var info_overlay = (function () {

var exports = {};

// Make it explicit that our toggler is undefined until
// set_up_toggler is called.
exports.toggler = undefined;

exports.set_up_toggler = function () {
    var opts = {
        selected: 0,
        child_wants_focus: true,
        values: [
            { label: i18n.t("Keyboard shortcuts"), key: "keyboard-shortcuts" },
            { label: i18n.t("Message formatting"), key: "message-formatting" },
            { label: i18n.t("Search operators"), key: "search-operators" },
        ],
        callback: function (name, key) {
            $(".overlay-modal").hide();
            $("#" + key).show();
            $("#" + key).find(".modal-body").focus();
        },
    };

    exports.toggler = components.toggle(opts);
    var elem = exports.toggler.get();
    elem.addClass('large allow-overflow');

    var modals = _.map(opts.values, function (item) {
        var key = item.key; // e.g. message-formatting
        var modal = $('#' + key).find('.modal-body');
        return modal;
    });

    _.each(modals, function (modal) {
        keydown_util.handle({
            elem: modal,
            handlers: {
                left_arrow: exports.toggler.maybe_go_left,
                right_arrow: exports.toggler.maybe_go_right,
            },
        });
    });

    $(".informational-overlays .overlay-tabs").append(elem);

    common.adjust_mac_shortcuts(".hotkeys_table .hotkey kbd");
    common.adjust_mac_shortcuts("#markdown-instructions kbd");
};

exports.show = function (target) {
    if (!exports.toggler) {
        exports.set_up_toggler();
    }

    var overlay = $(".informational-overlays");

    if (!overlay.hasClass("show")) {
        overlays.open_overlay({
            name: 'informationalOverlays',
            overlay: overlay,
            on_close: function () {
                hashchange.changehash("");
            },
        });
    }

    if (target) {
        exports.toggler.goto(target);
    }
};

exports.maybe_show_keyboard_shortcuts = function () {
    if (overlays.is_active()) {
        return;
    }
    if (popovers.any_active()) {
        return;
    }
    exports.show("keyboard-shortcuts");
};

return exports;
}());

if (typeof module !== 'undefined') {
    module.exports = info_overlay;
}
window.info_overlay = info_overlay;