Parse / Facebook wrapper

ParseFacebook.js

var FacebookAPI = function(app_id, app_secret) {
    return {
        auth_url : "https://graph.facebook.com/oauth/access_token?"+
        "client_id=" + app_id +
        "&client_secret=" + app_secret +
        "&grant_type=client_credentials",

        setAppToken: function(app_token){
            this.app_token = app_token;
        },
        authorizeUser: function(user){
            var self = this;
            if (!user.get("authData") || !user.get("authData").facebook) {
                return Parse.Promise.error("This account is not connected with Facebook");
            }else{
                self.access_token = user.get("authData").facebook.access_token;
                return Parse.Promise.as(self);
            }
        },
        authApp: function(callback){
            var self = this;
            return Parse.Cloud.httpRequest({
                url: self.auth_url,
                method: "GET",
            }).then(function(httpResponse){
                self.app_token = httpResponse.text.split("=")[1];
                return Parse.Promise.as();
            }, Parse.Promise.error);
        },
        app_token: undefined,
        user_id: undefined,
        access_token: undefined,
        get: function(path, params, callback){
            var url = "https://graph.facebook.com"+path;
            if (params === undefined) {
                params = {};
            }
            if (this.access_token) {
                params.access_token = this.access_token;
            }else if(this.app_token){
                params.access_token = this.app_token;
            }        
            var request_options = {
                url: url,
                params: params,
                method: "GET"
            };
            return Parse.Cloud.httpRequest(request_options).then(function(httpResponse){
                    var rsp = JSON.parse(httpResponse.text);
                    if (callback) {
                        callback(rsp);
                    }
                    return Parse.Promise.as(rsp);
            }, function(httpResponse){
                var err = JSON.parse(httpResponse.text);
                if (callback) {
                    callback(err);
                }
                return Parse.Promise.error(err)
            });
         },
         post: function (path, params, body, callback){
            var url = "https://graph.facebook.com"+path;
            if (params === undefined) {
                params = {};
            }
            if (this.access_token) {
                params.access_token = this.access_token;
            }else if(this.app_token){
                params.access_token = this.app_token;
            }
            if (body === undefined) {
                body = {};
            }
            var request_options = {
                url: url,
                params: params,
                body: body,
                method: "POST"
            };
            return Parse.Cloud.httpRequest(request_options).then(function(httpResponse){
                    var rsp = JSON.parse(httpResponse.text);
                    if (callback) {
                        callback(rsp);
                    }
                    return Parse.Promise.as(rsp);
            }, function(httpResponse){
                var err = JSON.parse(httpResponse.text);
                if (callback) {
                    callback(err);
                }
                return Parse.Promise.error(err)
            });
         }
    };
};


module.exports = FacebookAPI;