{# Inline SVG chart helpers. No JS deps; everything renders at request time.
   The SVGs scale via the .chart-svg width:100% rule in brains.css.
#}

{% macro bar_histogram(data, height=160, max_value=None, label_field='label', value_field='value', show_values=True) %}
{# data = list of {label, value}. Renders a vertical bar chart. #}
{% set n = data|length %}
{% if n %}
  {% set _max = max_value if max_value is not none else (data|map(attribute=value_field)|max) %}
  {% set _max = _max if _max else 1 %}
  {% set _padding_top = 18 %}
  {% set _padding_bottom = 28 %}
  {% set _chart_h = height - _padding_top - _padding_bottom %}
  {% set _gap = 4 %}
  {% set _viewbox_w = 480 %}
  {% set _bar_w = ((_viewbox_w - (_gap * (n + 1))) / n) | round(2) %}
  <svg class="chart-svg" viewBox="0 0 {{ _viewbox_w }} {{ height }}" preserveAspectRatio="none">
    <line class="axis"
          x1="0" x2="{{ _viewbox_w }}"
          y1="{{ _padding_top + _chart_h }}" y2="{{ _padding_top + _chart_h }}" />
    {% for row in data %}
      {% set v = row[value_field] %}
      {% set h = ((v / _max) * _chart_h) | round(2) %}
      {% set x = (_gap + loop.index0 * (_bar_w + _gap)) | round(2) %}
      {% set y = (_padding_top + _chart_h - h) | round(2) %}
      <rect class="bar"
            x="{{ x }}" y="{{ y }}"
            width="{{ _bar_w }}" height="{{ h }}"
            rx="2">
        <title>{{ row[label_field] }}: {{ v }}</title>
      </rect>
      {% if show_values %}
      <text class="axis-label"
            x="{{ (x + _bar_w / 2) | round(2) }}" y="{{ y - 4 }}"
            text-anchor="middle">{{ v }}</text>
      {% endif %}
      <text class="axis-label"
            x="{{ (x + _bar_w / 2) | round(2) }}" y="{{ height - 8 }}"
            text-anchor="middle">{{ row[label_field] }}</text>
    {% endfor %}
  </svg>
{% else %}
  <p class="muted" style="font-size: var(--fs-sm);">No data to chart.</p>
{% endif %}
{% endmacro %}

{% macro sparkline(values, width=120, height=28) %}
{# values = list of numbers. Renders a simple area + line sparkline. #}
{% if values and values|length > 1 %}
  {% set _max = (values|max) %}
  {% set _max = _max if _max else 1 %}
  {% set n = values|length %}
  {% set _step = (width / (n - 1)) | round(3) %}
  {% set _pts = [] %}
  {% for v in values %}
    {% set x = (loop.index0 * _step) | round(2) %}
    {% set y = (height - (v / _max) * (height - 2) - 1) | round(2) %}
    {% set _ = _pts.append(x ~ ',' ~ y) %}
  {% endfor %}
  {% set line = ' '.join(_pts) %}
  {% set area = 'M0,' ~ height ~ ' L' ~ line ~ ' L' ~ width ~ ',' ~ height ~ ' Z' %}
  <svg class="chart-svg" viewBox="0 0 {{ width }} {{ height }}" preserveAspectRatio="none" style="width: {{ width }}px; height: {{ height }}px;">
    <path class="spark-area" d="{{ area }}" />
    <polyline class="spark-line" points="{{ line }}" />
  </svg>
{% else %}
  <span class="muted" style="font-size: var(--fs-xs);">—</span>
{% endif %}
{% endmacro %}