private static async Task DownloadRoamingDataFromServerAsync(
IRemoteStorageProvider remoteStorageProvider,
IEnumerable <RemoteFileInfo> allOtherRoamingFiles,
IEnumerable <StorageFile> allOtherLocalFiles,
CancellationToken cancellationToken)
{
// Download the user data bundle file from the server.
HandleDownloadResult(await remoteStorageProvider.DownloadFileAsync(Constants.UserDataBundleFileName, cancellationToken).ConfigureAwait(false));
// Delete local data files that don't exist remotely
foreach (StorageFile localFile in allOtherLocalFiles)
{
if (!allOtherRoamingFiles.Any(roamingFile
=> string.Equals(Path.GetFileName(roamingFile.FullPath), localFile.Name, StringComparison.Ordinal)))
{
await localFile.DeleteAsync(StorageDeleteOption.PermanentDelete);
}
}
// Download remote data files that don't exist locally
foreach (RemoteFileInfo roamingFile in allOtherRoamingFiles)
{
if (!allOtherLocalFiles.Any(localFile
=> string.Equals(Path.GetFileName(roamingFile.FullPath), localFile.Name, StringComparison.Ordinal)))
{
HandleDownloadResult(await remoteStorageProvider.DownloadFileAsync(roamingFile.FullPath, cancellationToken).ConfigureAwait(false));
}
}
}
private static async Task UploadLocalDataToServerAsync(
IRemoteStorageProvider remoteStorageProvider,
StorageFile localUserDataBundleFile,
IEnumerable <RemoteFileInfo> allOtherRoamingFiles,
IEnumerable <StorageFile> allOtherLocalFiles,
CancellationToken cancellationToken)
{
// Upload the user data bundle file to the server.
HandleUploadResult(await remoteStorageProvider.UploadFileAsync(localUserDataBundleFile, cancellationToken).ConfigureAwait(false));
// Delete roaming data files that don't exist locally
foreach (RemoteFileInfo roamingFile in allOtherRoamingFiles)
{
if (!allOtherLocalFiles.Any(localFile
=> string.Equals(Path.GetFileName(roamingFile.FullPath), localFile.Name, StringComparison.Ordinal)))
{
await remoteStorageProvider.DeleteFileAsync(roamingFile.FullPath, cancellationToken).ConfigureAwait(false);
}
}
// Upload local data files that don't exist remotely
foreach (StorageFile localFile in allOtherLocalFiles)
{
if (!allOtherRoamingFiles.Any(roamingFile
=> string.Equals(Path.GetFileName(roamingFile.FullPath), localFile.Name, StringComparison.Ordinal)))
{
HandleUploadResult(await remoteStorageProvider.UploadFileAsync(localFile, cancellationToken).ConfigureAwait(false));
}
}
}
private async Task SynchronizeAsync(CancellationToken cancellationToken)
{
// The semaphore acts like queue.
using (await _sempahore.WaitAsync(cancellationToken).ConfigureAwait(false))
{
var synchronizationStarted = false;
var succeeded = false;
var requiresReloadLocalData = false;
try
{
if (!_settingsProvider.GetSetting(SettingsDefinitions.SyncDataWithCloud))
{
return;
}
string targetterProviderName = _settingsProvider.GetSetting(SettingsDefinitions.RemoteStorageProviderName);
IRemoteStorageProvider remoteStorageProvider = _remoteStorageProviders.SingleOrDefault(m => string.Equals(m.Metadata.ProviderName, targetterProviderName, StringComparison.Ordinal))?.Value;
if (remoteStorageProvider == null)
{
return;
}
if (!CoreHelper.IsInternetAccess())
{
return;
}
SynchronizationStarted?.Invoke(this, EventArgs.Empty);
synchronizationStarted = true;
if (!await remoteStorageProvider.SignInAsync(interactive: false, cancellationToken).ConfigureAwait(false))
{
// If fails to authenticate, disables synchronization and sign out.
_settingsProvider.SetSetting(SettingsDefinitions.SyncDataWithCloud, false);
await remoteStorageProvider.SignOutAsync().ConfigureAwait(false);
// TODO: Add a log to notify to let the user know it signed out and he should re-authenticate.
// returning here will still trigger the Finally block.
return;
}
// Retrieve the list of online files.
IReadOnlyList <RemoteFileInfo> roamingFiles =
await remoteStorageProvider.GetFilesAsync(Constants.DataFileCountLimit, cancellationToken).ConfigureAwait(false);
RemoteFileInfo roamingUserDataBundleFile = roamingFiles.FirstOrDefault(file
=> string.Equals(Path.GetFileName(file.FullPath), Constants.UserDataBundleFileName, StringComparison.Ordinal));
IEnumerable <RemoteFileInfo> allOtherRoamingFiles = roamingFiles.Where(file
=> !string.Equals(Path.GetFileName(file.FullPath), Constants.UserDataBundleFileName, StringComparison.Ordinal));
// Retrieve the list of local files.
var localUserDataFolder = await CoreHelper.GetOrCreateUserDataStorageFolderAsync().ConfigureAwait(false);
StorageFile localUserDataBundleFile = await localUserDataFolder.TryGetItemAsync(Constants.UserDataBundleFileName) as StorageFile;
IEnumerable <StorageFile> allOtherLocalFiles = (await localUserDataFolder.GetFilesAsync())
.Where(file => !string.Equals(file.Name, Constants.UserDataBundleFileName, StringComparison.Ordinal));
if (localUserDataBundleFile == null && roamingUserDataBundleFile == RemoteFileInfo.Empty)
{
// Nothing locally and remotely?
succeeded = true;
return;
}
if (localUserDataBundleFile == null ||
(roamingUserDataBundleFile != RemoteFileInfo.Empty &&
roamingUserDataBundleFile.CreatedDateTime.ToUniversalTime()
> (await localUserDataBundleFile.GetBasicPropertiesAsync()).DateModified.ToUniversalTime()))
{
// If there is no local user data file, or that the file on the server is more recent than the local one,
// then we want to merge by taking the version from the server.
await DownloadRoamingDataFromServerAsync(
remoteStorageProvider,
allOtherRoamingFiles,
allOtherLocalFiles,
cancellationToken).ConfigureAwait(false);
// The local file changed, since we downloaded the one from the server, so let's indicate
// that we want to reload (and merge) the local data.
requiresReloadLocalData = true;
}
else
{
// Else, then it means the local file is more recent than the one on the server,
// or that there is simply no file on the server,
// so we want to merge by taking the version from the local file.
await UploadLocalDataToServerAsync(
remoteStorageProvider,
localUserDataBundleFile,
allOtherRoamingFiles,
allOtherLocalFiles,
cancellationToken).ConfigureAwait(false);
}
succeeded = true;
}
catch (OperationCanceledException)
{
_logger.LogEvent(SynchronizeCanceledEvent, "The synchronization with the cloud has been canceled.");
}
catch (Exception ex)
{
_logger.LogFault(SynchronizeFaultEvent, "Failed to synchronize the data with the cloud.", ex);
}
finally
{
if (synchronizationStarted)
{
RaiseSynchronizationCompleted(succeeded, requiresReloadLocalData);
}
}
}
}