Pace

import { useId } from 'react';

const OPTIONS = [{"value": "walk", "label": "Walk"}, {"value": "jog", "label": "Jog"}, {"value": "run", "label": "Run"}];
const STEPS = [0, 1, 2, 3, 4, 5, 6];

const css = `
  .radio-pace { --i: 0; display: grid; justify-items: center; gap: 12px; width: 260px; }
  .radio-pace:has(.radio-pace__opt:nth-child(1) input:checked) { --i: 0; }
  .radio-pace:has(.radio-pace__opt:nth-child(2) input:checked) { --i: 1; }
  .radio-pace:has(.radio-pace__opt:nth-child(3) input:checked) { --i: 2; }
  @keyframes radio-pace-step { 0% { opacity: 0; transform: var(--t) scale(0.8); } 8% { opacity: 1; transform: var(--t); } 55% { opacity: 0.35; } 100% { opacity: 0; transform: var(--t); } }
  .radio-pace__trail { position: relative; width: 220px; height: 64px; }
  .radio-pace__print {
    --t: translate(calc(var(--k) * var(--gap)), calc(var(--side) * 9px)) rotate(90deg);
    position: absolute;
    left: 12px;
    top: 26px;
    width: 9px;
    height: 13px;
    border-radius: 50% 50% 45% 45% / 60% 60% 40% 40%;
    background: light-dark(#42454c, #e5e6e9);
    opacity: 0;
    transform: var(--t);
    transition: transform 0.4s;
    animation: radio-pace-step var(--dur) linear infinite calc(var(--k) * var(--dur) / 7);
  }
  .radio-pace__print::after { content: ''; position: absolute; left: 1.5px; top: 14px; width: 6px; height: 6px; border-radius: 50%; background: inherit; }
  .radio-pace:has(.radio-pace__opt:nth-child(1) input:checked) { --gap: 24px; --dur: 2.6s; }
  .radio-pace:has(.radio-pace__opt:nth-child(2) input:checked) { --gap: 29px; --dur: 1.7s; }
  .radio-pace:has(.radio-pace__opt:nth-child(3) input:checked) { --gap: 34px; --dur: 1.05s; }
  .radio-pace__read { display: grid; color: light-dark(#50535b, #c6c8cd); font-size: 12px; font-variant-numeric: tabular-nums; }
  .radio-pace__read > * { grid-area: 1 / 1; text-align: center; opacity: 0; transform: translateY(4px); transition: opacity 0.25s, transform 0.3s; }
  .radio-pace:has(.radio-pace__opt:nth-child(1) input:checked) .radio-pace__read > :nth-child(1) { opacity: 1; transform: none; }
  .radio-pace:has(.radio-pace__opt:nth-child(2) input:checked) .radio-pace__read > :nth-child(2) { opacity: 1; transform: none; }
  .radio-pace:has(.radio-pace__opt:nth-child(3) input:checked) .radio-pace__read > :nth-child(3) { opacity: 1; transform: none; }
  @media (prefers-reduced-motion: reduce) {
    .radio-pace__print { animation: none; opacity: 0.7; }
  }
  .radio-pace__opts { display: flex; gap: 3px; padding: 4px; border-radius: 12px; background: light-dark(#f3f4f7, #1a1c1f); box-shadow: inset 0 0 0 1px light-dark(#dbdde1, #2e3035); }
  .radio-pace__opt { position: relative; flex: 1; padding: 7px 10px; border-radius: 8px; color: light-dark(#5f626a, #a7abb2); font-size: 12.5px; font-weight: 500; text-align: center; white-space: nowrap; cursor: pointer; transition: background-color 0.25s, color 0.25s; }
  .radio-pace__opt:hover { color: light-dark(#42454c, #e5e6e9); }
  .radio-pace__opt:has(input:checked) { background: light-dark(#373a40, #f1f2f3); color: light-dark(#fbfcfd, #121417); }
  .radio-pace__opt:has(input:focus-visible) { outline: 2px solid light-dark(#50535b, #c6c8cd); outline-offset: 2px; }
  .radio-pace__input { position: absolute; width: 1px; height: 1px; margin: 0; opacity: 0; pointer-events: none; }
`;

export function PaceRadio() {
  const name = useId();
  return (
    <>
      <style>
        {css}
      </style>
      <div className="radio-pace">
        <div className="radio-pace__trail" aria-hidden="true">
          {STEPS.map((k) => (
            <span key={k} className="radio-pace__print" style={{ '--k': k, '--side': k % 2 ? 1 : -1 } as React.CSSProperties} />
          ))}
        </div>
        <span className="radio-pace__read" aria-hidden="true">
          <span>Walk, about 5 km/h</span>
          <span>Jog, about 9 km/h</span>
          <span>Run, about 14 km/h</span>
        </span>
        <div className="radio-pace__opts" role="radiogroup" aria-label="Pace">
          {OPTIONS.map((o, i) => (
            <label key={o.value} className="radio-pace__opt">
              <input className="radio-pace__input" type="radio" name={name} value={o.value} defaultChecked={i === 0} />
              {o.label}
            </label>
          ))}
        </div>
      </div>
    </>
  );
}