feat: map Synology errors to FailureReasons and improve exception handling

- Add NO_NAS_IN_ACCOUNT to global FailureReasons enum.
- Extend SynologyException from CopyExceptionWithFailureReason to allow returning specific FailureReasons (NO_NAS_IN_ACCOUNT, DESTINATION_FULL).
- Update SynologyDTPService to parse specific Synology error codes (2000, 2001) and HTTP 413 to throw exceptions with mapped failure reasons.
- Refactor SynologyUploader to use standard for-loops instead of streams to properly support checked exceptions.
- Update SynologyMediaAlbumBinder to use synchronized blocks for better concurrency control and exception propagation.
- Catch and rethrow SynologyException in importers to ensure failure reasons are propagated to the monitor/job manager.

Author: simonxander

extensions/data-transfer/portability-data-transfer-synology/src/main/java/org/datatransferproject/datatransfer/synology/constant/SynologyErrorCode.java

@@ -42,4 +42,6 @@ public interface SynologyErrorCode {
   // DTP Client Errors
   public static final int MAX_RETRIES_EXCEEDED = 11001;
   public static final int IMPORT_FAILED = 11002;
+  public static final int QUOTA_NOT_CLAIMED = 11003;
+  public static final int DESTINATION_FULL = 11004;
 }

extensions/data-transfer/portability-data-transfer-synology/src/main/java/org/datatransferproject/datatransfer/synology/exceptions/SynologyException.java

@@ -17,15 +17,20 @@
 
 package org.datatransferproject.datatransfer.synology.exceptions;
 
+import javax.annotation.Nonnull;
+import org.datatransferproject.datatransfer.synology.constant.SynologyErrorCode;
+import org.datatransferproject.spi.transfer.types.CopyExceptionWithFailureReason;
+import org.datatransferproject.spi.transfer.types.FailureReasons;
+
 /** Exception thrown when an error occurs during a Synology import / export operation. */
-public class SynologyException extends RuntimeException {
+public class SynologyException extends CopyExceptionWithFailureReason {
   private final String errorCode;
 
   /**
    * @param message error message
    */
   protected SynologyException(String message) {
-    super(message);
+    super(message, new RuntimeException(message));
     this.errorCode = null;
   }
 
@@ -34,7 +39,7 @@ protected SynologyException(String message) {
    * @param errorCode the error code
    */
   protected SynologyException(String message, String errorCode) {
-    super(message);
+    super(message, new RuntimeException(message));
     this.errorCode = errorCode;
   }
 
@@ -51,4 +56,19 @@ protected SynologyException(String message, Throwable cause, String errorCode) {
   public String getErrorCode() {
     return errorCode;
   }
+
+  @Nonnull
+  @Override
+  public String getFailureReason() {
+    if (errorCode == null) {
+      return FailureReasons.UPLOAD_ERROR.toString();
+    }
+    if (errorCode.equals(Integer.toString(SynologyErrorCode.QUOTA_NOT_CLAIMED))) {
+      return FailureReasons.NO_NAS_IN_ACCOUNT.toString();
+    }
+    if (errorCode.equals(Integer.toString(SynologyErrorCode.DESTINATION_FULL))) {
+      return FailureReasons.DESTINATION_FULL.toString();
+    }
+    return FailureReasons.UPLOAD_ERROR.toString();
+  }
 }

extensions/data-transfer/portability-data-transfer-synology/src/main/java/org/datatransferproject/datatransfer/synology/exceptions/SynologyImportException.java

@@ -25,6 +25,10 @@ public SynologyImportException(String message) {
     super(message, "IMPORT_ERROR");
   }
 
+  public SynologyImportException(String message, String errorCode) {
+    super(message, errorCode);
+  }
+
   public SynologyImportException(String message, Throwable cause) {
     super(message, cause, String.valueOf(SynologyErrorCode.IMPORT_FAILED));
   }

extensions/data-transfer/portability-data-transfer-synology/src/main/java/org/datatransferproject/datatransfer/synology/media/SynologyMediaImporter.java

@@ -2,6 +2,7 @@
 
 import java.util.UUID;
 import org.datatransferproject.api.launcher.Monitor;
+import org.datatransferproject.datatransfer.synology.exceptions.SynologyException;
 import org.datatransferproject.datatransfer.synology.service.SynologyOAuthTokenManager;
 import org.datatransferproject.datatransfer.synology.uploader.SynologyUploader;
 import org.datatransferproject.spi.transfer.idempotentexecutor.IdempotentImportExecutor;
@@ -39,6 +40,9 @@ public ImportResult importItem(
       synologyUploader.importAlbums(data.getAlbums(), jobId);
       synologyUploader.importPhotos(data.getPhotos(), jobId);
       synologyUploader.importVideos(data.getVideos(), jobId);
+    } catch (SynologyException e) {
+      monitor.severe(() -> "[SynologyImporter] SynologyMediaImporter failed to import data:" + e);
+      throw e;
     } catch (Exception e) {
       monitor.severe(() -> "[SynologyImporter] SynologyMediaImporter failed to import data:" + e);
       return new ImportResult(e);

extensions/data-transfer/portability-data-transfer-synology/src/main/java/org/datatransferproject/datatransfer/synology/photos/SynologyPhotosImporter.java

@@ -2,6 +2,7 @@
 
 import java.util.UUID;
 import org.datatransferproject.api.launcher.Monitor;
+import org.datatransferproject.datatransfer.synology.exceptions.SynologyException;
 import org.datatransferproject.datatransfer.synology.service.SynologyOAuthTokenManager;
 import org.datatransferproject.datatransfer.synology.uploader.SynologyUploader;
 import org.datatransferproject.spi.transfer.idempotentexecutor.IdempotentImportExecutor;
@@ -38,6 +39,9 @@ public ImportResult importItem(
     try {
       synologyUploader.importAlbums(data.getAlbums(), jobId);
       synologyUploader.importPhotos(data.getPhotos(), jobId);
+    } catch (SynologyException e) {
+      monitor.severe(() -> "[SynologyImporter] SynologyPhotosImporter failed to import data:" + e);
+      throw e;
     } catch (Exception e) {
       monitor.severe(() -> "[SynologyImporter] SynologyPhotosImporter failed to import data:" + e);
       return new ImportResult(e);

extensions/data-transfer/portability-data-transfer-synology/src/main/java/org/datatransferproject/datatransfer/synology/service/SynologyDTPService.java

@@ -24,7 +24,6 @@
 import java.io.IOException;
 import java.io.InputStream;
 import java.net.MalformedURLException;
-import java.util.Date;
 import java.net.URL;
 import java.util.Date;
 import java.util.Map;
@@ -37,6 +36,8 @@
 import okhttp3.RequestBody;
 import okhttp3.Response;
 import org.datatransferproject.api.launcher.Monitor;
+import org.datatransferproject.datatransfer.synology.constant.SynologyErrorCode;
+import org.datatransferproject.datatransfer.synology.exceptions.SynologyException;
 import org.datatransferproject.datatransfer.synology.exceptions.SynologyHttpException;
 import org.datatransferproject.datatransfer.synology.exceptions.SynologyImportException;
 import org.datatransferproject.datatransfer.synology.exceptions.SynologyMaxRetriesExceededException;
@@ -106,7 +107,7 @@ protected InputStream getInputStream(String url) throws IOException {
    * @param jobId the job ID
    * @return a map of shape {"data": {"album_id": <album_id>}}
    */
-  public Map<String, Object> createAlbum(MediaAlbum album, UUID jobId) {
+  public Map<String, Object> createAlbum(MediaAlbum album, UUID jobId) throws SynologyException {
     FormBody.Builder builder = new FormBody.Builder().add("title", album.getName());
     builder.add("album_id", album.getId());
     builder.add("job_id", jobId.toString());
@@ -124,7 +125,7 @@ public Map<String, Object> createAlbum(MediaAlbum album, UUID jobId) {
    * @param jobId the job ID
    * @return a map of shape {"data": {"item_id": <item_id>}}
    */
-  public Map<String, Object> createPhoto(PhotoModel photo, UUID jobId) {
+  public Map<String, Object> createPhoto(PhotoModel photo, UUID jobId) throws SynologyException {
     byte[] imageBytes;
     try {
       InputStream inputStream = null;
@@ -178,7 +179,7 @@ public Map<String, Object> createPhoto(PhotoModel photo, UUID jobId) {
    * @param jobId the job ID
    * @return a map of shape {"data": {"item_id": <item_id>}}
    */
-  public Map<String, Object> createVideo(VideoModel video, UUID jobId) {
+  public Map<String, Object> createVideo(VideoModel video, UUID jobId) throws SynologyException {
     byte[] videoBytes;
     try {
       InputStream inputStream = null;
@@ -232,7 +233,8 @@ public Map<String, Object> createVideo(VideoModel video, UUID jobId) {
    * @param itemId the item ID
    * @return a map of shape {"success": <bool>}
    */
-  public Map<String, Object> addItemToAlbum(String albumId, String itemId, UUID jobId) {
+  public Map<String, Object> addItemToAlbum(String albumId, String itemId, UUID jobId)
+      throws SynologyException {
     FormBody.Builder builder =
         new FormBody.Builder()
             .add("job_id", jobId.toString())
@@ -243,7 +245,40 @@ public Map<String, Object> addItemToAlbum(String albumId, String itemId, UUID jo
   }
 
   @VisibleForTesting
-  protected Map<String, Object> sendPostRequest(String url, RequestBody body, UUID jobId) {
+  protected void checkUnprocessableContent(Response response) throws SynologyImportException {
+    String errorCode = "";
+    String errorMessage = "";
+
+    try {
+      assert response.body() != null;
+
+      String bodyString = response.body().string();
+      Map<String, Object> responseData =
+          (Map<String, Object>) objectMapper.readValue(bodyString, Map.class);
+
+      if (!responseData.containsKey("error")) {
+        return;
+      }
+
+      Map<String, Object> errorData = (Map<String, Object>) responseData.get("error");
+      errorCode = errorData.getOrDefault("code", "").toString();
+      errorMessage = errorData.getOrDefault("msg", "").toString();
+    } catch (Exception e) {
+      monitor.severe(
+          () ->
+              "[SynologyImporter] Failed to parse unprocessable content response data, exception:",
+          e);
+    }
+
+    if (errorCode.equals("2000") || errorCode.equals("2001")) {
+      throw new SynologyImportException(
+          errorMessage, Integer.toString(SynologyErrorCode.QUOTA_NOT_CLAIMED));
+    }
+  }
+
+  @VisibleForTesting
+  protected Map<String, Object> sendPostRequest(String url, RequestBody body, UUID jobId)
+      throws SynologyException {
     boolean triedRefreshToken = false;
     Request.Builder requestBuilder = new Request.Builder().url(url).post(body);
 
@@ -255,6 +290,13 @@ protected Map<String, Object> sendPostRequest(String url, RequestBody body, UUID
         response = client.newCall(requestBuilder.build()).execute();
         if (!response.isSuccessful()) {
           int code = response.code();
+          if (code == 413) {
+            throw new SynologyImportException(
+                "Uploaded file is too large", Integer.toString(SynologyErrorCode.DESTINATION_FULL));
+          }
+          if (code == 422) {
+            checkUnprocessableContent(response);
+          }
           if (code == 401 && !triedRefreshToken) {
             triedRefreshToken = true;
             if (tokenManager.refreshToken(jobId, client, objectMapper)) {
@@ -263,6 +305,10 @@ protected Map<String, Object> sendPostRequest(String url, RequestBody body, UUID
           }
           throw new SynologyHttpException("Synology request failed", code, response.message());
         }
+      } catch (SynologyImportException e) {
+        monitor.severe(
+            () -> "[SynologyImporter] Failed to send post request,", "url:", url, "exception:", e);
+        throw e;
       } catch (Exception e) {
         monitor.severe(
             () -> "[SynologyImporter] Failed to send post request,", "url:", url, "exception:", e);

extensions/data-transfer/portability-data-transfer-synology/src/main/java/org/datatransferproject/datatransfer/synology/service/SynologyOAuthTokenManager.java

@@ -42,7 +42,7 @@ public SynologyOAuthTokenManager(AppCredentials appCredentials, Monitor monitor)
     this.monitor = monitor;
   }
 
-  public String getAccessToken(UUID jobId) {
+  public String getAccessToken(UUID jobId) throws SynologyImportException {
     if (!authMap.containsKey(jobId)) {
       throw new SynologyImportException("No auth data found for job: " + jobId);
     }