(function() {
    function getSimpleUser() {
        var table = [];
        var groupEnumerator = collGroup.getEnumerator();
        while (groupEnumerator.moveNext()) {
            var oGroup = groupEnumerator.get_current();
            var collUser = oGroup.get_users();
            var userEnumerator = collUser.getEnumerator();
            while (userEnumerator.moveNext()) {
                var oUser = userEnumerator.get_current();
                var user = {
                    group_id: oGroup.get_id(),
                    group_title: oGroup.get_title(),
                    user: oUser.get_title(),
                    user_login: oUser.get_loginName()
                };
                table.push(user);
            }
        }
        return table;
    }

    function onQuerySucceeded() {
        var table = getSimpleUser();

        var tableHead = "group_id;group_title;user;user_login";
        var t = table.map(function(userRow) {
            return [userRow.group_id, userRow.group_title, userRow.user, userRow.user_login].join(";");
        });
        var csv = [tableHead, t.join("\n")].join("\n");

        window.URL = window.URL || window.webkiURL;
        var blob = new Blob([csv], {
            type: 'text/csv;charset=utf-8;'
        });
        var blobURL = window.URL.createObjectURL(blob);

        var a = document.createElement("a");
        document.body.appendChild(a);
        a.style = "display: none";
        a.href = blobURL;
        a.download = "allusersingroups.csv";
        a.click();
    }

    function onQueryFailed(sender, args) {
        alert('Request failed. ' + args.get_message() + '\n' + args.get_stackTrace());
    }

    var collGroup = null;
    var clientContext = new SP.ClientContext.get_current();

    collGroup = clientContext.get_web().get_siteGroups();
    clientContext.load(collGroup, 'Include(Title,Id,Users.Include(Title,LoginName))');
    clientContext.executeQueryAsync(onQuerySucceeded, onQueryFailed);
})();