{#- chirp-ui: ASCII Skeleton
    Loading placeholder using cycling ASCII characters instead of shimmer blocks.

    Usage:
        from "chirpui/ascii_skeleton.html" import ascii_skeleton

        ascii_skeleton()                                  {# Single line #}
        ascii_skeleton(variant="text", lines=3)           {# Multi-line text block #}
        ascii_skeleton(variant="card")                    {# Card with header + lines #}
        ascii_skeleton(variant="avatar")                  {# Circular avatar #}
        ascii_skeleton(variant="heading")                 {# Wide heading line #}

    The skeleton fills its area with cycling braille/dot characters
    that animate in a wave pattern, replacing the standard shimmer gradient.
-#}

{% def ascii_skeleton(variant="", lines=1, width="", cls="") %}
{% set variant = variant | validate_variant(("", "text", "card", "avatar", "heading"), "") %}
{% set variant_class = " chirpui-ascii-skeleton--" ~ variant if variant else "" %}
{% set fill = "⠁⠂⠄⡀⢀⠠⠐⠈·⠁⠂⠄⡀⢀⠠⠐⠈·⠁⠂⠄⡀⢀⠠⠐⠈·⠁⠂⠄⡀⢀⠠⠐⠈·⠁⠂⠄⡀" %}
{% set short_fill = "⠁⠂⠄⡀⢀⠠⠐⠈·⠁⠂⠄⡀⢀⠠⠐⠈·⠁⠂⠄⡀⢀⠠" %}
{% if variant == "avatar" %}
<span class="chirpui-ascii-skeleton chirpui-ascii-skeleton--avatar{{ " " ~ cls if cls else "" }}" aria-hidden="true">
    <span class="chirpui-ascii-skeleton__fill">⊙</span>
</span>
{% elif variant == "card" %}
<div class="chirpui-ascii-skeleton chirpui-ascii-skeleton--card{{ " " ~ cls if cls else "" }}" aria-hidden="true">
    <span class="chirpui-ascii-skeleton__line chirpui-ascii-skeleton__line--header">{{ fill }}</span>
    {% for i in range(lines if lines > 1 else 3) %}
    <span class="chirpui-ascii-skeleton__line">{{ fill if not loop.last else short_fill }}</span>
    {% end %}
</div>
{% elif variant == "text" %}
<div class="chirpui-ascii-skeleton chirpui-ascii-skeleton--text{{ " " ~ cls if cls else "" }}" aria-hidden="true">
    {% for i in range(lines) %}
    <span class="chirpui-ascii-skeleton__line">{{ fill if not loop.last else short_fill }}</span>
    {% end %}
</div>
{% elif variant == "heading" %}
<span class="chirpui-ascii-skeleton chirpui-ascii-skeleton--heading{{ " " ~ cls if cls else "" }}" aria-hidden="true">
    <span class="chirpui-ascii-skeleton__fill">{{ short_fill }}</span>
</span>
{% else %}
<span class="chirpui-ascii-skeleton{{ " " ~ cls if cls else "" }}"{% if width %} style="width:{{ width }}"{% end %} aria-hidden="true">
    <span class="chirpui-ascii-skeleton__fill">{{ fill }}</span>
</span>
{% end %}
{% end %}