{#- chirp-ui: Breadcrumbs component
    Navigation trail. Items: list of {label, href?}. Last item (current) has no href.

    Usage:
        {% from "chirpui/breadcrumbs.html" import breadcrumbs %}

        breadcrumbs([
            {"label": "Home", "href": "/"},
            {"label": "Docs", "href": "/docs"},
            {"label": "Getting Started"}
        ])
-#}

{% def breadcrumb_item(item, current=false) %}
{% if item.get("href") %}
<a href="{{ item.href }}" class="chirpui-breadcrumbs__link"{% if current %} aria-current="page"{% end %}{{ route_link_attrs(item.href) | html_attrs }}>{{ item.label | default("") }}</a>
{% else %}
<span class="chirpui-breadcrumbs__current"{% if current %} aria-current="page"{% end %}>{{ item.label | default("") }}</span>
{% end %}
{% end %}

{% def breadcrumbs(items, cls="", overflow="", max_items=4) %}
{% set count = items | length %}
{% set collapse = overflow == "collapse" and count > max_items and count > 2 %}
{% set tail_count = (max_items - 2) if max_items > 3 else 1 %}
{% set tail_start = count - tail_count %}
<nav class="chirpui-breadcrumbs{{ " " ~ cls if cls else "" }}" aria-label="Breadcrumb">
    <ol class="chirpui-breadcrumbs__list">
        {% if collapse %}
        {% for item in items %}
        {% if loop.index0 == 0 %}
        <li class="chirpui-breadcrumbs__item">
            {{ breadcrumb_item(item, current=false) }}
        </li>
        {% elif loop.index0 == 1 %}
        <li class="chirpui-breadcrumbs__item chirpui-breadcrumbs__overflow">
            <details class="chirpui-breadcrumbs__overflow-menu">
                <summary class="chirpui-breadcrumbs__overflow-trigger" aria-label="Show collapsed breadcrumbs">...</summary>
                <ol class="chirpui-breadcrumbs__overflow-list">
                    {% for hidden_item in items %}
                    {% if loop.index0 > 0 and loop.index0 < tail_start %}
                    <li class="chirpui-breadcrumbs__overflow-item">
                        {{ breadcrumb_item(hidden_item, current=false) }}
                    </li>
                    {% end %}
                    {% end %}
                </ol>
            </details>
        </li>
        {% elif loop.index0 >= tail_start %}
        <li class="chirpui-breadcrumbs__item">
            {{ breadcrumb_item(item, current=loop.last) }}
        </li>
        {% end %}
        {% end %}
        {% else %}
        {% for item in items %}
        <li class="chirpui-breadcrumbs__item">
            {{ breadcrumb_item(item, current=loop.last) }}
        </li>
        {% end %}
        {% end %}
    </ol>
</nav>
{% end %}