/// <summary>
/// Get a working Provider for Google Drive.
/// </summary>
/// <param name="savedState">Serialized TokenResponse from the Google Api (and folderId).</param>
/// <param name="showForm">Show registration form, if the saved state did not work.</param>
/// <returns></returns>
public async Task <string> Register(string savedState = null, bool showForm = true)
{
var result = new TaskCompletionSource <string>();
try
{
state = new MemoryStore(Obscure.Base64Decode(savedState));
// Try to use the previously saved TokenResponse and if it fails, show the registration form (if the showForm parameter allows it)
var secret = new ClientSecrets()
{
ClientId = Obscure.CaesarDecode(Constants.AppKey), ClientSecret = Obscure.CaesarDecode(Constants.AppSecret)
};
var receiver = new CodeReceiver(showForm);
var credentials = await GoogleWebAuthorizationBroker.AuthorizeAsync(secret, Constants.Scopes, "token", CancellationToken.None, state, receiver);
service = new DriveService(new BaseClientService.Initializer()
{
HttpClientInitializer = credentials,
ApplicationName = "SharpCrop",
});
// Try to use the saved application folder or get a new one
// If the access token was expired or corrupted, it is safer to get the folder id again
if (receiver.Executed || await state.GetAsync <string>("folderId") == null)
{
var folder = await GetFolder();
await state.DeleteAsync <string>("folderId");
await state.StoreAsync("folderId", folder?.Id);
}
// Export the serialized TokenResponse which gonna be saved into the config
result.SetResult(Obscure.Base64Encode(state.Export()));
}
catch
{
result.SetResult(null);
}
return(await result.Task);
}
