fix : sound overlap issue (#38)

src/lib/sounds.ts

@@ -1,37 +1,40 @@
 import { Move } from "chess.js";
 
-let audioContext: AudioContext | null = null;
-let audio: HTMLAudioElement | null = null;
+let ctx: AudioContext | null = null;
+const bufferCache = new Map<string, AudioBuffer>();
 
-const playSound = async (url: string) => {
-  if (!audio) {
-    audioContext = new AudioContext();
-    audio = new Audio();
-    const source = audioContext.createMediaElementSource(audio);
-    const volume = audioContext.createGain();
-    volume.gain.value = 0.3;
-    source.connect(volume);
-    volume.connect(audioContext.destination);
-  }
+const urls = {
+  move: "/sounds/move.mp3",
+  capture: "/sounds/capture.mp3",
+  illegal: "/sounds/illegal-move.mp3"
+} as const;
+type Sound = keyof typeof urls;
 
-  audio.src = url;
+async function play(sound: Sound) {
   try {
-    await audio.play();
+    ctx ??= new (window.AudioContext || (window as any).webkitAudioContext)();
+    if (ctx.state === "suspended") await ctx.resume();
+    let buf = bufferCache.get(urls[sound]);
+    if (!buf) {
+      const res = await fetch(urls[sound]);
+      buf = await ctx.decodeAudioData(await res.arrayBuffer());
+      bufferCache.set(urls[sound], buf);
+    }
+    const src = ctx.createBufferSource();
+    src.buffer = buf;
+    src.connect(ctx.destination);
+    src.start();
   } catch {
-    console.warn("Audio play failed");
+    if ("vibrate" in navigator) navigator.vibrate(50);
   }
-};
+}
 
-export const playCaptureSound = () => playSound("/sounds/capture.mp3");
-export const playIllegalMoveSound = () => playSound("/sounds/error.mp3");
-export const playMoveSound = () => playSound("/sounds/move.mp3");
+export const playCaptureSound = () => play("capture");
+export const playIllegalMoveSound = () => play("illegal");
+export const playMoveSound = () => play("move");
 
-export const playSoundFromMove = async (move: Move | null) => {
-  if (!move) {
-    playIllegalMoveSound();
-  } else if (move.captured) {
-    playCaptureSound();
-  } else {
-    playMoveSound();
-  }
-};
+export async function playSoundFromMove(move: Move | null) {
+  if (!move) return playIllegalMoveSound();
+  if (move.captured) return playCaptureSound();
+  return playMoveSound();
+}