/// <summary>
/// Initializes the auth client. Detects if user is already signed in,
/// If user is already signed in, creates a valid Session.
/// This call is UI-less.
/// </summary>
/// <param name="scopes">The list of offers that the application is requesting user consent for.</param>
/// <returns>A Task object representing the asynchronous operation.</returns>
public async Task<LiveLoginResult> InitializeAsync(IEnumerable<string> scopes)
{
this.PrepareForAsync();
// Always make a call to the server instead of relying on cached access token for two reasons:
// 1. user may have revoked the scope
// 2. user may have previously consented to the scope via a web app, we should not ask again.
// Use a refresh token if present, if not, use silent flow.
LiveConnectSession currentSession = this.AuthClient.LoadSession(this);
this.scopes = (scopes == null) ? new List<string>() : new List<string>(scopes);
bool hasRefreshToken = currentSession != null && !string.IsNullOrEmpty(currentSession.RefreshToken);
if (hasRefreshToken)
{
var refreshOp = new RefreshTokenOperation(
this,
this.clientId,
currentSession.RefreshToken,
this.scopes,
null);
var tcs = new TaskCompletionSource<LiveLoginResult>();
try
{
LiveLoginResult refreshOpResult = await refreshOp.ExecuteAsync();
this.Session = refreshOpResult.Session;
this.AuthClient.SaveSession(this.Session);
tcs.TrySetResult(refreshOpResult);
}
catch (Exception exception)
{
this.Session = null;
tcs.TrySetException(exception);
}
finally
{
Interlocked.Decrement(ref this.asyncInProgress);
}
return await tcs.Task;
}
// If we do NOT have a refresh token, use the silent flow.
return await this.AuthenticateAsync(true /* silent flow */);
}
internal Task<LiveLoginResult> RefreshTokenAsync()
{
var refreshOp = new RefreshTokenOperation(
this,
this.clientId,
this.Session.RefreshToken,
this.Session.Scopes,
null);
return refreshOp.ExecuteAsync();
}
