feat: Add Synology Photos Importer extensions (#1461)

The Synology Photos application is a useful tool for photo and album
management, designed to operate on the DiskStation Manager (DSM) of
Synology NAS devices. Due to most NAS systems being behind NAT and not
accessible publicly, Synology offers a cloud service that acts as an
intermediary. This service facilitates the transfer of data from various
DTP extensions to the Synology cloud, from which users can subsequently
download their data to their NAS.

This PR includes:
- Synology Photos Importer
- Synology Videos Importer
- Synology Media Importer

---------

Co-authored-by: simonyeh <simonyeh@synology.com>
Co-authored-by: ehung <ehung@synology.com>
Co-authored-by: amychen <amychen@synology.com>

Author: 4 people

distributions/demo-server/build.gradle

@@ -82,6 +82,7 @@ dependencies {
     compile project(':extensions:auth:portability-auth-twitter')
     compile project(':extensions:auth:portability-auth-imgur')
     compile project(':extensions:auth:portability-auth-koofr')
+    compile project(':extensions:auth:portability-auth-synology')
 
     compile project(':extensions:data-transfer:portability-data-transfer-apple')
     compile project(':extensions:data-transfer:portability-data-transfer-daybook')
@@ -94,6 +95,7 @@ dependencies {
     compile project(':extensions:data-transfer:portability-data-transfer-rememberthemilk')
     compile project(':extensions:data-transfer:portability-data-transfer-smugmug')
     compile project(':extensions:data-transfer:portability-data-transfer-spotify')
+    compile project(':extensions:data-transfer:portability-data-transfer-synology')
     compile project(':extensions:data-transfer:portability-data-transfer-twitter')
     compile project(':extensions:data-transfer:portability-data-transfer-imgur')
     compile project(':extensions:data-transfer:portability-data-transfer-koofr')

extensions/auth/portability-auth-google/src/main/java/org/datatransferproject/auth/google/GoogleOAuthConfig.java

@@ -20,6 +20,7 @@
 import static org.datatransferproject.types.common.models.DataVertical.CALENDAR;
 import static org.datatransferproject.types.common.models.DataVertical.CONTACTS;
 import static org.datatransferproject.types.common.models.DataVertical.MAIL;
+import static org.datatransferproject.types.common.models.DataVertical.MEDIA;
 import static org.datatransferproject.types.common.models.DataVertical.MUSIC;
 import static org.datatransferproject.types.common.models.DataVertical.PHOTOS;
 import static org.datatransferproject.types.common.models.DataVertical.SOCIAL_POSTS;
@@ -70,6 +71,7 @@ public Map<DataVertical, Set<String>> getExportScopes() {
         .put(SOCIAL_POSTS, ImmutableSet.of("https://www.googleapis.com/auth/plus.login"))
         .put(TASKS, ImmutableSet.of("https://www.googleapis.com/auth/tasks.readonly"))
         .put(VIDEOS, ImmutableSet.of("https://www.googleapis.com/auth/photoslibrary.readonly"))
+        .put(MEDIA, ImmutableSet.of("https://www.googleapis.com/auth/photoslibrary.readonly"))
         .put(MUSIC, ImmutableSet.of("https://www.googleapis.com/auth/music"))
 	.build();
   }
@@ -85,6 +87,7 @@ public Map<DataVertical, Set<String>> getImportScopes() {
         .put(PHOTOS, ImmutableSet.of("https://www.googleapis.com/auth/photoslibrary.appendonly"))
         .put(TASKS, ImmutableSet.of("https://www.googleapis.com/auth/tasks"))
         .put(VIDEOS, ImmutableSet.of("https://www.googleapis.com/auth/photoslibrary"))
+        .put(MEDIA, ImmutableSet.of("https://www.googleapis.com/auth/photoslibrary"))
         .put(MUSIC, ImmutableSet.of("https://www.googleapis.com/auth/music"))
 	.build();
   }

extensions/auth/portability-auth-synology/build.gradle

@@ -0,0 +1,13 @@
+plugins {
+    id 'maven'
+    id 'signing'
+}
+
+dependencies {
+    compile project(':portability-spi-api')
+    compile project(':portability-spi-cloud')
+    compile project(':libraries:auth')
+}
+
+configurePublication(project)
+

extensions/auth/portability-auth-synology/src/main/java/org/datatransferproject/auth/synology/SynologyAuthServiceExtension.java

@@ -0,0 +1,9 @@
+package org.datatransferproject.auth.synology;
+
+import org.datatransferproject.auth.OAuth2ServiceExtension;
+
+public class SynologyAuthServiceExtension extends OAuth2ServiceExtension {
+  public SynologyAuthServiceExtension() {
+    super(new SynologyOAuthConfig());
+  }
+}

extensions/auth/portability-auth-synology/src/main/java/org/datatransferproject/auth/synology/SynologyOAuthConfig.java

@@ -0,0 +1,51 @@
+package org.datatransferproject.auth.synology;
+
+import static org.datatransferproject.types.common.models.DataVertical.MEDIA;
+import static org.datatransferproject.types.common.models.DataVertical.PHOTOS;
+import static org.datatransferproject.types.common.models.DataVertical.VIDEOS;
+
+import com.google.common.collect.ImmutableMap;
+import com.google.common.collect.ImmutableSet;
+import java.util.Map;
+import java.util.Set;
+import org.datatransferproject.auth.OAuth2Config;
+import org.datatransferproject.types.common.models.DataVertical;
+
+public class SynologyOAuthConfig implements OAuth2Config {
+  private static String AUTH_HOST = "https://identity.synology.com";
+  private static String USER_INFO_SCOPE = "userinfo";
+  private static String OFFLINE_ACCESS_SCOPE = "offline_access";
+
+  @Override
+  public String getServiceName() {
+    return "Synology";
+  }
+
+  @Override
+  public String getAuthUrl() {
+    return AUTH_HOST + "/oauth2/auth";
+  }
+
+  @Override
+  public String getTokenUrl() {
+    return AUTH_HOST + "/oauth2/token";
+  }
+
+  @Override
+  public Map<DataVertical, Set<String>> getExportScopes() {
+    return ImmutableMap.<DataVertical, Set<String>>builder()
+        .put(PHOTOS, ImmutableSet.of(USER_INFO_SCOPE, OFFLINE_ACCESS_SCOPE))
+        .put(VIDEOS, ImmutableSet.of(USER_INFO_SCOPE, OFFLINE_ACCESS_SCOPE))
+        .put(MEDIA, ImmutableSet.of(USER_INFO_SCOPE, OFFLINE_ACCESS_SCOPE))
+        .build();
+  }
+
+  @Override
+  public Map<DataVertical, Set<String>> getImportScopes() {
+    return ImmutableMap.<DataVertical, Set<String>>builder()
+        .put(PHOTOS, ImmutableSet.of(USER_INFO_SCOPE, OFFLINE_ACCESS_SCOPE))
+        .put(VIDEOS, ImmutableSet.of(USER_INFO_SCOPE, OFFLINE_ACCESS_SCOPE))
+        .put(MEDIA, ImmutableSet.of(USER_INFO_SCOPE, OFFLINE_ACCESS_SCOPE))
+        .build();
+  }
+}

extensions/auth/portability-auth-synology/src/main/java/org/datatransferproject/auth/synology/package-info.java

@@ -0,0 +1 @@
+package org.datatransferproject.auth.synology;

extensions/auth/portability-auth-synology/src/main/resources/META-INF/services/org.datatransferproject.spi.api.auth.extension.AuthServiceExtension

@@ -0,0 +1 @@
+org.datatransferproject.auth.synology.SynologyAuthServiceExtension

extensions/data-transfer/portability-data-transfer-synology/Readme.md

@@ -0,0 +1,23 @@
+# Synology
+This folder contains the extension implementation for the
+[Synology](https://www.synology.com).
+
+## Data Supported
+
+Synology currently supports the following data types:
+ - Photos
+ - Videos
+
+## Current State
+
+ - Photos/Videos:
+    - Exporting is supported via Synology Photos or Bee Photos.
+    - Importing is supported via the exporting source platforms (currently only Google Photos).
+
+## Keys & Auth
+Synology uses OAuth 2 for authorization.
+
+### Create an OAuth App
+Contact [Synology DTP Developer Team](dtp@synology.com) for further information.
+
+

extensions/data-transfer/portability-data-transfer-synology/build.gradle

@@ -0,0 +1,30 @@
+/*
+ * Copyright 2025 The Data Transfer Project Authors.
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ * https://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ *
+ */
+
+plugins {
+    id 'maven'
+    id 'signing'
+}
+
+dependencies {
+    compile project(':portability-spi-transfer')
+    compile project(':portability-spi-cloud')
+    compile project(':portability-transfer')
+    compile "com.squareup.okhttp3:okhttp:${okHttpVersion}"
+}
+
+configurePublication(project)

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

@@ -0,0 +1,120 @@
+package org.datatransferproject.datatransfer.synology;
+
+import static org.datatransferproject.types.common.models.DataVertical.MEDIA;
+import static org.datatransferproject.types.common.models.DataVertical.PHOTOS;
+import static org.datatransferproject.types.common.models.DataVertical.VIDEOS;
+
+import com.google.common.base.Preconditions;
+import com.google.common.collect.ImmutableList;
+import com.google.common.collect.ImmutableMap;
+import okhttp3.OkHttpClient;
+import org.datatransferproject.api.launcher.ExtensionContext;
+import org.datatransferproject.api.launcher.Monitor;
+import org.datatransferproject.datatransfer.synology.media.SynologyMediaImporter;
+import org.datatransferproject.datatransfer.synology.photos.SynologyPhotosImporter;
+import org.datatransferproject.datatransfer.synology.service.SynologyDTPService;
+import org.datatransferproject.datatransfer.synology.service.SynologyOAuthTokenManager;
+import org.datatransferproject.datatransfer.synology.uploader.SynologyUploader;
+import org.datatransferproject.datatransfer.synology.videos.SynologyVideosImporter;
+import org.datatransferproject.spi.cloud.storage.AppCredentialStore;
+import org.datatransferproject.spi.cloud.storage.JobStore;
+import org.datatransferproject.spi.transfer.extension.TransferExtension;
+import org.datatransferproject.spi.transfer.idempotentexecutor.IdempotentImportExecutor;
+import org.datatransferproject.spi.transfer.idempotentexecutor.IdempotentImportExecutorExtension;
+import org.datatransferproject.spi.transfer.provider.Exporter;
+import org.datatransferproject.spi.transfer.provider.Importer;
+import org.datatransferproject.transfer.JobMetadata;
+import org.datatransferproject.types.common.models.DataVertical;
+import org.datatransferproject.types.transfer.auth.AppCredentials;
+import org.datatransferproject.types.transfer.serviceconfig.TransferServiceConfig;
+
+public class SynologyTransferExtension implements TransferExtension {
+  private static final ImmutableList<DataVertical> SUPPORTED_SERVICES =
+      ImmutableList.of(PHOTOS, VIDEOS, MEDIA);
+  private Monitor monitor;
+
+  private boolean initialized = false;
+
+  private ImmutableMap<DataVertical, Importer> importerMap;
+
+  @Override
+  public String getServiceId() {
+    return "Synology";
+  }
+
+  private String getExtensionKey() {
+    return getServiceId().toUpperCase() + "_KEY";
+  }
+
+  private String getExtensionSecret() {
+    return getServiceId().toUpperCase() + "_SECRET";
+  }
+
+  @Override
+  public Exporter<?, ?> getExporter(DataVertical transferDataType) {
+    return null;
+  }
+
+  @Override
+  public Importer<?, ?> getImporter(DataVertical transferDataType) {
+    Preconditions.checkArgument(initialized);
+    Preconditions.checkArgument(SUPPORTED_SERVICES.contains(transferDataType));
+    monitor.info(() -> "Getting importer for " + transferDataType);
+    monitor.info(() -> "has importer: " + importerMap.containsKey(transferDataType));
+    return importerMap.get(transferDataType);
+  }
+
+  @Override
+  public void initialize(ExtensionContext context) {
+    if (initialized) {
+      return;
+    }
+
+    monitor = context.getMonitor();
+
+    AppCredentials appCredentials;
+    try {
+      appCredentials =
+          context
+              .getService(AppCredentialStore.class)
+              .getAppCredentials(getExtensionKey(), getExtensionSecret());
+
+    } catch (Exception e) {
+      monitor.info(
+          () ->
+              "Unable to retrieve Synology AppCredentials. Please configure Synology KEY and"
+                  + " SECRET.");
+      return;
+    }
+
+    JobStore jobStore = context.getService(JobStore.class);
+    IdempotentImportExecutor idempotentImportExecutor =
+        context
+            .getService(IdempotentImportExecutorExtension.class)
+            .getRetryingIdempotentImportExecutor(context);
+    SynologyOAuthTokenManager tokenManager = new SynologyOAuthTokenManager(appCredentials, monitor);
+    OkHttpClient client = context.getService(OkHttpClient.class);
+    TransferServiceConfig transferServiceConfig = context.getService(TransferServiceConfig.class);
+    SynologyDTPService synologyDTPService =
+        new SynologyDTPService(
+            monitor,
+            transferServiceConfig,
+            JobMetadata.getExportService(),
+            jobStore,
+            tokenManager,
+            client);
+    SynologyUploader synologyUploader =
+        new SynologyUploader(idempotentImportExecutor, monitor, synologyDTPService);
+
+    ImmutableMap.Builder<DataVertical, Importer> importerBuilder = ImmutableMap.builder();
+    importerBuilder.put(MEDIA, new SynologyMediaImporter(monitor, tokenManager, synologyUploader));
+    importerBuilder.put(
+        PHOTOS, new SynologyPhotosImporter(monitor, tokenManager, synologyUploader));
+    importerBuilder.put(
+        VIDEOS, new SynologyVideosImporter(monitor, tokenManager, synologyUploader));
+    importerMap = importerBuilder.build();
+
+    monitor.info(() -> "Initializing SynologyTransferExtension");
+    initialized = true;
+  }
+}