{#
/**
 * @file
 * Theme override to display a menu.
 *
 * Available variables:
 * - menu_name: The machine name of the menu.
 * - items: A nested list of menu items. Each menu item contains:
 *   - attributes: HTML attributes for the menu item.
 *   - below: The menu item child items.
 *   - title: The menu link title.
 *   - url: The menu link url, instance of \Drupal\Core\Url
 *   - localized_options: Menu link localized options.
 *   - is_expanded: TRUE if the link has visible children within the current
 *     menu tree.
 *   - is_collapsed: TRUE if the link has children within the current menu tree
 *     that are not currently visible.
 *   - in_active_trail: TRUE if the link is in the active trail.
 */
#}
{% import _self as menus %}

{#
  We call a macro which calls itself to render the full tree.
  @see http://twig.sensiolabs.org/doc/tags/macro.html
#}
{{ menus.menu_links(items, attributes, 0, menu_name) }}

{% macro menu_links(items, attributes, menu_level, menu_name) %}
  {% import _self as menus %}
  {% if items %}
      {% if menu_level == 0 %}
        {%
          set menu_classes = [
            'nav',
            "nav--#{menu_name}",
          ]
        %}
        <ul{{ attributes.addClass(menu_classes) }}>
      {% else %}
        <ul class="nav__subnav">
      {% endif %}
      {% for item in items %}
        {%
          set item_classes = [
            'nav__item',
            item.below ? 'has-subnav',
            item.in_active_trail ? 'is-active-trail',
            item.is_collapsed ? 'is-collapsed',
            item.is_expanded ? 'is-expanded',
          ]
        %}
        {%
          set link_attributes = {
            'class': [
              'nav__link',
              item.below ? 'has-subnav',
              item.in_active_trail ? 'is-active-trail',
              item.is_collapsed ? 'is-collapsed',
              item.is_expanded ? 'is-expanded',
            ]
          }
        %}
        <li{{ item.attributes.addClass(item_classes) }}>
          {{ link(item.title, item.url, link_attributes) }}
          {% if item.below %}
            {{ menus.menu_links(item.below, attributes, menu_level + 1) }}
          {% endif %}
        </li>
      {% endfor %}
      </ul>
  {% endif %}
{% endmacro %}