EffectiveBasePermissions not working as expected

I created a SharePoint Hosted App and trying to get the current user's permission on their web.

Please refer to the below code snippet, I'm passing the siteurl as parameter to which I have full control access.

I'm in fact a site collection admin on this "siteurl"  but when I check for its permissions it always returns 'false'. Is there a way do get the permissions of the current user on its web?  Below is the snippet of the code

 var ctx = new SP.ClientContext(appweburl);
    var factory = new SP.ProxyWebRequestExecutorFactory(appweburl);
    ctx.set_webRequestExecutorFactory(factory);
    var appContextSite = new SP.AppContextSite(ctx, siteurl);
    var web = appContextSite.get_web();
    ctx.load(web, 'EffectiveBasePermissions');
    ctx.executeQueryAsync(
        // OnSuccess
        function (sender, args) {
            var value = web.get_effectiveBasePermissions();
            console.log(value);
            var hasPermission = web.get_effectiveBasePermissions().has(SP.PermissionKind.viewListItems);
            var text = "<li>" + siteurl + ": " + "<b>" + hasPermission + "</b></li>";
            $('#message ul').append(text);
        },

        // OnFailure
        function (sender, args) {
            console.log('request failed ' + args.get_message() + '\n' + args.get_stackTrace());
        });

Vamsi Munagala