/* global uPlot */
'use strict';

// ════════════════════════════════════════════════════════════════════
// State
// ════════════════════════════════════════════════════════════════════

const MAX_TRACE_PTS = 100000;
const COLORS = [
  '#89b4fa','#f38ba8','#a6e3a1','#fab387','#f9e2af',
  '#cba6f7','#89dceb','#b4befe','#eba0ac','#94e2d5'
];

let ws = null;
let marteConnected = false;

// Signal registry: id(number) → {id, name, type, elements, dimensions, names:[]}
let signalsById = {};
// name → meta (same objects, multiple name entries per signal for array elems)
let signalsByName = {};

// Trace data: signalName → {ts:[], vals:[], lastVal:0, color:''}
let traceData = {};
// Set of names currently being traced
let tracedSet = new Set();
// Forced: name → value string
let forcedSignals = {};
// Breakpoints: name → {op, threshold}
let breakpoints = {};
// Thread list from TREE
let threads = [];
// All object paths (for autocomplete)
let allObjects = [];

// Plots: [{id, container, chart, series:[{name, color, gain, offset}], maxPts, follow, dirty}]
let plots = [];
let plotSeq = 0;

// Logs
let logs = [];
const MAX_LOGS = 2000;
let logDirty = false;

// Step status
let stepStatus = null; // {paused, gam, remaining, thread}
let stepPollTimer = null;

// Pending unforce target
let unforceTarget = '';

// UDP stats
let udpPackets = 0, udpDropped = 0;

// ════════════════════════════════════════════════════════════════════
// WebSocket
// ════════════════════════════════════════════════════════════════════

function connectWS() {
  const proto = location.protocol === 'https:' ? 'wss:' : 'ws:';
  ws = new WebSocket(proto + '//' + location.host + '/ws');
  ws.onopen    = () => { appendLog('sys','INFO','WebSocket connected to server'); };
  ws.onclose   = () => { appendLog('sys','WARNING','WebSocket disconnected — reconnecting…'); setTimeout(connectWS, 2000); };
  ws.onerror   = () => {};
  ws.onmessage = (e) => handleMsg(JSON.parse(e.data));
}

function sendWS(obj) {
  if (ws && ws.readyState === WebSocket.OPEN) ws.send(JSON.stringify(obj));
}
function sendCmd(cmd) { sendWS({type:'cmd', data:{cmd}}); }

// ════════════════════════════════════════════════════════════════════
// Message handlers
// ════════════════════════════════════════════════════════════════════

function handleMsg(msg) {
  switch (msg.type) {
    case 'connected':    onMarteConnected(); break;
    case 'disconnected': onMarteDisconnected(); break;
    case 'signal_cache': onSignalCache(msg); break;
    case 'response':     onResponse(msg); break;
    case 'text_line':    onTextLine(msg.data); break;
    case 'telemetry':    onTelemetry(msg); break;
    case 'log':          onLog(msg); break;
    case 'service_config': onServiceConfig(msg); break;
    case 'udp_stats':    onUdpStats(msg); break;
  }
}

function onMarteConnected() {
  marteConnected = true;
  document.getElementById('conn-status').classList.add('ok');
  document.getElementById('btn-connect').textContent = 'Disconnect';
  appendLog('sys','INFO','Connected to MARTe2');
  // Auto-discover
  sendCmd('DISCOVER');
  sendCmd('TREE');
  // Start polling step status
  startStepPoll();
}

function onMarteDisconnected() {
  marteConnected = false;
  document.getElementById('conn-status').classList.remove('ok');
  document.getElementById('btn-connect').textContent = 'Connect';
  appendLog('sys','WARNING','Disconnected from MARTe2');
  stopStepPoll();
}

function onSignalCache(msg) {
  // Server sends cached signal list when a new browser connects mid-session
  if (msg.signals) processDiscovery(msg.signals);
}

function onResponse(msg) {
  try {
    const data = msg.data ? JSON.parse(msg.data) : null;
    switch (msg.tag) {
      case 'DISCOVER': if (data) processDiscovery(data.Signals || []); break;
      case 'TREE':     if (data) processTree(data); break;
      case 'INFO':     showInfo(msg.tag, msg.data); break;
      case 'CONFIG':   showInfo('CONFIG', msg.data); break;
      case 'STEP_STATUS': processStepStatus(data); break;
      case 'VALUE':    processValue(data); break;
    }
  } catch(e) {
    // non-JSON responses (TRACE, FORCE, etc.) — silently ignore
  }
}

function onTextLine(line) {
  if (line.startsWith('OK ')) return; // handled by response handler
  appendLog('sys','DEBUG', line);
}

function onLog(msg) {
  // Normalise level names from MARTe2
  let lv = msg.level;
  if (lv === 'Information') lv = 'INFO';
  else if (lv === 'Warning') lv = 'WARNING';
  else if (lv === 'Debug') lv = 'DEBUG';
  else if (lv === 'FatalError' || lv === 'ParametersError' || lv === 'OSError') lv = 'ERROR';
  appendLog(msg.time, lv, msg.message);
}

function onServiceConfig(msg) {
  appendLog('sys','INFO',`ServiceConfig: UDP=${msg.udp_port} LOG=${msg.log_port}`);
}

function onUdpStats(msg) {
  udpPackets = msg.packets;
  udpDropped = msg.dropped;
  document.getElementById('udp-stats').textContent =
    `${udpPackets} pkts${udpDropped>0?' ⚠'+udpDropped+' drop':''}`;
}

function onTelemetry(msg) {
  if (!msg.signals) return;
  for (const s of msg.signals) {
    const names = s.names || [];
    const vals = s.values || [];
    for (let e = 0; e < vals.length; e++) {
      const n = vals.length > 1 ? `${names[0]}[${e}]` : (names[0] || '');
      if (!n || !tracedSet.has(n)) continue;
      let td = traceData[n];
      if (!td) {
        td = {ts:[], vals:[], lastVal:0, color: nextColor()};
        traceData[n] = td;
      }
      td.ts.push(s.ts);
      td.vals.push(vals[e]);
      td.lastVal = vals[e];
      // Trim to max points
      if (td.ts.length > MAX_TRACE_PTS) {
        const trim = td.ts.length - MAX_TRACE_PTS;
        td.ts.splice(0, trim);
        td.vals.splice(0, trim);
      }
    }
    // Mark plots dirty
    for (const p of plots) {
      for (const sr of p.series) {
        if (names.includes(sr.name) || (vals.length>1 && names.length>0 &&
            p.series.some(x => x.name.startsWith(names[0])))) {
          p.dirty = true;
          break;
        }
      }
    }
  }
  // Update only the value spans — never rebuild the DOM here
  updateTracedValues();
}

// ════════════════════════════════════════════════════════════════════
// Discovery
// ════════════════════════════════════════════════════════════════════

function processDiscovery(sigs) {
  signalsById = {};
  signalsByName = {};
  for (const s of sigs) {
    const el = s.elements || 1;
    const meta = {id:s.id, name:s.name, type:s.type||'', elements:el, dimensions:s.dimensions||0, names:[s.name]};
    signalsById[s.id] = meta;
    signalsByName[s.name] = meta;
    // Array element names
    if (el > 1) {
      for (let i=0; i<el; i++) signalsByName[`${s.name}[${i}]`] = meta;
    }
  }
  updateSignalAutocomplete();
  appendLog('sys','INFO',`Discovered ${sigs.length} signals`);
}

function updateSignalAutocomplete() {
  const names = Object.keys(signalsByName).filter(n=>!n.includes('['));
  ['force-sig-list','break-sig-list'].forEach(id=>{
    const dl = document.getElementById(id);
    dl.innerHTML = names.map(n=>`<option value="${esc(n)}">`).join('');
  });
}

// ════════════════════════════════════════════════════════════════════
// Tree
// ════════════════════════════════════════════════════════════════════

function processTree(root) {
  threads = [];
  allObjects = [];
  const body = document.getElementById('tree-body');
  body.innerHTML = '';
  if (root.Name === 'Root' && root.Children) {
    for (const child of root.Children) body.appendChild(buildTreeNode(child, ''));
  } else {
    body.appendChild(buildTreeNode(root, ''));
  }
  // Populate thread selects
  ['step-thread','step-thread-list','step-thread-inp'].forEach(id=>{
    const el = document.getElementById(id);
    if (!el) return;
    if (el.tagName === 'SELECT') {
      el.innerHTML = '<option value="">— all threads —</option>' +
        threads.map(t=>`<option value="${esc(t)}">${esc(t)}</option>`).join('');
    } else if (el.tagName === 'DATALIST') {
      el.innerHTML = threads.map(t=>`<option value="${esc(t)}">`).join('');
    }
  });
  // Populate msg dest autocomplete
  const dl = document.getElementById('msg-dest-list');
  dl.innerHTML = allObjects.map(n=>`<option value="${esc(n)}">`).join('');
}

function buildTreeNode(item, parentPath) {
  const path = parentPath ? parentPath + '.' + item.Name : item.Name;
  const isSig = item.Class === 'Signal' || item.IsTraceable;
  const isThread = item.Class === 'RealTimeThread';

  if (isThread && item.Name) threads.push(item.Name);
  if (item.Class && item.Class !== 'Signal' && item.Name) allObjects.push(path);

  if (item.Children && item.Children.length > 0) {
    const details = document.createElement('details');
    const summary = document.createElement('summary');
    summary.innerHTML = `<span class="tree-name">${esc(item.Name)}</span><span class="tree-class">[${esc(item.Class)}]</span>`;
    details.appendChild(summary);
    const children = document.createElement('div');
    children.className = 'children';
    // Info button for container nodes
    const leaf = makeLeafButtons(path);
    if (leaf) children.appendChild(leaf);
    for (const c of item.Children) children.appendChild(buildTreeNode(c, path));
    details.appendChild(children);
    return details;
  }

  // Leaf node
  const row = document.createElement('div');
  row.className = 'tree-node';
  const leaf = makeLeafRow(path, item, isSig);
  row.appendChild(leaf);

  // Array expansion
  if (isSig && item.Elements > 1) {
    const sub = document.createElement('div');
    sub.style.paddingLeft = '14px';
    for (let i = 0; i < item.Elements; i++) {
      const en = `${path}[${i}]`;
      sub.appendChild(makeLeafRow(en, {Name:`[${i}]`, Class:'Signal', IsTraceable:true, IsForcable:item.IsForcable}, true));
    }
    row.appendChild(sub);
  }
  return row;
}

function makeLeafRow(path, item, isSig) {
  const div = document.createElement('div');
  div.className = 'tree-leaf';
  div.draggable = isSig;
  if (isSig) {
    div.addEventListener('dragstart', e => {
      e.dataTransfer.setData('text/plain', path);
      e.dataTransfer.effectAllowed = 'copy';
    });
  }

  const name = document.createElement('span');
  name.className = 'tree-name';
  name.title = path;
  name.textContent = item.Name;
  div.appendChild(name);

  const cls = document.createElement('span');
  cls.className = 'tree-class';
  cls.textContent = `[${item.Class}]`;
  div.appendChild(cls);

  // Info
  const btnI = mkBtn('i', '', () => showNodeInfo(path));
  div.appendChild(btnI);

  if (isSig || item.IsTraceable) {
    const btnT = mkBtn('T', 't', () => traceSignal(path, true));
    btnT.title = 'Trace';
    div.appendChild(btnT);
  }
  if (item.IsForcable || isSig) {
    const btnF = mkBtn('F', 'f', () => openForceDialogFor(path));
    btnF.title = 'Force';
    div.appendChild(btnF);
  }
  if (isSig || item.IsTraceable) {
    const btnB = mkBtn('B', 'b', () => openBreakDialogFor(path));
    btnB.title = 'Break';
    div.appendChild(btnB);
  }
  return div;
}

function makeLeafButtons(path) {
  // Returns a row of buttons for container nodes (no name/class display)
  const div = document.createElement('div');
  div.style.cssText = 'display:flex;gap:4px;padding:2px 4px 2px 0';
  const btnI = mkBtn('ℹ info', '', () => showNodeInfo(path));
  div.appendChild(btnI);
  return div;
}

function mkBtn(label, cls, fn) {
  const b = document.createElement('button');
  b.className = `tree-btn${cls?' '+cls:''}`;
  b.textContent = label;
  b.addEventListener('click', e => { e.stopPropagation(); fn(); });
  return b;
}

function filterTree(q) {
  const body = document.getElementById('tree-body');
  q = q.toLowerCase();
  body.querySelectorAll('.tree-leaf').forEach(el => {
    if (!q) { el.style.display = ''; return; }
    const t = (el.querySelector('.tree-name')?.title || '').toLowerCase();
    el.style.display = t.includes(q) ? '' : 'none';
  });
  if (q) {
    body.querySelectorAll('details').forEach(d => d.open = true);
  }
}

// ════════════════════════════════════════════════════════════════════
// Tracing
// ════════════════════════════════════════════════════════════════════

function traceSignal(name, enable) {
  if (enable) {
    tracedSet.add(name);
    if (!traceData[name]) traceData[name] = {ts:[], vals:[], lastVal:0, color: nextColor()};
    sendCmd(`TRACE ${name} 1`);
  } else {
    tracedSet.delete(name);
    sendCmd(`TRACE ${name} 0`);
  }
  renderTracedTab();
}

function renderTracedTab() {
  const tab = document.getElementById('tab-traced');
  const hint = document.getElementById('no-traced-hint');
  hint.style.display = tracedSet.size ? 'none' : 'block';
  // Remove old sig-items
  tab.querySelectorAll('.sig-item').forEach(e=>e.remove());
  let colorIdx = 0;
  for (const name of tracedSet) {
    const td = traceData[name];
    const color = td ? td.color : COLORS[colorIdx++ % COLORS.length];
    const div = document.createElement('div');
    div.className = 'sig-item';
    div.draggable = true;
    div.addEventListener('dragstart', e => {
      e.dataTransfer.setData('text/plain', name);
      e.dataTransfer.effectAllowed = 'copy';
    });
    const dot = document.createElement('span');
    dot.className = 'sig-dot';
    dot.style.background = color;
    dot.draggable = false;
    const nm = document.createElement('span');
    nm.className = 'sig-name';
    nm.title = name;
    nm.textContent = shortName(name);
    nm.draggable = false;
    const val = document.createElement('span');
    val.className = 'sig-val';
    val.textContent = td ? fmtVal(td.lastVal) : '—';
    val.id = `tval-${CSS.escape(name)}`;
    val.draggable = false;
    const btnR = mkBtn('×', 'danger', () => traceSignal(name, false));
    btnR.style.cssText = 'font-size:11px;padding:0 4px;border-color:#f38ba8;color:#f38ba8;background:transparent';
    // Stop drag from starting when clicking the button
    btnR.addEventListener('dragstart', e => e.preventDefault());
    div.append(dot, nm, val, btnR);
    tab.appendChild(div);
  }
}

// Update only the value spans without touching the DOM structure.
// Called on every telemetry packet — must be fast and non-destructive.
function updateTracedValues() {
  for (const name of tracedSet) {
    const td = traceData[name];
    if (!td) continue;
    const el = document.getElementById(`tval-${CSS.escape(name)}`);
    if (el) el.textContent = fmtVal(td.lastVal);
  }
}

// ════════════════════════════════════════════════════════════════════
// Force
// ════════════════════════════════════════════════════════════════════

function openForceDialog() { openDlg('dlg-force'); }
function openForceDialogFor(name) {
  document.getElementById('force-sig').value = name;
  openDlg('dlg-force');
}
function doForce() {
  const sig = document.getElementById('force-sig').value.trim();
  const val = document.getElementById('force-val').value.trim();
  if (!sig || !val) return;
  sendCmd(`FORCE ${sig} ${val}`);
  forcedSignals[sig] = val;
  closeDlg('dlg-force');
  renderForcedTab();
}
function doUnforce() {
  if (unforceTarget) {
    sendCmd(`UNFORCE ${unforceTarget}`);
    delete forcedSignals[unforceTarget];
    unforceTarget = '';
    renderForcedTab();
  }
  closeDlg('dlg-unforce');
}
function confirmUnforce(name) {
  unforceTarget = name;
  document.getElementById('unforce-msg').textContent = `Remove force on "${name}"?`;
  openDlg('dlg-unforce');
}
function renderForcedTab() {
  const tab = document.getElementById('tab-forced');
  tab.querySelectorAll('.sig-item').forEach(e=>e.remove());
  const hint = document.getElementById('no-forced-hint');
  const keys = Object.keys(forcedSignals);
  hint.style.display = keys.length ? 'none' : 'block';
  for (const name of keys) {
    const div = document.createElement('div');
    div.className = 'sig-item';
    const nm = document.createElement('span');
    nm.className = 'sig-name';
    nm.title = name;
    nm.textContent = shortName(name);
    const val = document.createElement('span');
    val.className = 'sig-val';
    val.style.color = '#f9e2af';
    val.textContent = forcedSignals[name];
    const btnR = mkBtn('×', '', () => confirmUnforce(name));
    btnR.style.cssText = 'font-size:11px;padding:0 4px;border-color:#f38ba8;color:#f38ba8;background:transparent';
    div.append(nm, val, btnR);
    tab.appendChild(div);
  }
}

// ════════════════════════════════════════════════════════════════════
// Breakpoints
// ════════════════════════════════════════════════════════════════════

function openBreakDialog() { openDlg('dlg-break'); }
function openBreakDialogFor(name) {
  document.getElementById('break-sig').value = name;
  openDlg('dlg-break');
}
function doBreak() {
  const sig   = document.getElementById('break-sig').value.trim();
  const op    = document.getElementById('break-op').value;
  const thresh = document.getElementById('break-thresh').value.trim();
  if (!sig || !thresh) return;
  sendCmd(`BREAK ${sig} ${op} ${thresh}`);
  breakpoints[sig] = {op, threshold: thresh};
  closeDlg('dlg-break');
  renderBreaksTab();
}
function clearBreak(name) {
  sendCmd(`BREAK ${name} OFF`);
  delete breakpoints[name];
  renderBreaksTab();
}
function renderBreaksTab() {
  const tab = document.getElementById('tab-breaks');
  tab.querySelectorAll('.break-item').forEach(e=>e.remove());
  const hint = document.getElementById('no-breaks-hint');
  const keys = Object.keys(breakpoints);
  hint.style.display = keys.length ? 'none' : 'block';
  for (const name of keys) {
    const bp = breakpoints[name];
    const div = document.createElement('div');
    div.className = 'break-item';
    const sig = document.createElement('span');
    sig.className = 'break-sig';
    sig.title = name;
    sig.textContent = shortName(name);
    const cond = document.createElement('span');
    cond.style.color = '#fab387';
    cond.textContent = `${bp.op} ${bp.threshold}`;
    const btnR = mkBtn('×', '', () => clearBreak(name));
    btnR.style.cssText = 'font-size:11px;padding:0 4px;border-color:#f38ba8;color:#f38ba8;background:transparent';
    div.append(sig, cond, btnR);
    tab.appendChild(div);
  }
}

// ════════════════════════════════════════════════════════════════════
// Messages
// ════════════════════════════════════════════════════════════════════

let msgHistory = [];

function openMsgDialog() { openDlg('dlg-msg'); }
function doSendMsg() {
  const dest = document.getElementById('msg-dest').value.trim();
  const func = document.getElementById('msg-func').value.trim();
  const payload = document.getElementById('msg-payload').value.trim();
  const wait = document.getElementById('msg-wait').checked ? 1 : 0;
  if (!dest || !func) return;

  // Build key=value pairs on one line: K=V K2=V2
  const kvLine = payload.split('\n')
    .map(l=>l.trim()).filter(Boolean)
    .map(l=>l.replace(/\s*=\s*/,'=')).join(' ');

  const cmd = `MSG ${dest} ${func} ${wait}${kvLine ? ' '+kvLine : ''}`;
  sendCmd(cmd);

  const entry = {time: now(), dest, func, payload, cmd, status:'pending'};
  msgHistory.unshift(entry);
  closeDlg('dlg-msg');
  renderMsgsTab();
}
function renderMsgsTab() {
  const tab = document.getElementById('tab-msgs');
  tab.querySelectorAll('.msg-item').forEach(e=>e.remove());
  const hint = document.getElementById('no-msgs-hint');
  hint.style.display = msgHistory.length ? 'none' : 'block';
  for (const m of msgHistory.slice(0,50)) {
    const div = document.createElement('div');
    div.className = 'msg-item';
    const icon = m.status==='ok'?'✔':m.status==='err'?'✘':'…';
    div.innerHTML = `<div style="display:flex;gap:6px;align-items:center">
      <span style="color:${m.status==='ok'?'#a6e3a1':m.status==='err'?'#f38ba8':'#585b70'}">${icon}</span>
      <span style="color:#585b70;flex-shrink:0">${m.time}</span>
      <span style="overflow:hidden;text-overflow:ellipsis;white-space:nowrap;flex:1" title="${esc(m.cmd)}">${esc(m.dest)}.${esc(m.func)}</span>
      <button class="tree-btn" onclick="resendMsg(${msgHistory.indexOf(m)})">↺</button>
    </div>`;
    tab.appendChild(div);
  }
}
function resendMsg(idx) {
  const m = msgHistory[idx];
  if (!m) return;
  sendCmd(m.cmd);
}

// ════════════════════════════════════════════════════════════════════
// Step / Pause
// ════════════════════════════════════════════════════════════════════

let isPaused = false;

function togglePause() {
  if (isPaused) {
    sendCmd('RESUME');
    isPaused = false;
    document.getElementById('step-bar').classList.remove('visible');
  } else {
    sendCmd('PAUSE');
    isPaused = true;
  }
  document.getElementById('btn-pause').textContent = isPaused ? '▶ Resume' : '⏸ Pause';
}

function openStepDialog() { openDlg('dlg-step'); }
function doStep() {
  const count = document.getElementById('step-count').value || 1;
  const thread = document.getElementById('step-thread-inp').value.trim();
  const cmd = thread ? `STEP ${count} ${thread}` : `STEP ${count}`;
  sendCmd(cmd);
  closeDlg('dlg-step');
}
function step(n) {
  const thread = document.getElementById('step-thread').value;
  const cmd = thread ? `STEP ${n} ${thread}` : `STEP ${n}`;
  sendCmd(cmd);
}

function startStepPoll() {
  stopStepPoll();
  stepPollTimer = setInterval(() => sendCmd('STEP_STATUS'), 2000);
}
function stopStepPoll() {
  if (stepPollTimer) { clearInterval(stepPollTimer); stepPollTimer = null; }
}

function processStepStatus(data) {
  if (!data) return;
  stepStatus = data;
  const bar = document.getElementById('step-bar');
  if (data.Paused) {
    isPaused = true;
    bar.classList.add('visible');
    document.getElementById('paused-gam').textContent = data.PausedAtGam || '—';
    document.getElementById('step-remaining').textContent =
      data.StepRemaining > 0 ? `(${data.StepRemaining} remaining)` : '';
    document.getElementById('btn-pause').textContent = '▶ Resume';
    // Faster polling while paused
    stopStepPoll();
    stepPollTimer = setInterval(() => sendCmd('STEP_STATUS'), 500);
  } else {
    if (isPaused) {
      isPaused = false;
      bar.classList.remove('visible');
      document.getElementById('btn-pause').textContent = '⏸ Pause';
      // Back to slow poll
      startStepPoll();
    }
  }
}

function processValue(data) {
  if (!data || data.Error) return;
  const title = `Value: ${data.Name}`;
  const body = `${data.Value}\n(${data.Elements} element${data.Elements>1?'s':''})`;
  showInfo(title, body);
}

// ════════════════════════════════════════════════════════════════════
// Info dialog
// ════════════════════════════════════════════════════════════════════

function showNodeInfo(path) {
  document.getElementById('info-title').textContent = path;
  document.getElementById('info-body').textContent = 'Loading…';
  openDlg('dlg-info');
  sendCmd(`INFO ${path}`);
}
function showInfo(title, data) {
  let pretty = data;
  try { pretty = JSON.stringify(JSON.parse(data), null, 2); } catch(e){}
  document.getElementById('info-title').textContent = title;
  document.getElementById('info-body').textContent = pretty;
  // If dialog not visible, open it
  if (document.getElementById('dlg-info').style.display === 'none') openDlg('dlg-info');
}

// ════════════════════════════════════════════════════════════════════
// Connect / Disconnect
// ════════════════════════════════════════════════════════════════════

function toggleConnect() {
  if (marteConnected) {
    sendWS({type:'disconnect'});
  } else {
    const host = document.getElementById('host').value.trim() || '127.0.0.1';
    const port = parseInt(document.getElementById('port').value) || 8080;
    sendWS({type:'connect', data:{host, port, udp_port:port+1, log_port:port+2}});
  }
  closeAllMenus();
}

// ════════════════════════════════════════════════════════════════════
// Plots
// ════════════════════════════════════════════════════════════════════

function addPlot() {
  const id = ++plotSeq;
  document.getElementById('no-plots-hint').style.display = 'none';

  const card = document.createElement('div');
  card.className = 'plot-card';
  card.id = `plot-card-${id}`;

  card.innerHTML = `
    <div class="plot-header">
      <span class="plot-title">Plot ${id}</span>
      <label style="font-size:10px;color:#a6adc8">Max pts:
        <input type="number" value="50000" min="100" max="100000" step="1000"
          style="width:70px" onchange="setMaxPts(${id},this.value)">
      </label>
      <label style="font-size:10px"><input type="checkbox" checked onchange="setFollow(${id},this.checked)"> Follow</label>
      <button onclick="fitPlot(${id})" style="font-size:10px;padding:1px 6px">Fit</button>
      <button onclick="deletePlot(${id})" style="font-size:10px;padding:1px 6px;color:#f38ba8;border-color:#f38ba8">✕</button>
    </div>
    <div id="plot-series-${id}" class="plot-series-bar"></div>
    <div id="plot-drop-${id}" class="plot-drop">Drop signals here to plot</div>
    <div id="plot-wrap-${id}" class="uplot-wrap" style="display:none"></div>`;

  document.getElementById('center-panel').appendChild(card);

  // Counter to handle dragenter/dragleave across child elements reliably
  let dragDepth = 0;
  card.addEventListener('dragenter', e => {
    e.preventDefault();
    dragDepth++;
    card.classList.add('drop-active');
    document.getElementById(`plot-drop-${id}`)?.classList.add('over');
  });
  card.addEventListener('dragover', e => { e.preventDefault(); e.dataTransfer.dropEffect = 'copy'; });
  card.addEventListener('dragleave', () => {
    dragDepth--;
    if (dragDepth <= 0) {
      dragDepth = 0;
      card.classList.remove('drop-active');
      document.getElementById(`plot-drop-${id}`)?.classList.remove('over');
    }
  });
  card.addEventListener('drop', e => {
    e.preventDefault();
    dragDepth = 0;
    card.classList.remove('drop-active');
    document.getElementById(`plot-drop-${id}`)?.classList.remove('over');
    const name = e.dataTransfer.getData('text/plain');
    if (name) addSignalToPlot(id, name);
  });

  const plotObj = {id, card, chart:null, series:[], maxPts:50000, follow:true, dirty:false};
  plots.push(plotObj);
}

function findPlot(id) { return plots.find(p=>p.id===id); }

function deletePlot(id) {
  const idx = plots.findIndex(p=>p.id===id);
  if (idx>=0) { plots.splice(idx,1); }
  document.getElementById(`plot-card-${id}`)?.remove();
  if (plots.length === 0) document.getElementById('no-plots-hint').style.display = 'block';
}

function setMaxPts(id, v) { const p = findPlot(id); if(p) p.maxPts = parseInt(v)||50000; }
function setFollow(id, v) { const p = findPlot(id); if(p) { p.follow = v; if(v && p.chart) p.chart.setScale('x',{min:null,max:null}); } }
function fitPlot(id) { const p = findPlot(id); if(p&&p.chart) p.chart.setScale('x',{min:null,max:null}); }

function addSignalToPlot(id, name) {
  const p = findPlot(id);
  if (!p) return;
  if (p.series.find(s=>s.name===name)) return; // already added

  // Ensure tracing
  traceSignal(name, true);

  const color = traceData[name]?.color || nextColor();
  p.series.push({name, color, gain:1, offset:0});

  updateSeriesBar(p);
  rebuildChart(p);
  p.dirty = true;
}

function removeSignalFromPlot(id, name) {
  const p = findPlot(id);
  if (!p) return;
  p.series = p.series.filter(s=>s.name!==name);
  updateSeriesBar(p);
  rebuildChart(p);
}

function updateSeriesBar(p) {
  const bar = document.getElementById(`plot-series-${p.id}`);
  if (!bar) return;
  bar.innerHTML = '';
  for (const s of p.series) {
    const chip = document.createElement('span');
    chip.className = 'series-chip';
    chip.innerHTML =
      `<span class="series-chip-dot" style="background:${s.color}"></span>` +
      `<span class="series-chip-name" title="${esc(s.name)}">${esc(shortName(s.name))}</span>` +
      `<button class="series-chip-rm" title="Remove signal">×</button>`;
    chip.querySelector('.series-chip-rm').addEventListener('click', () => removeSignalFromPlot(p.id, s.name));
    bar.appendChild(chip);
  }
}

function rebuildChart(p) {
  const wrap = document.getElementById(`plot-wrap-${p.id}`);
  const drop = document.getElementById(`plot-drop-${p.id}`);
  if (!wrap) return;

  if (p.series.length === 0) {
    if (p.chart) { p.chart.destroy(); p.chart = null; }
    plotRO.unobserve(wrap);
    wrap.innerHTML = '';
    wrap.style.display = 'none';
    if (drop) drop.style.display = 'flex';
    return;
  }

  if (drop) drop.style.display = 'none';
  wrap.style.display = 'flex';

  if (p.chart) { p.chart.destroy(); p.chart = null; }
  wrap.innerHTML = '';

  // Build after the browser has laid out the flex container so clientHeight is real.
  requestAnimationFrame(() => {
    if (!document.getElementById(`plot-wrap-${p.id}`)) return; // deleted meanwhile
    const w = Math.max(wrap.clientWidth - 8, 200);
    const h = Math.max(wrap.clientHeight - 6, 120);

    const seriesOpts = [{label:'time'}];
    for (const s of p.series) {
      seriesOpts.push({
        label: shortName(s.name),
        stroke: s.color,
        width: 1.5,
        points: {show: false},
      });
    }

    const opts = {
      width: w,
      height: h,
      series: seriesOpts,
      axes: [
        {
          stroke: '#585b70',
          ticks: {stroke:'#313244'},
          grid: {stroke:'#313244'},
          values: (_u, ts) => ts.map(t => fmtTime(t)),
        },
        {
          stroke: '#585b70',
          ticks: {stroke:'#313244'},
          grid: {stroke:'#313244'},
          size: 60,
        }
      ],
      legend: { show: true, live: false },
      cursor: { drag: {x:true, y:false} },
      hooks: {
        ready: [uInst => {
          const legend = uInst.root.querySelector('.u-legend');
          if (legend) {
            legend.querySelectorAll('.u-label').forEach((lbl, i) => {
              if (i === 0) return;
              lbl.title = 'Right-click to remove';
              lbl.addEventListener('contextmenu', e => {
                e.preventDefault();
                const sName = p.series[i-1]?.name;
                if (sName) removeSignalFromPlot(p.id, sName);
              });
            });
          }
        }]
      },
    };

    const data = buildPlotData(p);
    try {
      p.chart = new uPlot(opts, data, wrap);
      plotRO.observe(wrap);
    } catch(e) {
      console.error('uPlot error', e);
    }
  });
}

function buildPlotData(p) {
  const maxPts = p.maxPts;
  // Find common time range: union of all series timestamps
  // uPlot requires aligned data — we use each series' own timestamps
  // For simplicity use the first non-empty series timestamps as X axis,
  // and for other series linearly interpolate.
  // Simpler approach: collect all unique timestamps (sorted) and use NaN for missing.

  // Per-series data
  const seriesTs = p.series.map(s => {
    const td = traceData[s.name];
    return td ? td.ts : [];
  });
  const seriesVs = p.series.map(s => {
    const td = traceData[s.name];
    if (!td) return [];
    return td.vals.map(v => v * s.gain + s.offset);
  });

  // Use first series with data as the X reference, or merge all
  let xRef = [];
  for (const ts of seriesTs) if (ts.length > 0) { xRef = ts; break; }
  if (xRef.length === 0) return [[]];

  // Trim to maxPts
  const start = Math.max(0, xRef.length - maxPts);
  const times = xRef.slice(start);

  const data = [times];
  for (let i = 0; i < p.series.length; i++) {
    const ts = seriesTs[i];
    const vs = seriesVs[i];
    if (ts.length === 0) {
      data.push(new Array(times.length).fill(NaN));
      continue;
    }
    const s = Math.max(0, ts.length - maxPts);
    data.push(vs.slice(s));
  }
  return data;
}

// ════════════════════════════════════════════════════════════════════
// Render loop
// ════════════════════════════════════════════════════════════════════

function renderLoop() {
  for (const p of plots) {
    if (p.dirty && p.chart && p.series.length > 0) {
      const data = buildPlotData(p);
      try { p.chart.setData(data, p.follow); } catch(e){}
      p.dirty = false;
    }
  }
  if (logDirty) { flushLogs(); logDirty = false; }
  requestAnimationFrame(renderLoop);
}

// ════════════════════════════════════════════════════════════════════
// Logs
// ════════════════════════════════════════════════════════════════════

function appendLog(time, level, message) {
  logs.push({time: time==='sys'?now():time, level, message});
  if (logs.length > MAX_LOGS) logs.shift();
  logDirty = true;
}

function flushLogs() {
  renderLogs();
}

function renderLogs() {
  logDirty = false;
  const body = document.getElementById('log-body');
  const showDebug = document.getElementById('lf-debug').checked;
  const showInfo  = document.getElementById('lf-info').checked;
  const showWarn  = document.getElementById('lf-warn').checked;
  const showError = document.getElementById('lf-error').checked;
  const filter    = document.getElementById('log-filter').value.toLowerCase();

  const visible = logs.filter(l => {
    const lv = l.level;
    if (lv==='DEBUG' && !showDebug) return false;
    if ((lv==='INFO'||lv==='Information') && !showInfo) return false;
    if ((lv==='WARNING'||lv==='Warning') && !showWarn) return false;
    if ((lv==='ERROR'||lv==='FatalError'||lv==='FATAL'||lv==='WARN') && !showError) return false;
    if (filter && !l.message.toLowerCase().includes(filter)) return false;
    return true;
  }).slice(-500);

  body.innerHTML = visible.map(l =>
    `<div class="log-line ${esc(l.level)}">` +
    `<span class="log-time">${esc(l.time)}</span>` +
    `<span class="log-lvl">${esc(l.level)}</span>` +
    `<span class="log-msg" title="${esc(l.message)}">${esc(l.message)}</span>` +
    `</div>`
  ).join('');

  if (document.getElementById('log-autoscroll').checked) {
    body.scrollTop = body.scrollHeight;
  }
}

// ════════════════════════════════════════════════════════════════════
// Tab switching
// ════════════════════════════════════════════════════════════════════

function switchTab(name) {
  document.querySelectorAll('.tab').forEach((t,i)=>{
    const names=['traced','forced','breaks','msgs'];
    t.classList.toggle('active', names[i]===name);
  });
  document.querySelectorAll('.tab-content').forEach(t=>{
    t.classList.remove('active');
  });
  document.getElementById(`tab-${name}`)?.classList.add('active');
}

// ════════════════════════════════════════════════════════════════════
// Dialogs
// ════════════════════════════════════════════════════════════════════

function openDlg(id) { document.getElementById(id).style.display='flex'; }
function closeDlg(id) { document.getElementById(id).style.display='none'; }

document.addEventListener('keydown', e => {
  if (e.key === 'Escape') {
    document.querySelectorAll('.dialog-overlay').forEach(d => d.style.display='none');
  }
});

// ════════════════════════════════════════════════════════════════════
// Helpers
// ════════════════════════════════════════════════════════════════════

let _colorIdx = 0;
function nextColor() { return COLORS[_colorIdx++ % COLORS.length]; }

function shortName(name) {
  const parts = name.split('.');
  return parts.length > 2 ? '…'+parts.slice(-2).join('.') : name;
}

function fmtVal(v) {
  if (v === undefined || v === null || isNaN(v)) return '—';
  if (Math.abs(v) < 1e-3 && v !== 0) return v.toExponential(3);
  if (Math.abs(v) >= 1e6) return v.toExponential(3);
  return v.toPrecision(6).replace(/\.?0+$/, '');
}

function fmtTime(t) {
  if (t == null) return '';
  const s = t;
  const h = Math.floor(s/3600);
  const m = Math.floor((s%3600)/60);
  const sec = (s%60).toFixed(2);
  if (h>0) return `${h}:${String(m).padStart(2,'0')}:${sec.padStart(5,'0')}`;
  if (m>0) return `${m}:${sec.padStart(5,'0')}`;
  return `${sec}s`;
}

function now() {
  return new Date().toLocaleTimeString('en',{hour12:false,hour:'2-digit',minute:'2-digit',second:'2-digit',fractionalSecondDigits:3});
}

function esc(s) {
  if (s==null) return '';
  return String(s).replace(/&/g,'&amp;').replace(/</g,'&lt;').replace(/>/g,'&gt;').replace(/"/g,'&quot;');
}

// ════════════════════════════════════════════════════════════════════
// Resize observer — per plot-wrap, keeps uPlot size in sync
// ════════════════════════════════════════════════════════════════════

const plotRO = new ResizeObserver(entries => {
  for (const entry of entries) {
    const wrap = entry.target;
    const m = wrap.id.match(/^plot-wrap-(\d+)$/);
    if (!m) continue;
    const p = findPlot(parseInt(m[1]));
    if (!p || !p.chart) continue;
    const w = Math.max(wrap.clientWidth - 8, 200);
    const h = Math.max(wrap.clientHeight - 6, 120);
    try { p.chart.setSize({width: w, height: h}); } catch(e) {}
  }
});

// ════════════════════════════════════════════════════════════════════
// Dropdown menus
// ════════════════════════════════════════════════════════════════════

function toggleMenu(id) {
  const el = document.getElementById(id);
  if (!el) return;
  const isOpen = el.classList.contains('open');
  closeAllMenus();
  if (!isOpen) el.classList.add('open');
}

function closeAllMenus() {
  document.querySelectorAll('.dropdown.open').forEach(d => d.classList.remove('open'));
}

// Close menus when clicking outside
document.addEventListener('click', e => {
  if (!e.target.closest('.menu-wrap')) closeAllMenus();
});

// ════════════════════════════════════════════════════════════════════
// Panel collapse
// ════════════════════════════════════════════════════════════════════

function togglePanelStrip(panelId, stripId, collapseIcon, expandIcon) {
  const panel = document.getElementById(panelId);
  const strip = document.getElementById(stripId);
  if (!panel) return;
  const collapsed = panel.classList.toggle('collapsed');
  if (strip) strip.textContent = collapsed ? expandIcon : collapseIcon;
}

function togglePanel(panelId, collapseIcon, expandIcon, btn) {
  const panel = document.getElementById(panelId);
  if (!panel) return;
  const collapsed = panel.classList.toggle('collapsed');
  if (btn) btn.textContent = collapsed ? expandIcon : collapseIcon;
}

// ════════════════════════════════════════════════════════════════════
// Boot
// ════════════════════════════════════════════════════════════════════

connectWS();
requestAnimationFrame(renderLoop);