/* appjet:version 0.1 */
/* appjet:library */
// Copyright (c) 2010, Herbert Vojčík
// Licensed by MIT license (http://www.opensource.org/licenses/mit-license.php)

import("facebook", "storage");

var _u = import({}, "lib-support/useful");

fb.OAuthInterface = function () {};

fb.OAuthInterface.prototype.restApi = function (method, args) {
  return wpost("https://api.facebook.com/method/"+method, this.withToken(args));
};

fb.OAuthInterface.prototype.graphApiGet = function (path, args) {
  return wget("https://graph.facebook.com/"+path, this.withToken(args));
};

fb.OAuthInterface.prototype.graphApiPost = function (path, args) {
  return wpost("https://graph.facebook.com/"+path, this.withToken(args));
};

fb.OAuthInterface.prototype.withToken = function (args) {
  var token = this._token || (this._token = this.obtainToken());
  return token ? _u.extend({access_token:token}, args) : args;
};

fb.free = new fb.OAuthInterface;
fb.free.obtainToken = function () {};

fb.offline = new fb.OAuthInterface;
fb.offline.obtainToken = function () {
  var obtained = fb.free.graphApiPost("oauth/access_token", {
    grant_type: "client_credentials",
    client_id: storage.facebooklib.appId,
    client_secret: storage.facebooklib.secret
  }).split('=');
  if (obtained[0] === "access_token") { return obtained[1]; }
};

fb.online = new fb.OAuthInterface;
fb.online.obtainToken = function () {
  var obtained = eval("("+fb.free.graphApiPost("oauth/exchange_sessions", {
    sessions: fb.sessionKey,
    client_id: storage.facebooklib.appId,
    client_secret: storage.facebooklib.secret
  })+")"); // XXX JSON.parse
  return obtained[0].access_token;
};