04残り時間値が角度値として削られるカウントダウンリング

<main class="stage">
<div class="ecr is-demo" id="ecrRoot">
  <div class="ecr__badge" id="ecrBadge">30秒残り</div>
  <button class="ecr__ctrl" id="ecrCtrl" type="button">一時停止</button>
  <div class="ecr__canvas-wrap">
    <canvas class="ecr__canvas" id="ecrCanvas" width="240" height="200"></canvas>
  </div>
</div>
</main>

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

// 핵심: 경과 비율을 0~360도 각도로 바꿔 링을 깎아 나가고, 남은 비율이 20% 아래로
// 내려가면 그 비율만큼 링 색을 파랑에서 빨강으로 보간한다. .is-demo 는 실 30000ms
// 상수는 그대로 둔 채 시연 배속(DEMO_ACCEL_FACTOR)만 곱해 2초 측정창에 맞춘다.

@include stage($stage-ink);

.ecr {
  position: relative;
  width: 100%;
  max-width: 424px;
  display: flex;
  flex-direction: column;
  align-items: center;
  gap: $sp-3;
}

.ecr__badge {
  padding: $sp-1 $sp-3;
  border-radius: $r-pill;
  background: rgba(255, 247, 230, .08);
  color: $subject-cream;
  font-weight: 700;
  font-size: 11px;
  font-variant-numeric: tabular-nums;
}

.ecr__ctrl {
  position: absolute;
  top: 0;
  right: 0;
  border: 0;
  border-radius: $r-xs;
  padding: $sp-1 $sp-2;
  background: rgba(255, 247, 230, .12);
  color: $subject-cream;
  font-weight: 600;
  font-size: 10px;
  line-height: 1.4;
  cursor: pointer;
}
.ecr__ctrl:focus-visible { outline: 2px solid $subject-blue-light; outline-offset: 2px; }

.ecr__canvas-wrap {
  width: 100%;
  height: 220px;
  border-radius: $r-card;
  background: rgba(255, 255, 255, .04);
  display: grid;
  place-items: center;
  overflow: hidden;
}

.ecr__canvas {
  width: 100%;
  height: 100%;
  display: block;
}

@media (max-width: 340px) {
  .ecr { gap: $sp-1; }
  .ecr__badge { padding: $sp-1 $sp-2; font-size: 10px; }
  .ecr__canvas-wrap { height: 124px; }
}

@media (prefers-reduced-motion: reduce) {
  .ecr__canvas-wrap { background: rgba(255, 255, 255, .04); }
}

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);
}

.ecr {
  position: relative;
  width: 100%;
  max-width: 424px;
  display: flex;
  flex-direction: column;
  align-items: center;
  gap: 12px;
}

.ecr__badge {
  padding: 4px 12px;
  border-radius: 999px;
  background: rgba(255, 247, 230, 0.08);
  color: #fff7e6;
  font-weight: 700;
  font-size: 11px;
  font-variant-numeric: tabular-nums;
}

.ecr__ctrl {
  position: absolute;
  top: 0;
  right: 0;
  border: 0;
  border-radius: 4px;
  padding: 4px 8px;
  background: rgba(255, 247, 230, 0.12);
  color: #fff7e6;
  font-weight: 600;
  font-size: 10px;
  line-height: 1.4;
  cursor: pointer;
}

.ecr__ctrl:focus-visible {
  outline: 2px solid #5b8cf8;
  outline-offset: 2px;
}

.ecr__canvas-wrap {
  width: 100%;
  height: 220px;
  border-radius: 16px;
  background: rgba(255, 255, 255, 0.04);
  display: grid;
  place-items: center;
  overflow: hidden;
}

.ecr__canvas {
  width: 100%;
  height: 100%;
  display: block;
}

@media (max-width: 340px) {
  .ecr {
    gap: 4px;
  }
  .ecr__badge {
    padding: 4px 8px;
    font-size: 10px;
  }
  .ecr__canvas-wrap {
    height: 124px;
  }
}
@media (prefers-reduced-motion: reduce) {
  .ecr__canvas-wrap {
    background: rgba(255, 255, 255, 0.04);
  }
}

(function () {
  // QR_EXPIRE_DURATION_MS — 변형 1: 30000 → 15000 으로 늘리면 만료까지 더 여유 있게 카운트다운한다.
  var QR_EXPIRE_DURATION_MS = 30000;
  // 시연 전용 가상 시계 배속: 30000ms 만료를 2초 측정 창 안에서 보여주기 위한 시연 장치일 뿐,
  // 상수 QR_EXPIRE_DURATION_MS 자체는 그대로 유지한다.
  var DEMO_ACCEL_FACTOR = 15;

  var canvas = document.getElementById('ecrCanvas');
  var ctx = canvas.getContext('2d');
  var wrap = canvas.parentElement;
  var badge = document.getElementById('ecrBadge');
  var ctrl = document.getElementById('ecrCtrl');
  var root = document.getElementById('ecrRoot');
  var isDemo = root.classList.contains('is-demo');

  function seedRand(seed) {
    var s = seed >>> 0;
    return function () { s = (s * 1664525 + 1013904223) >>> 0; return s / 4294967296; };
  }
  var rand = seedRand(407041);
  var dots = [];
  for (var y = 0; y < 9; y += 1) {
    for (var x = 0; x < 9; x += 1) {
      if (rand() < 0.42) dots.push({ x: x, y: y });
    }
  }

  function lerp(a, b, t) { return a + (b - a) * t; }

  // 계산된 시각 레이어: 캔버스 크기가 바뀌면 중심·링 반지름을 다시 잰다 —
  // 링이 항상 스테이지 폭까지 채우게(278px 캡 없이 반응형).
  var dpr = 1, cw = 240, ch = 200, cx = 120, cy = 100, radius = 70;
  function fit() {
    var r = wrap.getBoundingClientRect();
    dpr = window.devicePixelRatio || 1;
    cw = r.width; ch = r.height;
    canvas.width = Math.round(cw * dpr);
    canvas.height = Math.round(ch * dpr);
    ctx.setTransform(dpr, 0, 0, dpr, 0, 0);
    cx = cw / 2; cy = ch / 2;
    radius = Math.min(cw, ch) * 0.44;
    draw(lastElapsed);
  }

  var lastElapsed = 0;
  function draw(virtualElapsed) {
    lastElapsed = virtualElapsed;
    ctx.clearRect(0, 0, cw, ch);

    // 계산 한 겹: 경과 비율 → 각도(0~360) 로 링을 깎고, 만료 근접(20% 이하)일수록
    // 파랑→빨강으로 색을 보간한다. 같은 urgency 값이 배경 톤·링 외곽 글로우에도 반영돼
    // 화면 넓은 면이 함께 바뀐다.
    var ratio = Math.min(1, virtualElapsed / QR_EXPIRE_DURATION_MS);
    var remainRatio = 1 - ratio;
    var angle = ratio * 360;
    var urgency = remainRatio < 0.2 ? (0.2 - remainRatio) / 0.2 : 0;
    var r1 = lerp(120, 255, urgency), g1 = lerp(200, 90, urgency), b1 = lerp(255, 90, urgency);
    var ringColor = 'rgb(' + Math.round(r1) + ',' + Math.round(g1) + ',' + Math.round(b1) + ')';

    // 카드 배경 밝기 — urgency 가 오를수록 전체 캔버스가 옅은 붉은 톤으로 밝아진다.
    var bg = ctx.createRadialGradient(cx, cy, 0, cx, cy, Math.max(cw, ch) * 0.72);
    bg.addColorStop(0, 'rgba(' + Math.round(lerp(40, 120, urgency)) + ',' + Math.round(lerp(30, 26, urgency)) + ',' + Math.round(lerp(48, 30, urgency)) + ',1)');
    bg.addColorStop(1, 'rgba(18,20,30,1)');
    ctx.fillStyle = bg;
    ctx.fillRect(0, 0, cw, ch);

    var ringWidth = Math.max(6, cw * 0.034);

    // 링 외곽 글로우 — urgency 가 오를수록 더 크고 옅게 번진다.
    ctx.globalCompositeOperation = 'lighter';
    ctx.strokeStyle = 'rgba(' + Math.round(r1) + ',' + Math.round(g1) + ',' + Math.round(b1) + ',' + (0.16 + urgency * 0.22).toFixed(3) + ')';
    ctx.lineWidth = ringWidth * (2.4 + urgency * 1.6);
    ctx.beginPath();
    ctx.arc(cx, cy, radius, -Math.PI / 2, -Math.PI / 2 + (angle * Math.PI / 180));
    ctx.stroke();
    ctx.globalCompositeOperation = 'source-over';

    ctx.strokeStyle = 'rgba(255,255,255,.12)';
    ctx.lineWidth = ringWidth;
    ctx.beginPath();
    ctx.arc(cx, cy, radius, 0, Math.PI * 2);
    ctx.stroke();

    ctx.strokeStyle = ringColor;
    ctx.lineWidth = ringWidth;
    ctx.lineCap = 'round';
    ctx.beginPath();
    ctx.arc(cx, cy, radius, -Math.PI / 2, -Math.PI / 2 + (angle * Math.PI / 180));
    ctx.stroke();

    var box = Math.min(cw, ch) * 0.31;
    ctx.fillStyle = 'rgba(20,26,38,.9)';
    ctx.fillRect(cx - box / 2, cy - box / 2, box, box);
    var cell = box / 9;
    ctx.fillStyle = 'rgb(255,247,230)';
    dots.forEach(function (d) {
      var s = cell * 0.62;
      ctx.fillRect(cx - box / 2 + d.x * cell + (cell - s) / 2, cy - box / 2 + d.y * cell + (cell - s) / 2, s, s);
    });

    var remainSec = Math.max(0, Math.ceil((QR_EXPIRE_DURATION_MS - virtualElapsed) / 1000));
    badge.textContent = remainSec + '秒残り';
  }

  var reduce = window.matchMedia('(prefers-reduced-motion: reduce)').matches;
  var playing = true;
  var virtualElapsed = reduce ? QR_EXPIRE_DURATION_MS : 0;
  if (reduce) {
    playing = false;
    root.classList.remove('is-demo');
  }

  var lastTs = null;
  function tick(ts) {
    if (lastTs === null) lastTs = ts;
    var dt = ts - lastTs;
    lastTs = ts;
    if (playing) {
      var accel = isDemo ? DEMO_ACCEL_FACTOR : 1;
      virtualElapsed += dt * accel;
      if (virtualElapsed >= QR_EXPIRE_DURATION_MS) virtualElapsed -= QR_EXPIRE_DURATION_MS;
    }
    draw(virtualElapsed);
    requestAnimationFrame(tick);
  }
  fit();
  window.addEventListener('resize', fit);
  draw(virtualElapsed);
  requestAnimationFrame(tick);

  ctrl.addEventListener('click', function () {
    playing = !playing;
    ctrl.textContent = playing ? '一時停止' : '再生';
  });
  ctrl.addEventListener('keydown', function (e) {
    if ((e.key === 'r' || e.key === 'R') && !reduce) {
      virtualElapsed = 0;
      playing = true;
      ctrl.textContent = '一時停止';
    }
  });
})();

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

export default function ExpiryCountdownRing() {
  const rootRef = useRef<HTMLDivElement>(null);
  const canvasRef = useRef<HTMLCanvasElement>(null);
  const ctrlRef = useRef<HTMLButtonElement>(null);
  const [badge, setBadge] = useState("30초 남음");
  const [ctrlLabel, setCtrlLabel] = useState("일시정지");

  useEffect(() => {
    const root = rootRef.current;
    const canvas = canvasRef.current;
    const ctrl = ctrlRef.current;
    if (!root || !canvas || !ctrl) return;
    const ctx = canvas.getContext("2d");
    if (!ctx) return;

    // QR_EXPIRE_DURATION_MS — 변형 1: 30000 → 15000 으로 늘리면 만료까지 더 여유 있게 카운트다운한다.
    const QR_EXPIRE_DURATION_MS = 30000;
    // 시연 전용 가상 시계 배속: 30000ms 만료를 2초 측정 창 안에서 보여주기 위한 시연 장치일 뿐,
    // 상수 QR_EXPIRE_DURATION_MS 자체는 그대로 유지한다.
    const DEMO_ACCEL_FACTOR = 15;

    const isDemo = root.classList.contains("is-demo");
    const wrap = canvas.parentElement as HTMLElement;

    function seedRand(seed: number) {
      let s = seed >>> 0;
      return function () {
        s = (s * 1664525 + 1013904223) >>> 0;
        return s / 4294967296;
      };
    }
    const rand = seedRand(407041);
    const dots: { x: number; y: number }[] = [];
    for (let y = 0; y < 9; y += 1) {
      for (let x = 0; x < 9; x += 1) {
        if (rand() < 0.42) dots.push({ x, y });
      }
    }

    function lerp(a: number, b: number, t: number) { return a + (b - a) * t; }

    // 계산된 시각 레이어: 캔버스 크기가 바뀌면 중심·링 반지름을 다시 잰다 —
    // 링이 항상 스테이지 폭까지 채우게(278px 캡 없이 반응형).
    let dpr = 1, cw = 240, ch = 200, cx = 120, cy = 100, radius = 70;
    function fit() {
      const r = wrap.getBoundingClientRect();
      dpr = window.devicePixelRatio || 1;
      cw = r.width; ch = r.height;
      canvas!.width = Math.round(cw * dpr);
      canvas!.height = Math.round(ch * dpr);
      ctx!.setTransform(dpr, 0, 0, dpr, 0, 0);
      cx = cw / 2; cy = ch / 2;
      radius = Math.min(cw, ch) * 0.44;
      draw(lastElapsed);
    }

    let lastElapsed = 0;
    function draw(virtualElapsed: number) {
      lastElapsed = virtualElapsed;
      ctx!.clearRect(0, 0, cw, ch);

      // 계산 한 겹: 경과 비율 → 각도(0~360) 로 링을 깎고, 만료 근접(20% 이하)일수록
      // 파랑→빨강으로 색을 보간한다. 같은 urgency 값이 배경 톤·링 외곽 글로우에도 반영돼
      // 화면 넓은 면이 함께 바뀐다.
      const ratio = Math.min(1, virtualElapsed / QR_EXPIRE_DURATION_MS);
      const remainRatio = 1 - ratio;
      const angle = ratio * 360;
      const urgency = remainRatio < 0.2 ? (0.2 - remainRatio) / 0.2 : 0;
      const r1 = lerp(120, 255, urgency), g1 = lerp(200, 90, urgency), b1 = lerp(255, 90, urgency);
      const ringColor = "rgb(" + Math.round(r1) + "," + Math.round(g1) + "," + Math.round(b1) + ")";

      // 카드 배경 밝기 — urgency 가 오를수록 전체 캔버스가 옅은 붉은 톤으로 밝아진다.
      const bg = ctx!.createRadialGradient(cx, cy, 0, cx, cy, Math.max(cw, ch) * 0.72);
      bg.addColorStop(0, "rgba(" + Math.round(lerp(40, 120, urgency)) + "," + Math.round(lerp(30, 26, urgency)) + "," + Math.round(lerp(48, 30, urgency)) + ",1)");
      bg.addColorStop(1, "rgba(18,20,30,1)");
      ctx!.fillStyle = bg;
      ctx!.fillRect(0, 0, cw, ch);

      const ringWidth = Math.max(6, cw * 0.034);

      // 링 외곽 글로우 — urgency 가 오를수록 더 크고 옅게 번진다.
      ctx!.globalCompositeOperation = "lighter";
      ctx!.strokeStyle = "rgba(" + Math.round(r1) + "," + Math.round(g1) + "," + Math.round(b1) + "," + (0.16 + urgency * 0.22).toFixed(3) + ")";
      ctx!.lineWidth = ringWidth * (2.4 + urgency * 1.6);
      ctx!.beginPath();
      ctx!.arc(cx, cy, radius, -Math.PI / 2, -Math.PI / 2 + (angle * Math.PI) / 180);
      ctx!.stroke();
      ctx!.globalCompositeOperation = "source-over";

      ctx!.strokeStyle = "rgba(255,255,255,.12)";
      ctx!.lineWidth = ringWidth;
      ctx!.beginPath();
      ctx!.arc(cx, cy, radius, 0, Math.PI * 2);
      ctx!.stroke();

      ctx!.strokeStyle = ringColor;
      ctx!.lineWidth = ringWidth;
      ctx!.lineCap = "round";
      ctx!.beginPath();
      ctx!.arc(cx, cy, radius, -Math.PI / 2, -Math.PI / 2 + (angle * Math.PI) / 180);
      ctx!.stroke();

      const box = Math.min(cw, ch) * 0.31;
      ctx!.fillStyle = "rgba(20,26,38,.9)";
      ctx!.fillRect(cx - box / 2, cy - box / 2, box, box);
      const cell = box / 9;
      ctx!.fillStyle = "rgb(255,247,230)";
      dots.forEach((d) => {
        const s = cell * 0.62;
        ctx!.fillRect(cx - box / 2 + d.x * cell + (cell - s) / 2, cy - box / 2 + d.y * cell + (cell - s) / 2, s, s);
      });

      const remainSec = Math.max(0, Math.ceil((QR_EXPIRE_DURATION_MS - virtualElapsed) / 1000));
      setBadge(remainSec + "초 남음");
    }

    const reduce = window.matchMedia("(prefers-reduced-motion: reduce)").matches;
    let playing = true;
    let virtualElapsed = reduce ? QR_EXPIRE_DURATION_MS : 0;
    if (reduce) {
      playing = false;
      root.classList.remove("is-demo");
    }

    let lastTs: number | null = null;
    let raf = 0;
    function tick(ts: number) {
      if (lastTs === null) lastTs = ts;
      const dt = ts - lastTs;
      lastTs = ts;
      if (playing) {
        const accel = isDemo ? DEMO_ACCEL_FACTOR : 1;
        virtualElapsed += dt * accel;
        if (virtualElapsed >= QR_EXPIRE_DURATION_MS) virtualElapsed -= QR_EXPIRE_DURATION_MS;
      }
      draw(virtualElapsed);
      raf = requestAnimationFrame(tick);
    }
    fit();
    window.addEventListener("resize", fit);
    draw(virtualElapsed);
    raf = requestAnimationFrame(tick);

    function onClick() {
      playing = !playing;
      setCtrlLabel(playing ? "일시정지" : "재생");
    }
    function onKeydown(e: KeyboardEvent) {
      if ((e.key === "r" || e.key === "R") && !reduce) {
        virtualElapsed = 0;
        playing = true;
        setCtrlLabel("일시정지");
      }
    }
    ctrl.addEventListener("click", onClick);
    ctrl.addEventListener("keydown", onKeydown);

    return () => {
      cancelAnimationFrame(raf);
      window.removeEventListener("resize", fit);
      ctrl.removeEventListener("click", onClick);
      ctrl.removeEventListener("keydown", onKeydown);
    };
  }, []);

  return (
    <main className={styles.stage}>
      <div className={`${styles.ecr} is-demo`} ref={rootRef}>
        <div className={styles.ecr__badge}>{badge}</div>
        <button className={styles.ecr__ctrl} type="button" ref={ctrlRef}>{ctrlLabel}</button>
        <div className={styles["ecr__canvas-wrap"]}>
          <canvas className={styles.ecr__canvas} ref={canvasRef} width={240} height={200} />
        </div>
      </div>
    </main>
  );
}