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// The zap sound: "Jacobs Ladder from Side" by Parabolix, trimmed by egomassive
// (freesound.org/s/536741, CC0), transcoded to mp3 for Safari and encoded
// verbatim so hosted and standalone builds both include it. Decode ahead of
// the tap; no network request is needed.
import mp3 from './assets/zap.mp3.base64.txt' with { type: 'text' };
let context, buffer, loading, playing, idleTimer, sequence = 0;
// Decoding happens in an OfflineAudioContext, which never touches the
// speaker. A real AudioContext opens the phone's audio output the moment it
// runs — and in the installed app (where autoplay is allowed) one made at
// load ran at once, so every open or refocus re-opened the output with an
// audible pop. So the real one is made on the first tap, and suspended again
// once the sound has finished or the app goes to the background.
function decodeZap() {
if (loading) return loading;
const Offline = window.OfflineAudioContext || window.webkitOfflineAudioContext;
if (!Offline) return null;
const bytes = Uint8Array.from(atob(mp3.trim()), c => c.charCodeAt(0));
loading = new Offline(1, 1, 48000).decodeAudioData(bytes.buffer).then(decoded => (buffer = decoded));
loading.catch(() => { loading = null; });
return loading;
}
function audioContext() {
const AudioCtx = window.AudioContext || window.webkitAudioContext;
if (!AudioCtx) return null;
if (!context || context.state === 'closed') context = new AudioCtx({ latencyHint: 'interactive' });
return context;
}
function suspendSoon(ms = 1500) {
clearTimeout(idleTimer);
idleTimer = setTimeout(() => { if (!playing && context?.state === 'running') context.suspend().catch(() => {}); }, ms);
}
if (typeof document !== 'undefined') document.addEventListener('visibilitychange', () => {
if (document.visibilityState === 'hidden' && context?.state === 'running') context.suspend().catch(() => {});
});
// A browser without audio must still be able to load the wallet.
try { decodeZap(); } catch {}
// tappedAt: when the finger landed — the caller's clock, since this module
// may still have been loading when it did.
export function playZapSound(tappedAt = performance.now()) {
try {
const ready = decodeZap();
const ctx = audioContext();
if (!ready || !ctx) return;
const token = ++sequence;
clearTimeout(idleTimer);
if (ctx.state !== 'running') ctx.resume().catch(() => {});
const start = decoded => {
// A very early tap may beat decoding. Never queue an old sound behind
// a later zap or surprise the user after a stalled decoder recovers.
if (token !== sequence || context !== ctx || performance.now() - tappedAt > 250) { if (token === sequence) suspendSoon(); return; }
if (playing) { playing.stop(); playing.disconnect(); }
const source = ctx.createBufferSource(), gain = ctx.createGain();
source.buffer = decoded;
gain.gain.value = .65;
source.connect(gain);
gain.connect(ctx.destination);
source.onended = () => {
source.disconnect(); gain.disconnect();
if (playing === source) { playing = null; suspendSoon(); }
};
playing = source;
source.start();
};
if (buffer) start(buffer);
else ready.then(start).catch(() => {});
} catch {} // Unavailable audio never interrupts a payment or its animation.
}
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