const STATUS_LABELS = {
  disconnected: 'Disconnected — select a port and connect',
  connecting: 'Connecting…',
  connected_disarmed: 'Connected · Disarmed',
  armed: 'Connected · Armed',
  link_degraded: 'Signal lost — check tether',
};
const $=s=>document.querySelector(s), $$=s=>[...document.querySelectorAll(s)];
const control={forward:0,turn:0,vertical:0}, pressedKeys=new Set(); let bridgeReady=false, appState='disconnected', batteryConfig={}, linkConfig={baud:57600,control_hz:20,ping_hz:1,system_hz:1,servo_hz:2,rc_hz:2,esc_hz:1}, servoSignature='', lastAxisSend=0, axisTimer=0, demoActive=false, demoState=null;
const api=(name,...args)=>window.pywebview.api[name](...args);
const activity=[];
let lastReportedStatus='';
function recordActivity(message){
  if(!message||activity[0]===message)return;
  activity.unshift(String(message));activity.length=Math.min(activity.length,3);
  ['#status-text','#activity-previous','#activity-oldest'].forEach((selector,i)=>{
    const row=$(selector);if(row){const changed=row.textContent!==(activity[i]||'');row.textContent=activity[i]||'';row.hidden=!activity[i];if(changed&&!row.hidden&&!matchMedia('(prefers-reduced-motion:reduce)').matches)row.animate([{opacity:0},{opacity:1}],{duration:180,easing:'ease-out'})}
  });
}
function withTimeout(promise,ms=1500){return new Promise((resolve,reject)=>{const timer=setTimeout(()=>reject(new Error('Control bridge timed out')),ms);Promise.resolve(promise).then(value=>{clearTimeout(timer);resolve(value)},error=>{clearTimeout(timer);reject(error)})})}
let vehicleSnapshot={connected:false,armed:null}, view=ControlState.present(vehicleSnapshot), inputFocused=true,
    bridgeStale=false,lastBridgeAt=performance.now(),axisBusy=false,inputSequence=Date.now(),
    localRequest=null,commandError='',requestSerial=0,demoCommandTimer=0,lastSafetyTick=performance.now();
const canDrive=()=>view.drive&&!document.querySelector('dialog[open]')&&performance.now()-lastSafetyTick<750;

window.canDrive=canDrive;
let inputMode='keyboard',controllerKey=null,controllerConfig=null,controllerNeedCenter=true,controllerWasDriving=false;
const controllerMotion=new ControllerInput.Motion();
const controllerId=pad=>pad.index+':'+pad.id;
function getControllers(){try{return [...(navigator.getGamepads?.()||[])].filter(pad=>pad?.connected)}catch(_){return []}}
function loadControllerConfig(pad){
  let saved=null;try{saved=JSON.parse(localStorage.getItem('sub-controller:'+pad.id))}catch(_){}
  const defaults=ControllerInput.defaults(pad),config={...defaults,...(saved||{})};
  return Number.isFinite(config.deadZone)&&config.deadZone>=0&&config.deadZone<=.3&&ControllerInput.read(pad,config)?config:defaults;
}
function selectController(pad){
  resetInputs();controllerKey=controllerId(pad);controllerConfig=loadControllerConfig(pad);
}
function setInputMode(mode){
  if(mode===inputMode||inputConfigurationLocked())return false;
  resetInputs();inputMode=mode;document.body.dataset.inputMode=mode;
  $('#input-keyboard').setAttribute('aria-pressed',String(mode==='keyboard'));
  $('#input-joystick').setAttribute('aria-pressed',String(mode==='joystick'));
  $('#controller-settings').hidden=mode!=='joystick';
  $('#joystick-canvas').setAttribute('aria-label',mode==='joystick'?'Controller steering and throttle output; read only':'Steering and throttle joystick; W A S D keys');
  $('#heave').setAttribute('aria-label',mode==='joystick'?'Controller vertical output; read only':'Vertical thrust control');
  return true;
}
function inputConfigurationLocked(){
  return !!(engageStart||localRequest||view.pending||vehicleSnapshot.armed===true||(vehicleSnapshot.connected&&!view.known));
}
function syncInputModeControls(){
  const locked=inputConfigurationLocked(),pads=getControllers(),pad=pads.find(pad=>controllerId(pad)===controllerKey);
  $('.input-mode-switch').dataset.locked=String(locked);
  for(const button of [$('#input-keyboard'),$('#input-joystick')]){
    button.disabled=locked;button.title=locked?'Disengage before changing input mode':'Choose input mode';
  }
  $('#controller-settings').disabled=locked||!pads.length;
  $('#controller-settings').title=locked?'Disengage before changing joystick settings':'Joystick setup';
  if($('#controller-modal').open){
    const form=$('#controller-form');
    for(const field of form.querySelectorAll('input,select,button[type="submit"]'))field.disabled=locked||!pad;
    $('#controller-device').disabled=locked||!pads.length;
    const feedback=form.querySelector('.form-feedback'),message='Disengage before changing joystick settings.';
    if(locked)setFeedback(feedback,message);else if(feedback.textContent===message)setFeedback(feedback);
  }
}
window.canTouchControl=()=>inputMode==='keyboard'&&canDrive();
$('#input-keyboard').onclick=()=>setInputMode('keyboard');
$('#input-joystick').onclick=()=>setInputMode('joystick');
function fillControllerForm(){
  const pads=getControllers(),device=$('#controller-device'),form=$('#controller-form');
  device.replaceChildren(...pads.map(pad=>new Option(pad.id,controllerId(pad))));
  if(!pads.length)device.add(new Option('No controller detected',''));
  device.value=controllerKey||'';
  const pad=pads.find(pad=>controllerId(pad)===controllerKey);
  const config=controllerConfig||ControllerInput.defaults(pad);
  for(const name of ['turn','forward','vertical']){
    const field=form.elements[name];field.replaceChildren(new Option('Off','-1'));
    for(let axis=0;axis<(pad?.axes.length||0);axis++)field.add(new Option('Axis '+axis,String(axis)));
    field.value=String(config[name]);field.disabled=inputConfigurationLocked()||!pad;
    const invert='invert'+name[0].toUpperCase()+name.slice(1);
    form.elements[invert].checked=!!config[invert];form.elements[invert].disabled=inputConfigurationLocked()||!pad;
  }
  form.elements.deadZone.value=Math.round(config.deadZone*100);
  device.disabled=inputConfigurationLocked()||!pads.length;
  form.elements.deadZone.disabled=inputConfigurationLocked()||!pad;
  form.querySelector('[type=submit]').disabled=inputConfigurationLocked()||!pad;
}
$('#controller-device').onchange=e=>{
  if(inputConfigurationLocked())return;
  const pad=getControllers().find(pad=>controllerId(pad)===e.target.value);
  if(pad){selectController(pad);fillControllerForm()}
};
$('#controller-form').onsubmit=e=>{
  e.preventDefault();const form=e.currentTarget,pad=getControllers().find(pad=>controllerId(pad)===controllerKey);
  if(inputConfigurationLocked()){setFeedback(form.querySelector('.form-feedback'),'Disengage before changing joystick settings.');return}
  if(!pad){setFeedback(form.querySelector('.form-feedback'),'Controller disconnected. Reconnect it before saving.');return}
  const config={deadZone:Number(form.elements.deadZone.value)/100};
  for(const name of ['turn','forward','vertical']){
    config[name]=Number(form.elements[name].value);
    const invert='invert'+name[0].toUpperCase()+name.slice(1);config[invert]=form.elements[invert].checked;
  }
  if(!ControllerInput.read(pad,config)||!Number.isFinite(config.deadZone)||config.deadZone<0||config.deadZone>.3){
    setFeedback(form.querySelector('.form-feedback'),'Choose valid axes and a dead zone between 0 and 30%.');return;
  }
  controllerConfig=config;try{localStorage.setItem('sub-controller:'+pad.id,JSON.stringify(config))}catch(_){}
  resetInputs();closeModal($('#controller-modal'));
};
function pollController(now){
  try{
    if(inputMode==='joystick'){
      const pads=getControllers();
      if(controllerKey===null&&pads.length)selectController(pads[0]);
      const pad=pads.find(pad=>controllerId(pad)===controllerKey),target=pad&&ControllerInput.read(pad,controllerConfig);
      let status=!navigator.getGamepads?'Controller input unavailable in this webview':!pad?(pads.length?'Selected controller unavailable · choose Setup':'Waiting for controller · press a button to detect it'):!target?'Invalid axis mapping · open Setup':!canDrive()?'Controller ready · '+pad.id:controllerNeedCenter?'Center sticks to resume':pad.id;
      $('#controller-settings').disabled=inputConfigurationLocked()||!pads.length;
      if(!target||!canDrive()){
        if(controllerWasDriving)resetInputs();
        controllerMotion.reset();controllerNeedCenter=true;controllerWasDriving=false;
      }else{
        if(controllerNeedCenter&&!Object.values(target).some(value=>value!==0)){controllerNeedCenter=false;status=pad.id}
        if(!controllerNeedCenter){
          const demand=controllerMotion.step(target,now);controllerWasDriving=true;
          control.turn=demand.turn;control.forward=demand.forward;
          window.joystick3D?.setVisual(demand.turn,-demand.forward);
          setHeave(demand.vertical,false);updateReadouts();sendAxes();
        }
      }
      if($('#controller-status').textContent!==status)$('#controller-status').textContent=status;
      $('#controller-status').dataset.quiet=String(status===pad?.id||status.startsWith('Controller ready'));
      if($('#controller-modal').open){
        const axes=pad?'Axes · '+pad.axes.map((value,index)=>index+': '+value.toFixed(2)).join('   '):'Controller disconnected';
        if($('#controller-axes').textContent!==axes)$('#controller-axes').textContent=axes;
        if($('#controller-device').options.length!==Math.max(1,pads.length)||[...$('#controller-device').options].some(option=>option.value&&!pads.some(pad=>controllerId(pad)===option.value)))fillControllerForm();
      }
    }else {$('#controller-status').dataset.quiet='true';if($('#controller-status').textContent!=='Keyboard + touch')$('#controller-status').textContent='Keyboard + touch'}
  }catch(error){
    if(controllerWasDriving)resetInputs();
    $('#controller-status').dataset.quiet='false';$('#controller-status').textContent='Controller unavailable · reconnect or use keyboard';
  }
  requestAnimationFrame(pollController);
}
document.body.dataset.inputMode=inputMode;

function makeDemoState(){const servos={};for(let i=1;i<=16;i++)servos[String(i)]={function:i<=3?32+i:0,label:i<=3?`Motor ${i}`:'Unassigned',motor:i<=3?i:null,direction:i<=3?1:null};return {connected:true,link:'LINK OK',vehicle:'DEMO • DISARMED',armed:false,armed_known:true,mode:'MANUAL',app_state:'connected_disarmed',status:'Demo mode ready — no hardware or spoofer.',battery:{voltage:15.8,per_cell:3.95,percent:72,cells:4,low:false},link_quality:null,servos}}
function updateDemo(patch){Object.assign(demoState,patch);render(demoState)}
document.addEventListener('click',e=>{const btn=e.target.closest('.num-step');if(!btn)return;const pill=btn.closest('.number-pill');if(!pill)return;const input=pill.querySelector('input');if(!input)return;const step=+input.step||1,min=input.min!==''?+input.min:-Infinity,max=input.max!==''?+input.max:Infinity;let val=+input.value||0;if(btn.classList.contains('down'))val=Math.max(min,+(val-step).toFixed(4));else val=Math.min(max,+(val+step).toFixed(4));input.value=val;input.dispatchEvent(new Event('input',{bubbles:true}));input.dispatchEvent(new Event('change',{bubbles:true}))});
function toast(message,error=false){const el=$('#toast');el.textContent=message;el.className=`toast show${error?' error':''}`;clearTimeout(toast.t);toast.t=setTimeout(()=>el.className='toast',2600)}
window.showToast=toast;
const manualPorts=new Map();
function populatePorts(ports){
  const p=$('#port');
  if(!p)return;
  const old=p.value||'';
  p.innerHTML='';

  const allList=[];
  const seen=new Set();

  const addPort=item=>{
    let dev=item, lbl=item;
    if(item&&typeof item==='object'){
      dev=item.device||'';
      lbl=item.label||dev;
    }
    if(dev&&!seen.has(dev)){
      seen.add(dev);
      allList.push({device:dev, label:lbl});
    }
  };

  if(Array.isArray(ports)) ports.forEach(addPort);
  manualPorts.forEach(addPort);
  addPort({device:'demo', label:'Demo Mode (no hardware)'});

  let matched=false;
  allList.forEach(item=>{
    const opt=new Option(item.label, item.device);
    p.add(opt);
    if(item.device===old){
      p.value=item.device;
      matched=true;
    }
  });
  if(!matched&&allList.length>0){
    p.value=allList[0].device;
  }
}
function sendAxes(){
  if(!canDrive()||demoActive||!bridgeReady||axisBusy)return;
  const transmit=()=>{
    axisTimer=0;
    if(!canDrive()||demoActive||axisBusy)return;
    lastAxisSend=performance.now();axisBusy=true;
    withTimeout(api('set_axes',control.forward,control.turn,control.vertical,++inputSequence))
      .catch(()=>markBridgeStale()).finally(()=>axisBusy=false);
  };
  const wait=50-(performance.now()-lastAxisSend);
  if(wait<=0)transmit();else if(!axisTimer)axisTimer=setTimeout(transmit,wait);
}
// This is a local bridge lease, not extra MAVLink traffic. The worker retains
// the configured wire rate and neutralizes if the UI stops renewing its input.
setInterval(()=>{if(canDrive())sendAxes()},250);
function updateReadouts(){ if(!canDrive()){$('#surge-readout').textContent='—';$('#yaw-readout').textContent='—';$('#heave-readout').textContent='—';return;}$('#surge-readout').textContent=Math.round(control.forward*100);$('#yaw-readout').textContent=Math.round(control.turn*100);$('#heave-readout').textContent=Math.round(control.vertical*100);}

window.setJoyControl=(x,y)=>{if(!window.canTouchControl())return;control.turn=x;control.forward=-y;updateReadouts();sendAxes();};
function releaseHandle(el){el.classList.remove('pressed');el.classList.add('released');setTimeout(()=>el.classList.remove('released'),520)}

const heave=$('#heave'),hknob=$('#heave-knob'),hfill=$('#heave-fill');let heavePointer=null,heaveAnim=0;
function setHeave(v,send=true){if(!canDrive()&&v!==0)return;v=Math.max(-1,Math.min(1,v));control.vertical=v;heave.dataset.commanded=String(Math.abs(v)>.03);hknob.style.top=`${50-v*43}%`;hfill.style.top=v>=0?`${50-v*43}%`:'50%';hfill.style.height=`${Math.abs(v)*43}%`;updateReadouts();if(send&&canDrive())sendAxes();}
function heaveEvent(e){const b=heave.getBoundingClientRect();setHeave((b.top+b.height/2-e.clientY)/(b.height*.43))}
function releaseHeave(e){if(heavePointer===null||(e?.pointerId!=null&&e.pointerId!==heavePointer))return;const pointer=heavePointer;heavePointer=null;try{heave.releasePointerCapture(pointer)}catch(_){}releaseHandle(hknob);easeHeave()}
heave.addEventListener('pointerdown',e=>{if(!window.canTouchControl()||heavePointer!==null||e.button>0)return;heavePointer=e.pointerId;hknob.classList.remove('released');hknob.classList.add('pressed');cancelAnimationFrame(heaveAnim);heave.setPointerCapture(e.pointerId);heaveEvent(e);e.preventDefault()});heave.addEventListener('pointermove',e=>{if(e.pointerId===heavePointer)heaveEvent(e)});heave.addEventListener('pointerup',releaseHeave);heave.addEventListener('pointercancel',releaseHeave);heave.addEventListener('lostpointercapture',e=>{if(e.pointerId===heavePointer)releaseHeave(e)});
function easeHeave(target=0){cancelAnimationFrame(heaveAnim);const sv=control.vertical,start=performance.now();function frame(now){const p=Math.min(1,(now-start)/400),smooth=p*p*(3-2*p);setHeave(sv+(target-sv)*smooth);if(p<1)heaveAnim=requestAnimationFrame(frame)}heaveAnim=requestAnimationFrame(frame)}
window.verticalControl={setPos:value=>{cancelAnimationFrame(heaveAnim);setHeave(value)},easeBack:()=>{if(heavePointer===null)easeHeave()},getState:()=>({value:control.vertical,active:heavePointer!==null})};

function applyKeys(){if(inputMode!=='keyboard'||!canDrive()){pressedKeys.clear();return;}const turn=(pressedKeys.has('d')||pressedKeys.has('e')?1:0)-(pressedKeys.has('a')||pressedKeys.has('q')?1:0),forward=(pressedKeys.has('w')?1:0)-(pressedKeys.has('s')?1:0),vertical=(pressedKeys.has('r')?1:0)-(pressedKeys.has('f')?1:0);if(!window.joystick3D?.getState().active)window.joystick3D?.easeTo(turn,-forward);if(heavePointer===null)easeHeave(vertical)}
addEventListener('keydown',e=>{if(e.key==='F3'){e.preventDefault();if(!e.repeat&&view.action==='disarm')requestControl('disarm');return;}if(document.querySelector('dialog[open]')||/^(INPUT|SELECT|TEXTAREA)$/.test(e.target.tagName))return;if(e.key==='F2'){e.preventDefault();if(!e.repeat)startEngageHold();return;}const k=e.key.toLowerCase();if('wasdqerf'.includes(k)&&k.length===1){if(inputMode!=='keyboard'||!canDrive())return;e.preventDefault();if(e.repeat)return;if(!pressedKeys.has(k)){pressedKeys.add(k);applyKeys();}}});addEventListener('keyup',e=>{if(e.key==='F2'){e.preventDefault();cancelEngageHold(true);return;}const k=e.key.toLowerCase();if(pressedKeys.delete(k))applyKeys();});
function resetInputs(){
  controllerMotion.reset();controllerNeedCenter=true;controllerWasDriving=false;
  if(gainPointer!==null)releaseGain({pointerId:gainPointer});
  clearTimeout(axisTimer);axisTimer=0;pressedKeys.clear();cancelEngageHold(false);
  window.joystick3D?.reset();
  const pointer=heavePointer;heavePointer=null;cancelAnimationFrame(heaveAnim);
  if(pointer!==null)try{heave.releasePointerCapture(pointer)}catch(_){}
  hknob.classList.remove('pressed','released');
  control.forward=control.turn=control.vertical=0;setHeave(0,false);
  if(bridgeReady&&!demoActive)api('stop_controls',++inputSequence).catch(()=>{});
}
function focusChanged(focused){inputFocused=focused;if(!focused)resetInputs();render(vehicleSnapshot)}
addEventListener('blur',()=>focusChanged(false));
addEventListener('focus',()=>focusChanged(!document.hidden));
document.addEventListener('visibilitychange',()=>focusChanged(!document.hidden&&document.hasFocus()));
addEventListener('pagehide',()=>focusChanged(false));

function setFeedback(el,message=''){
  if(!el)return;
  el.textContent=message;el.hidden=!message;
}
function openModal(id){
  const el=typeof id==='string'?document.getElementById(id):id;
  if(!el||el.open)return;
  if(el.id==='controller-modal'&&inputConfigurationLocked()){toast('Disengage before changing joystick settings.');return}
  resetInputs();
  el._returnFocus=document.activeElement;
  if(el.id==='battery-modal')fillBatteryForm();
  if(el.id==='controller-modal')fillControllerForm();
  if(el.id==='link-modal'){
    fillLinkForm();
    $('#custom-port-status').textContent='';
    $('#custom-port-input').value='';
  }
  el.querySelectorAll('.form-feedback').forEach(feedback=>setFeedback(feedback));
  el.classList.remove('closing');
  el.showModal();
}
function closeModal(dialog){
  if(!dialog||!dialog.open||dialog.classList.contains('closing')||dialog.querySelector('[data-busy="true"]'))return;
  dialog.classList.add('closing');
  let done=false;
  const finish=()=>{
    if(done)return;
    done=true;
    dialog.removeEventListener('animationend',onEnd);
    dialog.classList.remove('closing');
    dialog.close();
    if(dialog._returnFocus?.isConnected)dialog._returnFocus.focus({preventScroll:true});
  };
  const onEnd=e=>{if(e.target===dialog)finish()};
  dialog.addEventListener('animationend',onEnd);
  setTimeout(finish,180);
}
$$('[data-open]').forEach(b=>b.onclick=()=>openModal(b.dataset.open));
$$('[data-close]').forEach(b=>b.onclick=()=>closeModal(b.closest('dialog')));
$('#link-quality').onclick=()=>openModal('link-quality-modal');
let heavyActionBusy=false;
async function requestHeavyTest(action){
  if(heavyActionBusy)return;
  heavyActionBusy=true;
  setFeedback($('#heavy-quality-error'));
  renderHeavyQuality(vehicleSnapshot.heavy_quality,vehicleSnapshot.connected,vehicleSnapshot.armed);
  try{
    const test=await api(action);
    vehicleSnapshot.heavy_quality=test;
    renderHeavyQuality(test,vehicleSnapshot.connected,vehicleSnapshot.armed);
  }catch(e){setFeedback($('#heavy-quality-error'),e.message||'Link test unavailable. Try again.')}
  finally{
    heavyActionBusy=false;
    renderHeavyQuality(vehicleSnapshot.heavy_quality,vehicleSnapshot.connected,vehicleSnapshot.armed);
  }
}
$('#heavy-quality-run').onclick=()=>requestHeavyTest('start_heavy_quality_test');
$('#heavy-quality-cancel').onclick=()=>requestHeavyTest('cancel_heavy_quality_test');
$$('dialog').forEach(d=>{
  d.addEventListener('cancel',e=>{e.preventDefault();closeModal(d)});
  d.addEventListener('click',e=>{
    const r=d.getBoundingClientRect();
    if(e.clientX<r.left||e.clientX>r.right||e.clientY<r.top||e.clientY>r.bottom)closeModal(d);
  });
});
$('#window-min').onclick=()=>api('minimize_window');$('#window-max').onclick=async()=>{const max=await api('toggle_maximize_window');document.body.classList.toggle('maximized',!!max)};$('#window-close').onclick=()=>{if(document.body.classList.contains('window-exiting'))return;document.body.classList.add('window-exiting');setTimeout(()=>api('close_window'),360)};const windowBar=$('.workspace-topbar');if(windowBar)windowBar.ondblclick=async e=>{if(!e.target.closest('button,select,input')){const max=await api('toggle_maximize_window');document.body.classList.toggle('maximized',!!max)}};
const modelInput=$('#model-input'), modelButton=$('#load-model'), rovStage=$('.rov-stage');

async function handleStlFile(file){
  if(!file)return;
  try{
    if(!file.name.toLowerCase().endsWith('.stl'))throw new Error('Choose an STL mesh (*.stl)');
    if(file.size>30*1024*1024)throw new Error('The STL is larger than 30 MB; export a lighter mesh');
    modelButton.disabled=true;
    modelButton.textContent='Loading…';
    const buffer=await file.arrayBuffer();
    const result=window.rovModel.loadBuffer(buffer,file.name);
    modelButton.textContent='Replace STL';
    toast(`Loaded ${result.name} • ${result.triangles.toLocaleString()} triangles`);
    if(bridgeReady&&window.pywebview?.api?.save_model){
      const dataUrl=await new Promise((resolve,reject)=>{
        const reader=new FileReader();
        reader.onload=()=>resolve(reader.result);
        reader.onerror=()=>reject(reader.error);
        reader.readAsDataURL(file);
      });
      api('save_model',file.name,String(dataUrl).split(',')[1]).catch(e=>console.warn(e));
    }
  }catch(error){
    toast(`STL import failed: ${error.message}`,true);
  }finally{
    modelButton.disabled=false;
    if(modelButton.textContent==='Loading…')modelButton.textContent='Load STL';
  }
}

modelButton.onclick=async()=>{
  let loaded=false;
  if(window.pywebview?.api?.choose_model){
    try{
      const model=await api('choose_model');
      if(model&&model.data){
        const res=window.rovModel.load(model);
        modelButton.textContent='Replace STL';
        toast(`Loaded ${res.name} • ${res.triangles.toLocaleString()} triangles`);
        loaded=true;
      }
    }catch(err){
      console.warn('choose_model error:', err);
    }
  }
  if(!loaded&&modelInput){
    modelInput.value='';
    modelInput.click();
  }
};

if(modelInput){
  modelInput.onchange=()=>{
    const file=modelInput.files?.[0];
    if(file)handleStlFile(file);
  };
}

if(rovStage){
  rovStage.addEventListener('dragover',e=>{e.preventDefault();e.stopPropagation();rovStage.classList.add('drag-over')});
  rovStage.addEventListener('dragleave',e=>{e.preventDefault();e.stopPropagation();rovStage.classList.remove('drag-over')});
  rovStage.addEventListener('drop',e=>{
    e.preventDefault();e.stopPropagation();rovStage.classList.remove('drag-over');
    const file=e.dataTransfer?.files?.[0];
    if(file)handleStlFile(file);
  });
}
$('#refresh').onclick=async e=>{
  const button=e.currentTarget;button.classList.remove('spinning');void button.offsetWidth;button.classList.add('spinning');setTimeout(()=>button.classList.remove('spinning'),650);
  try{
    if(typeof window.pywebview?.api?.refresh_ports!=='function')throw new Error('Desktop connection is not ready. Open the app using run.ps1.');
    populatePorts(await withTimeout(api('refresh_ports'),4000));
    if(!booted)boot();
  }catch(error){recordActivity(`Port refresh failed: ${error.message}`);toast(error.message,true)}
};
$('#connect').onclick=async()=>{
  const btn=$('#connect');
  const label=btn.querySelector('.btn-label')||btn;
  const p=$('#port');
  const port=p?p.value:'';

  if(port==='demo'||demoActive){
    resetInputs();clearTimeout(demoCommandTimer);requestSerial++;localRequest=null;commandError='';bridgeStale=false;
    if(demoActive){demoActive=false;demoState=null;render({app_state:'disconnected',connected:false,link:'DISCONNECTED',vehicle:'No heartbeat',armed:false,mode:null,status:'Demo mode disconnected',battery:null,servos:{}});toast('Demo disconnected')}
    else{demoActive=true;demoState=makeDemoState();render(demoState);toast('Demo connected — no hardware required')}
    return;
  }

  if(appState==='connecting'){
    label.textContent='Canceling…';
    try{ await api('disconnect'); }catch(_){}
    return;
  }

  if(appState!=='disconnected'){
    resetInputs();
    label.textContent='Disconnecting…';
    try{
      await api('disconnect');
      toast('Disconnected');
    }catch(e){
      toast(e.message,true);
    }
  }else{
    if(!port){
      toast('Select or enter a port to connect',true);
      return;
    }
    btn.classList.add('is-connecting');
    label.textContent='Connecting…';
    const statusEl=$('#status-text');
    recordActivity(`Connecting to ${port}…`);
    toast(`Connecting to ${port}…`);
    try{
      const confirmedState=await api('connect',port,+linkConfig.baud||57600,+linkConfig.control_hz||20);
      if(confirmedState)render(confirmedState);
      toast(confirmedState?.armed_known?'MAVLink connected':'Waiting for vehicle telemetry',!confirmedState?.armed_known);
    }catch(e){
      btn.classList.remove('is-connecting');
      label.textContent='Connect';
      toast(e.message,true);
      recordActivity(`Connection error: ${e.message}`);
    }
  }
};
const customPortBtn=$('#custom-port-btn'), customPortInput=$('#custom-port-input');
if(customPortBtn&&customPortInput){
  const applyCustomPort=()=>{
    const val=customPortInput.value.trim();
    if(!val){$('#custom-port-status').textContent='Enter a port first.';customPortInput.focus();return;}
    if(vehicleSnapshot.connected)return;
    manualPorts.set(val,{device:val,label:`Custom (${val})`});
    const p=$('#port');
    let exists=false;
    for(const opt of p.options){
      if(opt.value===val){opt.selected=true;exists=true;break;}
    }
    if(!exists){
      p.add(new Option(`Custom (${val})`, val), 0);
      p.value=val;
    }
    $('#custom-port-status').textContent=`Selected ${val}. Apply settings, then connect.`;
  };
  customPortBtn.onclick=applyCustomPort;
  customPortInput.onkeydown=e=>{if(e.key==='Enter'){e.preventDefault();applyCustomPort();}};
}
const engageButton=$('#engage');
const engageProgressLabel=engageButton?.querySelector('.engage-progress-label');
let engageHoldTimer=null,engageStart=0,engagePointer=null,completedEngagePointer=null,suppressEngageClick=false,engageVisualState='',engageTransitionTimer=null;
const ENGAGE_HOLD_MS=1400;

function applyEngageVisual(next){
  if(!engageButton)return;
  const label=({'ENGAGE':'engage','DISARM':'disengage','ENGAGING…':'engaging…','DISARMING…':'disengaging…','DISARM · ?':'disengage · ?','STATE UNKNOWN':'state unknown'})[next.label]||next.label.toLowerCase();
  // Interaction updates immediately; the short fade never gates emergency access.
  engageButton.disabled=!next.action;
  engageButton.setAttribute('aria-busy',String(next.pending));
  engageButton.setAttribute('aria-label',label);
  engageButton.title=next.action==='disarm'?'Request disarm immediately (F3)':next.action==='arm'?'Hold 1.4 seconds to engage (F2)':next.message;
  const key=`${next.label}/${next.tone}`;
  if(engageVisualState===key)return;
  const previous=engageVisualState;engageVisualState=key;
  clearTimeout(engageTransitionTimer);
  engageButton.classList.remove('arm','danger','subtle','charged','pending');
  engageButton.classList.add(next.tone==='danger'?'danger':next.tone==='pending'?'pending':'arm');
  engageButton.style.setProperty('--engage-progress',next.pending?'100%':'0%');
  $('#engage-label').textContent=label;
  if(engageProgressLabel)engageProgressLabel.textContent=label;
  const sheen=engageButton.querySelector('.engage-sheen-label');if(sheen)sheen.textContent=label;
  if(previous){
    engageButton.classList.remove('state-transition');void engageButton.offsetWidth;
    engageButton.classList.add('state-transition');
    engageTransitionTimer=setTimeout(()=>engageButton.classList.remove('state-transition'),240);
  }
}
function completeEngage(){
  const pointer=engagePointer;cancelAnimationFrame(engageHoldTimer);engageHoldTimer=null;engageStart=0;engagePointer=null;completedEngagePointer=typeof pointer==='number'?pointer:null;engageButton.classList.remove('charging');engageButton.classList.add('charged');engageButton.style.setProperty('--engage-progress','100%');
  requestControl('arm');
}
async function requestControl(name){
  if((name==='arm'&&view.action!=='arm')||(name==='disarm'&&view.action!=='disarm'))return;
  const id=++requestSerial;
  commandError='';localRequest={name,deadline:performance.now()+6000,sent:false};
  recordActivity(name==='arm'?'Engage requested':'Disengage requested');
  resetInputs();render(vehicleSnapshot);
  try{
    if(demoActive){
      // Separate simulated request and simulated heartbeat, just like the real UI.
      clearTimeout(demoCommandTimer);
      updateDemo({pending_command:name,command_error:''});
      demoCommandTimer=setTimeout(()=>{
        if(!demoActive||id!==requestSerial)return;
        localRequest=null;
        updateDemo({pending_command:null,armed:name==='arm',armed_known:true,
          app_state:name==='arm'?'armed':'connected_disarmed',
          vehicle:`DEMO • ${name==='arm'?'ARMED':'DISARMED'}`,status:`Demo: ${name} confirmed`});
      },650);
    }else{
      await api('command',name,++inputSequence,Date.now()+2000);
      if(id===requestSerial&&localRequest)localRequest.sent=true;
      // Only poll snapshots may confirm state; a send result is not confirmation.
    }
  }catch(error){
    if(id!==requestSerial)return;
    localRequest=null;commandError=`${name==='arm'?'Engage':'Disarm'} request failed: ${error.message}`;
    render(vehicleSnapshot);toast(commandError,true);
  }
}
function updateEngageProgress(now){
  if(!engageStart||view.action!=='arm'||!inputFocused)return cancelEngageHold(false);
  const progress=Math.min(1,(now-engageStart)/ENGAGE_HOLD_MS);engageButton.style.setProperty('--engage-progress',`${progress*100}%`);if(progress>=1)return void completeEngage();engageHoldTimer=requestAnimationFrame(updateEngageProgress);
}
function startEngageHold(e){
  if(view.action!=='arm'||!inputFocused||engageStart)return;
  if(e&&e.button!==undefined&&e.button!==0)return;
  engagePointer=e?.pointerId??'keyboard';engageStart=performance.now();engageButton.classList.add('charging');engageButton.style.setProperty('--engage-progress','0%');
  syncInputModeControls();
  if(e?.pointerId!=null)engageButton.setPointerCapture(e.pointerId);
  engageHoldTimer=requestAnimationFrame(updateEngageProgress);
}
function cancelEngageHold(showHint=true){
  if(!engageStart)return;
  const elapsed=performance.now()-engageStart,pointer=engagePointer;cancelAnimationFrame(engageHoldTimer);engageHoldTimer=null;engageStart=0;engagePointer=null;engageButton.classList.remove('charging');engageButton.classList.add('canceling');engageButton.style.setProperty('--engage-progress','0%');setTimeout(()=>engageButton.classList.remove('canceling'),280);if(typeof pointer==='number')try{engageButton.releasePointerCapture(pointer)}catch(_){}if(showHint&&elapsed>80)toast('Engagement canceled');
  syncInputModeControls();
}

if(engageButton){
  engageButton.addEventListener('pointerdown',startEngageHold);
  engageButton.addEventListener('pointerup',e=>{if(e.pointerId===completedEngagePointer){completedEngagePointer=null;try{engageButton.releasePointerCapture(e.pointerId)}catch(_){}suppressEngageClick=true;setTimeout(()=>suppressEngageClick=false,0);return}if(e.pointerId===engagePointer)cancelEngageHold(true)});
  engageButton.addEventListener('pointerleave',e=>{if(e.pointerId===engagePointer)cancelEngageHold(true)});
  engageButton.addEventListener('pointercancel',e=>{if(e.pointerId===completedEngagePointer)completedEngagePointer=null;if(e.pointerId===engagePointer)cancelEngageHold(false)});
  engageButton.addEventListener('lostpointercapture',e=>{if(e.pointerId===engagePointer)cancelEngageHold(false);if(e.pointerId===completedEngagePointer)completedEngagePointer=null});
  engageButton.addEventListener('pointermove',e=>{if(e.pointerId!==engagePointer)return;const r=engageButton.getBoundingClientRect();if(e.clientX<r.left||e.clientX>r.right||e.clientY<r.top||e.clientY>r.bottom)cancelEngageHold(false)});
  engageButton.addEventListener('contextmenu',e=>e.preventDefault());

  engageButton.onclick=()=>{
    if(suppressEngageClick){suppressEngageClick=false;return}
    if(view.action==='disarm')requestControl('disarm');
  };
}

$('#logs').onclick=()=>api('open_logs');
const consoleDock=$('#console-dock'),consoleRx=$('#console-rx-output'),consoleTx=$('#console-tx-output');
let consoleRefreshBusy=false,consolePaused=false,consoleCache={rx:[],tx:[]},consoleSignature='',consoleOpen=false,consoleCloseTimer=0;
const consolePulseTimers={};
function pulseConsole(side){
  const dot=$('.'+side+'-dot');
  clearTimeout(consolePulseTimers[side]);dot.classList.add('lit');
  consolePulseTimers[side]=setTimeout(()=>dot.classList.remove('lit'),260);
}
function renderConsole(){
  const filter=$('#console-filter').value,signature=filter+JSON.stringify(consoleCache);
  if(signature===consoleSignature)return;
  consoleSignature=signature;ConsoleView.render(consoleRx,consoleCache.rx||[],filter);ConsoleView.render(consoleTx,consoleCache.tx||[],filter);
}
function setConsoleOpen(open){
  consoleOpen=open;clearTimeout(consoleCloseTimer);consoleDock.classList.toggle('closing',!open);
  if(open){consoleDock.hidden=false;$('.app-shell').classList.add('console-open')}
  else consoleCloseTimer=setTimeout(()=>{consoleDock.hidden=true;$('.app-shell').classList.remove('console-open')},180);
  $('#console').setAttribute('aria-expanded',String(open));
  if(open)refreshConsole();else $('#console').focus({preventScroll:true});
}
$('#console').setAttribute('aria-controls','console-dock');
$('#console').setAttribute('aria-expanded','false');
$('#console').onclick=()=>setConsoleOpen(!consoleOpen);
$('#console-close').onclick=()=>setConsoleOpen(false);
$('#console-filter').onchange=renderConsole;
$('#console-pause').onclick=()=>{
  consolePaused=!consolePaused;
  $('#console-pause').textContent=consolePaused?'Resume':'Pause';
  $('#console-pause').setAttribute('aria-pressed',String(consolePaused));
  $('#console-state').textContent=consolePaused?'Paused':'';
  $('#console-state').hidden=!consolePaused;
  if(!consolePaused)refreshConsole();
};
async function refreshConsole(){
  if(!consoleOpen||!bridgeReady||consoleRefreshBusy||consolePaused)return;
  consoleRefreshBusy=true;
  try{
    const sides=await withTimeout(api('read_console',150),1500);
    if(consolePaused||!consoleOpen)return;
    const filter=$('#console-filter').value;
    for(const side of ['rx','tx']){
      const previous=new Set(consoleCache[side]||[]);
      if((sides[side]||[]).some(line=>!previous.has(line)&&(filter==='all'||!ConsoleView.parse(line).quiet)))pulseConsole(side);
    }
    consoleCache=sides;renderConsole();
    $('#console-state').textContent='';$('#console-state').hidden=true;
  }catch(error){if(consoleOpen){$('#console-state').hidden=false;$('#console-state').textContent='Unavailable: '+error.message}}
  finally{consoleRefreshBusy=false}
}
setInterval(refreshConsole,750);
function setGain(value){const gain=$('#gain');gain.value=Math.max(+gain.min,Math.min(+gain.max,value));$('#gain-value').textContent=`${gain.value}%`;if(bridgeReady)api('set_gain',+gain.value)}
$('#gain').oninput=e=>setGain(+e.target.value);$('#gain-down').onclick=()=>setGain(+$('#gain').value-5);$('#gain-up').onclick=()=>setGain(+$('#gain').value+5);
// Explicit pointer ownership makes the full range rail a reliable touch target
// in the embedded window, without depending on native range drag defaults.
const gainSlider=$('#gain');let gainPointer=null;
function gainFromPointer(e){const r=gainSlider.getBoundingClientRect(),fraction=Math.max(0,Math.min(1,(e.clientX-r.left-9)/Math.max(1,r.width-18)));setGain(Math.round(+gainSlider.min+fraction*(+gainSlider.max-+gainSlider.min)))}
function releaseGain(e){if(e.pointerId!==gainPointer)return;gainPointer=null;try{gainSlider.releasePointerCapture(e.pointerId)}catch(_){}}
gainSlider.addEventListener('pointerdown',e=>{if(gainPointer!==null||e.button>0)return;gainPointer=e.pointerId;gainSlider.setPointerCapture(e.pointerId);gainFromPointer(e);e.preventDefault()});
gainSlider.addEventListener('pointermove',e=>{if(e.pointerId===gainPointer)gainFromPointer(e)});
['pointerup','pointercancel','lostpointercapture'].forEach(type=>gainSlider.addEventListener(type,releaseGain));
gainSlider.addEventListener('keydown',e=>{const delta={ArrowRight:1,ArrowUp:1,ArrowLeft:-1,ArrowDown:-1}[e.key];if(delta){e.preventDefault();setGain(+gainSlider.value+delta)}else if(e.key==='Home'||e.key==='End'){e.preventDefault();setGain(+(e.key==='Home'?gainSlider.min:gainSlider.max))}});
async function saveSettings(form,method,commit,message){
  if(form.dataset.busy==='true'||!form.reportValidity())return;
  const data=Object.fromEntries(new FormData(form));
  const button=form.querySelector('[type="submit"]'),label=button.textContent;
  const disabled=new Map([...form.querySelectorAll('input,select,button')].map(el=>[el,el.disabled]));
  form.dataset.busy='true';disabled.forEach((_,el)=>el.disabled=true);button.textContent='Saving…';
  setFeedback(form.querySelector('.form-feedback'));
  let saved=false;
  try{commit(await api(method,data));saved=true;toast(message)}
  catch(error){setFeedback(form.querySelector('.form-feedback'),error.message||'Could not save settings. Try again.')}
  finally{
    delete form.dataset.busy;disabled.forEach((value,el)=>el.disabled=value);button.textContent=label;
    if(saved)closeModal(form.closest('dialog'));
  }
}
$('#battery-form').onsubmit=e=>{e.preventDefault();saveSettings(e.target,'save_battery',value=>batteryConfig=value,'Battery settings saved')};
function fillBatteryForm(){for(const [k,v] of Object.entries(batteryConfig)){const el=$(`#battery-form [name=${k}]`);if(el)el.value=v}}
$('#link-form').onsubmit=e=>{e.preventDefault();saveSettings(e.target,'save_link_settings',value=>linkConfig=value,'Link settings applied')};
function fillLinkForm(){for(const [k,v] of Object.entries(linkConfig)){const el=$(`#link-form [name=${k}]`);if(el)el.value=v}}
const motorEdits=new Map();
async function requestMotorEdit(servo,kind,value){
  if(motorEdits.has(servo))return;
  const s=vehicleSnapshot.servos?.[String(servo)]||{};
  const expected=kind==='function'?(value===0?0:value<=8?32+value:73+value):-s.direction;
  setFeedback($('#motor-feedback'));
  if(demoActive){
    if(kind==='function')Object.assign(s,{function:expected,motor:value||null,direction:value?1:null});
    else s.direction=expected;
    servoSignature='';renderMotors(demoState.servos);toast('Demo motor updated');return;
  }
  motorEdits.set(servo,{kind,expected,started:performance.now()});
  servoSignature='';renderMotors(vehicleSnapshot.servos||{});
  try{
    await api(kind==='function'?'set_servo_function':'reverse_motor',servo,...(kind==='function'?[value]:[]));
  }catch(error){
    motorEdits.delete(servo);
    setFeedback($('#motor-feedback'),error.message||'Motor change failed. Try again.');
    servoSignature='';renderMotors(vehicleSnapshot.servos||{});
  }
}
function renderMotors(servos){
  for(const [servo,edit] of motorEdits){
    const s=servos[String(servo)]||{};
    if((edit.kind==='function'?s.function:s.direction)===edit.expected){
      motorEdits.delete(servo);toast(`SERVO${servo} change confirmed`);
    }else if(!vehicleSnapshot.connected||performance.now()-edit.started>8000){
      motorEdits.delete(servo);
      setFeedback($('#motor-feedback'),`SERVO${servo}: confirmation not received. Check the reported assignment before retrying.`);
    }
  }
  const editable=!!vehicleSnapshot.connected&&!vehicleSnapshot.armed&&(demoActive||view.known);
  const assigned=Object.values(servos).filter(s=>s.motor).length;
  $('#motor-status').textContent=vehicleSnapshot.armed?'Disarm to change assignments or direction.':!vehicleSnapshot.connected?'Connect to read motor outputs.':assigned?`${assigned} motor${assigned===1?'':'s'} assigned · changes wait for vehicle confirmation.`:'Reading motor assignments…';
  const signature=JSON.stringify([servos,editable,[...motorEdits]]);
  if(signature===servoSignature)return;
  servoSignature=signature;
  const list=$('#motor-list'),expanded=list.querySelector('details')?.open;
  list.replaceChildren();
  const other=document.createElement('details');other.className='motor-other';other.open=!!expanded;
  const summary=document.createElement('summary');summary.textContent=`Other outputs (${16-assigned})`;other.append(summary);
  for(let i=1;i<=16;i++){
    const s=servos[String(i)]||{},pending=motorEdits.get(i),row=document.createElement('div');row.className='motor-row';
    row.innerHTML=`<strong>SERVO${i}</strong><select aria-label="SERVO${i} assignment"></select><span></span><button type="button" class="button subtle">Reverse</button>`;
    const select=row.querySelector('select');
    select.add(new Option(s.function==null?'Reading…':'Unassigned','0'));
    for(let motor=1;motor<=12;motor++)select.add(new Option(`Motor ${motor}`,String(motor)));
    select.value=String(s.motor||0);
    select.disabled=!editable||!!pending||s.function==null;
    select.onchange=e=>requestMotorEdit(i,'function',+e.target.value);
    row.querySelector('span').textContent=pending?'Confirming…':s.direction==null?'—':s.direction===-1?'Reversed':'Normal';
    const reverse=row.querySelector('button');reverse.disabled=!editable||!!pending||!s.motor||s.direction==null;
    reverse.setAttribute('aria-label',`Reverse SERVO${i} motor direction`);
    reverse.onclick=()=>requestMotorEdit(i,'direction');
    (s.motor?list:other).append(row);
  }
  if(!assigned){const empty=document.createElement('p');empty.className='note';empty.textContent='Assigned motors will appear here.';list.append(empty)}
  if(assigned<16)list.append(other);
}
function renderHeavyQuality(test,connected,armed){
  const status=$('#heavy-quality-status'),results=$('#heavy-quality-results'),run=$('#heavy-quality-run'),stop=$('#heavy-quality-cancel');
  if(!status||!results||!run||!stop)return;
  const quality=demoActive?null:vehicleSnapshot.link_quality;
  $('#quality-detail-rtt').textContent=quality?.rtt_median_ms==null?'—':`${Math.round(quality.rtt_median_ms)} ms`;
  $('#quality-detail-loss').textContent=quality?.probe_loss_percent==null?'—':`${quality.probe_loss_percent.toFixed(1)}%`;
  $('#quality-detail-downlink').textContent=quality?.rx_sequence_loss_percent==null?'—':`${quality.rx_sequence_loss_percent.toFixed(1)}%`;
  const running=!!test?.running;
  status.textContent=running?`${test.status} · ${test.replies||0}/${test.sent||0} replies`:(test?.status==='Complete'?'Test complete. Results below.':test?.status==='Cancelled'?'Test stopped. Partial results below.':demoActive?'Demo has no hardware link to measure.':!connected?'Connect to run a test.':armed?'Disarm to run a test.':'Ready to test.');
  run.disabled=heavyActionBusy||running||!connected||armed||demoActive;
  run.textContent=!connected?'Connect to run test':armed?'Disarm to run test':demoActive?'Unavailable in demo':test?.status==='Complete'?'Run again':'Run heavy test';
  stop.hidden=!running;
  stop.disabled=heavyActionBusy;
  results.replaceChildren();
  for(const row of test?.results||[]){
    const line=document.createElement('div');line.className='heavy-result-row';
    const rate=document.createElement('strong');rate.textContent=`${row.rate_hz} Hz`;
    const stats=document.createElement('span');
    const loss=row.loss_percent==null?'—':`${row.loss_percent.toFixed(1)}% loss`;
    const rtt=row.median_rtt_ms==null?'—':`${row.median_rtt_ms.toFixed(0)} ms median / ${row.p95_rtt_ms.toFixed(0)} ms p95`;
    stats.textContent=`${row.replies}/${row.sent} replies · ${loss} · ${rtt}`;
    line.append(rate,stats);results.append(line);
  }
}
function render(s,confirmed=false){
  vehicleSnapshot=s;
  if(confirmed&&localRequest?.sent && (s.pending_command===localRequest.name || s.command_error ||
      (s.armed_known&&s.armed===(localRequest.name==='arm')))) localRequest=null;
  const previous=view;
  view=ControlState.present(s,{stale:bridgeStale,focused:inputFocused,pending:localRequest?.name,error:commandError});
  syncInputModeControls();
  if((previous.drive&&!view.drive)||(previous.action==='arm'&&view.action!=='arm'))resetInputs();
  appState=bridgeStale&&s.connected?'link_degraded':s.app_state||'disconnected';
  renderHeavyQuality(s.heavy_quality,s.connected,s.armed);
  document.body.dataset.appState=appState;
  document.body.dataset.controlsEnabled=String(view.drive);
  document.body.dataset.telemetryStale=String(!view.known||!!s.battery_stale);
  $('#port').disabled=!!s.connected;
  $('#custom-port-input').disabled=!!s.connected||$('#link-form').dataset.busy==='true';
  $('#custom-port-btn').disabled=!!s.connected||$('#link-form').dataset.busy==='true';
  const isOnline=(appState==='connected_disarmed'||appState==='armed');
  const connectBtn=$('#connect');
  const connectLabel=connectBtn?connectBtn.querySelector('.btn-label'):null;
  if(connectBtn){
    if(appState==='connecting'){
      if(connectLabel)connectLabel.textContent='Connecting…';
      else connectBtn.textContent='Connecting…';
      connectBtn.classList.add('is-connecting');
      connectBtn.classList.remove('is-connected');
    }else if(appState!=='disconnected'){
      if(connectLabel)connectLabel.textContent='Disconnect';
      else connectBtn.textContent='Disconnect';
      connectBtn.classList.remove('is-connecting');
      connectBtn.classList.add('is-connected');
    }else{
      if(connectLabel)connectLabel.textContent='Connect';
      else connectBtn.textContent='Connect';
      connectBtn.classList.remove('is-connecting', 'is-connected');
    }
  }
  const engageBtn=$('#engage');
  const engageLabel=$('#engage-label');
  if(engageBtn&&engageLabel){
    applyEngageVisual(view);
  }
  const controlStatus=$('#control-status');
  controlStatus.textContent=view.message;
  controlStatus.classList.toggle('is-error',view.error);
  controlStatus.hidden=!(view.pending||view.error||(view.known&&s.armed&&!inputFocused));
  const motorBtn=$('[data-open="motors-modal"]');
  if(motorBtn)motorBtn.disabled=(!isOnline);

  const confirmedCommand=previous.pending&&!view.pending&&view.known&&!view.error;
  const reported=commandError||s.command_error||((!view.known&&s.connected&&appState!=='connecting')?'Telemetry stale — vehicle state unknown':s.status);
  if(reported&&reported!==lastReportedStatus){lastReportedStatus=reported;if(!confirmedCommand)recordActivity(reported)}
  if(confirmedCommand){
    recordActivity(s.armed?'Engage confirmed':'Disengage confirmed');
  }
  updateReadouts();
  const b=s.battery;
  if(b){
    $('#battery-title').textContent=`${b.voltage.toFixed(2)} V`;
    $('#battery-percent').textContent=`${Math.round(b.percent)}%`;
    $('.battery-card').dataset.stale=String(!view.known||!!s.battery_stale);
    $('.battery-card').title=`Estimated charge from voltage · ${b.cells}S${!view.known||s.battery_stale?' · stale reading':''} · Battery settings`;
    $('#battery-fill').style.width=`${b.percent}%`;
    $('#battery-fill').style.background=b.low?'var(--battery-low)':'var(--battery-charge)';
    $('.battery-card').dataset.low=String(!!b.low);
  }else{
    $('#battery-title').textContent='No voltage';
    $('#battery-percent').textContent='—';
    $('.battery-card').dataset.stale='false';
    $('.battery-card').title='Waiting for battery voltage · Battery settings';
    $('#battery-fill').style.width='0';
    $('.battery-card').dataset.low='false';
  }
  const quality=s.link_quality,qualityCard=$('#link-quality');
  if(qualityCard){
    if(demoActive){
      qualityCard.dataset.grade='offline';
      $('#link-quality-grade').textContent='Demo';
      $('#link-quality-roundtrip').textContent='no hardware link test';
      $('#link-quality-downlink').textContent='';
      renderMotors(s.servos||{});
      return;
    }
    const grade=quality?.grade||(s.connected?'testing':'offline');
    qualityCard.dataset.grade=grade;
    $('#link-quality-grade').textContent=grade.charAt(0).toUpperCase()+grade.slice(1);
    if(quality&&quality.probe_samples){
      const percent=value=>value==null?'—':`${value.toFixed(1)}%`;
      const median=quality.rtt_median_ms==null?'—':`${Math.round(quality.rtt_median_ms)} ms`;
      const p95=quality.rtt_p95_ms==null?'—':`${Math.round(quality.rtt_p95_ms)} ms`;
      $('#link-quality-roundtrip').textContent=`round trip ${median} / ${p95} p95 • loss ${percent(quality.probe_loss_percent)}`;
      const downLoss=percent(quality.rx_sequence_loss_percent);
      const badFrames=quality.rx_corrupt_frames_20s??0;
      const badBytes=quality.rx_corrupt_bytes_20s??0;
      const age=quality.heartbeat_age_s==null?'—':`${quality.heartbeat_age_s.toFixed(1)} s`;
      $('#link-quality-downlink').textContent=`FC → PC loss ${downLoss} • ${badFrames} bad frames (${badBytes} B) • heartbeat ${age}`;
      if(quality.probe_samples<10||quality.rx_packets_30s<10){
        $('#link-quality-grade').textContent=`Testing ${Math.min(quality.probe_samples,quality.rx_packets_30s)}/10`;
      }
    }else{
      $('#link-quality-roundtrip').textContent=s.connected?'testing round trip…':'waiting for connection';
      $('#link-quality-downlink').textContent='';
    }
  }
  renderMotors(s.servos||{});
}

function markBridgeStale(){
  if(demoActive||bridgeStale)return;
  bridgeStale=true;resetInputs();render(vehicleSnapshot);
}
setInterval(()=>{
  const now=performance.now();
  if(now-lastSafetyTick>750)resetInputs();
  lastSafetyTick=now;
  if(!demoActive&&bridgeReady&&vehicleSnapshot.connected&&performance.now()-lastBridgeAt>1500)markBridgeStale();
  if(localRequest&&performance.now()>localRequest.deadline){
    commandError=`${localRequest.name==='arm'?'Engage':'Disarm'} confirmation timed out. Check the vehicle state.`;
    localRequest=null;render(vehicleSnapshot);
  }
},100);
async function poll(){
  if(!bridgeReady)return;
  if(!demoActive)try{
    const snapshot=await withTimeout(api('poll'));
    if(!demoActive){lastBridgeAt=performance.now();bridgeStale=false;render(snapshot,true)}
  }catch(e){markBridgeStale()}
  setTimeout(poll,250);
}
let modelLoadPromise=null;
async function loadDefaultModel(){
  if(modelLoadPromise)return modelLoadPromise;
  modelLoadPromise=(async()=>{
    const statusEl=$('#model-status');

    // 1. Direct high-speed HTTP fetch (instant, ~20ms)
    for(const url of [
      '/model.stl',
      '/model',
      '/runtime/vehicle_model.stl',
      '/assets/Main%20Assembly%20V1%20(2).stl',
      '../runtime/vehicle_model.stl',
      '../assets/Main%20Assembly%20V1%20(2).stl'
    ]){
      try{
        const res=await fetch(url);
        if(res.ok){
          if(statusEl)statusEl.textContent='Loading mesh…';
          const buf=await res.arrayBuffer();
          if(window.rovModel){
            const result=window.rovModel.loadBuffer(buf,'Main Assembly V1 (2).stl');
            $('#load-model').textContent='Replace STL';
            console.log('[Direct Fetch] Model loaded:', result);
            return true;
          }
        }
      }catch(err){
        console.warn(`[Direct Fetch] ${url} failed:`, err);
      }
    }

    // 2. Python Bridge Chunked Stream (fallback)
    if(window.pywebview?.api?.get_saved_model_info){
      try{
        const info=await api('get_saved_model_info');
        if(info&&info.size){
          const total=info.size, chunk=262144;
          const bytes=new Uint8Array(total);
          let loaded=0;
          if(statusEl){
            statusEl.className='model-status';
            statusEl.textContent=`Streaming ${info.name} (0%)…`;
          }
          while(loaded<total){
            const reqSize=Math.min(chunk,total-loaded);
            const resp=await api('read_saved_model_chunk',loaded,reqSize);
            const part=atob(resp.data);
            for(let i=0;i<part.length;i++)bytes[loaded+i]=part.charCodeAt(i);
            loaded+=part.length;
            const pct=Math.round((loaded/total)*100);
            if(statusEl)statusEl.textContent=`Streaming ${pct}% (${(loaded/(1024*1024)).toFixed(1)}MB)…`;
            if(loaded%(chunk*4)===0)await new Promise(r=>setTimeout(r,0));
          }
          if(window.rovModel){
            const res=window.rovModel.loadBuffer(bytes.buffer,info.name);
            $('#load-model').textContent='Replace STL';
            return true;
          }
        }
      }catch(e){
        console.warn('[Bridge Stream] Failed:', e);
        if(statusEl){
          statusEl.className='model-status error';
          statusEl.textContent=`Bridge Error: ${e.message}`;
        }
      }
    }
    return false;
  })();
  return modelLoadPromise;
}

let booted=false,booting=false,bootRetry=0,portRefreshTimer=0;
function hasDesktopApi(){return ['initial_state','refresh_ports','poll'].every(name=>typeof window.pywebview?.api?.[name]==='function')}
async function boot(){
  if(booted||booting||!hasDesktopApi())return;
  booting=true;clearTimeout(bootRetry);
  try{
    // OS port discovery must not depend on model/config initialization succeeding.
    populatePorts(await withTimeout(api('refresh_ports'),4000));
    const init=await withTimeout(api('initial_state'),4000);
    batteryConfig=init.battery_config||{};
    linkConfig=init.link_config||{};
    populatePorts(init.ports);
    fillBatteryForm();
    fillLinkForm();
    bridgeReady=true;booted=true;lastBridgeAt=performance.now();
    if(!demoActive)render(init.state);
    poll();
    // Populate the serial selector before starting the optional model load.
    // A large cached mesh must never delay an operator seeing USB COM ports.
    loadDefaultModel();
    if(!portRefreshTimer)portRefreshTimer=setInterval(async()=>{
      if(appState==='disconnected'||demoActive){
        try{populatePorts(await withTimeout(api('refresh_ports'),1500))}
        catch(error){recordActivity(`Port scan failed: ${error.message}`)}
      }
    },2000);
  }catch(e){
    booted=false;bridgeReady=false;
    recordActivity(`Desktop startup failed; retrying: ${e.message}`);
    toast(`Python bridge: ${e.message}`,true);
    bootRetry=setTimeout(boot,1000);
  }finally{
    booting=false;
  }
}
function waitForBridge(){
  if(booted)return;
  if(hasDesktopApi())boot();
  setTimeout(waitForBridge,250);
}
addEventListener('pywebviewready',boot);
render(vehicleSnapshot);
if(document.readyState==='loading'){
  addEventListener('DOMContentLoaded',()=>{loadDefaultModel();waitForBridge()});
}else{
  loadDefaultModel();
  waitForBridge();
}


requestAnimationFrame(pollController);