{#- chirp-ui: Site Footer component
    Multi-section footer for full-page scroll sites.

    Layout variants:
      columns  — brand left + N link columns (default, fat footer)
      centered — stacked, center-aligned (simple sites)
      simple   — single row: brand left, links right

    Named slots: brand, default (columns), rule (decorative divider), colophon.

    Usage:
        from "chirpui/site_footer.html" import site_footer, footer_column, footer_link

        call site_footer(layout="columns")
            {% slot brand %}
                <a href="/">Logo</a>
                <p>Tagline text.</p>
            {% end %}
            {% call footer_column(title="Product") %}
                {{ footer_link("/docs", "Docs") }}
                {{ footer_link("/pricing", "Pricing") }}
            {% end %}
            {% call footer_column(title="Company") %}
                {{ footer_link("/about", "About") }}
                {{ footer_link("https://github.com/...", "GitHub", external=true) }}
            {% end %}
            {% slot rule %}<span>•</span>{% end %}
            {% slot colophon %}© 2026 My Company{% end %}
        end
-#}

{% def site_footer(layout="columns", cls="") %}
{% set layout = layout | validate_variant(("columns","centered","simple"), "columns") %}
{% set _cls = "chirpui-site-footer" ~ (" chirpui-site-footer--" ~ layout if layout != "columns" else "") ~ (" " ~ cls if cls else "") %}
<footer class="{{ _cls }}">
    <div class="chirpui-site-footer__grid">
        <div class="chirpui-site-footer__brand">{% slot brand %}</div>
        {% slot %}
    </div>
    <div class="chirpui-site-footer__rule">
        <span class="chirpui-site-footer__rule-line"></span>
        {% slot rule %}
        <span class="chirpui-site-footer__rule-line"></span>
    </div>
    <div class="chirpui-site-footer__colophon">{% slot colophon %}</div>
</footer>
{% end %}

{% def footer_column(title="", cls="") %}
<div class="chirpui-site-footer__column{{ " " ~ cls if cls else "" }}">
    {% if title %}<h3 class="chirpui-site-footer__column-title">{{ title }}</h3>{% end %}
    <ul class="chirpui-site-footer__list">
        {% slot %}
    </ul>
</div>
{% end %}

{% def footer_link(href, label, glyph="", external=false, cls="") %}
<li>
    <a class="chirpui-site-footer__link{{ " chirpui-site-footer__link--external" if external else "" }}{{ " " ~ cls if cls else "" }}"
       href="{{ href }}"{% if external %} rel="noopener noreferrer"{% end %}{{ route_link_attrs(href, external=external) | html_attrs }}>
        {%- if glyph %}<span class="chirpui-site-footer__link-glyph" aria-hidden="true">{{ glyph }}</span>{% end -%}
        {{ label -}}
    </a>
</li>
{% end %}