more robustly re-schedule key sync

OpenKeychain/src/main/java/org/sufficientlysecure/keychain/Constants.java

@@ -151,7 +151,7 @@ public final class Constants {
         public static final String SYNC_CONTACTS = "syncContacts";
         public static final String SYNC_KEYSERVER = "syncKeyserver";
         public static final String ENABLE_WIFI_SYNC_ONLY = "enableWifiSyncOnly";
-        public static final String SYNC_IS_SCHEDULED = "syncIsScheduled";
+        public static final String SYNC_WORK_UUID = "syncWorkUuid";
         // other settings
         public static final String EXPERIMENTAL_ENABLE_LINKED_IDENTITIES = "experimentalEnableLinkedIdentities";
         public static final String EXPERIMENTAL_ENABLE_KEYBASE = "experimentalEnableKeybase";

OpenKeychain/src/main/java/org/sufficientlysecure/keychain/KeychainApplication.java

@@ -104,7 +104,7 @@ public class KeychainApplication extends Application {
         TlsCertificatePinning.addPinnedCertificate("api.keybase.io", getAssets(), "api.keybase.io.CA.cer");
         TlsCertificatePinning.addPinnedCertificate("keyserver.ubuntu.com", getAssets(), "DigiCertGlobalRootCA.cer");
 
-        KeyserverSyncManager.updateKeyserverSyncScheduleAsync(this, Constants.DEBUG_KEYSERVER_SYNC);
+        KeyserverSyncManager.updateKeyserverSyncScheduleAsync(this, false);
 
         TemporaryFileProvider.scheduleCleanupImmediately();
 

OpenKeychain/src/main/java/org/sufficientlysecure/keychain/keysync/KeyserverSyncManager.java

@@ -18,19 +18,23 @@
 package org.sufficientlysecure.keychain.keysync;
 
 
+import java.util.UUID;
 import java.util.concurrent.TimeUnit;
 
 import android.content.Context;
 import android.os.AsyncTask;
 import android.os.Build.VERSION;
 import android.os.Build.VERSION_CODES;
+import android.support.annotation.WorkerThread;
 
 import androidx.work.Constraints.Builder;
 import androidx.work.NetworkType;
 import androidx.work.OneTimeWorkRequest;
 import androidx.work.PeriodicWorkRequest;
+import androidx.work.State;
 import androidx.work.SynchronousWorkManager;
 import androidx.work.WorkManager;
+import androidx.work.WorkStatus;
 import org.sufficientlysecure.keychain.util.Preferences;
 import timber.log.Timber;
 
@@ -42,11 +46,6 @@ public class KeyserverSyncManager {
     private static final String PERIODIC_WORK_TAG = "keyserverSync";
 
     public static void updateKeyserverSyncScheduleAsync(Context context, boolean forceReschedule) {
-        Preferences prefs = Preferences.getPreferences(context);
-        if (!forceReschedule && prefs.isKeyserverSyncScheduled() != prefs.isKeyserverSyncEnabled()) {
-            return;
-        }
-
         new AsyncTask<Void,Void,Void>() {
             @Override
             protected Void doInBackground(Void... voids) {
@@ -56,21 +55,37 @@ public class KeyserverSyncManager {
         }.execute();
     }
 
+    @WorkerThread
     private static void updateKeyserverSyncSchedule(Context context, boolean forceReschedule) {
         Preferences prefs = Preferences.getPreferences(context);
-        // for some reason, the task is not actually scheduled sometimes unless we  use the synchronous interface.
         WorkManager workManager = WorkManager.getInstance();
         if (workManager == null) {
             Timber.e("WorkManager unavailable!");
             return;
         }
         SynchronousWorkManager synchronousWorkManager = workManager.synchronous();
+
+        UUID workUuid = prefs.getKeyserverSyncWorkUuid();
+        WorkStatus status = workUuid != null ? synchronousWorkManager.getStatusByIdSync(workUuid) : null;
+        boolean workIsScheduled = status != null && status.getState() != State.CANCELLED;
+        if (workIsScheduled == prefs.isKeyserverSyncEnabled()) {
+            if (!forceReschedule) {
+                Timber.d("Key sync already scheduled, no changes necessary");
+                return;
+            }
+            Timber.d("Key sync already scheduled, but forcing reschedule");
+        }
+
+        Timber.d("Cancelling sync tasks…");
         synchronousWorkManager.cancelAllWorkByTagSync(PERIODIC_WORK_TAG);
 
         if (!prefs.isKeyserverSyncEnabled()) {
+            Timber.d("Key sync disabled");
             return;
         }
 
+        Timber.d("Scheduling periodic key sync");
+
         Builder constraints = new Builder()
                 .setRequiredNetworkType(prefs.getWifiOnlySync() ? NetworkType.UNMETERED : NetworkType.CONNECTED)
                 .setRequiresBatteryNotLow(true);
@@ -85,7 +100,8 @@ public class KeyserverSyncManager {
                         .build();
         synchronousWorkManager.enqueueSync(workRequest);
 
-        prefs.setKeyserverSyncScheduled(true);
+        Timber.d("Work id: %s", workRequest.getId());
+        prefs.setKeyserverSyncScheduled(workRequest.getId());
     }
 
     public static void debugRunSyncNow() {

OpenKeychain/src/main/java/org/sufficientlysecure/keychain/util/Preferences.java

@@ -21,6 +21,7 @@ package org.sufficientlysecure.keychain.util;
 import java.net.Proxy;
 import java.util.ArrayList;
 import java.util.ListIterator;
+import java.util.UUID;
 
 import android.annotation.SuppressLint;
 import android.content.Context;
@@ -33,7 +34,6 @@ import android.support.annotation.Nullable;
 import com.google.auto.value.AutoValue;
 import org.sufficientlysecure.keychain.Constants;
 import org.sufficientlysecure.keychain.Constants.Pref;
-import org.sufficientlysecure.keychain.analytics.AnalyticsManager;
 import org.sufficientlysecure.keychain.keyimport.HkpKeyserverAddress;
 import timber.log.Timber;
 
@@ -350,12 +350,14 @@ public class Preferences {
         return mSharedPreferences.getBoolean(Pref.SYNC_KEYSERVER, true);
     }
 
-    public boolean isKeyserverSyncScheduled() {
+    public UUID getKeyserverSyncWorkUuid() {
-        return mSharedPreferences.getBoolean(Pref.SYNC_IS_SCHEDULED, false);
+        String uuidString = mSharedPreferences.getString(Pref.SYNC_WORK_UUID, null);
+        return uuidString != null ? UUID.fromString(uuidString) : null;
     }
 
-    public void setKeyserverSyncScheduled(boolean isScheduled) {
+    public void setKeyserverSyncScheduled(UUID uuid) {
-        mSharedPreferences.edit().putBoolean(Pref.SYNC_IS_SCHEDULED, isScheduled).apply();
+        String value = uuid != null ? uuid.toString() : null;
+        mSharedPreferences.edit().putString(Pref.SYNC_WORK_UUID, value).apply();
     }
 
     public boolean isAnalyticsAskedPolitely() {