// 0. Get the code
// 1. Request POST https://www.googleapis.com/oauth2/v4/token with params code={}&client_id={client_id}&client_secret={}&redirect_uri={redirect_uri}&grant_type=authorization_code
// 2. Google responsds with JSON object that contais access token (short live period), refresh token (NOTE: refresh token returns only if access_type=offline in initial requst),
// expires_in (the remaining lifetime of the access token in seconds), token_type (=Bearer)
// 3. Access Google APIs with access_token (for example, GET https://www.googleapis.com/drive/v2/files?access_token=<access_token>)
// 4. Refresh access_token if needed: Request POST https://www.googleapis.com/oauth2/v4/token with params refresh_token={refresh_token}&client_id={client_id}&client_secret={}&grant_type=refresh_token.
// 5. Google respods with the JSON object with access_token, expires_in and token_type (see pt 2)
// 6. Revoke token if needed by request to https://accounts.google.com/o/oauth2/revoke?token={token}
public async Task InvokeAsync(HttpContext context) //не менять на синхронный, прога руинится!!
{
if (context.Request.Query.ContainsKey("code") && context.Request.Query.ContainsKey("state"))
{
var code = context.Request.Query["code"];
var state = context.Request.Query["state"].ToString();
var userId = state.Split('_')[0];
var chatId = state.Split('_')[1];
var user = Bot.GetUserById(userId);
await user.SetCredentialAsync(chatId, code);
long id;
long.TryParse(chatId, out id);
await PubSubHubbub.PuSH.AddAllChannelsAsync(id, user);
}
else if (context.Request.Query.ContainsKey("error") && context.Request.Query.ContainsKey("state"))
{
var error = context.Request.Query["error"];
var state = context.Request.Query["state"];
await Bot.SendDebugMessageAsync($"An error occured during Google Authentication Proccess. Message: {error.ToString()}");
}
context.Response.Redirect(AppSettings.BotUrl);
}