Treemap Chart

---
/**
 * TreemapChart — Squarified treemap where each rectangle's area is proportional
 * to its value. Labels appear on tiles large enough to hold them.
 *
 * @param {Array<{label: string, value: number, group?: number}>} items - Tiles (group = color slot index).
 * @param {string} prefix - Value prefix.
 * @param {string} suffix - Value suffix.
 * @param {number} height - SVG height in viewBox units (width is 640).
 * @param {string[]} colors - Optional color overrides.
 * @param {string} variant - Card style (glass|solid|ghost).
 * @param {string} size - Density (sm|md|lg).
 */
import ChartFrame from './ChartFrame.astro';
import { squarify, colorAt, formatValue, sum } from './chart-utils';

interface Props {
  title?: string;
  subtitle?: string;
  items?: Array<{ label: string; value: number; group?: number }>;
  groups?: string[];
  prefix?: string;
  suffix?: string;
  height?: number;
  colors?: string[];
  variant?: 'glass' | 'solid' | 'ghost';
  size?: 'sm' | 'md' | 'lg';
  className?: string;
}

const {
  title = 'Bundle size by module',
  subtitle = 'Gzipped KB',
  items = [
    { label: 'react-dom', value: 42, group: 0 },
    { label: 'astro runtime', value: 18, group: 1 },
    { label: 'charts', value: 24, group: 2 },
    { label: 'date-fns', value: 12, group: 0 },
    { label: 'router', value: 9, group: 1 },
    { label: 'icons', value: 15, group: 2 },
    { label: 'i18n', value: 7, group: 1 },
    { label: 'utils', value: 5, group: 2 },
    { label: 'zod', value: 11, group: 0 },
    { label: 'analytics', value: 6, group: 0 },
  ],
  groups = ['Vendor', 'Framework', 'App'],
  prefix = '',
  suffix = ' KB',
  height = 320,
  colors,
  variant = 'glass',
  size = 'md',
  className = '',
} = Astro.props;

const W = 640;
const H = height;
const rects = squarify(items.map((i) => i.value), { x: 0, y: 0, w: W, h: H });
const total = sum(items.map((i) => i.value)) || 1;
const fmt = (v: number) => formatValue(v, prefix, suffix, false);
const GAP = 2;
---

<ChartFrame
  title={title}
  subtitle={subtitle}
  variant={variant}
  size={size}
  className={className}
  legend={groups.map((g, i) => ({ label: g, color: colorAt(i, colors) }))}
  table={{ headers: ['Item', 'Group', 'Value', 'Share'], rows: items.map((i) => [i.label, groups[i.group ?? 0] ?? '—', fmt(i.value), `${((i.value / total) * 100).toFixed(1)}%`]) }}
>
  <svg viewBox={`0 0 ${W} ${H}`} role="img" aria-label={`${title}: treemap of ${items.length} items`}>
    {items.map((it, i) => {
      const r = rects[i];
      const c = colorAt(it.group ?? 0, colors);
      const w = Math.max(0, r.w - GAP);
      const h = Math.max(0, r.h - GAP);
      const showLabel = w > 64 && h > 34;
      return (
        <g class="cf-mark cf-dim" tabindex="0" role="img" aria-label={`${it.label}: ${fmt(it.value)}`}
          data-tip-title={it.label} data-tip={`${c}::${fmt(it.value)} · ${((it.value / total) * 100).toFixed(1)}%`}>
          <rect x={r.x + GAP / 2} y={r.y + GAP / 2} width={w} height={h} rx="6" fill={c} fill-opacity="0.85" />
          {showLabel && (
            <>
              <text x={r.x + 10} y={r.y + 20} fill="#fff" font-size="12" font-weight="650">{it.label}</text>
              <text x={r.x + 10} y={r.y + 36} fill="rgb(var(--ink-rgb, 255 255 255) / 0.8)" font-size="11">{fmt(it.value)}</text>
            </>
          )}
        </g>
      );
    })}
  </svg>
</ChartFrame>