// VIDEO PLAYER
let pc = null;
let resourceURL = null;       // from Location header (for DELETE)
let retryTimer = null;

function setStatus(t, cls) {
statusEl.textContent = t;
statusEl.classList.remove('ok','warn','err');
if (cls) statusEl.classList.add(cls);
}
function note(t) { msgEl.textContent = t || ''; }

function waitIce(pc) {
return new Promise((resolve) => {
  if (pc.iceGatheringState === 'complete') return resolve();
  pc.addEventListener('icegatheringstatechange', () => {
	if (pc.iceGatheringState === 'complete') resolve();
  });
});
}

async function teardown() {
try { if (resourceURL) await fetch(resourceURL, { method:'DELETE' }); } catch {}
resourceURL = null;
if (pc) {
  pc.ontrack = null;
  pc.onconnectionstatechange = null;
  try { pc.close(); } catch {}
  pc = null;
}
if (videoEl.srcObject) {
  try { videoEl.srcObject.getTracks().forEach(t => t.stop?.()); } catch {}
  videoEl.srcObject = null;
}
}

function scheduleRetry(ms=10000) {
if (retryTimer) return;
retryTimer = setTimeout(() => { retryTimer = null; start().catch(()=>scheduleRetry()); }, ms);
}

async function start() {
setStatus('Connecting…');
note('');

await teardown();

pc = new RTCPeerConnection({ bundlePolicy: 'max-bundle' });
pc.addTransceiver('video', { direction: 'recvonly' });
pc.addTransceiver('audio', { direction: 'recvonly' });

const inbound = new MediaStream();
pc.ontrack = (e) => {
inbound.addTrack(e.track);
if (!videoEl.srcObject) videoEl.srcObject = inbound;
};

pc.onconnectionstatechange = () => {
const st = pc.connectionState;
if (st === 'connected') {
  setStatus('Live', 'ok');
  videoEl.play().catch(()=>{});
} else if (st === 'failed' || st === 'disconnected') {
  setStatus('Reconnecting…', 'warn'); scheduleRetry();
} else if (st === 'closed') {
  setStatus('Closed', 'err'); scheduleRetry();
} else if (st === 'connecting') {
  setStatus('Connecting…');
}
};

const offer = await pc.createOffer();
offer.sdp = offer.sdp.replace("useinbandfec=1", "useinbandfec=1;stereo=1;sprop-stereo=1;")
await pc.setLocalDescription(offer);
await waitIce(pc);

// ---- brute-force append stereo=1 ----
let sdp = pc.localDescription.sdp.replace("useinbandfec=1", "useinbandfec=1;stereo=1;sprop-stereo=1;");


const resp = await fetch(WHEP_URL, {
method: 'POST',
headers: { 'Content-Type': 'application/sdp' },
body: sdp
});


if (!resp.ok) {
setStatus('Error', 'err'); throw new Error(`WHEP POST ${resp.status}`);
}

const answerSdp = await resp.text();
resourceURL = resp.headers.get('Location') || resp.headers.get('location');
await pc.setRemoteDescription({ type: 'answer', sdp: answerSdp });

if (videoEl.muted) note('Autoplay is muted. Click the speaker icon to unmute.');
}


window.addEventListener('beforeunload', teardown);

// boot
start().catch(err => { setStatus('Error', 'err'); note(String(err)); scheduleRetry(); });