/// Reads the settings from the Google Drive App Data Folder settings file. If the file doesn't
/// exist, it will return null. If there is a failure in reading the file, a LoadSettingsFailed
/// exception will be thrown.
private async Task <UserData> DeserializeFromDriveAsync(CancellationToken token)
{
var fileId = await GetSettingsFileIdAsync(token);
if (string.IsNullOrEmpty(fileId))
{
return(null);
}
var downloadRequest = m_DriveService.Files.Get(fileId);
MemoryStream jsonStream = new MemoryStream();
var result = await DriveAccess.Retry(() => {
jsonStream.Seek(0, SeekOrigin.Begin);
return(downloadRequest.DownloadAsync(jsonStream, token));
});
if (result.Status != DownloadStatus.Completed)
{
throw new LoadSettingsFailed($"{sm_SettingsFileName} failed to download.");
}
try {
jsonStream.Seek(0, SeekOrigin.Begin);
return(NewtonsoftJsonSerializer.Instance.Deserialize <UserData>(jsonStream));
} catch (JsonException ex) {
throw new LoadSettingsFailed($"{sm_SettingsFileName} was incorrectly formatted.", ex);
}
}
/// Saves the User data to Google Drive AppData folder. Will overwrite an existing Settings.json
/// if it exists.
private async Task <bool> SerializeToDriveAsync(CancellationToken token)
{
string json = JsonConvert.SerializeObject(m_UserData);
var jsonStream = new MemoryStream(Encoding.UTF8.GetBytes(json));
var fileId = await GetSettingsFileIdAsync(token);
// the action varies slightly depending on whether we're creating a new file or overwriting an
// old one.
if (string.IsNullOrEmpty(fileId))
{
var file = new DriveData.File {
Parents = new[] { "appDataFolder" },
Name = sm_SettingsFileName,
};
var request = m_DriveService.Files.Create(file, jsonStream, "application/json");
var result = await DriveAccess.Retry(() => {
jsonStream.Seek(0, SeekOrigin.Begin);
return(request.UploadAsync(token));
});
return(result.Status == UploadStatus.Completed);
}
else
{
var request = m_DriveService.Files.Update(new DriveData.File(), fileId, jsonStream,
"application/json");
var result = await DriveAccess.Retry(() => {
jsonStream.Seek(0, SeekOrigin.Begin);
return(request.UploadAsync(token));
});
return(result.Status == UploadStatus.Completed);
}
}
/// Attempts to find the id of the settings file in the drive appdata folder. Will return null
/// if no settings file is found.
private async Task <string> GetSettingsFileIdAsync(CancellationToken token)
{
var findRequest = m_DriveService.Files.List();
findRequest.Q = $"name = '{sm_SettingsFileName}' and trashed = false";
findRequest.Spaces = "appDataFolder";
findRequest.Fields = "nextPageToken, files(id, name, modifiedTime)";
var files = await DriveAccess.Retry(() => findRequest.ExecuteAsync(token));
return(files.Files.OrderByDescending(x => x.ModifiedTime).FirstOrDefault()?.Id);
}