Fix the issue that the timing of saving lastCreated is inappropriate

Covid19Radar/Covid19Radar/Services/ExposureNotificationHandler.cs

@@ -130,6 +130,7 @@ await Device.InvokeOnMainThreadAsync(() =>
  public async Task FetchExposureKeyBatchFilesFromServerAsync(Func<IEnumerable<string>, Task> submitBatches, CancellationToken cancellationToken)
  {
  var loggerService = LoggerService;
+ var exposureNotificationService = ExposureNotificationService;
 
  if (Interlocked.Exchange(ref fetchExposureKeysIsRunning, 1) == 1)
  {
@@ -148,35 +149,40 @@ public async Task FetchExposureKeyBatchFilesFromServerAsync(Func<IEnumerable<str
 
  foreach (var serverRegion in AppSettings.Instance.SupportedRegions)
  {
+ var lastCreated = exposureNotificationService.GetLastProcessTekTimestamp(serverRegion);
+ loggerService.Info($"region: {serverRegion}, lastCreated: {lastCreated}");
+
  cancellationToken.ThrowIfCancellationRequested();
 
  loggerService.Info("Start download files");
- var (batchNumber, downloadedFiles) = await DownloadBatchAsync(serverRegion, cancellationToken);
+
+ var (batchNumber, newCreated, downloadedFiles) = await DownloadBatchAsync(serverRegion, lastCreated, cancellationToken);
  loggerService.Info("End to download files");
- loggerService.Info($"Batch number: {batchNumber}, Downloaded files: {downloadedFiles.Count}");
+ loggerService.Info($"Batch number: {batchNumber}, Downloaded files: {downloadedFiles.Count}, newCreated: {newCreated}");
 
- if (batchNumber == 0)
+ if (batchNumber == 0 || newCreated == -1 || downloadedFiles.Count == 0)
  {
  continue;
  }
 
- if (downloadedFiles.Count > 0)
- {
- loggerService.Info("C19R Submit Batches");
- await submitBatches(downloadedFiles);
+ loggerService.Info("C19R Submit Batches");
+ await submitBatches(downloadedFiles);
 
- // delete all temporary files
- foreach (var file in downloadedFiles)
+ lastCreated = newCreated;
+ exposureNotificationService.SetLastProcessTekTimestamp(serverRegion, lastCreated);
+ loggerService.Info($"region: {serverRegion}, lastCreated: {lastCreated}");
+
+ // delete all temporary files
+ foreach (var file in downloadedFiles)
+ {
+ try
  {
- try
- {
- File.Delete(file);
- }
- catch (Exception ex)
- {
- // no-op
- loggerService.Exception("Fail to delete downloaded files", ex);
- }
+ File.Delete(file);
+ }
+ catch (Exception ex)
+ {
+ // no-op
+ loggerService.Exception("Fail to delete downloaded files", ex);
  }
  }
  }
@@ -193,7 +199,7 @@ public async Task FetchExposureKeyBatchFilesFromServerAsync(Func<IEnumerable<str
  }
  }
 
- private async Task<(int, List<string>)> DownloadBatchAsync(string region, CancellationToken cancellationToken)
+ private async Task<(int, long, List<string>)> DownloadBatchAsync(string region, long lastCreated, CancellationToken cancellationToken)
  {
  var loggerService = LoggerService;
  loggerService.StartMethod();
@@ -214,28 +220,24 @@ public async Task FetchExposureKeyBatchFilesFromServerAsync(Func<IEnumerable<str
  loggerService.Exception("Failed to create directory", ex);
  loggerService.EndMethod();
  // catch error return batchnumber 0 / fileList 0
- return (batchNumber, downloadedFiles);
+ return (batchNumber, -1, downloadedFiles);
  }
 
  var httpDataService = HttpDataService;
- var exposureNotificationService = ExposureNotificationService;
 
  List<TemporaryExposureKeyExportFileModel> tekList = await httpDataService.GetTemporaryExposureKeyList(region, cancellationToken);
  if (tekList.Count == 0)
  {
  loggerService.EndMethod();
- return (batchNumber, downloadedFiles);
+ return (batchNumber, -1, downloadedFiles);
  }
  Debug.WriteLine("C19R Fetch Exposure Key");
 
- var lastCreated = exposureNotificationService.GetLastProcessTekTimestamp(region);
- loggerService.Info($"lastCreated: {lastCreated}");
-
  var newCreated = lastCreated;
  foreach (var tekItem in tekList)
  {
  loggerService.Info($"tekItem.Created: {tekItem.Created}");
- if (tekItem.Created > lastCreated || lastCreated == 0)
+ if (tekItem.Created > newCreated || newCreated == 0)
  {
  var tmpFile = Path.Combine(tmpDir, Guid.NewGuid().ToString() + ".zip");
  Debug.WriteLine(Utils.SerializeToJson(tekItem));
@@ -263,12 +265,9 @@ public async Task FetchExposureKeyBatchFilesFromServerAsync(Func<IEnumerable<str
  }
  loggerService.Info($"Batch number: {batchNumber}, Downloaded files: {downloadedFiles.Count()}");
 
- exposureNotificationService.SetLastProcessTekTimestamp(region, newCreated);
- loggerService.Info($"region: {region}, newCreated: {newCreated}");
-
  loggerService.EndMethod();
 
- return (batchNumber, downloadedFiles);
+ return (batchNumber, newCreated, downloadedFiles);
  }
 
  // this will be called when the user is submitting a diagnosis and the local keys need to go to the server