Sync local only tasks & subtask in proper order to preserve hierarchy & sorting

Author: opatry

tasks-core/src/commonMain/kotlin/net/opatry/tasks/data/TaskRepository.kt

@@ -226,8 +226,8 @@ class TaskRepository(
             entries.map { (list, tasks) ->
                 // FIXME Where should happen the sorting, on SQL side or here or in UI layer?
                 list.asTaskListDataModel(tasks)
+            }
         }
-    }
 
     suspend fun sync() {
         val taskListIds = mutableMapOf<Long, String>()
@@ -281,19 +281,40 @@ class TaskRepository(
                 taskDao.upsert(remoteTask.asTaskEntity(localListId, existingEntity?.id))
             }
             taskDao.deleteStaleTasks(localListId, remoteTasks.map(Task::id))
-            taskDao.getLocalOnlyTasks(localListId).onEach { localTask ->
-                val remoteTask = withContext(Dispatchers.IO) {
-                    try {
-                        tasksApi.insert(remoteListId, localTask.asTask())
-                    } catch (e: Exception) {
-                        null
-                    }
-                }
-                if (remoteTask != null) {
-                    taskDao.upsert(remoteTask.asTaskEntity(localListId, localTask.id))
+            val localOnlyTasks = taskDao.getLocalOnlyTasks(localListId)
+            val sortedRootTasks = computeTaskPositions(localOnlyTasks.filter { it.parentTaskLocalId == null })
+            var previousTaskId: String? = null
+            sortedRootTasks.onEach { localRootTask ->
+                val remoteTask = syncLocalTask(localListId, remoteListId, localRootTask, null, previousTaskId)
+                val sortedSubTasks = computeTaskPositions(localOnlyTasks.filter { it.parentTaskLocalId == localRootTask.id })
+                var previousSubTaskId: String? = null
+                sortedSubTasks.onEach { localSubTask ->
+                    val remoteSubTask = syncLocalTask(localListId, remoteListId, localSubTask, remoteTask?.id, previousSubTaskId)
+                    previousSubTaskId = remoteSubTask?.id
                 }
+                previousTaskId = remoteTask?.id
+            }
+        }
+    }
+
+    private suspend fun syncLocalTask(
+        localTaskListId: Long,
+        remoteTaskListId: String,
+        localTask: TaskEntity,
+        parentTaskId: String?,
+        previousTaskId: String?
+    ): Task? {
+        val remoteTask = withContext(Dispatchers.IO) {
+            try {
+                tasksApi.insert(remoteTaskListId, localTask.asTask(), parentTaskId, previousTaskId)
+            } catch (e: Exception) {
+                null
             }
         }
+        if (remoteTask != null) {
+            taskDao.upsert(remoteTask.asTaskEntity(localTaskListId, localTask.id))
+        }
+        return remoteTask
     }
 
     suspend fun createTaskList(title: String) {