONTAINER, filename));
+            } catch (Exception ex) {
+                throw new IllegalArgumentException("Avatar file was not found");
+            }
         }
         Path filePath = resolveStoredAvatarPath(user.getAvatarUrl());
         if (!Files.exists(filePath) || !Files.isRegularFile(filePath)) {
@@ -63,6 +68,18 @@ public class AvatarStorageService {
         return new PathResource(filePath);
     }
 
+    public Resource loadDefaultAvatarResource() {
+        InputStream is = getClass().getResourceAsStream("/static/default-avatar.svg");
+        if (is == null) {
+            throw new IllegalStateException("Default avatar resource not found");
+        }
+        try {
+            return new ByteArrayResource(is.readAllBytes());
+        } catch (IOException e) {
+            throw new IllegalStateException("Failed to read default avatar", e);
+        }
+    }
+
     public void deleteAvatar(User user) throws IOException {
         if (user.getAvatarUrl() == null || user.getAvatarUrl().isBlank()) return;
         if (blobService.isEnabled()) {
@@ -80,7 +97,7 @@ public class AvatarStorageService {
     }
 
     public String toOwnerAvatarUrl(User user) {
-        return hasAvatar(user) ? "/api/v1/users/" + user.getId() + "/avatar/file" : null;
+        return "/api/v1/users/" + user.getId() + "/avatar/file";
     }
 
     public String toStoredAvatarUrl(String avatarFilenamePath) {

backend/src/main/java/com/petshop/backend/service/ChatService.java

@@ -146,6 +146,12 @@ public class ChatService {
             }
         }
 
+        boolean hasContent = request.getContent() != null && !request.getContent().isBlank();
+        boolean hasAttachment = request.getAttachmentUrl() != null && !request.getAttachmentUrl().isBlank();
+        if (!hasContent && !hasAttachment) {
+            throw new BusinessException("Message must have content or an attachment");
+        }
+
         ContentFilter.validate(request.getContent());
 
         Message message = new Message();

backend/src/main/java/com/petshop/backend/service/CouponService.java

@@ -89,6 +89,10 @@ public class CouponService {
     }
 
     private void updateCouponFields(Coupon coupon, CouponRequest request) {
+        if ("PERCENTAGE".equalsIgnoreCase(request.getDiscountType())
+                && request.getDiscountValue().compareTo(new BigDecimal("100")) >= 0) {
+            throw new BusinessException("Percentage discount must be less than 100");
+        }
         coupon.setCouponCode(request.getCouponCode());
         coupon.setDiscountType(request.getDiscountType());
         coupon.setDiscountValue(request.getDiscountValue());

backend/src/main/resources/static/default-avatar.svg

@@ -0,0 +1 @@
+<svg xmlns="http://www.w3.org/2000/svg" viewBox="0 0 128 128" width="128" height="128"><circle cx="64" cy="64" r="64" fill="#9e9e9e"/><circle cx="64" cy="50" r="22" fill="#fff"/><ellipse cx="64" cy="114" rx="40" ry="36" fill="#fff"/></svg>