// The workspace of the Терминал view: panes - terminals, file managers - of
// one or more machines, in tabs. It lives as long as the page, so moving to
// Машины or Настройки and back keeps every session. With one tab there is
// only a faint "+" in the corner; a second tab brings the tab strip in. On a
// computer a tab can be dragged onto the current one to share it - up to four
// panes, split side by side or one above the other - and a pane dragged out
// of it back to the strip. Splits resize by their gutters; a tab is renamed
// by a double click on its title. Pane types register in Workspace.paneTypes.
(function () {
  'use strict';
  const touch = matchMedia('(pointer: coarse)').matches;
  const desk = !touch; // drag and drop, splits: computers only
  if (touch) document.body.classList.add('touch');
  const $ = id => document.getElementById(id);
  const statusEl = $('status'), area = $('area'), tablist = $('tablist'), addBtn = $('tabadd'),
    floatAdd = $('floatadd'), addMenu = $('addmenu'), hint = $('hint'), mark = $('tabmark');
  const base = '/api/panel/term/';
  const GAP = 6;
  const X = '<svg width="12" height="12" viewBox="0 0 24 24" fill="none" stroke="currentColor" stroke-width="2.6" stroke-linecap="round"><path d="M18 6 6 18M6 6l12 12"/></svg>';

  // ---------- tabs ----------
  const tabs = [];
  let active = null, activePane = null;
  const tabOf = s => tabs.find(t => t.panes.includes(s));

  function makeTab(panes, index) {
    const t = { title: null, panes: panes, layout: panes.length === 1 ? '1' : 'h', c: 0.5, r: 0.5, gutters: [] };
    t.view = document.createElement('div');
    t.view.className = 'tabview';
    area.insertBefore(t.view, hint);
    panes.forEach(s => t.view.appendChild(s.el));
    t.el = document.createElement('div');
    t.el.className = 'tab enter';
    t.el.innerHTML = '<span class="dot wait"></span><span class="tab-title"></span>' +
      '<button type="button" class="tab-x" title="Закрыть вкладку" aria-label="Закрыть вкладку">' + X + '</button>';
    t.el.addEventListener('click', ev => { if (!ev.target.closest('.tab-x, input') && !dragJustEnded) activate(t); });
    t.el.querySelector('.tab-x').onclick = ev => { ev.stopPropagation(); closeTab(t); };
    t.el.querySelector('.tab-title').addEventListener('dblclick', ev => { ev.stopPropagation(); rename(t); });
    // Its machine's Порты, Статус, Изменить: a right click on the title.
    t.el.addEventListener('contextmenu', ev => {
      const p = t.panes.includes(activePane) ? activePane : t.panes[0];
      if (window.MachineDialog && !ev.target.closest('input')) MachineDialog.menu(ev, p.agent);
    });
    if (desk) t.el.addEventListener('pointerdown', ev => { if (!ev.target.closest('.tab-x, input')) startDrag(ev, 'tab', t); });
    const at = index == null ? tabs.length : index;
    tablist.insertBefore(t.el, tabs[at] ? tabs[at].el : mark);
    tabs.splice(at, 0, t);
    renderTab(t);
    fitTabs();
    requestAnimationFrame(() => requestAnimationFrame(() => t.el.classList.remove('enter')));
    return t;
  }
  function tabTitle(t) {
    if (t.title) return t.title;
    const name = t.panes[0].title();
    return t.panes.length > 1 ? name + ' +' + (t.panes.length - 1) : name;
  }
  // Tab widths: as wide as the title wants, from a comfortable minimum up to
  // a maximum; when they do not fit, all give way evenly down to a floor,
  // titles cut with "…", and below the floor the strip scrolls instead.
  const ruler = document.createElement('canvas').getContext('2d');
  const W = touch ? { min: 76, base: 124, max: 180, font: 12 } : { min: 96, base: 180, max: 300, font: 13 };
  const CHROME = touch ? 52 : 62; // padding, dot, gaps, close button, borders
  function fitTabs() {
    ruler.font = W.font + 'px ' + getComputedStyle(document.body).fontFamily;
    const live = tabs;
    const want = live.map(t => Math.min(W.max, Math.max(W.base, Math.ceil(ruler.measureText(tabTitle(t)).width) + CHROME + (t.panes.some(p => p.ssh) ? 46 : 0))));
    const strip = $('tabs');
    const room = strip.clientWidth - parseFloat(getComputedStyle(strip).paddingLeft) * 2 - addBtn.offsetWidth - 4 * (live.length + 1);
    let cap = W.max;
    if (want.reduce((a, b) => a + b, 0) > room) {
      // The widest give way first, to one width for all at the most.
      let lo = W.min, hi = W.max;
      for (let k = 0; k < 20; k++) {
        const mid = (lo + hi) / 2;
        if (want.reduce((a, b) => a + Math.min(b, mid), 0) > room) hi = mid; else lo = mid;
      }
      cap = Math.max(W.min, Math.floor(lo));
    }
    live.forEach((t, i) => { t.el.style.width = Math.min(want[i], cap) + 'px'; });
  }
  window.addEventListener('resize', () => fitTabs());

  function renderTab(t) {
    t.el.querySelector('.tab-title').textContent = tabTitle(t);
    const ssh = t.panes.some(s => s.ssh);
    if (ssh !== !!t.el.querySelector('.badge-ssh')) {
      if (ssh) t.el.querySelector('.dot').insertAdjacentHTML('afterend', '<span class="badge-ssh">SSH</span>');
      else t.el.querySelector('.badge-ssh').remove();
    }
    requestAnimationFrame(fitTabs);
    t.el.title = t.panes.map(p => p.tooltip ? p.tooltip() : p.title()).join(', ');
    // The tab's dot: red if any shell failed, amber while one connects.
    const st = t.panes.map(s => s.state);
    t.el.querySelector('.dot').className = 'dot ' + (st.includes('err') ? 'err' : st.includes('wait') ? 'wait' : st.includes('ok') ? 'ok' : 'off');
    t.el.classList.toggle('on', t === active);
    t.view.classList.toggle('split', t.panes.length > 1);
    syncFloat();
  }
  function activate(t) {
    if (!t) return;
    active = t;
    tabs.forEach(x => { x.view.classList.toggle('on', x === t); renderTab(x); });
    if (!t.panes.includes(activePane)) setActivePane(t.panes[0]);
    layout(t, false);
    t.el.scrollIntoView({ block: 'nearest', inline: 'nearest', behavior: 'smooth' });
    if (desk && activePane) activePane.focus();
    updateMode();
    // The tab comes in moving a little; the "+" goes by where it ends up.
    setTimeout(placeFloat, 260);
  }
  function setActivePane(s) {
    activePane = s;
    // The phone's extra keys are a terminal's: a file pane goes without.
    const term = s.kind === 'term' || s.kind === 'ssh';
    if (touch && document.body.classList.contains('term-active') !== term) {
      document.body.classList.toggle('term-active', term);
      setTimeout(() => active && layout(active, false), 0);
    }
    document.querySelectorAll('.pane.active').forEach(p => p.classList.toggle('active', p === s.el));
    s.el.classList.add('active');
    showStatus();
  }
  function showStatus() {
    // The header's status line is the workspace's only while it is shown.
    if (!activePane || document.querySelector('main#app').dataset.view !== 'terminal') { statusEl.textContent = ''; return; }
    statusEl.textContent = activePane.text;
    statusEl.title = activePane.text;
    statusEl.className = activePane.state === 'ok' ? 'st-ok' : activePane.state === 'err' ? 'st-err' : 'muted';
  }
  // The corner "+" moves down out of the way of a split tab's title bars.
  function syncFloat() {
    document.body.classList.toggle('split1', tabs.length === 1 && tabs[0].panes.length > 1);
    placeFloat();
  }
  // With one tab and a file pane in the top right corner, the "+" joins
  // that pane's top bar: right of "Обновить", above "Удалить выбранное",
  // a button of the same size. Otherwise it is back in the corner.
  function placeFloat() {
    const p = tabs.length === 1 ? tabs[0].panes.find(s => s.el.classList.contains('under-plus')) : null;
    const bars = p && /files$/.test(p.kind) ? p.el.querySelectorAll('.fm-bar') : [];
    // A bar folded in two (a phone) keeps the corner "+".
    const on = bars.length > 1 && bars[0].offsetParent !== null && bars[0].offsetHeight < 48;
    floatAdd.classList.toggle('in-files', on);
    if (!on) { floatAdd.style.top = floatAdd.style.right = ''; return; }
    const a = area.getBoundingClientRect(), top = bars[0].getBoundingClientRect(), row = bars[1].getBoundingClientRect();
    floatAdd.style.top = (top.top - a.top - area.clientTop) + 'px';
    floatAdd.style.right = (a.left + area.clientLeft + area.clientWidth - row.right) + 'px';
  }
  // One tab: a plain terminal, the strip folded into the corner "+".
  function updateMode() {
    syncFloat();
    const multi = tabs.length > 1;
    if (document.body.classList.contains('multi') === multi) return;
    document.body.classList.toggle('multi', multi);
    setTimeout(() => active && layout(active, false), 280);
  }
  function openPane(kind, agent, opts) {
    const make = paneTypes[kind];
    if (!make) return null;
    $('empty').hidden = true;
    const t = makeTab([make(agent, opts || {})]);
    activate(t);
    return t;
  }
  function openTerminal(agent, ssh) { return openPane(ssh ? 'ssh' : 'term', agent, {ssh}); }
  async function closeTab(t) {
    const i = tabs.indexOf(t);
    if (i < 0) return;
    if (t.panes.length > 1 && !await UI.confirm('Закрыть вкладку с ' + t.panes.length + ' панелями?', {ok: 'Закрыть', danger: true})) return;
    tabs.splice(i, 1);
    t.panes.forEach(s => s.close());
    t.el.classList.add('leave');
    t.view.classList.remove('on');
    setTimeout(() => { t.el.remove(); t.view.remove(); }, 220);
    if (active === t) {
      active = null;
      activate(tabs[Math.min(i, tabs.length - 1)]);
    }
    if (!tabs.length) { activePane = null; showStatus(); $('empty').hidden = false; document.body.classList.remove('term-active'); }
    updateMode();
  }
  function rename(t) {
    const span = t.el.querySelector('.tab-title');
    const inp = document.createElement('input');
    inp.className = 'tab-edit';
    inp.value = tabTitle(t);
    inp.size = Math.max(6, inp.value.length);
    span.replaceWith(inp);
    inp.focus(); inp.select();
    let done = false;
    const end = save => {
      if (done) return;
      done = true;
      if (save) t.title = inp.value.trim() || null;
      inp.replaceWith(span);
      renderTab(t);
    };
    inp.onkeydown = ev => { if (ev.key === 'Enter') end(true); else if (ev.key === 'Escape') end(false); ev.stopPropagation(); };
    inp.onblur = () => end(true);
    inp.onpointerdown = ev => ev.stopPropagation();
  }

  // ---------- splits ----------
  // Where each terminal of a tab goes, and its gutters, for a layout:
  // 1, h (side by side), v (one above the other), top2 (two over one),
  // bottom2 (one over two), grid (two over two). c and r are where the
  // column and the row divide.
  function rects(layout, c, r, W, H) {
    const g = GAP, cw = Math.round((W - g) * c), rh = Math.round((H - g) * r);
    const top = (y, h) => [{ x: 0, y, w: cw, h }, { x: cw + g, y, w: W - cw - g, h }];
    const colG = (y, h) => ({ k: 'c', x: cw, y, w: g, h });
    const rowG = { k: 'r', x: 0, y: rh, w: W, h: g };
    const bottomY = rh + g, bottomH = H - rh - g;
    switch (layout) {
      case 'h': return { panes: top(0, H), gutters: [colG(0, H)] };
      case 'v': return { panes: [{ x: 0, y: 0, w: W, h: rh }, { x: 0, y: bottomY, w: W, h: bottomH }], gutters: [rowG] };
      case 'top2': return { panes: top(0, rh).concat([{ x: 0, y: bottomY, w: W, h: bottomH }]), gutters: [colG(0, rh), rowG] };
      case 'bottom2': return { panes: [{ x: 0, y: 0, w: W, h: rh }].concat(top(bottomY, bottomH)), gutters: [colG(bottomY, bottomH), rowG] };
      case 'grid': return { panes: top(0, rh).concat(top(bottomY, bottomH)), gutters: [colG(0, H), rowG] };
      default: return { panes: [{ x: 0, y: 0, w: W, h: H }], gutters: [] };
    }
  }
  function layout(t, animate) {
    const W = t.view.clientWidth, H = t.view.clientHeight;
    if (!W || !H) return;
    const L = rects(t.layout, t.c, t.r, W, H);
    t.view.classList.toggle('instant', !animate);
    // The pane in the top right corner sits under the corner "+": it keeps
    // its first bar clear of it.
    let corner = 0;
    L.panes.forEach((p, i) => { const c = L.panes[corner]; if (p.y < c.y || (p.y === c.y && p.x + p.w > c.x + c.w)) corner = i; });
    t.panes.forEach((s, i) => {
      const p = L.panes[i];
      s.el.style.left = p.x + 'px'; s.el.style.top = p.y + 'px';
      s.el.style.width = p.w + 'px'; s.el.style.height = p.h + 'px';
      s.el.classList.toggle('under-plus', i === corner);
    });
    while (t.gutters.length < L.gutters.length) {
      const g = document.createElement('div');
      g.className = 'gutter';
      g.addEventListener('pointerdown', ev => startResize(ev, t, g));
      t.view.appendChild(g);
      t.gutters.push(g);
    }
    t.gutters.forEach((g, i) => {
      const d = L.gutters[i];
      g.hidden = !d;
      if (!d) return;
      g.className = 'gutter ' + d.k;
      g.style.left = d.x + 'px'; g.style.top = d.y + 'px'; g.style.width = d.w + 'px'; g.style.height = d.h + 'px';
    });
    clearTimeout(t.fitTimer);
    t.fitTimer = setTimeout(() => { t.panes.forEach(s => s.fit()); placeFloat(); }, animate ? 270 : 0);
  }
  function startResize(ev, t, g) {
    ev.preventDefault();
    g.setPointerCapture(ev.pointerId);
    const box = t.view.getBoundingClientRect(), k = g.classList.contains('c') ? 'c' : 'r';
    g.classList.add('drag');
    let raf = 0;
    const move = e => {
      const v = k === 'c' ? (e.clientX - box.left) / box.width : (e.clientY - box.top) / box.height;
      t[k] = Math.min(0.85, Math.max(0.15, v));
      if (!raf) raf = requestAnimationFrame(() => { raf = 0; layout(t, false); });
    };
    const up = () => {
      g.classList.remove('drag');
      g.removeEventListener('pointermove', move);
      g.removeEventListener('pointerup', up);
      layout(t, false);
    };
    g.addEventListener('pointermove', move);
    g.addEventListener('pointerup', up);
  }
  // A layout with one terminal fewer, the others keeping their places.
  function withoutPane(layout, i) {
    if (layout === 'h' || layout === 'v') return '1';
    if (layout === 'top2') return i === 2 ? 'h' : 'v';
    if (layout === 'bottom2') return i === 0 ? 'h' : 'v';
    if (layout === 'grid') return i < 2 ? 'bottom2' : 'top2';
    return '1';
  }
  function takePane(t, s) {
    const i = t.panes.indexOf(s);
    t.layout = withoutPane(t.layout, i);
    t.panes.splice(i, 1);
  }
  function closePane(s) {
    const t = tabOf(s);
    if (!t) return;
    if (t.panes.length === 1) { closeTab(t); return; }
    takePane(t, s);
    s.close();
    if (activePane === s) setActivePane(t.panes[0]);
    renderTab(t);
    layout(t, true);
  }
  // Where a terminal dropped on tab t at (x, y) would go: the new layout,
  // the order of its terminals ('P' the new one), and its place.
  const SIDE = { left: 'слева', right: 'справа', top: 'сверху', bottom: 'снизу' };
  function mergePlan(t, x, y) {
    const n = t.panes.length, W = t.view.clientWidth, H = t.view.clientHeight;
    const fx = x / W, fy = y / H;
    let lay, order, label;
    if (n === 1) {
      const d = { left: fx, right: 1 - fx, top: fy, bottom: 1 - fy };
      const k = Object.keys(d).reduce((a, b) => d[a] <= d[b] ? a : b);
      lay = k === 'left' || k === 'right' ? 'h' : 'v';
      order = k === 'left' || k === 'top' ? ['P', 0] : [0, 'P'];
      label = SIDE[k];
    } else if (n === 2 && t.layout === 'h') {
      if (fy < 0.5) { lay = 'bottom2'; order = ['P', 0, 1]; label = 'сверху'; }
      else { lay = 'top2'; order = [0, 1, 'P']; label = 'снизу'; }
    } else if (n === 2) {
      if (fy < 0.5) { lay = 'top2'; order = fx < 0.5 ? ['P', 0, 1] : [0, 'P', 1]; }
      else { lay = 'bottom2'; order = fx < 0.5 ? [0, 'P', 1] : [0, 1, 'P']; }
      label = (fy < 0.5 ? 'сверху ' : 'снизу ') + (fx < 0.5 ? 'слева' : 'справа');
    } else if (n === 3) {
      lay = 'grid';
      if (t.layout === 'top2') { order = fx < 0.5 ? [0, 1, 'P', 2] : [0, 1, 2, 'P']; label = 'снизу ' + (fx < 0.5 ? 'слева' : 'справа'); }
      else { order = fx < 0.5 ? ['P', 0, 1, 2] : [0, 'P', 1, 2]; label = 'сверху ' + (fx < 0.5 ? 'слева' : 'справа'); }
    } else return null;
    return { layout: lay, order, label, rect: rects(lay, t.c, t.r, W, H).panes[order.indexOf('P')] };
  }

  // ---------- drag and drop ----------
  // A tab: along the strip to reorder it, or onto the current tab to join
  // it. A terminal from a split, by its title bar: to the strip to make it a
  // tab of its own, or onto another terminal of its tab to swap places.
  let drag = null, dragJustEnded = false;
  function startDrag(ev, kind, obj) {
    if (ev.button !== 0) return;
    drag = { kind, obj, x0: ev.clientX, y0: ev.clientY, on: false, id: ev.pointerId };
  }
  function beginDrag() {
    drag.on = true;
    const src = drag.kind === 'tab' ? drag.obj.el : drag.obj.el.querySelector('.pane-head');
    const g = document.createElement('div');
    g.className = 'drag-ghost ' + drag.kind;
    g.textContent = drag.kind === 'tab' ? tabTitle(drag.obj) : (drag.obj.tooltip ? drag.obj.tooltip() : drag.obj.title());
    document.body.appendChild(g);
    drag.ghost = g;
    drag.src = src;
    src.classList.add('dragging');
    document.body.classList.add('dnd');
    // Pulling a terminal out: the strip shows, one tab or not, to drop it on.
    if (drag.kind === 'pane') document.body.classList.add('multi-hint');
  }
  function stripIndex(x) {
    const others = tabs.filter(t => !(drag.kind === 'tab' && t === drag.obj));
    let i = others.findIndex(t => { const r = t.el.getBoundingClientRect(); return x < r.left + r.width / 2; });
    if (i < 0) i = others.length;
    const ref = others[i] ? others[i].el.getBoundingClientRect() : (others.length ? others[others.length - 1].el.getBoundingClientRect() : null);
    const lr = tablist.getBoundingClientRect();
    const mx = others[i] ? ref.left - 3 : ref ? ref.right + 1 : lr.left;
    return { i, others, mx: mx - lr.left + tablist.scrollLeft };
  }
  function showHint(r, label, bad) {
    hint.hidden = false;
    hint.classList.toggle('bad', !!bad);
    const v = active.view;
    hint.style.left = (v.offsetLeft + r.x) + 'px'; hint.style.top = (v.offsetTop + r.y) + 'px';
    hint.style.width = r.w + 'px'; hint.style.height = r.h + 'px';
    hint.textContent = label;
  }
  function onDragMove(ev) {
    if (!drag || ev.pointerId !== drag.id) return;
    if (!drag.on) {
      if (Math.hypot(ev.clientX - drag.x0, ev.clientY - drag.y0) < 6) return;
      beginDrag();
    }
    drag.ghost.style.transform = 'translate(' + (ev.clientX + 10) + 'px,' + (ev.clientY + 8) + 'px)';
    drag.target = null;
    hint.hidden = true; mark.hidden = true;
    const strip = $('tabs').getBoundingClientRect();
    const stripShown = document.body.classList.contains('multi') || document.body.classList.contains('multi-hint');
    const inStrip = stripShown && ev.clientY >= strip.top - 6 && ev.clientY <= strip.bottom + 10;
    const inArea = active && (() => { const r = active.view.getBoundingClientRect(); return ev.clientX >= r.left && ev.clientX <= r.right && ev.clientY >= r.top && ev.clientY <= r.bottom; })();
    if (inStrip) {
      const s = stripIndex(ev.clientX);
      mark.hidden = false; mark.style.left = s.mx + 'px';
      drag.target = { kind: 'strip', index: s.i, others: s.others };
      drag.ghost.dataset.hint = drag.kind === 'tab' ? 'переставить' : 'отдельной вкладкой';
    } else if (inArea && drag.kind === 'tab' && drag.obj !== active) {
      const r = active.view.getBoundingClientRect();
      if (drag.obj.panes.length > 1) {
        showHint({ x: 0, y: 0, w: r.width, h: r.height }, 'вкладку с несколькими терминалами не объединить', true);
      } else if (active.panes.length >= 4) {
        showHint({ x: 0, y: 0, w: r.width, h: r.height }, 'в одной вкладке не больше 4 терминалов', true);
      } else {
        const plan = mergePlan(active, ev.clientX - r.left, ev.clientY - r.top);
        showHint(plan.rect, plan.label);
        drag.target = { kind: 'merge', plan };
      }
      drag.ghost.dataset.hint = '';
    } else if (inArea && drag.kind === 'pane' && tabOf(drag.obj) === active) {
      const r = active.view.getBoundingClientRect();
      const over = active.panes.find(s => { const p = s.el.getBoundingClientRect(); return s !== drag.obj && ev.clientX >= p.left && ev.clientX <= p.right && ev.clientY >= p.top && ev.clientY <= p.bottom; });
      if (over) {
        const p = over.el.getBoundingClientRect();
        showHint({ x: p.left - r.left, y: p.top - r.top, w: p.width, h: p.height }, 'поменять местами');
        drag.target = { kind: 'swap', with: over };
      }
      drag.ghost.dataset.hint = over ? '' : 'к вкладкам - отдельной вкладкой';
    } else {
      drag.ghost.dataset.hint = '';
    }
  }
  function onDragEnd(ev) {
    if (!drag || ev.pointerId !== drag.id) return;
    const d = drag;
    drag = null;
    if (!d.on) return;
    d.ghost.remove();
    d.src.classList.remove('dragging');
    document.body.classList.remove('dnd', 'multi-hint');
    hint.hidden = true; mark.hidden = true;
    dragJustEnded = true;
    setTimeout(() => { dragJustEnded = false; }, 0);
    const tg = d.target;
    if (!tg) return;
    if (d.kind === 'tab' && tg.kind === 'strip') {
      const t = d.obj, ref = tg.others[tg.index];
      tabs.splice(tabs.indexOf(t), 1);
      tabs.splice(ref ? tabs.indexOf(ref) : tabs.length, 0, t);
      tablist.insertBefore(t.el, ref ? ref.el : mark);
    } else if (d.kind === 'tab' && tg.kind === 'merge') {
      const src = d.obj, s = src.panes[0], t = active, plan = tg.plan;
      // The joining terminal starts where the hint showed it.
      s.el.classList.add('instant');
      s.el.style.left = plan.rect.x + 'px'; s.el.style.top = plan.rect.y + 'px';
      s.el.style.width = plan.rect.w + 'px'; s.el.style.height = plan.rect.h + 'px';
      t.view.appendChild(s.el);
      requestAnimationFrame(() => s.el.classList.remove('instant'));
      t.panes = plan.order.map(o => o === 'P' ? s : t.panes[o]);
      t.layout = plan.layout;
      tabs.splice(tabs.indexOf(src), 1);
      src.el.classList.add('leave');
      setTimeout(() => { src.el.remove(); src.view.remove(); }, 220);
      setActivePane(s);
      renderTab(t);
      layout(t, true);
      updateMode();
      s.focus();
    } else if (d.kind === 'pane' && tg.kind === 'strip') {
      const s = d.obj, from = tabOf(s), ref = tg.others[tg.index];
      takePane(from, s);
      renderTab(from);
      const t = makeTab([s], ref ? tabs.indexOf(ref) : tabs.length);
      layout(from, true);
      activate(t);
    } else if (d.kind === 'pane' && tg.kind === 'swap') {
      const t = active, a = t.panes.indexOf(d.obj), b = t.panes.indexOf(tg.with);
      [t.panes[a], t.panes[b]] = [t.panes[b], t.panes[a]];
      layout(t, true);
    }
  }
  window.addEventListener('pointermove', onDragMove);
  window.addEventListener('pointerup', onDragEnd);
  window.addEventListener('pointercancel', onDragEnd);

  // ---------- the "+" menu ----------
  let agentsCache = null;
  function openMenu(anchor) {
    const here = activePane && activePane.agent;
    addMenu.innerHTML = '';
    const esc = v => String(v).replace(/[&<>"]/g, c => ({ '&': '&amp;', '<': '&lt;', '>': '&gt;', '"': '&quot;' }[c]));
    const item = (parent, html, fn, cls) => {
      const b = document.createElement('button');
      b.type = 'button'; b.className = 'item ' + (cls || ''); b.innerHTML = html;
      b.onclick = fn;
      parent.appendChild(b);
      return b;
    };
    const FILES = '<svg width="16" height="16" viewBox="0 0 24 24" fill="none" stroke="currentColor" stroke-width="2" stroke-linecap="round" stroke-linejoin="round"><path d="M3 7a2 2 0 0 1 2-2h4l2 2.5h8a2 2 0 0 1 2 2V17a2 2 0 0 1-2 2H5a2 2 0 0 1-2-2z"/></svg>';
    // Both groups keep their contents mounted so they can animate in both directions.
    const group = (icon, label, kind, mode) => {
      let loaded = false;
      const g = item(addMenu, '<span class="ico">' + icon + '</span><span><b>' + label + '</b></span><span class="chev" aria-hidden="true">›</span>', () => {
        const opening = g.getAttribute('aria-expanded') !== 'true';
        addMenu.querySelectorAll('.item[aria-expanded="true"]').forEach(b => {
          b.setAttribute('aria-expanded', 'false');
          b.nextSibling.classList.remove('open');
          b.nextSibling.inert = true;
        });
        if (!opening) { placeMenu(anchor); return; }
        g.setAttribute('aria-expanded', 'true');
        list.classList.add('open');
        list.inert = false;
        placeMenu(anchor);
        if (loaded) return;
        loaded = true;
        (agentsCache ? Promise.resolve(agentsCache) : fetch('/api/panel/agents/presence', { cache: 'no-store' }).then(r => r.json()))
          .then(all => {
            agentsCache = all;
            box.innerHTML = '';
            all.filter(a => !here || a.id !== here.id).forEach(a => {
              const b = item(box, '<span class="dot ' + (a.online ? 'ok' : 'off') + '"></span><span><b>' + esc(a.name) + '</b><small>' +
                esc(a.user + '@' + a.hostname) + (a.online ? '' : ' · ' + esc(a.seen)) + '</small></span>',
                () => { closeMenu(); openPane(kind, { id: a.id, name: a.name, host: a.hostname, user: a.user }); }, 'machine');
              b.disabled = !a.online;
            });
            if (list.isConnected) placeMenu(anchor);
          })
          .catch(() => { box.innerHTML = '<div class="muted" style="padding:8px 10px">не загрузилось</div>'; });
      });
      g.setAttribute('aria-expanded', 'false');
      const list = document.createElement('div');
      list.className = 'mlist';
      list.inert = true;
      const inner = document.createElement('div');
      inner.className = 'mlist-inner';
      const content = document.createElement('div');
      content.className = 'mlist-content';
      inner.appendChild(content);
      list.appendChild(inner);
      g.after(list);
      if (here) item(content, '<span class="ico">+</span><span><b>Здесь</b><small>' + esc(here.name) + ' · ' + esc(here.user + '@' + here.host) + '</small></span>',
        () => { closeMenu(); openPane(kind, here); });
      const box = document.createElement('div');
      box.innerHTML = '<div class="muted" style="padding:8px 10px;font-size:13px">загрузка…</div>';
      content.appendChild(box);
      item(content, '<span class="ico">' + KEYI + '</span><span><b>SSH-хост…</b><small>машина откроет SSH к другому хосту</small></span>',
        () => { closeMenu(); openSSH(here, mode); });
      if (!paneTypes[kind]) g.disabled = true;
      return g;
    };
    group('&gt;_', 'Терминал', 'term', 'term');
    group(FILES, 'Файловый менеджер', 'files', 'files');
    addMenu.hidden = false;
    placeMenu(anchor);
    setTimeout(() => document.addEventListener('pointerdown', outside, true), 0);
  }
  function placeMenu(anchor) {
    const r = anchor.getBoundingClientRect(), m = addMenu.getBoundingClientRect();
    addMenu.style.left = Math.max(8, Math.min(innerWidth - m.width - 8, r.right - m.width)) + 'px';
    addMenu.style.top = Math.min(innerHeight - m.height - 8, r.bottom + 6) + 'px';
  }
  function outside(ev) { if (!addMenu.contains(ev.target)) closeMenu(); }
  function closeMenu() {
    addMenu.hidden = true;
    agentsCache = null;
    document.removeEventListener('pointerdown', outside, true);
  }
  addBtn.onclick = () => openMenu(addBtn);
  floatAdd.onclick = () => openMenu(floatAdd);
  $('emptyadd').onclick = ev => openMenu(ev.currentTarget);
  document.addEventListener('keydown', ev => { if (ev.key === 'Escape' && !addMenu.hidden) closeMenu(); });

  // ---------- the SSH dialog ----------
  const KEYI = '<svg width="16" height="16" viewBox="0 0 24 24" fill="none" stroke="currentColor" stroke-width="2" stroke-linecap="round" stroke-linejoin="round"><circle cx="7.5" cy="15.5" r="4.5"/><path d="m21 2-9.6 9.6M15.5 7.5l3 3L22 7l-3-3"/></svg>';
  let sshInto = null, sshDlg = null, sshMode = 'term';
  // openSSH asks where to connect; mode says what opens there: a terminal
  // ('term') or a file manager ('files', through Workspace.sshFiles).
  // into: a file pane whose SSH connection is lost - the dialog comes with
  // its host, port and user, and connects that pane again.
  function openSSH(here, mode, into) {
    if (!sshDlg) sshDlg = makeSSHDialog();
    sshDlg.show(here, mode || 'term', into);
  }
  function makeSSHDialog() {
    const d = document.createElement('dialog');
    d.className = 'sshdlg';
    d.innerHTML =
      '<form method="dialog" autocomplete="off">' +
      '<div class="dlg-h"><span class="ico">' + KEYI + '</span><strong style="flex:1">SSH-подключение</strong>' +
      '<button type="button" class="btn ghost small icon close x" data-close aria-label="Закрыть">' + X + '</button></div>' +
      '<div class="dlg-b">' +
      '<label class="f"><span>Подключаться с машины</span><select name="agent"></select></label>' +
      '<div class="f saved-row"><span>Сохранённый хост</span><div class="frow"><select name="saved" class="grow"><option value="">новый хост</option></select>' +
      '<button type="button" class="btn ghost small icon close x" data-delsaved title="Удалить из сохранённых" aria-label="Удалить из сохранённых" hidden>' + X + '</button></div></div>' +
      '<div class="frow"><label class="f grow"><span>Хост</span><input type="text" name="host" placeholder="example.com или 10.0.0.5" required autocapitalize="off" spellcheck="false"></label>' +
      '<label class="f port"><span>Порт</span><input type="number" name="port" min="1" max="65535" value="22" required></label></div>' +
      '<label class="f"><span>Пользователь</span><input type="text" name="user" placeholder="root" required autocapitalize="off" spellcheck="false"></label>' +
      '<div class="f auth-row"><span>Вход</span><div class="seg" role="tablist">' +
      '<button type="button" data-auth="password" class="on">Пароль</button><button type="button" data-auth="key">Ключ</button><button type="button" data-auth="agent">Ключи агента</button></div></div>' +
      '<div class="auth" data-for="password"><input type="password" name="password" placeholder="пароль" autocomplete="off"></div>' +
      '<div class="auth" data-for="key" hidden>' +
      '<textarea name="key" rows="5" spellcheck="false" placeholder="-----BEGIN OPENSSH PRIVATE KEY-----&#10;…вставьте ключ или загрузите файл"></textarea>' +
      '<div class="frow"><button type="button" class="btn ghost small" data-load>Загрузить файл…</button><span class="muted keyname"></span>' +
      '<input type="file" hidden></div>' +
      '<input type="password" name="passphrase" placeholder="фраза ключа, если есть" autocomplete="off"></div>' +
      '<p class="auth muted" data-for="agent" hidden>Агент войдёт своими ключами из ~/.ssh (id_ed25519, id_ecdsa, id_rsa) без фразы.</p>' +
      '<label class="chk save-row"><input type="checkbox" name="save"> Сохранить хост и вход - на сервере, зашифровано, только для вас</label>' +
      '<p class="sshmsg"></p>' +
      '<div class="row end"><button type="button" class="btn ghost" data-close>Отмена</button><button type="submit">Подключиться</button></div>' +
      '</div></form>';
    document.body.appendChild(d);
    const f = d.querySelector('form'), msg = d.querySelector('.sshmsg');
    // say: a line under the form - red for what went wrong, quiet for what goes on.
    const say = (t, going) => { msg.textContent = t; msg.classList.toggle('going', !!going); };
    let auth = 'password';
    const setAuth = a => {
      auth = a;
      d.querySelectorAll('.seg button').forEach(b => b.classList.toggle('on', b.dataset.auth === a));
      d.querySelectorAll('.auth').forEach(el => { el.hidden = el.dataset.for !== a; });
    };
    d.querySelectorAll('.seg button').forEach(b => { b.onclick = () => setAuth(b.dataset.auth); });
    d.querySelectorAll('[data-close]').forEach(b => { b.onclick = () => close(); });
    const file = d.querySelector('input[type=file]');
    d.querySelector('[data-load]').onclick = () => file.click();
    file.onchange = () => {
      const fl = file.files[0];
      if (!fl) return;
      if (fl.size > 32768) { say('файл великоват для ключа'); return; }
      fl.text().then(t => { f.key.value = t.trim() + '\n'; d.querySelector('.keyname').textContent = fl.name; say(''); });
      file.value = '';
    };
    // then runs once the dialog is shut and focus is back where it was, so
    // what it focuses stays focused.
    function close(then) {
      d.close();
      if (then) then();
    }
    d.addEventListener('cancel', ev => { ev.preventDefault(); close(); });
    d.addEventListener('click', ev => { if (ev.target === d) close(); });
    let agents = [], saved = [];
    // A saved host: its address shows, the way in stays on the server.
    const useSaved = () => {
      const h = saved.find(x => String(x.id) === f.saved.value);
      d.querySelector('[data-delsaved]').hidden = !h;
      d.querySelectorAll('.auth-row, .auth, .save-row').forEach(el => { el.style.display = h ? 'none' : ''; });
      if (!h) { setAuth(auth); return; }
      f.host.value = h.host; f.port.value = h.port; f.user.value = h.user;
    };
    f.saved.onchange = useSaved;
    const loadSaved = () => fetch('/api/panel/ssh/hosts', { cache: 'no-store' }).then(r => r.json()).then(list => {
      saved = list || [];
      const keep = f.saved.value;
      f.saved.innerHTML = '<option value="">новый хост</option>' + saved.map(h => '<option value="' + h.id + '">' +
        String(h.label).replace(/[&<>"]/g, c => ({ '&': '&amp;', '<': '&lt;', '>': '&gt;', '"': '&quot;' }[c])) + '</option>').join('');
      f.saved.value = saved.some(h => String(h.id) === keep) ? keep : '';
      d.querySelector('.saved-row').hidden = !saved.length;
      useSaved();
    }).catch(() => {});
    d.querySelector('[data-delsaved]').onclick = async () => {
      const h = saved.find(x => String(x.id) === f.saved.value);
      if (!h || !await UI.confirm('Удалить «' + h.label + '» из сохранённых?', { ok: 'Удалить', danger: true })) return;
      await fetch('/api/panel/ssh/hosts/' + h.id + '/delete', { method: 'POST' });
      f.saved.value = '';
      loadSaved();
    };
    f.onsubmit = async ev => {
      ev.preventDefault();
      const a = agents.find(x => x.id === f.agent.value);
      if (!a) { say('выберите машину'); return; }
      const t = { host: f.host.value.trim(), port: Number(f.port.value) || 22, user: f.user.value.trim() };
      if (f.saved.value) {
        t.saved = Number(f.saved.value);
      } else if (auth === 'password') {
        if (!f.password.value) { say('введите пароль'); f.password.focus(); return; }
        t.password = f.password.value;
      } else if (auth === 'key') {
        if (!/PRIVATE KEY/.test(f.key.value)) { say('вставьте закрытый ключ или загрузите файл'); return; }
        t.key = f.key.value;
        if (f.passphrase.value) t.passphrase = f.passphrase.value;
      }
      if (!t.saved && f.save.checked) {
        // Saved first, then used by its id like any saved host.
        const r = await fetch('/api/panel/ssh/hosts', { method: 'POST', headers: { 'Content-Type': 'application/json' },
          body: JSON.stringify(Object.assign({ auth: auth }, t)) }).then(x => x.json()).catch(() => ({ ok: false, error: 'ошибка сети' }));
        if (!r.ok) { say(r.error || 'не сохранилось'); return; }
        f.save.checked = false;
        loadSaved();
      }
      try { localStorage.setItem('lpra.ssh.last', JSON.stringify({ agent: a.id, host: t.host, port: t.port, user: t.user, auth: auth, saved: t.saved || 0 })); } catch (e) { /* not kept */ }
      f.password.value = ''; f.passphrase.value = ''; f.key.value = '';
      d.querySelector('.keyname').textContent = '';
      if (sshMode === 'files') {
        // The machine connects first; the pane opens once it is in.
        const btn = f.querySelector('button[type=submit]');
        btn.disabled = true;
        say('подключение…', true);
        window.Workspace.sshFiles(a, t, sshInto).then(r => {
          btn.disabled = false;
          if (!r.ok) { say(r.error || 'не подключилось'); return; }
          say('');
          close();
        });
        return;
      }
      close(() => openTerminal(a, t));
    };
    return {
      show(here, mode, into) {
        sshMode = mode;
        sshInto = into || null;
        d.querySelector('.dlg-h strong').textContent = mode === 'files' ? 'Файлы по SSH' : 'SSH-подключение';
        say('');
        let last = {};
        try { last = JSON.parse(localStorage.getItem('lpra.ssh.last') || '{}'); } catch (e) { /* none */ }
        agents = here ? [here] : [];
        const fill = () => {
          f.agent.innerHTML = '';
          agents.forEach(a => {
            const o = document.createElement('option');
            o.value = a.id; o.textContent = a.name + ' · ' + a.user + '@' + a.host + (a.online === false ? ' (не в сети)' : '');
            o.disabled = a.online === false;
            f.agent.appendChild(o);
          });
          f.agent.value = agents.some(a => a.id === last.agent && a.online !== false) ? last.agent : (here ? here.id : (agents.find(a => a.online !== false) || {}).id || '');
        };
        fill();
        fetch('/api/panel/agents/presence', { cache: 'no-store' }).then(r => r.json()).then(all => {
          agents = all.map(a => ({ id: a.id, name: a.name, host: a.hostname, user: a.user, online: a.online }));
          if (here && !agents.some(a => a.id === here.id)) agents.unshift(here);
          fill();
        }).catch(() => {});
        if (into) last = { agent: here.id, host: into.ssh.host, port: into.ssh.port, user: into.ssh.user, auth: last.auth, saved: last.saved };
        f.saved.value = '';
        loadSaved().then(() => {
          // The host used last, if it was a saved one and still is.
          if (last.saved && saved.some(h => h.id === last.saved && h.host === last.host)) { f.saved.value = String(last.saved); useSaved(); }
        });
        if (last.host) { f.host.value = last.host; f.port.value = last.port || 22; f.user.value = last.user || ''; }
        setAuth(last.auth === 'key' || last.auth === 'agent' ? last.auth : 'password');
        d.showModal();
        // On a phone the keyboard waits for a tap.
        if (desk) (last.host ? (last.auth === 'password' || !last.auth ? f.password : f.host) : f.host).focus();
      }
    };
  }

  // ---------- page ----------
  function refit() {
    if (touch && window.visualViewport) {
      // Follow the visible area, so the extra keys sit right above the
      // on-screen keyboard.
      const vv = window.visualViewport;
      document.body.style.top = vv.offsetTop + 'px';
      document.body.style.height = vv.height + 'px';
    }
    if (active) layout(active, false);
  }
  window.addEventListener('resize', refit);
  if (touch && window.visualViewport) {
    window.visualViewport.addEventListener('resize', refit);
    window.visualViewport.addEventListener('scroll', refit);
  }
  window.addEventListener('pagehide', () => {
    tabs.forEach(t => t.panes.forEach(s => {
      if (s.sid) navigator.sendBeacon(base + s.sid + '/close');
      // A file pane on an SSH host lets the machine drop its connection.
      if (s.src && s.src.close) s.src.close();
    }));
  });

  // The view coming into sight: fit the panes, show the status line.
  document.addEventListener('app:view', ev => {
    if (ev.detail === 'terminal') { refit(); showStatus(); } else statusEl.textContent = '';
  });
  $('empty').hidden = tabs.length > 0;

  const paneTypes = {};
  // open opens a pane of kind on agent in a new tab and shows the view.
  function open(kind, agent, opts) {
    const t = openPane(kind, agent, opts);
    if (location.pathname !== '/workspace' && window.App) App.go('/workspace');
    return t;
  }
  const in_ = (el, x, y) => { const r = el.getBoundingClientRect(); return x >= r.left && x <= r.right && y >= r.top && y <= r.bottom; };
  window.Workspace = {
    paneTypes, desk, touch, open, activate,
    hasLiveSessions: () => tabs.some(t => t.panes.some(p => p.live())),
    panes: () => tabs.flatMap(t => t.panes),
    activePane: () => activePane,
    renderPane: p => { const t = tabOf(p); if (t) renderTab(t); if (p === activePane) showStatus(); },
    setActivePane, tabOf, renderTab, showStatus, closePane, startDrag, openSSH,
    // paneAt, tabAt: the pane of the shown tab, the tab title at a point.
    paneAt: (x, y) => active && active.panes.find(p => in_(p.el, x, y)),
    tabAt: (x, y) => document.body.classList.contains('multi') ? tabs.find(t => in_(t.el, x, y)) : null
  };
})();