Add synchronization with gPodder Nextcloud server app (#5243)

7 files changed, 417 insertions, 97 deletions

diff --git a/net/sync/gpoddernet/build.gradle b/net/sync/gpoddernet/build.gradle
index eb5af1b60..77e9ce0f3 100644
--- a/net/sync/gpoddernet/build.gradle
+++ b/net/sync/gpoddernet/build.gradle
@@ -9,4 +9,7 @@ dependencies {
 
     implementation "com.squareup.okhttp3:okhttp:$okhttpVersion"
     implementation "org.apache.commons:commons-lang3:$commonslangVersion"
+    implementation 'commons-io:commons-io:2.5'
+    implementation "io.reactivex.rxjava2:rxandroid:$rxAndroidVersion"
+    implementation "io.reactivex.rxjava2:rxjava:$rxJavaVersion"
 }
diff --git a/net/sync/gpoddernet/src/main/java/de/danoeh/antennapod/net/sync/HostnameParser.java b/net/sync/gpoddernet/src/main/java/de/danoeh/antennapod/net/sync/HostnameParser.java
new file mode 100644
index 000000000..ebb415248
--- /dev/null
+++ b/net/sync/gpoddernet/src/main/java/de/danoeh/antennapod/net/sync/HostnameParser.java
@@ -0,0 +1,41 @@
+package de.danoeh.antennapod.net.sync;
+
+import java.util.regex.Matcher;
+import java.util.regex.Pattern;
+
+public class HostnameParser {
+    public String scheme;
+    public int port;
+    public String host;
+
+    // split into schema, host and port - missing parts are null
+    private static final Pattern URLSPLIT_REGEX = Pattern.compile("(?:(https?)://)?([^:]+)(?::(\\d+))?");
+
+    public HostnameParser(String hosturl) {
+        Matcher m = URLSPLIT_REGEX.matcher(hosturl);
+        if (m.matches()) {
+            scheme = m.group(1);
+            host = m.group(2);
+            if (m.group(3) == null) {
+                port = -1;
+            } else {
+                port = Integer.parseInt(m.group(3));    // regex -> can only be digits
+            }
+        } else {
+            // URL does not match regex: use it anyway -> this will cause an exception on connect
+            scheme = "https";
+            host = hosturl;
+            port = 443;
+        }
+
+        if (scheme == null) {      // assume https
+            scheme = "https";
+        }
+
+        if (scheme.equals("https") && port == -1) {
+            port = 443;
+        } else if (scheme.equals("http") && port == -1) {
+            port = 80;
+        }
+    }
+}
diff --git a/net/sync/gpoddernet/src/main/java/de/danoeh/antennapod/net/sync/gpoddernet/GpodnetService.java b/net/sync/gpoddernet/src/main/java/de/danoeh/antennapod/net/sync/gpoddernet/GpodnetService.java
index eb18da80b..439a528b7 100644
--- a/net/sync/gpoddernet/src/main/java/de/danoeh/antennapod/net/sync/gpoddernet/GpodnetService.java
+++ b/net/sync/gpoddernet/src/main/java/de/danoeh/antennapod/net/sync/gpoddernet/GpodnetService.java
@@ -1,25 +1,10 @@
 package de.danoeh.antennapod.net.sync.gpoddernet;
 
 import android.util.Log;
+
 import androidx.annotation.NonNull;
-import de.danoeh.antennapod.net.sync.gpoddernet.model.GpodnetDevice;
-import de.danoeh.antennapod.net.sync.model.EpisodeAction;
-import de.danoeh.antennapod.net.sync.model.EpisodeActionChanges;
-import de.danoeh.antennapod.net.sync.gpoddernet.model.GpodnetEpisodeActionPostResponse;
-import de.danoeh.antennapod.net.sync.gpoddernet.model.GpodnetPodcast;
-import de.danoeh.antennapod.net.sync.model.ISyncService;
-import de.danoeh.antennapod.net.sync.model.SubscriptionChanges;
-import de.danoeh.antennapod.net.sync.gpoddernet.model.GpodnetTag;
-import de.danoeh.antennapod.net.sync.gpoddernet.model.GpodnetUploadChangesResponse;
-import de.danoeh.antennapod.net.sync.model.SyncServiceException;
-import de.danoeh.antennapod.net.sync.model.UploadChangesResponse;
-import okhttp3.Credentials;
-import okhttp3.MediaType;
-import okhttp3.OkHttpClient;
-import okhttp3.Request;
-import okhttp3.RequestBody;
-import okhttp3.Response;
-import okhttp3.ResponseBody;
+
+import de.danoeh.antennapod.net.sync.HostnameParser;
 import org.json.JSONArray;
 import org.json.JSONException;
 import org.json.JSONObject;
@@ -35,12 +20,28 @@ import java.net.URL;
 import java.nio.charset.Charset;
 import java.util.ArrayList;
 import java.util.Collections;
-import java.util.LinkedList;
 import java.util.List;
 import java.util.Locale;
 
-import java.util.regex.Matcher;
-import java.util.regex.Pattern;
+import de.danoeh.antennapod.net.sync.gpoddernet.mapper.ResponseMapper;
+import de.danoeh.antennapod.net.sync.gpoddernet.model.GpodnetDevice;
+import de.danoeh.antennapod.net.sync.gpoddernet.model.GpodnetEpisodeActionPostResponse;
+import de.danoeh.antennapod.net.sync.gpoddernet.model.GpodnetPodcast;
+import de.danoeh.antennapod.net.sync.gpoddernet.model.GpodnetTag;
+import de.danoeh.antennapod.net.sync.gpoddernet.model.GpodnetUploadChangesResponse;
+import de.danoeh.antennapod.net.sync.model.EpisodeAction;
+import de.danoeh.antennapod.net.sync.model.EpisodeActionChanges;
+import de.danoeh.antennapod.net.sync.model.ISyncService;
+import de.danoeh.antennapod.net.sync.model.SubscriptionChanges;
+import de.danoeh.antennapod.net.sync.model.SyncServiceException;
+import de.danoeh.antennapod.net.sync.model.UploadChangesResponse;
+import okhttp3.Credentials;
+import okhttp3.MediaType;
+import okhttp3.OkHttpClient;
+import okhttp3.Request;
+import okhttp3.RequestBody;
+import okhttp3.Response;
+import okhttp3.ResponseBody;
 
 /**
  * Communicates with the gpodder.net service.
@@ -61,43 +62,16 @@ public class GpodnetService implements ISyncService {
 
     private final OkHttpClient httpClient;
 
-    // split into schema, host and port - missing parts are null
-    private static final Pattern URLSPLIT_REGEX = Pattern.compile("(?:(https?)://)?([^:]+)(?::(\\d+))?");
-
     public GpodnetService(OkHttpClient httpClient, String baseHosturl,
                           String deviceId, String username, String password)  {
         this.httpClient = httpClient;
         this.deviceId = deviceId;
         this.username = username;
         this.password = password;
-
-        Matcher m = URLSPLIT_REGEX.matcher(baseHosturl);
-        if (m.matches()) {
-            this.baseScheme = m.group(1);
-            this.baseHost = m.group(2);
-            if (m.group(3) == null) {
-                this.basePort = -1;
-            } else {
-                this.basePort = Integer.parseInt(m.group(3));    // regex -> can only be digits
-            }
-        } else {
-            // URL does not match regex: use it anyway -> this will cause an exception on connect
-            this.baseScheme = "https";
-            this.baseHost = baseHosturl;
-            this.basePort = 443;
-        }
-
-        if (this.baseScheme == null) {      // assume https
-            this.baseScheme = "https";
-        }
-
-        if (this.baseScheme.equals("https") && this.basePort == -1) {
-            this.basePort = 443;
-        }
-
-        if (this.baseScheme.equals("http") && this.basePort == -1) {
-            this.basePort = 80;
-        }
+        HostnameParser hostname = new HostnameParser(baseHosturl == null ? DEFAULT_BASE_HOST : baseHosturl);
+        this.baseHost = hostname.host;
+        this.basePort = hostname.port;
+        this.baseScheme = hostname.scheme;
     }
 
     private void requireLoggedIn() {
@@ -434,7 +408,7 @@ public class GpodnetService implements ISyncService {
 
             String response = executeRequest(request);
             JSONObject changes = new JSONObject(response);
-            return readSubscriptionChangesFromJsonObject(changes);
+            return ResponseMapper.readSubscriptionChangesFromJsonObject(changes);
         } catch (URISyntaxException e) {
             e.printStackTrace();
             throw new IllegalStateException(e);
@@ -515,7 +489,7 @@ public class GpodnetService implements ISyncService {
 
             String response = executeRequest(request);
             JSONObject json = new JSONObject(response);
-            return readEpisodeActionsFromJsonObject(json);
+            return ResponseMapper.readEpisodeActionsFromJsonObject(json);
         } catch (URISyntaxException e) {
             e.printStackTrace();
             throw new IllegalStateException(e);
@@ -526,7 +500,6 @@ public class GpodnetService implements ISyncService {
 
     }
 
-
     /**
      * Logs in a specific user. This method must be called if any of the methods
      * that require authentication is used.
@@ -689,48 +662,6 @@ public class GpodnetService implements ISyncService {
         return new GpodnetDevice(id, caption, type, subscriptions);
     }
 
-    private SubscriptionChanges readSubscriptionChangesFromJsonObject(@NonNull JSONObject object)
-            throws JSONException {
-
-        List<String> added = new LinkedList<>();
-        JSONArray jsonAdded = object.getJSONArray("add");
-        for (int i = 0; i < jsonAdded.length(); i++) {
-            String addedUrl = jsonAdded.getString(i);
-            // gpodder escapes colons unnecessarily
-            addedUrl = addedUrl.replace("%3A", ":");
-            added.add(addedUrl);
-        }
-
-        List<String> removed = new LinkedList<>();
-        JSONArray jsonRemoved = object.getJSONArray("remove");
-        for (int i = 0; i < jsonRemoved.length(); i++) {
-            String removedUrl = jsonRemoved.getString(i);
-            // gpodder escapes colons unnecessarily
-            removedUrl = removedUrl.replace("%3A", ":");
-            removed.add(removedUrl);
-        }
-
-        long timestamp = object.getLong("timestamp");
-        return new SubscriptionChanges(added, removed, timestamp);
-    }
-
-    private EpisodeActionChanges readEpisodeActionsFromJsonObject(@NonNull JSONObject object)
-            throws JSONException {
-
-        List<EpisodeAction> episodeActions = new ArrayList<>();
-
-        long timestamp = object.getLong("timestamp");
-        JSONArray jsonActions = object.getJSONArray("actions");
-        for (int i = 0; i < jsonActions.length(); i++) {
-            JSONObject jsonAction = jsonActions.getJSONObject(i);
-            EpisodeAction episodeAction = EpisodeAction.readFromJsonObject(jsonAction);
-            if (episodeAction != null) {
-                episodeActions.add(episodeAction);
-            }
-        }
-        return new EpisodeActionChanges(episodeActions, timestamp);
-    }
-
     @Override
     public void logout() {
 
diff --git a/net/sync/gpoddernet/src/main/java/de/danoeh/antennapod/net/sync/gpoddernet/mapper/ResponseMapper.java b/net/sync/gpoddernet/src/main/java/de/danoeh/antennapod/net/sync/gpoddernet/mapper/ResponseMapper.java
new file mode 100644
index 000000000..c8e607d74
--- /dev/null
+++ b/net/sync/gpoddernet/src/main/java/de/danoeh/antennapod/net/sync/gpoddernet/mapper/ResponseMapper.java
@@ -0,0 +1,60 @@
+package de.danoeh.antennapod.net.sync.gpoddernet.mapper;
+
+import androidx.annotation.NonNull;
+
+import org.json.JSONArray;
+import org.json.JSONException;
+import org.json.JSONObject;
+
+import java.util.ArrayList;
+import java.util.LinkedList;
+import java.util.List;
+
+import de.danoeh.antennapod.net.sync.model.EpisodeAction;
+import de.danoeh.antennapod.net.sync.model.EpisodeActionChanges;
+import de.danoeh.antennapod.net.sync.model.SubscriptionChanges;
+
+public class ResponseMapper {
+
+    public static SubscriptionChanges readSubscriptionChangesFromJsonObject(@NonNull JSONObject object)
+            throws JSONException {
+
+        List<String> added = new LinkedList<>();
+        JSONArray jsonAdded = object.getJSONArray("add");
+        for (int i = 0; i < jsonAdded.length(); i++) {
+            String addedUrl = jsonAdded.getString(i);
+            // gpodder escapes colons unnecessarily
+            addedUrl = addedUrl.replace("%3A", ":");
+            added.add(addedUrl);
+        }
+
+        List<String> removed = new LinkedList<>();
+        JSONArray jsonRemoved = object.getJSONArray("remove");
+        for (int i = 0; i < jsonRemoved.length(); i++) {
+            String removedUrl = jsonRemoved.getString(i);
+            // gpodder escapes colons unnecessarily
+            removedUrl = removedUrl.replace("%3A", ":");
+            removed.add(removedUrl);
+        }
+
+        long timestamp = object.getLong("timestamp");
+        return new SubscriptionChanges(added, removed, timestamp);
+    }
+
+    public static EpisodeActionChanges readEpisodeActionsFromJsonObject(@NonNull JSONObject object)
+            throws JSONException {
+
+        List<EpisodeAction> episodeActions = new ArrayList<>();
+
+        long timestamp = object.getLong("timestamp");
+        JSONArray jsonActions = object.getJSONArray("actions");
+        for (int i = 0; i < jsonActions.length(); i++) {
+            JSONObject jsonAction = jsonActions.getJSONObject(i);
+            EpisodeAction episodeAction = EpisodeAction.readFromJsonObject(jsonAction);
+            if (episodeAction != null) {
+                episodeActions.add(episodeAction);
+            }
+        }
+        return new EpisodeActionChanges(episodeActions, timestamp);
+    }
+}
diff --git a/net/sync/gpoddernet/src/main/java/de/danoeh/antennapod/net/sync/nextcloud/NextcloudLoginFlow.java b/net/sync/gpoddernet/src/main/java/de/danoeh/antennapod/net/sync/nextcloud/NextcloudLoginFlow.java
new file mode 100644
index 000000000..b66c44402
--- /dev/null
+++ b/net/sync/gpoddernet/src/main/java/de/danoeh/antennapod/net/sync/nextcloud/NextcloudLoginFlow.java
@@ -0,0 +1,107 @@
+package de.danoeh.antennapod.net.sync.nextcloud;
+
+import android.content.Context;
+import android.content.Intent;
+import android.net.Uri;
+import de.danoeh.antennapod.net.sync.HostnameParser;
+import io.reactivex.Observable;
+import io.reactivex.android.schedulers.AndroidSchedulers;
+import io.reactivex.disposables.Disposable;
+import io.reactivex.schedulers.Schedulers;
+import okhttp3.MediaType;
+import okhttp3.OkHttpClient;
+import okhttp3.Request;
+import okhttp3.RequestBody;
+import okhttp3.Response;
+import okhttp3.ResponseBody;
+import org.json.JSONException;
+import org.json.JSONObject;
+import android.util.Log;
+
+import java.io.IOException;
+import java.net.URI;
+import java.net.URL;
+import java.util.concurrent.TimeUnit;
+
+public class NextcloudLoginFlow {
+    private static final String TAG = "NextcloudLoginFlow";
+
+    private final OkHttpClient httpClient;
+    private final HostnameParser hostname;
+    private final Context context;
+    private final AuthenticationCallback callback;
+    private String token;
+    private String endpoint;
+    private Disposable startDisposable;
+    private Disposable pollDisposable;
+
+    public NextcloudLoginFlow(OkHttpClient httpClient, String hostUrl, Context context,
+                              AuthenticationCallback callback) {
+        this.httpClient = httpClient;
+        this.hostname = new HostnameParser(hostUrl);
+        this.context = context;
+        this.callback = callback;
+    }
+
+    public void start() {
+        startDisposable = Observable.fromCallable(() -> {
+            URL url = new URI(hostname.scheme, null, hostname.host, hostname.port,
+                    "/index.php/login/v2", null, null).toURL();
+            JSONObject result = doRequest(url, "");
+            String loginUrl = result.getString("login");
+            this.token = result.getJSONObject("poll").getString("token");
+            this.endpoint = result.getJSONObject("poll").getString("endpoint");
+            return loginUrl;
+        })
+                .subscribeOn(Schedulers.io())
+                .observeOn(AndroidSchedulers.mainThread())
+                .subscribe(
+                    result -> {
+                        Intent browserIntent = new Intent(Intent.ACTION_VIEW, Uri.parse(result));
+                        context.startActivity(browserIntent);
+                        poll();
+                    }, error -> {
+                        Log.e(TAG, Log.getStackTraceString(error));
+                        callback.onNextcloudAuthError(error.getLocalizedMessage());
+                    });
+    }
+
+    private void poll() {
+        pollDisposable = Observable.fromCallable(() -> doRequest(URI.create(endpoint).toURL(), "token=" + token))
+                .delay(1, TimeUnit.SECONDS)
+                .retry(60 * 10) // 10 minutes
+                .subscribeOn(Schedulers.io())
+                .observeOn(AndroidSchedulers.mainThread())
+                .subscribe(result -> {
+                    callback.onNextcloudAuthenticated(result.getString("server"),
+                            result.getString("loginName"), result.getString("appPassword"));
+                }, Throwable::printStackTrace);
+    }
+
+    public void cancel() {
+        if (startDisposable != null) {
+            startDisposable.dispose();
+        }
+        if (pollDisposable != null) {
+            pollDisposable.dispose();
+        }
+    }
+
+    private JSONObject doRequest(URL url, String bodyContent) throws IOException, JSONException {
+        RequestBody requestBody = RequestBody.create(
+                MediaType.get("application/x-www-form-urlencoded"), bodyContent);
+        Request request = new Request.Builder().url(url).method("POST", requestBody).build();
+        Response response = httpClient.newCall(request).execute();
+        if (response.code() != 200) {
+            throw new IOException("Return code " + response.code());
+        }
+        ResponseBody body = response.body();
+        return new JSONObject(body.string());
+    }
+
+    public interface AuthenticationCallback {
+        void onNextcloudAuthenticated(String server, String username, String password);
+
+        void onNextcloudAuthError(String errorMessage);
+    }
+}
diff --git a/net/sync/gpoddernet/src/main/java/de/danoeh/antennapod/net/sync/nextcloud/NextcloudSyncService.java b/net/sync/gpoddernet/src/main/java/de/danoeh/antennapod/net/sync/nextcloud/NextcloudSyncService.java
new file mode 100644
index 000000000..647a9073c
--- /dev/null
+++ b/net/sync/gpoddernet/src/main/java/de/danoeh/antennapod/net/sync/nextcloud/NextcloudSyncService.java
@@ -0,0 +1,169 @@
+package de.danoeh.antennapod.net.sync.nextcloud;
+
+import de.danoeh.antennapod.net.sync.HostnameParser;
+import de.danoeh.antennapod.net.sync.gpoddernet.mapper.ResponseMapper;
+import de.danoeh.antennapod.net.sync.gpoddernet.model.GpodnetUploadChangesResponse;
+import de.danoeh.antennapod.net.sync.model.EpisodeAction;
+import de.danoeh.antennapod.net.sync.model.EpisodeActionChanges;
+import de.danoeh.antennapod.net.sync.model.ISyncService;
+import de.danoeh.antennapod.net.sync.model.SubscriptionChanges;
+import de.danoeh.antennapod.net.sync.model.SyncServiceException;
+import de.danoeh.antennapod.net.sync.model.UploadChangesResponse;
+import okhttp3.Credentials;
+import okhttp3.HttpUrl;
+import okhttp3.MediaType;
+import okhttp3.OkHttpClient;
+import okhttp3.Request;
+import okhttp3.RequestBody;
+import okhttp3.Response;
+import org.json.JSONArray;
+import org.json.JSONException;
+import org.json.JSONObject;
+
+import java.io.IOException;
+import java.net.MalformedURLException;
+import java.util.HashMap;
+import java.util.List;
+
+public class NextcloudSyncService implements ISyncService {
+    private static final int UPLOAD_BULK_SIZE = 30;
+    private final OkHttpClient httpClient;
+    private final String baseScheme;
+    private final int basePort;
+    private final String baseHost;
+    private final String username;
+    private final String password;
+
+    public NextcloudSyncService(OkHttpClient httpClient, String baseHosturl,
+                          String username, String password)  {
+        this.httpClient = httpClient;
+        this.username = username;
+        this.password = password;
+        HostnameParser hostname = new HostnameParser(baseHosturl);
+        this.baseHost = hostname.host;
+        this.basePort = hostname.port;
+        this.baseScheme = hostname.scheme;
+    }
+
+    @Override
+    public void login() {
+    }
+
+    @Override
+    public SubscriptionChanges getSubscriptionChanges(long lastSync) throws SyncServiceException {
+        try {
+            HttpUrl.Builder url = makeUrl("/index.php/apps/gpoddersync/subscriptions");
+            url.addQueryParameter("since", "" + lastSync);
+            String responseString = performRequest(url, "GET", null);
+            JSONObject json = new JSONObject(responseString);
+            return ResponseMapper.readSubscriptionChangesFromJsonObject(json);
+        } catch (JSONException | MalformedURLException e) {
+            e.printStackTrace();
+            throw new SyncServiceException(e);
+        } catch (Exception e) {
+            e.printStackTrace();
+            throw new SyncServiceException(e);
+        }
+    }
+
+    @Override
+    public UploadChangesResponse uploadSubscriptionChanges(List<String> addedFeeds,
+                                                           List<String> removedFeeds)
+            throws NextcloudSynchronizationServiceException {
+        try {
+            HttpUrl.Builder url = makeUrl("/index.php/apps/gpoddersync/subscription_change/create");
+            final JSONObject requestObject = new JSONObject();
+            requestObject.put("add", new JSONArray(addedFeeds));
+            requestObject.put("remove", new JSONArray(removedFeeds));
+            RequestBody requestBody = RequestBody.create(
+                    MediaType.get("application/json"), requestObject.toString());
+            performRequest(url, "POST", requestBody);
+        } catch (Exception e) {
+            e.printStackTrace();
+            throw new NextcloudSynchronizationServiceException(e);
+        }
+
+        return new GpodnetUploadChangesResponse(System.currentTimeMillis() / 1000, new HashMap<>());
+    }
+
+    @Override
+    public EpisodeActionChanges getEpisodeActionChanges(long timestamp) throws SyncServiceException {
+        try {
+            HttpUrl.Builder uri = makeUrl("/index.php/apps/gpoddersync/episode_action");
+            uri.addQueryParameter("since", "" + timestamp);
+            String responseString = performRequest(uri, "GET", null);
+            JSONObject json = new JSONObject(responseString);
+            return ResponseMapper.readEpisodeActionsFromJsonObject(json);
+        } catch (JSONException | MalformedURLException e) {
+            e.printStackTrace();
+            throw new SyncServiceException(e);
+        } catch (Exception e) {
+            e.printStackTrace();
+            throw new SyncServiceException(e);
+        }
+    }
+
+    @Override
+    public UploadChangesResponse uploadEpisodeActions(List<EpisodeAction> queuedEpisodeActions)
+            throws NextcloudSynchronizationServiceException {
+        for (int i = 0; i < queuedEpisodeActions.size(); i += UPLOAD_BULK_SIZE) {
+            uploadEpisodeActionsPartial(queuedEpisodeActions,
+                    i, Math.min(queuedEpisodeActions.size(), i + UPLOAD_BULK_SIZE));
+        }
+        return new NextcloudGpodderEpisodeActionPostResponse(System.currentTimeMillis() / 1000);
+    }
+
+    private void uploadEpisodeActionsPartial(List<EpisodeAction> queuedEpisodeActions, int from, int to)
+            throws NextcloudSynchronizationServiceException {
+        try {
+            final JSONArray list = new JSONArray();
+            for (int i = from; i < to; i++) {
+                EpisodeAction episodeAction = queuedEpisodeActions.get(i);
+                JSONObject obj = episodeAction.writeToJsonObject();
+                if (obj != null) {
+                    list.put(obj);
+                }
+            }
+            HttpUrl.Builder url = makeUrl("/index.php/apps/gpoddersync/episode_action/create");
+            RequestBody requestBody = RequestBody.create(
+                    MediaType.get("application/json"), list.toString());
+            performRequest(url, "POST", requestBody);
+        } catch (Exception e) {
+            e.printStackTrace();
+            throw new NextcloudSynchronizationServiceException(e);
+        }
+    }
+
+    private String performRequest(HttpUrl.Builder url, String method, RequestBody body) throws IOException {
+        Request request = new Request.Builder()
+                .url(url.build())
+                .header("Authorization", Credentials.basic(username, password))
+                .header("Accept", "application/json")
+                .method(method, body)
+                .build();
+        Response response = httpClient.newCall(request).execute();
+        if (response.code() != 200) {
+            throw new IOException("Response code: " + response.code());
+        }
+        return response.body().string();
+    }
+
+    private HttpUrl.Builder makeUrl(String path) {
+        return new HttpUrl.Builder()
+                .scheme(baseScheme)
+                .host(baseHost)
+                .port(basePort)
+                .addPathSegments(path);
+    }
+
+    @Override
+    public void logout() {
+    }
+
+    private static class NextcloudGpodderEpisodeActionPostResponse extends UploadChangesResponse {
+        public NextcloudGpodderEpisodeActionPostResponse(long epochSecond) {
+            super(epochSecond);
+        }
+    }
+}
+
diff --git a/net/sync/gpoddernet/src/main/java/de/danoeh/antennapod/net/sync/nextcloud/NextcloudSynchronizationServiceException.java b/net/sync/gpoddernet/src/main/java/de/danoeh/antennapod/net/sync/nextcloud/NextcloudSynchronizationServiceException.java
new file mode 100644
index 000000000..d907c229e
--- /dev/null
+++ b/net/sync/gpoddernet/src/main/java/de/danoeh/antennapod/net/sync/nextcloud/NextcloudSynchronizationServiceException.java
@@ -0,0 +1,9 @@
+package de.danoeh.antennapod.net.sync.nextcloud;
+
+import de.danoeh.antennapod.net.sync.model.SyncServiceException;
+
+public class NextcloudSynchronizationServiceException extends SyncServiceException {
+    public NextcloudSynchronizationServiceException(Throwable e) {
+        super(e);
+    }
+}