Recursively delete caldav children

app/src/main/java/com/todoroo/astrid/service/TaskDeleter.java

@@ -17,6 +17,7 @@ import javax.inject.Inject;
 import org.tasks.LocalBroadcastManager;
 import org.tasks.data.CaldavAccount;
 import org.tasks.data.CaldavCalendar;
+import org.tasks.data.CaldavDao;
 import org.tasks.data.DeletionDao;
 import org.tasks.data.GoogleTaskAccount;
 import org.tasks.data.GoogleTaskDao;
@@ -29,6 +30,7 @@ public class TaskDeleter {
   private final TaskDao taskDao;
   private final LocalBroadcastManager localBroadcastManager;
   private final GoogleTaskDao googleTaskDao;
+  private final CaldavDao caldavDao;
   private final DeletionDao deletionDao;
 
   @Inject
@@ -37,12 +39,14 @@ public class TaskDeleter {
       WorkManager workManager,
       TaskDao taskDao,
       LocalBroadcastManager localBroadcastManager,
-      GoogleTaskDao googleTaskDao) {
+      GoogleTaskDao googleTaskDao,
+      CaldavDao caldavDao) {
     this.deletionDao = deletionDao;
     this.workManager = workManager;
     this.taskDao = taskDao;
     this.localBroadcastManager = localBroadcastManager;
     this.googleTaskDao = googleTaskDao;
+    this.caldavDao = caldavDao;
   }
 
   public int purgeDeleted() {
@@ -58,6 +62,7 @@ public class TaskDeleter {
   public List<Task> markDeleted(List<Long> taskIds) {
     Set<Long> ids = new HashSet<>(taskIds);
     batch(taskIds, i -> ids.addAll(googleTaskDao.getChildren(i)));
+    batch(taskIds, i -> ids.addAll(caldavDao.getChildren(i)));
     deletionDao.markDeleted(ids);
     workManager.cleanup(taskIds);
     workManager.sync(false);

app/src/main/java/org/tasks/data/CaldavDao.java

@@ -110,4 +110,24 @@ public interface CaldavDao {
           + "INNER JOIN caldav_tasks ON cd_task = tasks._id "
           + "GROUP BY tasks._id")
   List<Long> getTasksWithTags();
+
+  @Query("WITH RECURSIVE "
+          + " recursive_caldav (cd_task) AS ( "
+          + " SELECT cd_task "
+          + " FROM tasks "
+          + " INNER JOIN caldav_tasks "
+          + "  ON _id = cd_task "
+          + " WHERE cd_parent IN (:ids) "
+          + " AND tasks.deleted = 0 "
+          + "UNION ALL "
+          + " SELECT caldav_tasks.cd_task "
+          + " FROM tasks "
+          + " INNER JOIN caldav_tasks "
+          + "  ON _id = caldav_tasks.cd_task "
+          + " INNER JOIN recursive_caldav "
+          + "  ON recursive_caldav.cd_task = caldav_tasks.cd_parent "
+          + " WHERE tasks.deleted = 0 "
+          + " ) "
+          + "SELECT cd_task FROM recursive_caldav")
+  List<Long> getChildren(List<Long> ids);
 }