05Count breakdown bars — each score's response count value splits into a horizontal bar length value

<main class="stage">
<div class="sr is-demo" id="sr">
  <div class="sr__list" id="srList" role="list">
    <button class="sr__row" type="button" role="listitem" data-star="5" aria-pressed="false">
      <span class="sr__label">5</span>
      <span class="sr__track"><span class="sr__bar" data-bar></span></span>
      <span class="sr__pct" data-pct>0%</span>
    </button>
    <button class="sr__row" type="button" role="listitem" data-star="4" aria-pressed="false">
      <span class="sr__label">4</span>
      <span class="sr__track"><span class="sr__bar" data-bar></span></span>
      <span class="sr__pct" data-pct>0%</span>
    </button>
    <button class="sr__row" type="button" role="listitem" data-star="3" aria-pressed="false">
      <span class="sr__label">3</span>
      <span class="sr__track"><span class="sr__bar" data-bar></span></span>
      <span class="sr__pct" data-pct>0%</span>
    </button>
    <button class="sr__row" type="button" role="listitem" data-star="2" aria-pressed="false">
      <span class="sr__label">2</span>
      <span class="sr__track"><span class="sr__bar" data-bar></span></span>
      <span class="sr__pct" data-pct>0%</span>
    </button>
    <button class="sr__row" type="button" role="listitem" data-star="1" aria-pressed="false">
      <span class="sr__label">1</span>
      <span class="sr__track"><span class="sr__bar" data-bar></span></span>
      <span class="sr__pct" data-pct>0%</span>
    </button>
  </div>
</div>
</main>

@use "../../../../site/static/demo-tokens" as *;

// 계산 겹: 별점별 응답 개수를 전체 응답 개수 합으로 나눈 비율(%)을 막대 길이 값으로 쓴다 (paint()).
@include stage($stage-ink);

.sr__list {
  display: grid;
  gap: $sp-2;
  width: clamp(220px, 70vw, 320px);
}

.sr__row {
  display: grid;
  grid-template-columns: 16px 1fr 68px;
  align-items: center;
  gap: $sp-3;
  border: 0;
  background: none;
  padding: $sp-1 $sp-2;
  border-radius: $r-sm;
  cursor: pointer;
  transition: background $dur-quick $ease-out;

  &--on { background: rgba($subject-blue-light, .18); }
}

.sr__label {
  color: $stage-paper;
  font: 600 13px/1 -apple-system, "Segoe UI", "Noto Sans KR", sans-serif;
  text-align: center;
}

.sr__track {
  height: 10px;
  border-radius: $r-pill;
  background: rgba($stage-paper, .14);
  overflow: hidden;
}

.sr__bar {
  display: block;
  height: 100%;
  width: 0%;
  border-radius: $r-pill;
  background: $subject-mint;
  transition: width $dur-base $ease-out;
}

.sr__row--on .sr__bar { background: $subject-pink; }

.sr__pct {
  color: $stage-paper;
  font: 500 12px/1 -apple-system, "Segoe UI", "Noto Sans KR", sans-serif;
  text-align: right;
  font-variant-numeric: tabular-nums;
}

@media (max-width: 340px) {
  .sr__list { width: 100%; gap: $sp-1; }
  .sr__row { grid-template-columns: 14px 1fr 56px; gap: $sp-2; }
  .sr__pct { font-size: 11px; }
}

@media (prefers-reduced-motion: reduce) {
  .sr__row, .sr__bar { transition: none; }
}

html, body {
  margin: 0;
  overflow: hidden;
}

.stage {
  box-sizing: border-box;
  min-height: 100vh;
  display: grid;
  place-items: center;
  margin: 0;
  background: #17141a;
  font-family: -apple-system, "Segoe UI", "Noto Sans KR", sans-serif;
  padding: clamp(8px, 4vw, 24px);
}

.sr__list {
  display: grid;
  gap: 8px;
  width: clamp(220px, 70vw, 320px);
}

.sr__row {
  display: grid;
  grid-template-columns: 16px 1fr 68px;
  align-items: center;
  gap: 12px;
  border: 0;
  background: none;
  padding: 4px 8px;
  border-radius: 8px;
  cursor: pointer;
  transition: background 220ms ease-out;
}
.sr__row--on {
  background: rgba(91, 140, 248, 0.18);
}

.sr__label {
  color: #ffffff;
  font: 600 13px/1 -apple-system, "Segoe UI", "Noto Sans KR", sans-serif;
  text-align: center;
}

.sr__track {
  height: 10px;
  border-radius: 999px;
  background: rgba(255, 255, 255, 0.14);
  overflow: hidden;
}

.sr__bar {
  display: block;
  height: 100%;
  width: 0%;
  border-radius: 999px;
  background: #4cd4a6;
  transition: width 300ms ease-out;
}

.sr__row--on .sr__bar {
  background: #ff9ebb;
}

.sr__pct {
  color: #ffffff;
  font: 500 12px/1 -apple-system, "Segoe UI", "Noto Sans KR", sans-serif;
  text-align: right;
  font-variant-numeric: tabular-nums;
}

@media (max-width: 340px) {
  .sr__list {
    width: 100%;
    gap: 4px;
  }
  .sr__row {
    grid-template-columns: 14px 1fr 56px;
    gap: 8px;
  }
  .sr__pct {
    font-size: 11px;
  }
}
@media (prefers-reduced-motion: reduce) {
  .sr__row, .sr__bar {
    transition: none;
  }
}

(function () {
  var root = document.getElementById('sr');
  var rows = Array.prototype.slice.call(document.querySelectorAll('.sr__row'));
  var counts = { 5: 42, 4: 21, 3: 9, 2: 4, 1: 3 };
  var selected = null;

  // 계산 겹: 각 별점의 응답 개수를 전체 응답 개수 합으로 나눈 비율(%)을 막대 길이 값으로 쓴다.
  function total() {
    var t = 0;
    for (var k in counts) t += counts[k];
    return t;
  }

  function paint() {
    var t = total();
    rows.forEach(function (row) {
      var star = Number(row.getAttribute('data-star'));
      var pct = t ? (counts[star] / t) * 100 : 0;
      row.querySelector('[data-bar]').style.width = pct.toFixed(1) + '%';
      row.querySelector('[data-pct]').textContent = Math.round(pct) + '% (' + counts[star] + ')';
      row.classList.toggle('sr__row--on', star === selected);
      row.setAttribute('aria-pressed', String(star === selected));
    });
  }

  rows.forEach(function (row) {
    row.addEventListener('click', function () {
      root.classList.remove('is-demo'); stopAutoplay();
      var star = Number(row.getAttribute('data-star'));
      selected = selected === star ? null : star;
      paint();
    });
  });

  paint();

  // 자동 루프: Star rating 5→1 순서로 한 줄씩 Selected 상태를 옮기고, 한 바퀴마다 응답 개수 하나를
  // 늘려 막대 길이 비율이 실시간으로 바뀌는 것을 보여준다.
  var order = [5, 4, 3, 2, 1];
  var oi = 0;
  var bump = [5, 3, 4, 5, 2, 5, 1, 4, 5, 3];
  var bi = 0;
  var autoTimer = null;
  function autoTick() {
    selected = order[oi];
    oi = (oi + 1) % order.length;
    if (oi === 0) { var v = bump[bi % bump.length]; bi++; counts[v] = counts[v] + 1; }
    paint();
  }
  var reduce = window.matchMedia('(prefers-reduced-motion: reduce)').matches;
  function stopAutoplay() { if (autoTimer) { clearInterval(autoTimer); autoTimer = null; } }
  if (!reduce) { autoTimer = setInterval(autoTick, 380); autoTick(); }
})();

import { useEffect, useRef } from "react";
import styles from "./CountBreakdownBars.module.scss";

const STARS = [5, 4, 3, 2, 1];

export default function CountBreakdownBars() {
  const rootRef = useRef<HTMLDivElement | null>(null);

  useEffect(() => {
    const root = rootRef.current;
    if (!root) return;
    const rows = Array.prototype.slice.call(
      root.querySelectorAll(`.${styles.row}`)
    ) as HTMLElement[];
    let counts: Record<number, number> = { 5: 42, 4: 21, 3: 9, 2: 4, 1: 3 };
    let selected: number | null = null;

    // 계산 겹: 각 별점의 응답 개수를 전체 응답 개수 합으로 나눈 비율(%)을 막대 길이 값으로 쓴다.
    function total() {
      let t = 0;
      for (const k in counts) t += counts[Number(k)];
      return t;
    }

    function paint() {
      const t = total();
      rows.forEach((row, idx) => {
        const star = STARS[idx];
        const pct = t ? (counts[star] / t) * 100 : 0;
        row.querySelector<HTMLElement>(`.${styles.bar}`)!.style.width = pct.toFixed(1) + "%";
        row.querySelector<HTMLElement>(`.${styles.pct}`)!.textContent =
          Math.round(pct) + "% (" + counts[star] + ")";
        row.classList.toggle(styles.on, star === selected);
        row.setAttribute("aria-pressed", String(star === selected));
      });
    }

    const clickHandlers: Array<() => void> = [];
    rows.forEach((row, idx) => {
      const handler = () => {
        stopAutoplay();
        const star = STARS[idx];
        selected = selected === star ? null : star;
        paint();
      };
      clickHandlers.push(handler);
      row.addEventListener("click", handler);
    });

    paint();

    // 자동 루프: 별점 5→1 순서로 한 줄씩 선택 상태를 옮기고, 한 바퀴마다 응답 개수 하나를
    // 늘려 막대 길이 비율이 실시간으로 바뀌는 것을 보여준다.
    const order = [5, 4, 3, 2, 1];
    let oi = 0;
    const bump = [5, 3, 4, 5, 2, 5, 1, 4, 5, 3];
    let bi = 0;
    let autoTimer: number | null = null;
    function autoTick() {
      selected = order[oi];
      oi = (oi + 1) % order.length;
      if (oi === 0) { const v = bump[bi % bump.length]; bi++; counts[v] = counts[v] + 1; }
      paint();
    }
    function stopAutoplay() { if (autoTimer !== null) { window.clearInterval(autoTimer); autoTimer = null; } }
    const reduce = window.matchMedia("(prefers-reduced-motion: reduce)").matches;
    if (!reduce) { autoTimer = window.setInterval(autoTick, 380); autoTick(); }

    return () => {
      stopAutoplay();
      rows.forEach((row, idx) => row.removeEventListener("click", clickHandlers[idx]));
    };
  }, []);

  return (
    <div ref={rootRef} className={styles.stage}>
      <div className={styles.list} role="list">
        {STARS.map((star) => (
          <button key={star} type="button" className={styles.row} role="listitem" aria-pressed="false">
            <span className={styles.label}>{star}</span>
            <span className={styles.track}><span className={styles.bar} /></span>
            <span className={styles.pct}>0%</span>
          </button>
        ))}
      </div>
    </div>
  );
}