03Role tabs — a switch that computes the filtered count into its own label

<main class="stage">
<section class="tabs" id="tabsWrap">
  <p class="tabs__hint" id="tabsHint">The filtered headcount is calculated and appended to each tab label, and the underline follows the selected tab's measured position.</p>
  <div class="tabs__bar" id="tabsBar" role="tablist" aria-label="Role filter">
    <button class="tabs__tab" id="tab-all" role="tab" aria-selected="true" type="button">All <span class="tabs__count" id="cnt-all">10</span></button>
    <button class="tabs__tab" id="tab-design" role="tab" aria-selected="false" type="button">Design <span class="tabs__count" id="cnt-design">4</span></button>
    <button class="tabs__tab" id="tab-dev" role="tab" aria-selected="false" type="button">Dev <span class="tabs__count" id="cnt-dev">4</span></button>
    <button class="tabs__tab" id="tab-ops" role="tab" aria-selected="false" type="button">Ops <span class="tabs__count" id="cnt-ops">2</span></button>
    <span class="tabs__indicator" id="tabsIndicator" aria-hidden="true"></span>
  </div>
  <div class="tabs__panel" id="tabsPanel" role="list" aria-label="Filter results"></div>
</section>
</main>

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

$duration: $dur-quick;        // 220ms — 인디케이터 이동
$easing: $ease-out;
$color: $subject-ink;

@include stage($stage-orange);

.tabs {
  width: 100%;
  max-width: 420px;
  display: flex;
  flex-direction: column;
  gap: $sp-3;
  align-items: center;
  text-align: center;
}

.tabs__hint {
  margin: 0;
  padding: 0 $sp-2;
  font-weight: 400;
  font-size: 11px;
  line-height: 1.4;
  color: rgba($subject-ink, .72);
}

.tabs__bar {
  position: relative;
  display: flex;
  gap: $sp-3;
  width: 100%;
  justify-content: center;
  padding-bottom: $sp-2;
}

.tabs__tab {
  flex: 0 0 auto;
  appearance: none;
  border: 0;
  background: none;
  padding: $sp-1 0;
  font-weight: 500;
  font-size: 13px;
  color: rgba($subject-ink, .72);
  cursor: pointer;
}

.tabs__tab[aria-selected="true"] {
  color: $subject-ink;
  font-weight: 700;
}

.tabs__count {
  display: inline-block;
  margin-left: $sp-1;
  font-weight: 700;
  font-size: 11px;
  color: $subject-ink;
}

.tabs__indicator {
  position: absolute;
  left: 0;
  bottom: 0;
  height: 3px;
  width: var(--iw, 0px);
  border-radius: $r-pill;
  background: $color;
  transform: translateX(var(--ix, 0px));
  transition: transform $duration $easing, width $duration $easing;
}

.tabs__panel {
  display: flex;
  gap: $sp-2;
  justify-content: center;
  min-height: 34px;
}

.tabs__chip {
  display: flex;
  align-items: center;
  justify-content: center;
  opacity: 0;
  transform: scale(.8);
  transition: opacity $dur-quick $ease-out, transform $duration $ease-pop;
}

.tabs__panel.is-in .tabs__chip {
  opacity: 1;
  transform: scale(1);
}

.tabs__cv {
  display: block;
  width: 22px;
  height: 22px;
  border-radius: $r-pill;
}

@media (max-width: 340px) {
  .tabs { max-width: 300px; gap: $sp-2; }
  .tabs__hint { font-size: 9px; }
  .tabs__bar { gap: $sp-2; }
  .tabs__tab { font-size: 11px; }
  .tabs__cv { width: 18px; height: 18px; }
}

@media (prefers-reduced-motion: reduce) {
  .tabs__indicator,
  .tabs__chip {
    transition: none;
  }
  .tabs__chip {
    opacity: 1;
    transform: none;
  }
}

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

.stage {
  box-sizing: border-box;
  min-height: 100vh;
  display: grid;
  place-items: center;
  margin: 0;
  background: #ff4d1f;
  font-family: -apple-system, "Segoe UI", "Noto Sans KR", sans-serif;
  padding: clamp(8px, 4vw, 24px);
}

.tabs {
  width: 100%;
  max-width: 420px;
  display: flex;
  flex-direction: column;
  gap: 12px;
  align-items: center;
  text-align: center;
}

.tabs__hint {
  margin: 0;
  padding: 0 8px;
  font-weight: 400;
  font-size: 11px;
  line-height: 1.4;
  color: rgba(23, 20, 26, 0.72);
}

.tabs__bar {
  position: relative;
  display: flex;
  gap: 12px;
  width: 100%;
  justify-content: center;
  padding-bottom: 8px;
}

.tabs__tab {
  flex: 0 0 auto;
  appearance: none;
  border: 0;
  background: none;
  padding: 4px 0;
  font-weight: 500;
  font-size: 13px;
  color: rgba(23, 20, 26, 0.72);
  cursor: pointer;
}

.tabs__tab[aria-selected=true] {
  color: #17141a;
  font-weight: 700;
}

.tabs__count {
  display: inline-block;
  margin-left: 4px;
  font-weight: 700;
  font-size: 11px;
  color: #17141a;
}

.tabs__indicator {
  position: absolute;
  left: 0;
  bottom: 0;
  height: 3px;
  width: var(--iw, 0px);
  border-radius: 999px;
  background: #17141a;
  transform: translateX(var(--ix, 0px));
  transition: transform 220ms ease-out, width 220ms ease-out;
}

.tabs__panel {
  display: flex;
  gap: 8px;
  justify-content: center;
  min-height: 34px;
}

.tabs__chip {
  display: flex;
  align-items: center;
  justify-content: center;
  opacity: 0;
  transform: scale(0.8);
  transition: opacity 220ms ease-out, transform 220ms cubic-bezier(0.2, 1.4, 0.4, 1);
}

.tabs__panel.is-in .tabs__chip {
  opacity: 1;
  transform: scale(1);
}

.tabs__cv {
  display: block;
  width: 22px;
  height: 22px;
  border-radius: 999px;
}

@media (max-width: 340px) {
  .tabs {
    max-width: 300px;
    gap: 8px;
  }
  .tabs__hint {
    font-size: 9px;
  }
  .tabs__bar {
    gap: 8px;
  }
  .tabs__tab {
    font-size: 11px;
  }
  .tabs__cv {
    width: 18px;
    height: 18px;
  }
}
@media (prefers-reduced-motion: reduce) {
  .tabs__indicator,
  .tabs__chip {
    transition: none;
  }
  .tabs__chip {
    opacity: 1;
    transform: none;
  }
}

// 역할 탭(03) — Members 배열을 role 값으로 filter 해 탭 라벨의 인원수를 계산하고, 선택된 탭의
// getBoundingClientRect 로 좌표·너비를 읽어 밑줄 인디케이터의 translateX·width 를 맞춘다(계산 한 겹).
(function () {
  var wrap = document.getElementById('tabsWrap');
  var bar = document.getElementById('tabsBar');
  var indicator = document.getElementById('tabsIndicator');
  var panel = document.getElementById('tabsPanel');
  if (!wrap || !bar || !indicator || !panel) return;
  var tabs = Array.prototype.slice.call(bar.querySelectorAll('.tabs__tab'));
  var reduce = window.matchMedia('(prefers-reduced-motion: reduce)').matches;

  var ROLES = ['design', 'design', 'design', 'design', 'dev', 'dev', 'dev', 'dev', 'ops', 'ops'];
  var members = ROLES.map(function (role, i) { return { id: i, role: role }; });
  var KEYS = ['all', 'design', 'dev', 'ops'];

  function mulberry32(a) {
    return function () {
      a |= 0; a = a + 0x6D2B79F5 | 0;
      var t = Math.imul(a ^ a >>> 15, 1 | a);
      t = t + Math.imul(t ^ t >>> 7, 61 | t) ^ t;
      return ((t ^ t >>> 14) >>> 0) / 4294967296;
    };
  }
  var HEXES = ['#9fc9ec', '#93d9c0', '#b9a0ff', '#f6c6d3'];

  function drawAvatar(cv, seed, label) {
    var ctx = cv.getContext('2d');
    if (!ctx) return;
    var rnd = mulberry32(seed);
    var s = cv.width;
    ctx.save();
    ctx.beginPath(); ctx.arc(s / 2, s / 2, s / 2, 0, Math.PI * 2); ctx.clip();
    var cell = 6;
    for (var y = 0; y < s; y += cell) {
      for (var x = 0; x < s; x += cell) {
        var v = rnd();
        ctx.fillStyle = v > .5 ? HEXES[Math.floor(rnd() * HEXES.length)] : 'rgba(23,20,26,.08)';
        ctx.fillRect(x, y, cell, cell);
      }
    }
    ctx.restore();
    ctx.fillStyle = 'rgba(23,20,26,.55)';
    ctx.beginPath(); ctx.arc(s / 2, s / 2, s / 2, 0, Math.PI * 2); ctx.fill();
    ctx.fillStyle = '#fff7e6';
    ctx.font = '700 ' + Math.round(s * .4) + 'px -apple-system, "Segoe UI", sans-serif';
    ctx.textAlign = 'center'; ctx.textBaseline = 'middle';
    ctx.fillText(label, s / 2, s / 2 + 1);
  }

  // 인원수 계산 — role 값으로 filter 한 배열의 길이를 각 탭 라벨에 붙인다
  KEYS.forEach(function (key) {
    var span = document.getElementById('cnt-' + key);
    if (!span) return;
    var n = key === 'all' ? members.length : members.filter(function (m) { return m.role === key; }).length;
    span.textContent = String(n);
  });

  function moveIndicator(tab) {
    var barRect = bar.getBoundingClientRect();
    var tabRect = tab.getBoundingClientRect();
    var ix = tabRect.left - barRect.left;
    var iw = tabRect.width;
    indicator.style.setProperty('--ix', ix.toFixed(1) + 'px');
    indicator.style.setProperty('--iw', iw.toFixed(1) + 'px');
  }

  function renderPanel(key) {
    var list = key === 'all' ? members : members.filter(function (m) { return m.role === key; });
    panel.innerHTML = '';
    list.slice(0, 6).forEach(function (m) {
      var chip = document.createElement('div');
      chip.className = 'tabs__chip';
      chip.setAttribute('role', 'listitem');
      var cv = document.createElement('canvas');
      cv.width = 22; cv.height = 22; cv.className = 'tabs__cv';
      cv.setAttribute('aria-hidden', 'true');
      chip.appendChild(cv);
      panel.appendChild(chip);
      drawAvatar(cv, 5 + m.id * 9, 'M' + (m.id + 1));
    });
    panel.classList.remove('is-in');
    void panel.offsetWidth;
    panel.classList.add('is-in');
  }

  function selectTab(key) {
    var target = document.getElementById('tab-' + key);
    if (!target) return;
    tabs.forEach(function (t) { t.setAttribute('aria-selected', t === target ? 'true' : 'false'); });
    moveIndicator(target);
    renderPanel(key);
  }

  tabs.forEach(function (t) {
    t.addEventListener('click', function () {
      var key = t.id.replace('tab-', '');
      idx = KEYS.indexOf(key);
      selectTab(key);
    });
  });

  var idx = 0;
  selectTab(KEYS[0]);
  window.addEventListener('resize', function () { selectTab(KEYS[idx]); });

  if (!reduce) {
    setInterval(function () {
      idx = (idx + 1) % KEYS.length;
      selectTab(KEYS[idx]);
    }, 340);
  }
})();

// TeamRoleTabs — vanilla 판(run/338/demo/03-team-role-tabs/index.html) 의 React 포트.
// 팀원 배열을 role 값으로 filter 해 탭 라벨의 인원수를 계산하고, 선택된 탭의 getBoundingClientRect
// 로 좌표·너비를 읽어 밑줄 인디케이터의 translateX·width 를 맞춘다(계산 한 겹).
import { useEffect, useRef } from "react";
import styles from "./TeamRoleTabs.module.scss";

export type TeamRoleTabsProps = {
  duration?: string;
  easing?: string;
  color?: string;
};

const HINT = "필터 결과 인원수를 탭 라벨에 계산해 붙이고 밑줄은 선택된 탭의 실측 좌표를 따라갑니다";
const BAR_LABEL = "역할 필터";
const PANEL_LABEL = "필터 결과";

type Role = "all" | "design" | "dev" | "ops";
type Member = { id: number; role: "design" | "dev" | "ops" };

const TAB_TEXT: { key: Role; label: string }[] = [
  { key: "all", label: "전체" },
  { key: "design", label: "디자인" },
  { key: "dev", label: "개발" },
  { key: "ops", label: "운영" }
];

const ROLES: Member["role"][] = ["design", "design", "design", "design", "dev", "dev", "dev", "dev", "ops", "ops"];
const MEMBERS: Member[] = ROLES.map((role, i) => ({ id: i, role }));
const KEYS: Role[] = ["all", "design", "dev", "ops"];

function mulberry32(a: number): () => number {
  return function (): number {
    a |= 0; a = a + 0x6d2b79f5 | 0;
    let t = Math.imul(a ^ (a >>> 15), 1 | a);
    t = (t + Math.imul(t ^ (t >>> 7), 61 | t)) ^ t;
    return ((t ^ (t >>> 14)) >>> 0) / 4294967296;
  };
}

const HEXES = ["#9fc9ec", "#93d9c0", "#b9a0ff", "#f6c6d3"];

function drawAvatar(cv: HTMLCanvasElement, seed: number, label: string): void {
  const ctx = cv.getContext("2d");
  if (!ctx) return;
  const rnd = mulberry32(seed);
  const s = cv.width;
  ctx.save();
  ctx.beginPath();
  ctx.arc(s / 2, s / 2, s / 2, 0, Math.PI * 2);
  ctx.clip();
  const cell = 6;
  for (let y = 0; y < s; y += cell) {
    for (let x = 0; x < s; x += cell) {
      const v = rnd();
      ctx.fillStyle = v > 0.5 ? HEXES[Math.floor(rnd() * HEXES.length)] : "rgba(23,20,26,.08)";
      ctx.fillRect(x, y, cell, cell);
    }
  }
  ctx.restore();
  ctx.fillStyle = "rgba(23,20,26,.55)";
  ctx.beginPath();
  ctx.arc(s / 2, s / 2, s / 2, 0, Math.PI * 2);
  ctx.fill();
  ctx.fillStyle = "#fff7e6";
  ctx.font = "700 " + Math.round(s * 0.4) + 'px -apple-system, "Segoe UI", sans-serif';
  ctx.textAlign = "center";
  ctx.textBaseline = "middle";
  ctx.fillText(label, s / 2, s / 2 + 1);
}

function countFor(key: Role): number {
  return key === "all" ? MEMBERS.length : MEMBERS.filter((m) => m.role === key).length;
}

export default function TeamRoleTabs({
  duration = "220ms",
  easing = "ease-out",
  color = "#17141a"
}: TeamRoleTabsProps) {
  const barRef = useRef<HTMLDivElement | null>(null);
  const indicatorRef = useRef<HTMLSpanElement | null>(null);
  const panelRef = useRef<HTMLDivElement | null>(null);

  useEffect(() => {
    const bar = barRef.current;
    const indicator = indicatorRef.current;
    const panel = panelRef.current;
    if (!bar || !indicator || !panel) return;
    const tabs = Array.prototype.slice.call(bar.querySelectorAll("." + styles.tab)) as HTMLButtonElement[];
    const reduce = window.matchMedia("(prefers-reduced-motion: reduce)").matches;

    function moveIndicator(tab: HTMLElement): void {
      const barRect = bar!.getBoundingClientRect();
      const tabRect = tab.getBoundingClientRect();
      const ix = tabRect.left - barRect.left;
      const iw = tabRect.width;
      indicator!.style.setProperty("--ix", ix.toFixed(1) + "px");
      indicator!.style.setProperty("--iw", iw.toFixed(1) + "px");
    }

    function renderPanel(key: Role): void {
      const list = key === "all" ? MEMBERS : MEMBERS.filter((m) => m.role === key);
      panel!.innerHTML = "";
      list.slice(0, 6).forEach((m) => {
        const chip = document.createElement("div");
        chip.className = styles.chip;
        chip.setAttribute("role", "listitem");
        const cv = document.createElement("canvas");
        cv.width = 22; cv.height = 22; cv.className = styles.cv;
        cv.setAttribute("aria-hidden", "true");
        chip.appendChild(cv);
        panel!.appendChild(chip);
        drawAvatar(cv, 5 + m.id * 9, "M" + (m.id + 1));
      });
      panel!.classList.remove(styles.panelIn);
      void panel!.offsetWidth;
      panel!.classList.add(styles.panelIn);
    }

    function selectTab(key: Role): void {
      const target = bar!.querySelector('[data-key="' + key + '"]') as HTMLElement | null;
      if (!target) return;
      tabs.forEach((t) => t.setAttribute("aria-selected", t === target ? "true" : "false"));
      moveIndicator(target);
      renderPanel(key);
    }

    let idx = 0;
    tabs.forEach((t) => {
      t.addEventListener("click", () => {
        const key = t.getAttribute("data-key") as Role;
        idx = KEYS.indexOf(key);
        selectTab(key);
      });
    });

    selectTab(KEYS[0]);
    const onResize = (): void => selectTab(KEYS[idx]);
    window.addEventListener("resize", onResize);

    let timer = 0;
    if (!reduce) {
      timer = window.setInterval(() => {
        idx = (idx + 1) % KEYS.length;
        selectTab(KEYS[idx]);
      }, 340);
    }

    return () => {
      window.removeEventListener("resize", onResize);
      if (timer) window.clearInterval(timer);
    };
    // eslint-disable-next-line react-hooks/exhaustive-deps
  }, []);

  return (
    <main className={styles.stage}>
      <section className={styles.tabs}>
        <p className={styles.hint}>{HINT}</p>
        <div className={styles.bar} ref={barRef} role="tablist" aria-label={BAR_LABEL}>
          {TAB_TEXT.map((t, i) => (
            <button
              key={t.key}
              className={styles.tab}
              data-key={t.key}
              role="tab"
              aria-selected={i === 0 ? "true" : "false"}
              type="button"
            >
              {t.label + " "}
              <span className={styles.count}>{countFor(t.key)}</span>
            </button>
          ))}
          <span className={styles.indicator} ref={indicatorRef} aria-hidden="true" />
        </div>
        <div className={styles.panel} ref={panelRef} role="list" aria-label={PANEL_LABEL} />
      </section>
    </main>
  );
}