/* ============================================================== preferences */
function clamp(v, lo, hi) { return Math.max(lo, Math.min(hi, v)); }
function savePrefs() { store.set('prefs', S.prefs); }

function applyPrefs() {
  var root = document.documentElement;
  if (S.prefs.theme === 'auto') root.removeAttribute('data-theme'); else root.setAttribute('data-theme', S.prefs.theme);
  root.style.setProperty('--fs', S.prefs.fs + 'px');
  root.style.setProperty('--lh', Math.round(S.prefs.fs * 1.55) + 'px');
  metricCache = {};
  $('autorun').checked = !!S.prefs.autorun;
}

function applyLayout() {
  var d = S.prefs.diagram, o = S.prefs.output;
  $('p-diagram').hidden = !d;
  $('p-output').hidden = !o;
  $('split-h').hidden = !(d && o);
  $('right').classList.toggle('one', !(d && o));
  $('main').classList.toggle('no-right', !(d || o));
  var root = document.documentElement;
  root.style.setProperty('--leftw', (clamp(S.prefs.lw || 0.5, 0.2, 0.8) * 100) + '%');
  root.style.setProperty('--toph', (clamp(S.prefs.th || 0.62, 0.15, 0.85) * 100) + '%');
  setTimeout(function () { if (!V.userMoved) fit(); }, 0);
}

function initSplit(id, vertical) {
  var sp = $(id);
  sp.addEventListener('pointerdown', function (ev) {
    if (ev.button) return;
    sp.setPointerCapture(ev.pointerId);
    sp.classList.add('drag');
  });
  sp.addEventListener('pointermove', function (ev) {
    if (!sp.classList.contains('drag')) return;
    if (vertical) {
      var r = $('main').getBoundingClientRect();
      S.prefs.lw = clamp((ev.clientX - r.left - 8) / (r.width - 16), 0.2, 0.8);
    } else {
      var r2 = $('right').getBoundingClientRect();
      S.prefs.th = clamp((ev.clientY - r2.top) / r2.height, 0.15, 0.85);
    }
    applyLayout();
  });
  var end = function () { if (sp.classList.contains('drag')) { sp.classList.remove('drag'); savePrefs(); } };
  sp.addEventListener('pointerup', end);
  sp.addEventListener('pointercancel', end);
  sp.addEventListener('keydown', function (ev) {
    var step = ev.key === (vertical ? 'ArrowRight' : 'ArrowDown') ? 0.02 : ev.key === (vertical ? 'ArrowLeft' : 'ArrowUp') ? -0.02 : 0;
    if (!step) return;
    ev.preventDefault();
    if (vertical) S.prefs.lw = clamp((S.prefs.lw || 0.5) + step, 0.2, 0.8); else S.prefs.th = clamp((S.prefs.th || 0.62) + step, 0.15, 0.85);
    applyLayout();
    savePrefs();
  });
}

/* ================================================================== results */
function currentInput() { return getTab(S.lastInput); }
function currentResult() {
  var it = currentInput();
  return it ? (S.results[it.id] || null) : null;
}
function isStale() {
  var it = currentInput(), r = currentResult();
  if (!it || !r) return false;
  return r.rev !== it.rev || r.grev !== S.grev || r.main !== S.lastGrammar || !!(S.gres && !S.gres.ok) || !!S.crash;
}

function parseToolLog(log) {
  var out = [];
  String(log || '').split(/\r?\n/).forEach(function (line) {
    var m = /^(error|warning)\((\d+)\): (.*?):(\d+):(\d+): (.*)$/.exec(line);
    if (m) { out.push({ sev: m[1], code: m[2], file: basename(m[3].replace(/\\/g, '/')), line: +m[4], col: +m[5], msg: m[6] }); return; }
    var m2 = /^(error|warning)\((\d+)\): (.*)$/.exec(line);
    if (m2) out.push({ sev: m2[1], code: m2[2], file: '', line: 0, col: 0, msg: m2[3] });
  });
  return out;
}

function setRange(kind, s, e) {
  var it = currentInput();
  if (!it) return;
  var r = S.results[it.id];
  if (s < 0 || !r || r.rev !== it.rev) { setEditorRange(it.ed, kind, null); return; }
  var m = cpMap(it.ed.ta.value);
  setEditorRange(it.ed, kind, [m(s), m(e + 1)]);
}
function togglePin(s, e) {
  var it = currentInput();
  if (!it || s < 0) return;
  if (S.active !== it.id) activate(it.id, false);
  var cur = it.ed.pin, m = cpMap(it.ed.ta.value), a = m(s), b = m(e + 1);
  if (cur && cur[0] === a && cur[1] === b) { setEditorRange(it.ed, 'pin', null); return; }
  setEditorRange(it.ed, 'pin', [a, b]);
  revealUnit(it.ed, a);
}

function applyMarks() {
  // input editor: syntax problems of the latest run
  S.tabs.forEach(function (t) {
    if (t.kind === 'input') {
      var r = S.results[t.id], list = [];
      if (r && r.rev === t.rev) {
        var m = cpMap(t.ed.ta.value);
        r.data.diagnostics.forEach(function (d) {
          if (d.s >= 0) list.push({ s: m(d.s), e: m(d.e + 1), bit: d.sev === 'warning' ? 2 : 1 });
        });
      }
      t.ed.diag = list;
      paintEditor(t.ed);
    } else {
      var g = S.gres, marks = [];
      if (g && g.snap && g.snap.revs[t.id] === t.rev) {
        parseToolLog(g.log).forEach(function (p) {
          if (p.file !== tabTitle(t) || p.line < 1) return;
          var s = unitAt(t.ed, p.line, p.col), e = s, v = t.ed.ta.value;
          while (e < v.length && isIdChar(v.charAt(e))) e++;
          if (e === s) e = Math.min(v.length, s + 1);
          marks.push({ s: s, e: e, bit: p.sev === 'warning' ? 2 : 1 });
        });
      }
      t.ed.diag = marks;
      paintEditor(t.ed);
    }
  });
}

function diagramNote() {
  if (!getTab(S.lastGrammar)) return 'Open or create a grammar (File menu) to see a diagram.';
  if (!currentInput()) return 'Open or create an input file (File menu). Its parse tree appears here.';
  if (S.gres && !S.gres.ok) return 'The grammar has errors. See the Output panel.';
  if (S.crash) return S.crash.message;
  var r = currentResult();
  if (r && r.data.noDiagram) return r.data.noDiagram;
  if (S.running) return 'Running...';
  return 'Press Run to parse this input.';
}

var shownData = null;     // result data currently drawn in the heavy views

function refreshPanels() {
  var it = currentInput(), gt = getTab(S.lastGrammar), r = currentResult();
  $('dtitle').textContent = 'Diagram' + (it ? ' (' + tabTitle(it) + ')' : '');
  $('otitle').textContent = 'Output' + (gt ? ' (' + stem(tabTitle(gt)) + ')' : '');

  var chip = $('chip'), kind = null, text = '';
  if (S.gres && !S.gres.ok) { kind = 'fail'; text = 'Grammar has errors'; }
  else if (S.crash) { kind = 'fail'; text = S.crash.kind === 'timeout' ? 'Run timed out' : S.crash.kind === 'crashed' ? 'Run crashed' : 'Run failed'; }
  else if (r) { kind = r.data.status.kind; text = r.data.status.text; }
  chip.hidden = !kind;
  if (kind) {
    chip.className = 'chip ' + kind + (isStale() ? ' stale' : '');
    chip.textContent = text;
    chip.title = S.crash ? S.crash.message : (r && r.data.status.detail ? r.data.status.detail : '');
  }
  $('dgm').classList.toggle('stale', isStale());

  var data = r ? r.data : null;
  if (data !== shownData) { shownData = data; paintResultViews(data); }
  else if (!data) paintResultViews(null);

  paintProblems();
  paintLog();
  paintStartRule();
  var busy = $('run');
  busy.setAttribute('data-busy', S.running ? 'true' : 'false');
  busy.textContent = S.running ? 'Running' : 'Run';
  busy.disabled = !getTab(S.lastGrammar);
  $('o-problems').setAttribute('aria-selected', S.prefs.out === 'problems' ? 'true' : 'false');
  $('o-log').setAttribute('aria-selected', S.prefs.out === 'log' ? 'true' : 'false');
  $('probview').hidden = S.prefs.out !== 'problems';
  $('logview').hidden = S.prefs.out !== 'log';
}

function paintResultViews(data) {
  paintDiagram(data);
  var tree = $('treeout');
  tree.textContent = data && data.tree ? (V.pretty ? data.treePretty : data.tree) : diagramNote();
  paintTokens(data);
  showView(S.prefs.view);
}

function showView(v) {
  S.prefs.view = v;
  ['diagram', 'tree', 'tokens'].forEach(function (id) {
    $('v-' + id).setAttribute('aria-selected', id === v ? 'true' : 'false');
  });
  $('dgm').hidden = v !== 'diagram';
  $('treeview').hidden = v !== 'tree';
  $('tokview').hidden = v !== 'tokens';
  $('dtools').hidden = v !== 'diagram';
  $('ttools').hidden = v !== 'tree';
  $('b-pretty').setAttribute('aria-pressed', V.pretty ? 'true' : 'false');
  $('b-flat').setAttribute('aria-pressed', V.pretty ? 'false' : 'true');
  if (v === 'diagram' && V.needFit) fit();
}

function paintStartRule() {
  var wrap = $('startwrap'), sel = $('startrule'), g = S.gres;
  var show = !!(g && g.ok && g.hasParser && g.rules.length);
  wrap.hidden = !show;
  if (!show) return;
  var sig = g.name + '|' + g.rules.join(',');
  var chosen = S.start[g.name] || g.rules[0];
  if (sel.getAttribute('data-sig') !== sig) {
    clear(sel);
    g.rules.forEach(function (n) { var o = el('option', '', n); o.value = n; sel.appendChild(o); });
    sel.setAttribute('data-sig', sig);
  }
  sel.value = g.rules.indexOf(chosen) >= 0 ? chosen : g.rules[0];
}

/* -------------------------------------------------------------- problems */
function jumpToRange(tab, s, e) {
  if (!tab) return;
  activate(tab.id, true);
  tab.ed.ta.setSelectionRange(s, e);
  revealUnit(tab.ed, s);
}

function paintProblems() {
  var list = $('problist');
  clear(list);
  var items = [], g = S.gres, r = currentResult(), it = currentInput();
  if (g) {
    var parsed = parseToolLog(g.log);
    parsed.forEach(function (p) {
      items.push({ src: 'grammar', sev: p.sev, loc: p.line ? p.file + ' ' + p.line + ':' + p.col : p.file, msg: p.msg, go: function () {
        var t = null;
        S.tabs.forEach(function (x) { if (x.kind === 'grammar' && tabTitle(x) === p.file) t = x; });
        t = t || getTab(S.lastGrammar);
        if (t && p.line) { var s = unitAt(t.ed, p.line, p.col); jumpToRange(t, s, s); }
      } });
    });
    if (!g.ok && !parsed.some(function (p) { return p.sev === 'error'; })) {
      items.push({ src: 'grammar', sev: 'error', loc: '', msg: g.error || 'The grammar could not be compiled.', go: null });
    }
  }
  if (S.crash && !(g && !g.ok)) {
    items.push({ src: 'runtime', sev: 'error', loc: S.crash.phase ? S.crash.phase : '', msg: S.crash.message, go: null });
  }
  if (r && it && !(g && !g.ok) && !S.crash) {
    r.data.diagnostics.forEach(function (d) {
      items.push({ src: d.src, sev: d.sev, loc: d.line ? d.line + ':' + d.col : '', msg: d.msg, go: function () {
        if (r.rev !== it.rev) return;
        var m = cpMap(it.ed.ta.value);
        if (d.s >= 0) { jumpToRange(it, m(d.s), m(d.e + 1)); setEditorRange(it.ed, 'pin', [m(d.s), m(d.e + 1)]); }
        else { var u = unitAt(it.ed, d.line, d.col); jumpToRange(it, u, u); }
      } });
    });
  }
  $('noprob').hidden = items.length > 0;
  var errs = 0, warns = 0;
  items.forEach(function (p) {
    if (p.sev === 'error') errs++; else warns++;
    var li = el('li', 'prob ' + p.sev);
    li.tabIndex = 0;
    li.appendChild(el('span', 'sev', p.sev));
    li.appendChild(el('span', 'loc', p.loc));
    li.appendChild(el('span', 'msg', p.msg));
    li.appendChild(el('span', 'src', p.src));
    if (p.go) {
      li.onclick = function () {
        Array.prototype.forEach.call(list.children, function (c) { c.removeAttribute('aria-current'); });
        li.setAttribute('aria-current', 'true');
        p.go();
      };
      li.onkeydown = function (ev) { if (ev.key === 'Enter') { ev.preventDefault(); li.click(); } };
    }
    list.appendChild(li);
  });
  var badge = $('badge');
  badge.hidden = !items.length;
  badge.className = 'badge' + (errs ? '' : ' warn');
  badge.textContent = String(errs || warns);
}

function paintLog() {
  var g = S.gres, text = '';
  if (g) {
    text = g.log && g.log.trim() ? g.log : (g.ok ? 'The ANTLR tool reported nothing.' : (g.error || ''));
    if (g.ok) text += (text.slice(-1) === '\n' ? '' : '\n') + '\nGrammar files: ' + (g.entry || []).join(', ') + (g.cached ? '  (unchanged, reused)' : '  (compiled in ' + g.compileMs + ' ms)');
  } else {
    text = 'Nothing has run yet.';
  }
  $('logout').textContent = text;
}

/* ---------------------------------------------------------------- tokens */
function paintTokens(data) {
  var wrap = $('tokview');
  clear(wrap);
  var toks = data ? data.tokens : [];
  if (!toks.length) { wrap.appendChild(el('p', 'note', data ? 'No tokens.' : diagramNote())); return; }
  var table = el('table'), head = el('tr');
  ['#', 'Text', 'Type', 'Channel', 'Line:col'].forEach(function (h) { head.appendChild(el('th', '', h)); });
  var th = el('thead');
  th.appendChild(head);
  table.appendChild(th);
  var body = el('tbody');
  toks.slice(0, 5000).forEach(function (t) {
    var tr = el('tr', t.ch && t.ch !== 'DEFAULT_TOKEN_CHANNEL' && t.ch !== '0' ? 'side' : '');
    tr.appendChild(el('td', 'num', String(t.i)));
    tr.appendChild(el('td', 'mono', t.t));
    tr.appendChild(el('td', 'mono', t.ty));
    tr.appendChild(el('td', 'mono', t.ch));
    tr.appendChild(el('td', 'mono', t.l + ':' + t.c));
    tr.onmouseenter = function () { setRange('hover', t.s, t.e); };
    tr.onmouseleave = function () { setRange('hover', -1, -1); };
    tr.onclick = function () { togglePin(t.s, t.e); };
    body.appendChild(tr);
  });
  table.appendChild(body);
  wrap.appendChild(table);
  if (toks.length > 5000) wrap.appendChild(el('p', 'note', 'Showing the first 5000 of ' + toks.length + ' tokens.'));
}

/* ================================================================== diagram */
var V = { z: 1, x: 0, y: 0, w: 0, h: 0, key: '', owner: '', needFit: true, userMoved: false, pretty: true };

function applyView() { $('stage').style.transform = 'translate(' + V.x + 'px,' + V.y + 'px) scale(' + V.z + ')'; }

function fit() {
  var c = $('dgm'), cw = c.clientWidth, ch = c.clientHeight;
  if (!V.w || !cw || !ch) return;
  var z = Math.max(0.05, Math.min(1.35, (cw - 40) / V.w, (ch - 40) / V.h));
  V.z = z;
  V.x = (cw - V.w * z) / 2;
  V.y = Math.max(20, (ch - V.h * z) / 2);
  V.needFit = false;
  V.userMoved = false;
  applyView();
}

function zoomAt(cx, cy, f) {
  var z = clamp(V.z * f, 0.05, 8), k = z / V.z;
  V.x = cx - (cx - V.x) * k;
  V.y = cy - (cy - V.y) * k;
  V.z = z;
  V.userMoved = true;
  applyView();
}
function zoomCentre(f) { var c = $('dgm'); zoomAt(c.clientWidth / 2, c.clientHeight / 2, f); }

function paintDiagram(data) {
  var stage = $('stage'), note = $('dnote'), box = $('dgm');
  var svg = data && data.svg ? data.svg : '';
  var owner = S.lastInput || '';
  if (owner !== V.owner) { V.owner = owner; V.needFit = true; V.userMoved = false; V.key = '\u0000'; }
  if (svg && svg === V.key) return;
  V.key = svg;
  clear(stage);
  if (!svg) {
    note.textContent = diagramNote();
    note.hidden = false;
    box.classList.add('empty');
    V.w = V.h = 0;
    V.needFit = true;
    return;
  }
  note.hidden = true;
  box.classList.remove('empty');
  stage.innerHTML = svg;
  var vb = stage.querySelector('svg').getAttribute('viewBox').split(' ');
  V.w = parseFloat(vb[2]);
  V.h = parseFloat(vb[3]);
  if (V.needFit || !V.userMoved) fit(); else applyView();
}

function svgMarkup(data) {
  var NS = 'http://www.w3.org/2000/svg';
  var c = $('stage').querySelector('svg').cloneNode(true);
  var st = document.createElementNS(NS, 'style');
  st.textContent = data.svgStyle;
  var bg = document.createElementNS(NS, 'rect');
  bg.setAttribute('class', 'al-bg');
  bg.setAttribute('width', '100%');
  bg.setAttribute('height', '100%');
  c.insertBefore(bg, c.firstChild);
  c.insertBefore(st, c.firstChild);
  return '<?xml version="1.0" encoding="UTF-8"?>\n' + new XMLSerializer().serializeToString(c);
}

function download(name, blob) {
  var a = document.createElement('a');
  a.href = URL.createObjectURL(blob);
  a.download = name;
  document.body.appendChild(a);
  a.click();
  a.remove();
  setTimeout(function () { URL.revokeObjectURL(a.href); }, 2000);
}

function exportName(ext) {
  var it = currentInput();
  return (it ? stem(tabTitle(it)) : 'tree') + '-tree.' + ext;
}

function savePng(data) {
  var scale = Math.min(2, 8000 / Math.max(V.w, V.h));
  var img = new Image();
  img.onload = function () {
    var c = document.createElement('canvas');
    c.width = Math.max(1, Math.round(V.w * scale));
    c.height = Math.max(1, Math.round(V.h * scale));
    c.getContext('2d').drawImage(img, 0, 0, c.width, c.height);
    c.toBlob(function (b) { if (b) download(exportName('png'), b); }, 'image/png');
  };
  img.src = 'data:image/svg+xml;charset=utf-8,' + encodeURIComponent(svgMarkup(data));
}

function initDiagram() {
  var box = $('dgm'), stage = $('stage'), drag = null, moved = false;
  box.addEventListener('wheel', function (ev) {
    if (!V.w) return;
    ev.preventDefault();
    var r = box.getBoundingClientRect(), unit = ev.deltaMode === 1 ? 16 : 1;
    zoomAt(ev.clientX - r.left, ev.clientY - r.top, Math.exp(-ev.deltaY * unit * (ev.ctrlKey ? 0.01 : 0.0015)));
  }, { passive: false });
  box.addEventListener('pointerdown', function (ev) {
    if (ev.button !== 0 || !V.w) return;
    drag = { x: ev.clientX, y: ev.clientY, vx: V.x, vy: V.y };
    moved = false;
    box.setPointerCapture(ev.pointerId);
    box.classList.add('drag');
  });
  box.addEventListener('pointermove', function (ev) {
    if (!drag) return;
    var dx = ev.clientX - drag.x, dy = ev.clientY - drag.y;
    if (Math.abs(dx) + Math.abs(dy) > 3) moved = true;
    V.x = drag.vx + dx;
    V.y = drag.vy + dy;
    V.userMoved = true;
    applyView();
  });
  var end = function () { drag = null; box.classList.remove('drag'); };
  box.addEventListener('pointerup', end);
  box.addEventListener('pointercancel', end);
  box.addEventListener('dblclick', fit);
  stage.addEventListener('click', function (ev) {
    if (moved) return;
    var g = ev.target.closest('.al-node');
    if (g && g.hasAttribute('data-s')) togglePin(+g.getAttribute('data-s'), +g.getAttribute('data-e'));
  });
  stage.addEventListener('mouseover', function (ev) {
    var g = ev.target.closest('.al-node');
    if (g && g.hasAttribute('data-s')) setRange('hover', +g.getAttribute('data-s'), +g.getAttribute('data-e'));
  });
  stage.addEventListener('mouseout', function (ev) { if (ev.target.closest('.al-node')) setRange('hover', -1, -1); });
  box.addEventListener('keydown', function (ev) {
    var k = ev.key;
    if (k === '+' || k === '=') zoomCentre(1.25);
    else if (k === '-') zoomCentre(0.8);
    else if (k === '0') fit();
    else if (k === 'ArrowLeft') { V.x += 60; V.userMoved = true; applyView(); }
    else if (k === 'ArrowRight') { V.x -= 60; V.userMoved = true; applyView(); }
    else if (k === 'ArrowUp') { V.y += 60; V.userMoved = true; applyView(); }
    else if (k === 'ArrowDown') { V.y -= 60; V.userMoved = true; applyView(); }
    else return;
    ev.preventDefault();
  });
  $('zin').onclick = function () { zoomCentre(1.25); };
  $('zout').onclick = function () { zoomCentre(0.8); };
  $('zfit').onclick = fit;
  $('psvg').onclick = function () { var r = currentResult(); if (r && V.w) download(exportName('svg'), new Blob([svgMarkup(r.data)], { type: 'image/svg+xml' })); };
  $('ppng').onclick = function () { var r = currentResult(); if (r && V.w) savePng(r.data); };
  if (window.ResizeObserver) new ResizeObserver(function () { if (!V.userMoved && V.w) fit(); }).observe(box);

  ['diagram', 'tree', 'tokens'].forEach(function (id) {
    $('v-' + id).onclick = function () { showView(id); savePrefs(); };
  });
  $('b-pretty').onclick = function () { V.pretty = true; shownData = null; refreshPanels(); };
  $('b-flat').onclick = function () { V.pretty = false; shownData = null; refreshPanels(); };
  $('b-copy').onclick = function () {
    var text = $('treeout').textContent, b = $('b-copy');
    var done = function () { var old = b.textContent; b.textContent = 'Copied'; setTimeout(function () { b.textContent = old; }, 1200); };
    if (navigator.clipboard && window.isSecureContext) navigator.clipboard.writeText(text).then(done, function () {});
    else {
      var ta = document.createElement('textarea');
      ta.value = text;
      document.body.appendChild(ta);
      ta.select();
      try { document.execCommand('copy'); done(); } catch (e) { /* ignore */ }
      ta.remove();
    }
  };
  $('o-problems').onclick = function () { S.prefs.out = 'problems'; savePrefs(); refreshPanels(); };
  $('o-log').onclick = function () { S.prefs.out = 'log'; savePrefs(); refreshPanels(); };
}

/* ====================================================================== run */
var runTimer = null;
function scheduleRun(ms) {
  clearTimeout(runTimer);
  if (!S.prefs.autorun) return;
  runTimer = setTimeout(runNow, ms);
}

function runNow() {
  clearTimeout(runTimer);
  ensureLast();
  var main = getTab(S.lastGrammar), inp = getTab(S.lastInput);
  if (!main) { S.gres = null; refreshPanels(); return; }
  if (S.running) { S.queued = true; return; }
  S.running = true;
  var snap = { revs: {}, inputRev: inp ? inp.rev : 0, grev: S.grev, inputId: inp ? inp.id : null };
  var grammars = S.tabs.filter(function (t) { return t.kind === 'grammar'; });
  grammars.forEach(function (t) { snap.revs[t.id] = t.rev; });
  var name = stem(tabTitle(main));
  var body = {
    grammars: grammars.map(function (t) { return { name: tabTitle(t), path: t.path, text: t.ed.ta.value }; }),
    main: tabTitle(main),
    start: S.start[name] || ''
  };
  if (inp) body.input = { name: tabTitle(inp), text: inp.ed.ta.value };
  refreshPanels();

  api('POST', '/api/run', body).then(function (r) {
    var g = r.grammar;
    S.gres = { ok: !!g.ok, name: g.name, log: g.log || '', error: g.error || '', rules: g.rules || [], hasParser: !!g.hasParser,
               entry: g.entry || [], cached: !!g.cached, compileMs: g.compileMs, snap: snap };
    if (r.result && inp) S.results[inp.id] = { data: r.result, rev: snap.inputRev, grev: snap.grev, main: main.id };
    var wasCrash = !!S.crash;
    S.crash = r.crash || null;
    if (S.crash && !wasCrash) toast(S.crash.kind === 'timeout' ? 'The run took too long and was stopped.' : 'The ANTLR runtime failed on this input. See Problems.', 'error');
    if (r.runError) toast(r.runError, 'error');
    if (!g.ok && S.prefs.out !== 'problems') { S.prefs.out = 'problems'; }
  }).catch(function (e) {
    S.gres = { ok: false, name: name, log: '', error: e.message, rules: [], hasParser: false, entry: [], cached: false, compileMs: 0, snap: snap };
    toast('Run failed: ' + e.message, 'error');
  }).then(function () {
    S.running = false;
    shownData = null;
    applyMarks();
    refreshPanels();
    if (S.queued) { S.queued = false; runNow(); }
  });
}

/* =================================================================== wiring */
function withEditor(fn) {
  var t = getTab(S.active);
  if (t) fn(t);
}
function changeFont(delta) {
  S.prefs.fs = delta === 0 ? 13 : clamp(S.prefs.fs + delta, 10, 24);
  applyPrefs();
  savePrefs();
}
function setPref(key, value) {
  S.prefs[key] = value;
  applyPrefs();
  applyLayout();
  savePrefs();
}

function buildMenus() {
  var hasTab = function () { return !!getTab(S.active); };
  defineMenus([
    { label: 'File', items: function () {
      var t = getTab(S.active);
      return [
        { label: 'New grammar', action: newGrammar },
        { label: 'New input', action: newInput },
        { sep: true },
        { label: 'Open\u2026', key: 'Ctrl+O', action: openDialog },
        { sep: true },
        { label: 'Save', key: 'Ctrl+S', disabled: !t, action: function () { withEditor(saveTab); } },
        { label: 'Save as\u2026', key: 'Ctrl+Shift+S', disabled: !t, action: function () { withEditor(saveAs); } },
        { label: 'Save all', disabled: !S.tabs.some(function (x) { return x.dirty; }), action: saveAll },
        { sep: true },
        { label: 'Reload from disk', disabled: !(t && t.path), action: reloadActive },
        { label: 'Close tab', key: 'Alt+W', disabled: !t, action: function () { withEditor(function (x) { closeTab(x.id); }); } }
      ];
    } },
    { label: 'Edit', items: function () {
      return [
        { label: 'Undo', key: 'Ctrl+Z', disabled: !hasTab(), action: function () { withEditor(function (t) { t.ed.ta.focus(); document.execCommand('undo'); }); } },
        { label: 'Redo', key: 'Ctrl+Y', disabled: !hasTab(), action: function () { withEditor(function (t) { t.ed.ta.focus(); document.execCommand('redo'); }); } },
        { sep: true },
        { label: 'Find and replace', key: 'Ctrl+F', disabled: !hasTab(), action: function () { withEditor(function (t) { openFind(t.ed); }); } },
        { label: 'Toggle comment', key: 'Ctrl+/', disabled: !(getTab(S.active) && getTab(S.active).kind === 'grammar'), action: function () { withEditor(function (t) { t.ed.ta.focus(); toggleComment(t.ed); }); } }
      ];
    } },
    { label: 'View', items: function () {
      return [
        { label: 'Diagram panel', checked: S.prefs.diagram, action: function () { setPref('diagram', !S.prefs.diagram); } },
        { label: 'Output panel', checked: S.prefs.output, action: function () { setPref('output', !S.prefs.output); } },
        { sep: true },
        { label: 'Auto-run', checked: S.prefs.autorun, action: function () { setPref('autorun', !S.prefs.autorun); if (S.prefs.autorun) scheduleRun(100); } },
        { sep: true },
        { label: 'Theme: match system', checked: S.prefs.theme === 'auto', action: function () { setPref('theme', 'auto'); } },
        { label: 'Theme: light', checked: S.prefs.theme === 'light', action: function () { setPref('theme', 'light'); } },
        { label: 'Theme: dark', checked: S.prefs.theme === 'dark', action: function () { setPref('theme', 'dark'); } },
        { sep: true },
        { label: 'Larger text', action: function () { changeFont(1); } },
        { label: 'Smaller text', action: function () { changeFont(-1); } },
        { label: 'Reset text size', action: function () { changeFont(0); } }
      ];
    } }
  ]);
}

function initShortcuts() {
  document.addEventListener('keydown', function (ev) {
    if ($('modal-root').firstChild) return;
    var mod = ev.ctrlKey || ev.metaKey, k = ev.key;
    if (mod && k === 'Enter') { ev.preventDefault(); runNow(); }
    else if (mod && (k === 's' || k === 'S')) { ev.preventDefault(); withEditor(ev.shiftKey ? saveAs : saveTab); }
    else if (mod && (k === 'o' || k === 'O')) { ev.preventDefault(); openDialog(); }
    else if (ev.altKey && (k === 'w' || k === 'W')) { ev.preventDefault(); withEditor(function (t) { closeTab(t.id); }); }
    else if (k === 'Escape') closeMenu(true);
  });
}

function fatal(e) {
  var m = $('main');
  clear(m);
  m.style.display = 'block';
  var box = el('div', 'note');
  box.appendChild(el('h2', '', 'Cannot reach antlrlab'));
  box.appendChild(el('p', '', (e && e.message ? e.message + '. ' : '') + 'The server may have stopped, or this page was opened without its token. Restart antlrlab and open the address it prints.'));
  m.appendChild(box);
}

function boot() {
  var saved = store.get('prefs', null);
  if (saved) Object.keys(saved).forEach(function (k) { S.prefs[k] = saved[k]; });
  buildMenus();
  applyPrefs();
  applyLayout();
  initDiagram();
  initSplit('split-v', true);
  initSplit('split-h', false);
  initShortcuts();
  $('run').onclick = runNow;
  $('autorun').onchange = function () { setPref('autorun', this.checked); if (S.prefs.autorun) scheduleRun(100); };
  $('startrule').onchange = function () {
    var g = S.gres;
    if (g) S.start[g.name] = this.value;
    runNow();
  };
  $('x-diagram').onclick = function () { setPref('diagram', false); };
  $('x-output').onclick = function () { setPref('output', false); };
  $('w-open').onclick = openDialog;
  $('w-grammar').onclick = newGrammar;
  $('w-input').onclick = newInput;
  showView(S.prefs.view || 'diagram');
  refreshPanels();

  api('GET', '/api/info').then(function (info) {
    S.info = info;
    $('rootname').textContent = info.rootName;
    $('rootname').title = info.root;
    if (!info.tool.found) toast(info.tool.error, 'error');
    var session = store.get('session:' + info.root, null);
    var fromCli = info.open.length > 0;
    var list = fromCli ? info.open.map(function (p) { return { path: p }; }) : (session ? session.open : []);
    var chain = Promise.resolve();
    list.forEach(function (f) { chain = chain.then(function () { return openFile(f.path, { noFocus: true, kind: fromCli ? undefined : f.kind }); }); });
    return chain.then(function () {
      if (!S.tabs.length) { showEmpty(); return; }
      var pick = null;
      if (!fromCli && session && session.active) S.tabs.forEach(function (t) { if (t.path === session.active) pick = t; });
      pick = pick || firstOfKind('input') || S.tabs[0];
      activate(pick.id, true);
      if (firstOfKind('grammar')) { S.lastGrammar = firstOfKind('grammar').id; }
      scheduleRun(50);
    });
  }).catch(fatal);
}

boot();
})();