Only sync gtask lists with updates

src/main/java/com/todoroo/astrid/gtasks/GtasksListService.java

@@ -10,6 +10,9 @@ import com.google.api.services.tasks.model.TaskLists;
 import com.todoroo.astrid.dao.StoreObjectDao;
 import com.todoroo.astrid.data.StoreObject;
 
+import org.slf4j.Logger;
+import org.slf4j.LoggerFactory;
+
 import java.util.ArrayList;
 import java.util.HashSet;
 import java.util.List;
@@ -21,28 +24,19 @@ import javax.inject.Singleton;
 @Singleton
 public class GtasksListService {
 
+    private static final Logger log = LoggerFactory.getLogger(GtasksListService.class);
+
     public static final StoreObject LIST_NOT_FOUND_OBJECT = null;
 
     private final StoreObjectDao storeObjectDao;
 
-    private List<StoreObject> lists;
-
     @Inject
     public GtasksListService(StoreObjectDao storeObjectDao) {
         this.storeObjectDao = storeObjectDao;
     }
 
-    private void readLists() {
-        if(lists != null) {
-            return;
-        }
-
-        lists = storeObjectDao.getByType(GtasksList.TYPE);
-    }
-
     public List<StoreObject> getLists() {
-        readLists();
+        return storeObjectDao.getByType(GtasksList.TYPE);
-        return lists;
     }
 
     /**
@@ -51,7 +45,7 @@ public class GtasksListService {
      * @param remoteLists remote information about your lists
      */
     public synchronized void updateLists(TaskLists remoteLists) {
-        readLists();
+        List<StoreObject> lists = getLists();
 
         Set<Long> previousLists = new HashSet<>();
         for(StoreObject list : lists) {
@@ -59,7 +53,6 @@ public class GtasksListService {
         }
 
         List<TaskList> items = remoteLists.getItems();
-        List<StoreObject> newLists = new ArrayList<>();
         for(int i = 0; i < items.size(); i++) {
             com.google.api.services.tasks.model.TaskList remote = items.get(i);
 
@@ -72,19 +65,20 @@ public class GtasksListService {
                 }
             }
 
+            String title = remote.getTitle();
             if(local == null) {
+                log.debug("Adding new gtask list {}", title);
                 local = new StoreObject();
+                local.setValue(GtasksList.LAST_SYNC, 0L);
             }
 
             local.setType(GtasksList.TYPE);
             local.setValue(GtasksList.REMOTE_ID, id);
-            local.setValue(GtasksList.NAME, remote.getTitle());
+            local.setValue(GtasksList.NAME, title);
             local.setValue(GtasksList.ORDER, i);
             storeObjectDao.persist(local);
             previousLists.remove(local.getId());
-            newLists.add(local);
         }
-        lists = newLists;
 
         // check for lists that aren't on remote server
         for(Long listId : previousLists) {
@@ -93,8 +87,7 @@ public class GtasksListService {
     }
 
     public StoreObject getList(String listId) {
-        readLists();
+        for(StoreObject list : getLists()) {
-        for(StoreObject list : lists) {
             if (list != null && list.getValue(GtasksList.REMOTE_ID).equals(listId)) {
                 return list;
             }

src/main/java/com/todoroo/astrid/gtasks/sync/GtasksSyncV2Provider.java

@@ -8,6 +8,8 @@ package com.todoroo.astrid.gtasks.sync;
 import android.content.Context;
 import android.text.TextUtils;
 
+import com.google.api.services.tasks.model.TaskList;
+import com.google.api.services.tasks.model.TaskLists;
 import com.google.api.services.tasks.model.Tasks;
 import com.todoroo.andlib.data.AbstractModel;
 import com.todoroo.andlib.data.TodorooCursor;
@@ -49,7 +51,9 @@ import java.util.concurrent.atomic.AtomicInteger;
 import javax.inject.Inject;
 import javax.inject.Singleton;
 
+import static com.google.common.collect.Lists.newArrayList;
 import static org.tasks.date.DateTimeUtils.newDate;
+import static org.tasks.date.DateTimeUtils.newDateTime;
 
 @Singleton
 public class GtasksSyncV2Provider {
@@ -132,25 +136,44 @@ public class GtasksSyncV2Provider {
             public void run() {
                 callback.started();
 
+                try {
                     String authToken = getValidatedAuthToken();
                     final GtasksInvoker invoker = new GtasksInvoker(gtasksTokenValidator, authToken);
+                    TaskLists remoteLists = null;
                     try {
-                    gtasksListService.updateLists(invoker.allGtaskLists());
+                        remoteLists = invoker.allGtaskLists();
+                        gtasksListService.updateLists(remoteLists);
                     } catch (IOException e) {
                         handler.handleException("gtasks-sync=io", e); //$NON-NLS-1$
                     }
 
-                List<StoreObject> lists = gtasksListService.getLists();
+                    if (remoteLists == null) {
-                if (lists.isEmpty()) {
                         finishSync(callback);
                         return;
                     }
 
-                final AtomicInteger finisher = new AtomicInteger(lists.size());
+                    List<StoreObject> listsToUpdate = newArrayList();
+                    for (TaskList remoteList : remoteLists.getItems()) {
+                        StoreObject localList = gtasksListService.getList(remoteList.getId());
+                        String listName = localList.getValue(GtasksList.NAME);
+                        Long lastSync = localList.getValue(GtasksList.LAST_SYNC);
+                        long lastUpdate = remoteList.getUpdated().getValue();
+                        if (lastSync < lastUpdate) {
+                            listsToUpdate.add(localList);
+                            log.debug("{} out of date [local={}] [remote={}]", listName, newDateTime(lastSync), newDateTime(lastUpdate));
+                        } else {
+                            log.debug("{} up to date", listName);
+                        }
+                    }
 
-                // TODO: Check timestamps from invoker.allGtaskLists and pare down lists to sync
+                    if (listsToUpdate.isEmpty()) {
+                        finishSync(callback);
+                        return;
+                    }
+
+                    final AtomicInteger finisher = new AtomicInteger(listsToUpdate.size());
 
-                for (final StoreObject list : lists) {
+                    for (final StoreObject list : listsToUpdate) {
                         executor.execute(callback, new Runnable() {
                             @Override
                             public void run() {
@@ -162,6 +185,10 @@ public class GtasksSyncV2Provider {
                             }
                         });
                     }
+                } catch(Exception e) {
+                    handler.handleException("gtasks-sync=io", e); //$NON-NLS-1$
+                    callback.finished();
+                }
             }
         });
     }