// Burn-up chart with Monte Carlo forecast cone — geometry, not decoration.
function BurnUpCone({ width = 640, height = 220 }) {
  const pad = { l: 34, r: 96, t: 16, b: 26 };
  const W = width - pad.l - pad.r;
  const H = height - pad.t - pad.b;
  const x = (f) => pad.l + f * W;
  const y = (f) => pad.t + (1 - f) * H;

  // scope line (total work), actual completed, cone from today
  const today = 0.58;
  const actual = [[0, 0], [0.08, 0.05], [0.18, 0.13], [0.26, 0.16], [0.36, 0.27], [0.46, 0.38], [0.58, 0.47]];
  const coneHi = [[0.58, 0.47], [0.72, 0.66], [0.86, 0.88], [0.95, 1.0]];
  const coneLo = [[0.58, 0.47], [0.74, 0.58], [0.9, 0.74], [1.0, 0.86]];
  const mid = [[0.58, 0.47], [0.76, 0.63], [0.92, 0.83], [1.0, 0.93]];
  const pts = (arr) => arr.map(([a, b]) => `${x(a)},${y(b)}`).join(' ');
  const cone = [...coneHi, ...[...coneLo].reverse()];

  return (
    <svg width="100%" viewBox={`0 0 ${width} ${height}`} style={{ display: 'block' }}>
      {/* gridlines */}
      {[0, 0.25, 0.5, 0.75, 1].map((f) => (
        <line key={f} x1={pad.l} x2={width - pad.r} y1={y(f)} y2={y(f)}
              stroke="var(--line-1)" strokeWidth="1" />
      ))}
      {/* scope */}
      <line x1={pad.l} x2={width - pad.r} y1={y(1)} y2={y(1)} stroke="var(--line-2)" strokeWidth="1.5" />
      <text x={pad.l} y={y(1) - 6} style={{ font: '400 10.5px var(--font-mono)', fill: 'var(--ink-3)' }}>scope · 42 issues</text>
      {/* cone */}
      <polygon points={pts(cone)} fill="var(--cone-fill)" />
      <polyline points={pts(coneHi)} fill="none" stroke="var(--cone-line)" strokeWidth="1.2" strokeDasharray="3 3" />
      <polyline points={pts(coneLo)} fill="none" stroke="var(--cone-line)" strokeWidth="1.2" strokeDasharray="3 3" />
      <polyline points={pts(mid)} fill="none" stroke="var(--cone-line)" strokeWidth="1.4" />
      {/* actual */}
      <polyline points={pts(actual)} fill="none" stroke="var(--cone-actual)" strokeWidth="2" />
      <circle cx={x(0.58)} cy={y(0.47)} r="3.5" fill="var(--cone-actual)" />
      {/* today rule */}
      <line x1={x(today)} x2={x(today)} y1={pad.t} y2={height - pad.b} stroke="var(--jade)" strokeWidth="1" />
      <text x={x(today) + 5} y={pad.t + 10} style={{ font: '400 10.5px var(--font-mono)', fill: 'var(--jade-7)' }}>today</text>
      {/* 80% band bracket */}
      <line x1={x(0.95) + 4} x2={x(0.95) + 4} y1={y(1.0)} y2={y(0.86) + H * 0.14 * 0 + (y(0.86) - y(0.86))} stroke="none" />
      <text x={width - pad.r + 10} y={y(0.95)} style={{ font: '500 11.5px var(--font-mono)', fill: 'var(--ink-1)' }}>80%</text>
      <text x={width - pad.r + 10} y={y(0.95) + 14} style={{ font: '400 11px var(--font-mono)', fill: 'var(--ink-2)' }}>Mar 3–12</text>
      {/* x labels */}
      <text x={pad.l} y={height - 8} style={{ font: '400 10.5px var(--font-mono)', fill: 'var(--ink-3)' }}>Jan 6</text>
      <text x={width - pad.r - 34} y={height - 8} style={{ font: '400 10.5px var(--font-mono)', fill: 'var(--ink-3)' }}>Mar 15</text>
    </svg>
  );
}

// Runway bar: milestone due date vs forecast range position
function RunwayBar({ m }) {
  const toneColor = m.tone === 'warn' ? 'var(--warn)' : 'var(--ok)';
  const left = Math.max(0, (m.pos - m.spread / 2) * 100);
  const w = Math.min(100 - left, m.spread * 100);
  return (
    <div style={{ position: 'relative', height: 22, background: 'var(--paper-2)', borderRadius: 4, overflow: 'hidden' }}>
      <div style={{
        position: 'absolute', left: `${left}%`, width: `${w}%`, top: 0, bottom: 0,
        background: 'var(--cone-fill)', borderLeft: `1.5px solid ${toneColor}`, borderRight: `1.5px solid ${toneColor}`,
      }}></div>
      <div style={{
        position: 'absolute', left: `${m.pos * 100}%`, top: 0, bottom: 0, width: 2, background: toneColor,
      }}></div>
      {/* due marker */}
      <div style={{ position: 'absolute', left: 'calc(88% - 1px)', top: 0, bottom: 0, width: 2, background: 'var(--ink-1)' }}></div>
    </div>
  );
}

Object.assign(window, { BurnUpCone, RunwayBar });