02Transfer-speed value graph — the per-second transfer-rate value keeps redrawing as a graph

<main class="stage">
<div class="dsg is-demo" id="dsg">
  <div class="dsg__head">
    <span class="dsg__label">Transfer speed</span>
    <span class="dsg__val" id="dsgVal">0MB/s</span>
  </div>
  <svg class="dsg__graph" viewBox="0 0 220 80" preserveAspectRatio="none">
    <polyline class="dsg__raw" id="dsgRaw" points=""></polyline>
    <polyline class="dsg__avg" id="dsgAvg" points=""></polyline>
  </svg>
  <button class="dsg__btn" id="dsgBtn" type="button">Pause</button>
</div>
</main>

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

// 계산 겹: 원시 표본의 이동평균(최근 N개) 폴리라인 — index.html movingAvg() 참조
@include stage($stage-paper);

.dsg {
  width: 100%;
  max-width: 260px;
  display: grid;
  gap: $sp-2;
}

.dsg__head {
  display: flex;
  align-items: baseline;
  justify-content: space-between;
  font: 600 13px/1 -apple-system, "Segoe UI", "Noto Sans KR", sans-serif;
  color: $subject-ink;
}

.dsg__val { font-variant-numeric: tabular-nums; color: $subject-blue-deep; }

.dsg__graph {
  width: 100%;
  height: 96px;
  border-radius: $r-sm;
  background: $subject-cream;
}

.dsg__raw {
  fill: none;
  stroke: $chart-2;
  stroke-width: 1;
  opacity: .35;
  vector-effect: non-scaling-stroke;
}

.dsg__avg {
  fill: none;
  stroke: $chart-1;
  stroke-width: 2.4;
  stroke-linejoin: round;
  stroke-linecap: round;
  vector-effect: non-scaling-stroke;
}

.dsg__btn {
  width: 100%;
  border: 0;
  border-radius: $r-control;
  padding: $sp-2 $sp-4;
  background: $subject-ink;
  color: $subject-cream;
  font: 700 12px/1 -apple-system, "Segoe UI", "Noto Sans KR", sans-serif;
  cursor: pointer;
  transition: transform $dur-instant $ease-out;

  &:active { transform: scale(.96); }
}

@media (max-width: 340px) {
  .dsg { max-width: 200px; }
  .dsg__graph { height: 72px; }
}

@media (prefers-reduced-motion: reduce) {
  .dsg__avg, .dsg__raw { transition: none; }
  .dsg__btn { transition: none; }
}

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

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

.dsg {
  width: 100%;
  max-width: 260px;
  display: grid;
  gap: 8px;
}

.dsg__head {
  display: flex;
  align-items: baseline;
  justify-content: space-between;
  font: 600 13px/1 -apple-system, "Segoe UI", "Noto Sans KR", sans-serif;
  color: #17141a;
}

.dsg__val {
  font-variant-numeric: tabular-nums;
  color: #0a4fe8;
}

.dsg__graph {
  width: 100%;
  height: 96px;
  border-radius: 8px;
  background: #fff7e6;
}

.dsg__raw {
  fill: none;
  stroke: #c2361a;
  stroke-width: 1;
  opacity: 0.35;
  vector-effect: non-scaling-stroke;
}

.dsg__avg {
  fill: none;
  stroke: #2f6df6;
  stroke-width: 2.4;
  stroke-linejoin: round;
  stroke-linecap: round;
  vector-effect: non-scaling-stroke;
}

.dsg__btn {
  width: 100%;
  border: 0;
  border-radius: 12px;
  padding: 8px 16px;
  background: #17141a;
  color: #fff7e6;
  font: 700 12px/1 -apple-system, "Segoe UI", "Noto Sans KR", sans-serif;
  cursor: pointer;
  transition: transform 140ms ease-out;
}
.dsg__btn:active {
  transform: scale(0.96);
}

@media (max-width: 340px) {
  .dsg {
    max-width: 200px;
  }
  .dsg__graph {
    height: 72px;
  }
}
@media (prefers-reduced-motion: reduce) {
  .dsg__avg, .dsg__raw {
    transition: none;
  }
  .dsg__btn {
    transition: none;
  }
}

(function () {
  var root = document.getElementById('dsg');
  var val = document.getElementById('dsgVal');
  var rawLine = document.getElementById('dsgRaw');
  var avgLine = document.getElementById('dsgAvg');

  // 시드 고정: 초당 전송량 원시 표본(MB/s ×10, 정수). 실 네트워크 측정 0
  var SAMPLES = [12, 18, 15, 26, 32, 28, 40, 36, 44, 52, 48, 58, 54, 62, 46, 38, 44, 50, 42, 34, 28, 22, 16, 20];
  var N = 5; // 이동평균 창(최근 N 개 표본)
  var W = 220, H = 80, MAXV = 65;
  var TICK_MS = 160;

  var buf = [];
  var i = 0;
  var paused = false;
  var timer = 0;
  var btn = document.getElementById('dsgBtn');

  function pt(idx, v, count) {
    var x = count <= 1 ? W : (idx / (count - 1)) * W;
    var y = H - (v / MAXV) * H;
    return x.toFixed(1) + ',' + y.toFixed(1);
  }

  // 계산 겹: 최근 N개 원시 표본의 이동평균 — 그래프 선은 이 평균값을 잇는다(원시값 자체가 아님)
  function movingAvg(arr) {
    var out = [];
    for (var k = 0; k < arr.length; k++) {
      var s = Math.max(0, k - N + 1);
      var sum = 0, c = 0;
      for (var j = s; j <= k; j++) { sum += arr[j]; c++; }
      out.push(sum / c);
    }
    return out;
  }

  function paint() {
    var avg = movingAvg(buf);
    var rawPts = [], avgPts = [];
    for (var k = 0; k < buf.length; k++) {
      rawPts.push(pt(k, buf[k], buf.length));
      avgPts.push(pt(k, avg[k], buf.length));
    }
    rawLine.setAttribute('points', rawPts.join(' '));
    avgLine.setAttribute('points', avgPts.join(' '));
    var last = avg.length ? avg[avg.length - 1] : 0;
    val.textContent = (last / 10).toFixed(1) + 'MB/s';
  }

  function tick() {
    if (paused) return;
    buf.push(SAMPLES[i % SAMPLES.length]);
    if (buf.length > 14) buf.shift();
    i++;
    paint();
    timer = setTimeout(tick, TICK_MS);
  }

  tick();

  btn.addEventListener('click', function () {
    root.classList.remove('is-demo');
    paused = !paused;
    btn.textContent = paused ? 'Resume' : 'Pause';
    if (!paused) tick();
    else clearTimeout(timer);
  });
})();

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

type Box<T> = { current: T };

export default function DownloadManagerSpeedGraph() {
  const rootRef = useRef(null) as unknown as Box<HTMLDivElement | null>;

  useEffect(() => {
    const root = rootRef.current;
    if (!root) return;
    const val = root.querySelector(`.${styles.val}`) as HTMLElement | null;
    const rawLine = root.querySelector(`.${styles.raw}`) as SVGPolylineElement | null;
    const avgLine = root.querySelector(`.${styles.avg}`) as SVGPolylineElement | null;
    const btn = root.querySelector(`.${styles.btn}`) as HTMLElement | null;
    if (!val || !rawLine || !avgLine || !btn) return;

    // 시드 고정: 초당 전송량 원시 표본(MB/s ×10, 정수). 실 네트워크 측정 0
    const SAMPLES = [12, 18, 15, 26, 32, 28, 40, 36, 44, 52, 48, 58, 54, 62, 46, 38, 44, 50, 42, 34, 28, 22, 16, 20];
    const N = 5;
    const W = 220, H = 80, MAXV = 65;
    const TICK_MS = 160;

    let buf: number[] = [];
    let i = 0;
    let paused = false;
    let timer = 0;
    let stopped = false;

    function pt(idx: number, v: number, count: number) {
      const x = count <= 1 ? W : (idx / (count - 1)) * W;
      const y = H - (v / MAXV) * H;
      return x.toFixed(1) + "," + y.toFixed(1);
    }

    // 계산 겹: 최근 N개 원시 표본의 이동평균 — 그래프 선은 이 평균값을 잇는다(원시값 자체가 아님)
    function movingAvg(arr: number[]) {
      const out: number[] = [];
      for (let k = 0; k < arr.length; k++) {
        const s = Math.max(0, k - N + 1);
        let sum = 0, c = 0;
        for (let j = s; j <= k; j++) { sum += arr[j]; c++; }
        out.push(sum / c);
      }
      return out;
    }

    function paint() {
      const avg = movingAvg(buf);
      const rawPts: string[] = [], avgPts: string[] = [];
      for (let k = 0; k < buf.length; k++) {
        rawPts.push(pt(k, buf[k], buf.length));
        avgPts.push(pt(k, avg[k], buf.length));
      }
      rawLine!.setAttribute("points", rawPts.join(" "));
      avgLine!.setAttribute("points", avgPts.join(" "));
      const last = avg.length ? avg[avg.length - 1] : 0;
      val!.textContent = (last / 10).toFixed(1) + "MB/s";
    }

    function tick() {
      if (paused || stopped) return;
      buf.push(SAMPLES[i % SAMPLES.length]);
      if (buf.length > 14) buf.shift();
      i++;
      paint();
      timer = window.setTimeout(tick, TICK_MS);
    }

    tick();

    function onClick() {
      root!.classList.remove(styles["is-demo"]);
      paused = !paused;
      btn!.textContent = paused ? "재개" : "일시정지";
      if (!paused) tick();
      else window.clearTimeout(timer);
    }
    btn.addEventListener("click", onClick);

    return () => {
      stopped = true;
      window.clearTimeout(timer);
      btn.removeEventListener("click", onClick);
    };
  }, []);

  return (
    <div ref={rootRef} className={`${styles.stage} ${styles.dsg} ${styles["is-demo"]}`}>
      <div className={styles.head}>
        <span className={styles.label}>전송 속도</span>
        <span className={styles.val}>0MB/s</span>
      </div>
      <svg className={styles.graph} viewBox="0 0 220 80" preserveAspectRatio="none">
        <polyline className={styles.raw} points="" />
        <polyline className={styles.avg} points="" />
      </svg>
      <button className={styles.btn} type="button">일시정지</button>
    </div>
  );
}