/// <summary>
/// Add a token to the token manager.
/// </summary>
/// <remarks>
/// For each added token a <see cref="TokenItem"/> is created.
/// The token item CreatedTicks is set to DateTime.Now.Ticks and is used
/// in the Get functions to check if a tokens needs a refresh before it is returned.
/// Client id and secret are needed to refresh the access token.
/// </remarks>
/// <param name="clientId">The client id this token referes to.</param>
/// <param name="clientSecret">The client secret this token referes to.</param>
/// <param name="tokenEndpoint">The token endpoint where to refresh the access token.</param>
/// <param name="token">The token that is added to the manager.</param>
public void Add(string clientId, string clientSecret, string tokenEndpoint, OAuthToken token)
{
if (!String.IsNullOrEmpty(clientId))
{
TokenItem item = new TokenItem()
{
ClientId = clientId,
ClientSecret = clientSecret,
TokenEndpoint = tokenEndpoint,
Token = token,
CreatedTicks = DateTime.Now.Ticks
};
Write(() => tokens[clientId] = item);
}
}
/// <summary>
/// Retreive a token for a given client id.
/// </summary>
/// <remarks>
/// If the OAuth access token is already expired it is refreshed before returned.
/// </remarks>
/// <param name="clientId">The client id of the token that will be returned.</param>
/// <returns>The OAuthToken or null if not found.</returns>
public async Task <OAuthToken> Get(string clientId)
{
TokenItem token = null;
OAuthToken result = null;
Read(() => tokens.TryGetValue(clientId, out token));
if (token != null)
{
await Read(token.RwLock, () => Refresh(token)); // get new access token if needed
result = token.Token;
}
return(result);
}
private async Task Refresh(TokenItem item)
{
var elapsedTime = new TimeSpan(DateTime.Now.Ticks - item.CreatedTicks);
if (item.Token.ExpiresIn.HasValue && elapsedTime.TotalSeconds >= item.Token.ExpiresIn - REFRESH_DELTA)
{
var tokenResponse = await Rest.OAuth.RefreshAccessToken(item.TokenEndpoint, item.Token.RefreshToken, item.ClientId, item.ClientSecret);
if (tokenResponse.HasData)
{
item.Token.AccessToken = tokenResponse.Data.AccessToken;
item.Token.ExpiresIn = tokenResponse.Data.ExpiresIn;
item.Token.Scope = tokenResponse.Data.Scope;
}
}
}