/// <summary>
/// Worker method to acquire, refresh a token
/// this method will show a browser as needed to
/// complete the authentication flow
/// </summary>
/// <param name="browser"></param>
/// <returns></returns>
public Task <string> AcquireToken(WebBrowser browser)
{
_Browser = browser;
_TCS = new TaskCompletionSource <string>();
//Check if existing token has expired, if so try refresh
if (_AuthContext.IsAccessTokenExpired())
{
//If expired and we have a refresh token, try that
if (_AuthContext.IsRefreshViable())
{
GetRefreshToken();
}
else
{
//Start the flow from the top with the user providing credentials
NavigateBrowserToAuthScreen();
}
}
else
{
_TCS.SetResult(_AuthContext.AccessToken);
}
return(_TCS.Task);
}
