/* =====================================================================
   L2 Physical Topology — display-only interactive map.
   Groups switches into frames (COBCO outer → workshop/DataCenter/Core),
   colours links by speed, nodes by latency & alarm, supports dark mode,
   terminal show / only-offline, live + historical snapshots, MAC/IP search.
   ===================================================================== */
(function () {
  'use strict';

  var CFG = window.L2_CFG || {};
  var T = window.L2_I18N || {};
  var META = window.L2_META || {};
  var SNAP = window.L2SNAP || null;

  var colors = CFG.colors || {100:'#F39C12',1000:'#2ECC71',10000:'#3498DB',20000:'#9B59B6',unknown:'#E74C3C',down:'#C0392B'};
  var LATW = (CFG.latency_warn != null) ? +CFG.latency_warn : 3;
  var LATB = (CFG.latency_bad != null) ? +CFG.latency_bad : 5;

  var TIER_BG = {core:'#1F4E78', dist:'#2E75B6', access:'#548235'};
  var TIER_BG_DARK = {core:'#1B4A72', dist:'#2A5E93', access:'#3E6B2E'};
  var SEV_COLORS = ['#97AAB3','#7499FF','#FFC859','#FFA059','#E97659','#E45959'];

  var NODE_W = 156, NODE_H = 50, GX = 26, GY = 18, PADX = 20, PADY = 42;
  var DGAP_X = 18, DGAP_Y = 26;
  var GROUP_GAP_X = 46, GROUP_GAP_Y = 48, MAXW = 2800;
  // overview ("全景") tiles
  var TILE_W = 232, TILE_H = 116, TILE_GAP_X = 24, TILE_GAP_Y = 22;

  var cy = null;
  var dark = false;
  var showTerm = false;
  var onlyOff = false;
  var paused = false;
  var countdown = 0;
  var timer = null;
  var lastSnap = null;
  var viewGroup = null;       // null = overview, otherwise workshop label

  function el(id) { return document.getElementById(id); }
  function t(k, d) { return (T[k] != null) ? T[k] : (d != null ? d : k); }

  /* ---------------- name parsing / grouping ---------------- */
  function parseName(name) {
    var r = {workshop:'', floor:'', cab:'', u:'', area:'', role:'', ip:''};
    if (!name) return r;
    var toks = String(name).split('-');
    for (var i = 0; i < toks.length; i++) {
      var tk = toks[i];
      if (/^\d{1,3}(\.\d{1,3}){3}$/.test(tk)) { r.ip = tk; continue; }
      if (!r.workshop && /^\d{4}$/.test(tk)) { r.workshop = tk; continue; }
      if (!r.floor && /^\d[A-Z]\w*$/i.test(tk)) {
        var m = /^(\d)([A-Z])(\w+)$/i.exec(tk);
        if (m) { r.floor = m[1]; r.cab = m[2]; r.u = m[3]; continue; }
      }
      if (!r.area && /^(OFFICE|SURVE|GRDA|DC|IDC|LAB|PROD)$/i.test(tk)) { r.area = tk.toUpperCase(); continue; }
      if (!r.role && /^(Dist|Access|Core)$/i.test(tk)) { r.role = tk; }
    }
    return r;
  }

  function labelFor(n) {
    var p = parseName(n.name);
    var l1 = [];
    if (p.workshop) l1.push(p.workshop);
    if (p.area) l1.push(p.area);
    if (!l1.length) {
      l1.push((n.name || '').split('-')[0] || n.ip);
    }
    var l2 = [];
    if (p.floor) { var loc = p.floor + 'F' + (p.cab || '') + (p.u ? '-' + p.u + 'U' : ''); l1.push(loc); }
    if (p.role) l2.push(p.role);
    l2.push(n.ip);
    return l1.join(' · ') + '\n' + l2.join(' · ');
  }

  function expandLabel(tpl, m) {
    return String(tpl).replace(/\$(\d)/g, function (_, d) { return m && m[+d] != null ? m[+d] : ''; });
  }

  function groupOf(n) {
    var name = n.name || n.ip || '';
    var rules = CFG.group_rules || [];
    for (var i = 0; i < rules.length; i++) {
      var r = rules[i];
      if (r.match === 'regex') {
        var re;
        try { re = new RegExp(r.pattern); } catch (e) { continue; }
        var m = re.exec(name);
        if (m) return {label: expandLabel(r.label, m) || (CFG.other_label || 'Other'), big: !!r.big};
      } else {
        if (name.toLowerCase().indexOf(String(r.pattern).toLowerCase()) >= 0) return {label: r.label || (CFG.other_label || 'Other'), big: !!r.big};
      }
    }
    return {label: CFG.other_label || 'Other', big: false};
  }

  /* ---------------- overview layout (workshop tiles) ---------------- */
  function groupStats(snap) {
    var map = {};
    var nodeById = {};
    (snap.nodes || []).forEach(function (n) {
      nodeById[n.id] = n;
      var g = groupOf(n);
      var s = map[g.label] || (map[g.label] = {label: g.label, big: g.big, nodes: [], alarms: 0, offline: 0, maxsev: -1, latmax: 0, up: 0});
      s.nodes.push(n);
      s.offline += (+n.term_offline || 0);
      if (n.alarms && n.alarms.length) {
        s.alarms += n.alarms.length;
        var sev = (n.maxsev != null && +n.maxsev >= 0) ? +n.maxsev : -1;
        n.alarms.forEach(function (a) { if (a && a.sev != null && +a.sev > sev) sev = +a.sev; });
        if (sev > s.maxsev) s.maxsev = sev;
      }
      if (n.latency_ms != null && +n.latency_ms > s.latmax) s.latmax = +n.latency_ms;
    });
    (snap.edges || []).forEach(function (e) {
      var a = nodeById[e.source], b = nodeById[e.target];
      if (!a || !b) return;
      var ga = groupOf(a), gb = groupOf(b);
      if (ga.label === gb.label) return;
      // count links that leave this workshop towards a core switch
      if ((/core/i.test(a.tier || '') || /core/i.test(a.name || '')) && map[gb.label]) map[gb.label].up++;
      if ((/core/i.test(b.tier || '') || /core/i.test(b.name || '')) && map[ga.label]) map[ga.label].up++;
    });
    return map;
  }

  function groupRank(l) {
    if (/core/i.test(l)) return 0;
    if (/data\s*center/i.test(l)) return 1;
    var m = /^(\d{4})([A-Za-z]?)$/.exec(l);
    if (m) return 1000 + parseInt(m[1], 10) * 40 + (m[2] ? m[2].toUpperCase().charCodeAt(0) - 64 : 0);
    return 5000;
  }

  function computeOverview(snap) {
    var stats = groupStats(snap);
    var labels = Object.keys(stats).sort(function (a, b) { return groupRank(a) - groupRank(b); });
    var special = labels.filter(function (l) { return groupRank(l) < 1000; });
    var others = labels.filter(function (l) { return groupRank(l) >= 1000; });

    var COLS = Math.max(4, Math.min(7, Math.ceil(Math.sqrt(Math.max(1, others.length)))));
    var gridW = COLS * TILE_W + (COLS - 1) * TILE_GAP_X;
    var pos = {}, tiles = [], y = 0;

    if (special.length) {
      var sW = special.length * TILE_W + (special.length - 1) * TILE_GAP_X;
      var sx = Math.max(0, (gridW - sW) / 2);
      special.forEach(function (l) {
        tiles.push({label: l, x: sx, y: y, w: TILE_W, h: TILE_H});
        pos[l] = {x: sx + TILE_W / 2, y: y + TILE_H / 2};
        sx += TILE_W + TILE_GAP_X;
      });
      y += TILE_H + 46;
    }

    var maxX = gridW, maxY = y;
    for (var i = 0; i < others.length; i += COLS) {
      var row = others.slice(i, i + COLS);
      var rW = row.length * TILE_W + (row.length - 1) * TILE_GAP_X;
      var rx = Math.max(0, (gridW - rW) / 2);
      row.forEach(function (l, j) {
        tiles.push({label: l, x: rx + j * (TILE_W + TILE_GAP_X), y: y, w: TILE_W, h: TILE_H});
        pos[l] = {x: rx + j * (TILE_W + TILE_GAP_X) + TILE_W / 2, y: y + TILE_H / 2};
      });
      y += TILE_H + TILE_GAP_Y;
      maxY = y - TILE_GAP_Y;
      maxX = Math.max(maxX, rx + rW);
    }

    var root = {x: -34, y: -64, w: maxX + 68, h: maxY + 64 + 40};
    root.cx = root.x + root.w / 2; root.cy = root.y + root.h / 2;
    return {stats: stats, labels: labels, pos: pos, tiles: tiles, root: root};
  }

  function aggregateEdges(snap) {
    var gid = {};
    (snap.nodes || []).forEach(function (n) { gid[n.id] = groupOf(n).label; });
    var pairs = {};
    (snap.edges || []).forEach(function (e) {
      var a = gid[e.source], b = gid[e.target];
      if (!a || !b || a === b) return;
      var k = (a < b) ? (a + '\u0001' + b) : (b + '\u0001' + a);
      var p = pairs[k] || (pairs[k] = {a: a, b: b, count: 0, speed: 0, down: false});
      p.count++;
      if ((parseFloat(e.speed) || 0) > p.speed) p.speed = parseFloat(e.speed) || 0;
      if (e.state && e.state !== 'up') p.down = true;
    });
    return Object.keys(pairs).map(function (k) { return pairs[k]; });
  }

  /* ---------------- detail layout (one workshop, tidy tree) ---------------- */
  function computeDetail(snap, label) {
    var all = snap.nodes || [];
    var byId = {}, nodes = [];
    all.forEach(function (n) { byId[n.id] = n; if (groupOf(n).label === label) nodes.push(n); });
    var ids = {};
    nodes.forEach(function (n) { ids[n.id] = true; });
    var internal = [], external = [];
    (snap.edges || []).forEach(function (e) {
      var a = ids[e.source], b = ids[e.target];
      if (a && b) internal.push(e);
      else if (a || b) external.push(e);
    });

    var adj = {}, kids = {};
    nodes.forEach(function (n) { adj[n.id] = []; kids[n.id] = []; });
    internal.forEach(function (e) { adj[e.source].push(e.target); adj[e.target].push(e.source); });

    function rankNode(n) {
      var tier = n.tier || '';
      if (/core/i.test(tier)) return 0;
      if (/dist/i.test(tier)) return 1;
      return 2;
    }
    var roots = nodes.slice().sort(function (a, b) {
      var ra = rankNode(a), rb = rankNode(b);
      if (ra !== rb) return ra - rb;
      return adj[b.id].length - adj[a.id].length;
    });
    var seen = {}, orderedRoots = [];
    roots.forEach(function (r) {
      if (seen[r.id]) return;
      orderedRoots.push(r);
      var queue = [r.id]; seen[r.id] = true;
      while (queue.length) {
        var cur = queue.shift();
        adj[cur].forEach(function (nb) {
          if (seen[nb]) return;
          seen[nb] = true;
          kids[cur].push(nb);
          queue.push(nb);
        });
      }
    });
    nodes.forEach(function (n) { if (!seen[n.id]) { seen[n.id] = true; orderedRoots.push(n); } });

    // Compact blocks: each dist root gets a grid of access switches underneath it.
    var pos = {}, blockX = 0, maxBlockH = 0;
    orderedRoots.forEach(function (rootN) {
      var d1 = kids[rootN.id] || [];
      var cols = Math.max(1, Math.min(5, Math.ceil(Math.sqrt(Math.max(1, d1.length) * 1.2))));
      var blockW = cols * NODE_W + (cols - 1) * DGAP_X;
      pos[rootN.id] = {x: blockX + blockW / 2, y: 0};
      d1.forEach(function (c, i) {
        var col = i % cols, row = Math.floor(i / cols);
        pos[c] = {x: blockX + col * (NODE_W + DGAP_X) + NODE_W / 2, y: (row + 1) * (NODE_H + DGAP_Y)};
      });
      var rows = Math.ceil(d1.length / cols);
      var d2 = [];
      d1.forEach(function (c) {
        (kids[c] || []).forEach(function (k) { if (k !== rootN.id) d2.push(k); });
      });
      var y2 = (rows + 1) * (NODE_H + DGAP_Y) + 16;
      d2.forEach(function (id, i) {
        pos[id] = {x: blockX + (i % cols) * (NODE_W + DGAP_X) + NODE_W / 2, y: y2 + Math.floor(i / cols) * (NODE_H + DGAP_Y)};
      });
      maxBlockH = Math.max(maxBlockH, y2 + Math.ceil(d2.length / cols) * (NODE_H + DGAP_Y));
      blockX += blockW + 70;
    });
    var missing = [];
    nodes.forEach(function (n) { if (!pos[n.id]) missing.push(n.id); });
    missing.forEach(function (id, i) {
      pos[id] = {x: (i % 6) * (NODE_W + DGAP_X) + NODE_W / 2, y: maxBlockH + 70 + Math.floor(i / 6) * (NODE_H + DGAP_Y)};
    });
    var totalW = Math.max(NODE_W, blockX - 70);

    var ghosts = [], ghostSeen = {};
    external.forEach(function (e) {
      var inside = ids[e.source] ? e.source : e.target;
      var outside = ids[e.source] ? e.target : e.source;
      if (!ghostSeen[outside]) {
        ghostSeen[outside] = {id: outside, to: inside, node: byId[outside], speed: e.speed, state: e.state};
        ghosts.push(ghostSeen[outside]);
      }
    });
    var ghostAt = {};
    ghosts.forEach(function (g) {
      var base = pos[g.to] || {x: 80};
      var k = ghostAt[g.to] || 0;
      ghostAt[g.to] = k + 1;
      g.x = base.x + (k ? (k % 2 ? 1 : -1) * 95 * Math.ceil(k / 2) : 0);
      g.y = -86 - Math.floor(k / 2) * 48;
    });

    var maxY = 0, minX = 0, maxX2 = totalW;
    Object.keys(pos).forEach(function (id) {
      maxY = Math.max(maxY, pos[id].y + NODE_H);
      minX = Math.min(minX, pos[id].x - NODE_W / 2);
      maxX2 = Math.max(maxX2, pos[id].x + NODE_W / 2);
    });
    ghosts.forEach(function (g) {
      minX = Math.min(minX, g.x - 95);
      maxX2 = Math.max(maxX2, g.x + 95);
    });
    var top = ghosts.length ? -168 : -120;
    var root = {x: minX - 38, y: top, w: (maxX2 - minX) + 76, h: maxY - top + 54};
    root.cx = root.x + root.w / 2; root.cy = root.y + root.h / 2;
    return {nodes: nodes, byId: byId, pos: pos, ghosts: ghosts, root: root, totalW: totalW, ids: ids, internal: internal};
  }

  /* ---------------- speed colour ---------------- */
  function speedColor(speed, state) {
    if (state && state !== 'up') return colors.down;
    var s = parseFloat(speed);
    if (!isFinite(s) || s <= 0) return colors.unknown;
    if (s <= 100) return colors['100'];
    if (s <= 1000) return colors['1000'];
    if (s <= 10000) return colors['10000'];
    return colors['20000'];
  }
  function speedWidth(speed) {
    var s = parseFloat(speed) || 0;
    if (s >= 20000) return 4.5;
    if (s >= 10000) return 3.6;
    if (s >= 1000) return 2.6;
    return 1.8;
  }
  function speedText(speed) {
    var s = parseFloat(speed) || 0;
    if (!s) return '?';
    if (s >= 1000) return (s / 1000) + 'G';
    return s + 'M';
  }

  /* ---------------- style ---------------- */
  function styleFor(d) {
    var bg = d ? TIER_BG_DARK : TIER_BG;
    return [
      {selector: 'node', style: {
        'width': 'data(w)', 'height': 'data(h)', 'shape': 'round-rectangle',
        'background-color': 'data(bg)', 'border-width': 2, 'border-color': 'data(bd)',
        'label': 'data(label)', 'color': d ? '#eaf1fb' : '#ffffff',
        'font-size': 11.5, 'font-weight': 600, 'text-valign': 'center', 'text-halign': 'center',
        'text-wrap': 'wrap', 'text-max-width': NODE_W - 16, 'padding': '2px',
        'overlay-opacity': 0, 'z-index-compare': 'manual', 'z-index': 20
      }},
      {selector: 'node[type="frame"]', style: {
        'background-opacity': d ? 0.05 : 0.035, 'background-color': d ? '#5b7bb0' : '#8fa6c4',
        'border-width': 1.6, 'border-style': 'dashed', 'border-color': d ? '#3f5377' : '#c2ccdb',
        'label': 'data(label)', 'text-valign': 'top', 'text-halign': 'center',
        'font-size': 'data(fs)', 'font-weight': 800, 'color': d ? '#aebfd8' : '#526178',
        'text-margin-y': 8, 'padding': '0px', 'events': 'no', 'z-index-compare': 'manual', 'z-index': 2
      }},
      {selector: 'node[type="root"]', style: {
        'background-opacity': d ? 0.02 : 0.012, 'background-color': d ? '#7aa0d8' : '#8ea6c2',
        'border-width': 2.2, 'border-style': 'solid', 'border-color': d ? '#476492' : '#9fb0c6',
        'label': 'data(label)', 'text-valign': 'top', 'text-halign': 'center',
        'font-size': 28, 'font-weight': 900, 'color': d ? '#cfe0ff' : '#33465f',
        'text-margin-y': 10, 'events': 'no', 'z-index-compare': 'manual', 'z-index': 0
      }},
      {selector: 'node[type="tile"]', style: {
        'width': 'data(w)', 'height': 'data(h)', 'shape': 'round-rectangle',
        'background-color': 'data(bg)', 'background-opacity': 0.97,
        'border-width': 2.5, 'border-color': 'data(bd)',
        'label': 'data(label)', 'color': 'data(fg)',
        'font-size': 16, 'font-weight': 700, 'text-valign': 'center', 'text-halign': 'center',
        'text-wrap': 'wrap', 'text-max-width': TILE_W - 26, 'line-height': 1.45,
        'padding': '6px', 'overlay-opacity': 0, 'z-index-compare': 'manual', 'z-index': 20
      }},
      {selector: 'node[type="tile"].alarm', style: {'border-width': 5}},
      {selector: 'node[type="tile"].core', style: {'border-width': 3.5}},
      {selector: 'node[type="ghost"]', style: {
        'width': 190, 'height': 40, 'shape': 'round-rectangle',
        'background-color': d ? '#52667f' : '#c8d3e2', 'background-opacity': 0.55,
        'border-width': 1.2, 'border-style': 'dashed', 'border-color': d ? '#7d93ad' : '#8fa3bc',
        'label': 'data(label)', 'color': d ? '#dce8fa' : '#3b4f68',
        'font-size': 11, 'font-weight': 600, 'text-wrap': 'wrap', 'text-max-width': 176,
        'z-index-compare': 'manual', 'z-index': 15
      }},
      {selector: 'node[type="term"]', style: {
        'width': 12, 'height': 12, 'shape': 'ellipse', 'background-color': 'data(bg)',
        'border-width': 1, 'border-color': d ? '#2a3648' : '#cfd8e3', 'label': '',
        'z-index-compare': 'manual', 'z-index': 30
      }},
      {selector: 'edge[type="tilelink"]', style: {
        'width': 'data(w)', 'line-color': 'data(color)', 'opacity': 0.55,
        'curve-style': 'bezier', 'target-arrow-shape': 'none',
        'z-index-compare': 'manual', 'z-index': 5
      }},
      {selector: 'edge[type="ghost"]', style: {
        'width': 1.2, 'line-color': d ? '#6b809b' : '#a9b6c8', 'line-style': 'dashed', 'opacity': 0.7,
        'curve-style': 'bezier', 'target-arrow-shape': 'none',
        'z-index-compare': 'manual', 'z-index': 8
      }},
      {selector: 'edge[type="uplink"]', style: {
        'width': 'data(w)', 'line-color': 'data(color)', 'line-style': 'data(ls)', 'opacity': 0.95,
        'curve-style': 'bezier', 'target-arrow-shape': 'none',
        'label': 'data(lbl)', 'font-size': 10, 'font-weight': 700,
        'color': d ? '#dce8fa' : '#25405f',
        'text-background-color': d ? '#0d1b2a' : '#ffffff', 'text-background-opacity': 0.88,
        'text-background-padding': '2px', 'text-rotation': 'autorotate',
        'z-index-compare': 'manual', 'z-index': 40
      }},
      {selector: 'edge', style: {
        'width': 'data(w)', 'line-color': 'data(color)', 'line-style': 'data(ls)',
        'curve-style': 'bezier', 'opacity': 0.92, 'target-arrow-shape': 'none',
        'z-index-compare': 'manual', 'z-index': 12
      }},
      {selector: 'edge[type="term"]', style: {
        'width': 0.7, 'line-color': d ? '#3b4a5e' : '#c5cfdb', 'opacity': 0.55,
        'curve-style': 'bezier', 'z-index-compare': 'manual', 'z-index': 11
      }},
      {selector: 'node.alarm', style: {'border-width': 6}},
      {selector: 'node.dim', style: {'opacity': 0.12}},
      {selector: 'edge.dim', style: {'opacity': 0.08}},
      {selector: 'edge.hl', style: {'width': 5, 'line-color': '#FFD54A', 'opacity': 1, 'z-index-compare': 'manual', 'z-index': 45}},
      {selector: 'node.lat-warn', style: {'border-color': '#F39C12'}},
      {selector: 'node.lat-bad', style: {'border-color': '#E74C3C', 'border-width': 6}},
      {selector: 'node.hl', style: {'border-color': '#ff0', 'border-width': 7, 'overlay-color': '#ff0', 'overlay-opacity': 0.25, 'overlay-padding': 6}},
      {selector: 'node[type="switch"]', style: {'background-color': function (e) { return e.data('bg'); }}}
    ];
  }

  /* ---------------- render ---------------- */
  function applyElements(els) {
    if (!cy) {
      cy = cytoscape({
        container: el('l2-cy'),
        elements: els,
        style: styleFor(dark),
        layout: {name: 'preset', fit: true, padding: 40},
        wheelSensitivity: 0.2,
        minZoom: 0.15, maxZoom: 4
      });
      bindCy();
    } else {
      cy.elements().remove();
      cy.add(els);
      cy.style(styleFor(dark));
      cy.layout({name: 'preset', fit: true, padding: 40}).run();
    }
  }

  function render(snap) {
    if (!snap || !snap.nodes) {
      el('l2-cy').innerHTML = '<div class="l2-empty">' + t('l2.no_data', 'No data') + '</div>';
      return;
    }
    lastSnap = snap;
    if (viewGroup) {
      var exists = (snap.nodes || []).some(function (n) { return groupOf(n).label === viewGroup; });
      if (!exists) viewGroup = null;
    }
    if (viewGroup) renderDetail(snap); else renderOverview(snap);
    if (el('l2-back')) el('l2-back').style.display = viewGroup ? '' : 'none';
    updateStats(snap);
    buildLegend();
    buildAlarms(snap);
    buildOffline(snap);
  }

  function renderOverview(snap) {
    var O = computeOverview(snap), els = [], idx = {};
    if (O.root) {
      els.push({group: 'nodes', data: {id: '__root', type: 'root', label: CFG.root_label || 'COBCO', w: O.root.w, h: O.root.h},
        position: {x: O.root.cx, y: O.root.cy}, selectable: false, grabbable: false});
    }
    O.tiles.forEach(function (tile, i) {
      var s = O.stats[tile.label] || {nodes: [], alarms: 0, offline: 0, maxsev: -1};
      idx[tile.label] = 'grp_' + i;
      var isCore = /core/i.test(tile.label) || /data\s*center/i.test(tile.label);
      var bd = s.alarms ? '#E45959' : (dark ? '#41597c' : '#b9c8dc');
      var bg = isCore ? TIER_BG.core : (dark ? '#22344e' : '#eef3fb');
      var fg = isCore ? '#ffffff' : (dark ? '#dfe9fb' : '#1e3352');
      var lbl = tile.label + '\n' + s.nodes.length + ' ' + t('l2.unit_sw', 'sw') +
        (s.up ? '   ↑ ' + s.up : '') + (s.alarms ? '   ⚠ ' + s.alarms : '') + (s.offline ? '   ◌ ' + s.offline : '');
      var cls = [];
      if (s.alarms) cls.push('alarm');
      if (isCore) cls.push('core');
      els.push({group: 'nodes', data: {
        id: idx[tile.label], type: 'tile', group: tile.label,
        n: s.nodes.length, alarms: s.alarms, offline: s.offline, maxsev: s.maxsev, up: s.up,
        label: lbl, bg: bg, fg: fg, bd: bd, w: TILE_W, h: TILE_H
      }, position: {x: tile.x + tile.w / 2, y: tile.y + tile.h / 2}, classes: cls.join(' ')});
    });
    applyElements(els);
  }

  function renderDetail(snap) {
    var D = computeDetail(snap, viewGroup), els = [];
    if (D.root) {
      els.push({group: 'nodes', data: {id: '__root', type: 'root', label: (CFG.root_label || 'COBCO') + ' / ' + viewGroup, w: D.root.w, h: D.root.h},
        position: {x: D.root.cx, y: D.root.cy}, selectable: false, grabbable: false});
    }
    (D.ghosts || []).forEach(function (g) {
      var nm = (g.node && g.node.name) || g.id;
      var ip = (g.node && g.node.ip) || '';
      var tail = String(nm).split(/[-\s]+/).filter(Boolean).slice(-1)[0] || '';
      var short = (tail ? tail + ' · ' : '') + ip;
      els.push({group: 'nodes', data: {id: g.id, type: 'ghost', label: short}, position: {x: g.x, y: g.y}, selectable: false, grabbable: false});
      els.push({group: 'edges', data: {
        id: 'ghe_' + g.id, type: 'uplink', source: g.id, target: g.to,
        speed: g.speed, state: g.state, lbl: speedText(g.speed),
        color: speedColor(g.speed, g.state), ls: (g.state && g.state !== 'up') ? 'dashed' : 'solid',
        w: Math.max(2.6, speedWidth(g.speed))
      }});
    });
    var switchIds = {};
    D.nodes.forEach(function (n) {
      switchIds[n.id] = true;
      var p = D.pos[n.id] || {x: 0, y: 0};
      var tier = n.tier || 'access';
      var tkey = (tier.indexOf('dist') === 0) ? 'dist' : (tier.indexOf('core') === 0 ? 'core' : 'access');
      var cls = [];
      var bd = (dark ? TIER_BG_DARK[tkey] : TIER_BG[tkey]) || '#555';
      if (n.alarms && n.alarms.length) {
        cls.push('alarm');
        bd = '#E45959';
      }
      if (n.latency_ms != null) {
        if (+n.latency_ms > LATB) cls.push('lat-bad');
        else if (+n.latency_ms > LATW) cls.push('lat-warn');
      }
      els.push({group: 'nodes', data: {
        id: n.id, type: 'switch', name: n.name, ip: n.ip, tier: tier, depth: n.depth,
        hostid: n.hostid, oper: n.oper, maxsev: n.maxsev, alarms: n.alarms || [],
        term_online: n.term_online, term_offline: n.term_offline, latency_ms: n.latency_ms,
        label: labelFor(n), bg: (dark ? TIER_BG_DARK[tkey] : TIER_BG[tkey]) || '#777',
        bd: bd, w: NODE_W, h: NODE_H, group: viewGroup
      }, position: p, classes: cls.join(' ')});
    });
    D.internal.forEach(function (e, i) {
      els.push({group: 'edges', data: {
        id: 'e_' + i, source: e.source, target: e.target, speed: e.speed, state: e.state,
        a_port: e.a_port, b_port: e.b_port,
        color: speedColor(e.speed, e.state), ls: (e.state && e.state !== 'up') ? 'dashed' : 'solid',
        w: speedWidth(e.speed)
      }});
    });
    if (showTerm) {
      var bySw = {};
      (snap.terminals || []).forEach(function (tm) {
        if (!switchIds[tm.sw_ip]) return;
        if (onlyOff && tm.online) return;
        (bySw[tm.sw_ip] = bySw[tm.sw_ip] || []).push(tm);
      });
      Object.keys(bySw).forEach(function (sw) {
        var base = D.pos[sw]; if (!base) return;
        bySw[sw].sort(function (a, b) { return (a.online === b.online) ? 0 : (a.online ? -1 : 1); });
        bySw[sw].forEach(function (tm, k) {
          var col = k % 9, row = Math.floor(k / 9);
          var x = base.x - 54 + col * 13;
          var y = base.y + NODE_H / 2 + 16 + row * 13;
          els.push({group: 'nodes', data: {id: 't_' + tm.mac, type: 'term', bg: tm.online ? '#2ECC71' : '#95a5a6', mac: tm.mac, ip: tm.ip, online: tm.online},
            position: {x: x, y: y}, selectable: false});
          els.push({group: 'edges', data: {id: 'te_' + tm.mac, type: 'term', source: sw, target: 't_' + tm.mac}});
        });
      });
    }
    applyElements(els);
  }

  /* ---------------- side panels & stats ---------------- */
  function updateStats(snap) {
    var s = snap.stats || {};
    var txt = '● ' + (s.switches || 0) + '  |  ⇄ ' + (s.edges || 0) + '  |  ' +
      (s.term_total || 0) + '(' + (s.term_online || 0) + '/' + (s.term_offline || 0) + ')  |  ⚠ ' + (s.alarms || 0);
    var up = snap.generated_iso ? ('  ·  ' + t('l2.updated', 'Updated') + ' ' + snap.generated_iso) : '';
    el('l2-stats').textContent = txt + up;
  }

  function buildLegend() {
    var h = '';
    function sw(c, label, dashed) { return '<div class="lg-row"><span class="lg-line' + (dashed ? ' lg-dash' : '') + '" style="border-top-color:' + c + '"></span>' + label + '</div>'; }
    h += '<div class="lg-title">' + t('l2.legend_speed', 'Link speed') + '</div>';
    h += sw(colors['100'], '100M') + sw(colors['1000'], '1G') + sw(colors['10000'], '10G') + sw(colors['20000'], '20G+');
    h += sw(colors.unknown, t('lbl.color_unknown', 'Unknown'));
    h += sw(colors.down, t('lbl.color_down', 'Down'), true);
    h += '<div class="lg-title">' + t('l2.legend_tier', 'Tier') + '</div>';
    h += '<div class="lg-row"><span class="lg-box" style="background:' + TIER_BG.core + '"></span>' + t('l2.core', 'Core') +
         '<span class="lg-box" style="background:' + TIER_BG.dist + ';margin-left:8px"></span>' + t('l2.dist', 'Distribution') +
         '<span class="lg-box" style="background:' + TIER_BG.access + ';margin-left:8px"></span>' + t('l2.access', 'Access') + '</div>';
    h += '<div class="lg-title">' + t('l2.legend_lat', 'Latency') + '</div>';
    h += '<div class="lg-row"><span class="lg-box" style="background:#F39C12;border-radius:2px"></span>&gt;' + LATW + 'ms' +
         '<span class="lg-box" style="background:#E74C3C;border-radius:2px;margin-left:8px"></span>&gt;' + LATB + 'ms</div>';
    h += '<div class="lg-row"><span class="lg-box" style="background:#E45959;border-radius:2px"></span>' + t('l2.alarms', 'Alarms') + '</div>';
    h += '<div class="lg-row"><span class="lg-box" style="background:#2ECC71;border-radius:50%"></span>' + t('l2.term_on', 'Online') +
         '<span class="lg-box" style="background:#95a5a6;border-radius:50%;margin-left:8px"></span>' + t('l2.term_off', 'Offline') + '</div>';
    h += '<div class="lg-row" style="opacity:.72;margin-top:4px">' + t('l2.click_hint', 'Click a switch to highlight its links') + '</div>';
    el('l2-legend').innerHTML = h;
  }

  function buildAlarms(snap) {
    var items = [];
    (snap.nodes || []).forEach(function (n) {
      if (n.maxsev != null && n.maxsev >= 0 && n.alarms && n.alarms.length) {
        n.alarms.forEach(function (a) {
          items.push({sev: n.maxsev, title: (a.name || a.description || ''), host: n.name, ip: n.ip, id: n.id, hostid: n.hostid});
        });
      }
    });
    el('l2-alarm-count').textContent = items.length;
    if (!items.length) { el('l2-alarm-list').innerHTML = '<div class="panel-empty">' + t('l2.alarm_empty', 'No active alarms.') + '</div>'; return; }
    items.sort(function (a, b) { return b.sev - a.sev; });
    var h = '';
    items.forEach(function (it) {
      var col = SEV_COLORS[Math.max(0, Math.min(5, it.sev))] || '#999';
      h += '<div class="alarm-row" data-id="' + (it.id || '') + '" data-hostid="' + (it.hostid || '') + '">' +
        '<span class="alarm-dot" style="background:' + col + '"></span>' +
        '<div class="alarm-main"><div class="alarm-title">' + esc(it.title) + '</div>' +
        '<div class="alarm-sub">' + esc(it.host || '') + (it.ip ? ' · ' + esc(it.ip) : '') + '</div></div></div>';
    });
    var box = el('l2-alarm-list');
    box.innerHTML = h;
    box.querySelectorAll('.alarm-row').forEach(function (r) {
      r.addEventListener('click', function () {
        var id = r.getAttribute('data-id');
        if (id) revealById(id);
        else { var hid = r.getAttribute('data-hostid'); if (hid) window.open(META.zabbixHostUrl.replace('__HOSTID__', hid), '_blank'); }
      });
    });
  }

  function buildOffline(snap) {
    var off = (snap.terminals || []).filter(function (tm) { return !tm.online; });
    el('l2-offline-count').textContent = off.length;
    if (!off.length) { el('l2-offline-list').innerHTML = '<div class="panel-empty">' + t('l2.offline_empty', 'No offline terminals.') + '</div>'; return; }
    var h = '';
    off.forEach(function (tm) {
      h += '<div class="off-row" data-mac="' + esc(tm.mac) + '">' +
        '<div class="off-main"><div class="off-mac">' + esc(tm.mac) + '</div>' +
        '<div class="off-sub">' + esc(tm.sw_name || tm.sw_ip) + ' · ' + esc(tm.port || '') + '</div></div></div>';
    });
    var box = el('l2-offline-list');
    box.innerHTML = h;
    box.querySelectorAll('.off-row').forEach(function (r) {
      r.addEventListener('click', function () {
        var mac = r.getAttribute('data-mac');
        revealById('t_' + mac);
      });
    });
  }

  function esc(s) { return String(s == null ? '' : s).replace(/[&<>"']/g, function (c) { return ({'&':'&amp;','<':'&lt;','>':'&gt;','"':'&quot;',"'":'&#39;'})[c]; }); }

  /* ---------------- interactions ---------------- */
  function focusNode(id) {
    if (!cy) return;
    var n = cy.getElementById(id);
    if (!n || n.empty() || n.length === 0) return;
    cy.elements().removeClass('hl');
    n.addClass('hl');
    cy.animate({center: {eles: n}, zoom: Math.max(cy.zoom(), 1.1), duration: 380});
    setTimeout(function () { n.removeClass('hl'); }, 2600);
  }

  function groupOfNodeId(id) {
    var hit = (lastSnap && lastSnap.nodes || []).filter(function (n) { return n.id === id; })[0];
    return hit ? groupOf(hit).label : null;
  }

  // Make sure a switch/terminal is visible (auto-opens its workshop from overview).
  function revealById(id) {
    if (!lastSnap) return;
    id = String(id);
    if (id.indexOf('t_') === 0) {
      var tm = (lastSnap.terminals || []).filter(function (x) { return 't_' + x.mac === id; })[0];
      if (!tm) return;
      var g = groupOfNodeId(tm.sw_ip);
      if (g) viewGroup = g;
      showTerm = true;
      if (el('l2-showterm')) el('l2-showterm').checked = true;
      render(lastSnap);
      setTimeout(function () { focusNode(id); }, 90);
    } else {
      var g2 = groupOfNodeId(id);
      if (g2 && viewGroup !== g2) { viewGroup = g2; render(lastSnap); }
      setTimeout(function () { focusNode(id); }, 90);
    }
  }

  function bindCy() {
    cy.on('mouseover', 'node[type="switch"]', function (e) {
      var d = e.target.data();
      var arr = d.alarms || [];
      var sev = (d.maxsev != null && d.maxsev >= 0) ? ('<span style="color:' + SEV_COLORS[d.maxsev] + '">● ' + SEV_NAMES[d.maxsev] + '</span>') : '—';
      var lat = (d.latency_ms != null) ? (d.latency_ms + ' ms') : '—';
      var html = '<b>' + esc(d.name) + '</b><br>' + esc(d.ip) + ' · ' + esc(d.group || '') + '<br>' +
        'Tier: ' + esc(d.tier) + ' · ' + (d.oper || '') + '<br>' +
        'Latency: ' + lat + '<br>' +
        'Terminals: ' + (d.term_online || 0) + ' on / ' + (d.term_offline || 0) + ' off<br>' +
        'Alarm: ' + sev;
      if (arr.length) html += '<hr>' + arr.map(function (a) { return esc(a.name || a.description || ''); }).join('<br>');
      showTip(e, html);
    });
    cy.on('mouseout', 'node[type="switch"]', hideTip);
    cy.on('mouseover', 'node[type="tile"]', function (e) {
      var d = e.target.data();
      var html = '<b>' + esc(d.group) + '</b><br>' + d.n + ' ' + t('l2.unit_sw', 'sw') + '<br>' +
        '↑ Core: ' + (d.up || 0) + ' · ⚠ ' + (d.alarms || 0) + ' · ◌ ' + (d.offline || 0) +
        '<br><span style="opacity:.7">' + t('l2.tile_hint', 'Click to open this workshop') + '</span>';
      showTip(e, html);
    });
    cy.on('mouseout', 'node[type="tile"]', hideTip);
    cy.on('tap', 'node[type="tile"]', function (e) {
      var g = e.target.data('group');
      if (g) { viewGroup = g; render(lastSnap); }
    });
    cy.on('mouseover', 'edge:not([type="term"])', function (e) {
      var d = e.target.data();
      var sp = (parseFloat(d.speed) || 0) >= 1000 ? ((parseFloat(d.speed) / 1000) + 'G') : (d.speed + 'M');
      showTip(e, 'Link ' + esc(d.a_port || '') + ' ↔ ' + esc(d.b_port || '') + '<br>' + sp + ' · ' + esc(d.state || ''));
    });
    cy.on('mouseout', 'edge', hideTip);
    cy.on('tap', 'node[type="switch"]', function (e) {
      var n = e.target;
      cy.elements().removeClass('dim hl');
      cy.elements().not(n).addClass('dim');
      n.removeClass('dim');
      var links = n.connectedEdges();
      links.removeClass('dim').addClass('hl');
      links.connectedNodes().removeClass('dim');
    });
    cy.on('tap', function (e) {
      if (e.target === cy) cy.elements().removeClass('dim hl');
    });
    cy.on('dbltap', 'node[type="switch"]', function (e) {
      var hid = e.target.data('hostid');
      if (hid) window.open(META.zabbixHostUrl.replace('__HOSTID__', hid), '_blank');
    });
  }

  var SEV_NAMES = ['未分类','信息','警告','一般严重','严重','灾难'];

  function showTip(e, html) {
    var tip = el('l2-tip');
    tip.innerHTML = html;
    tip.style.display = 'block';
    var p = e.renderedPosition || {x: 0, y: 0};
    var box = el('l2-cy').getBoundingClientRect();
    var x = box.left + p.x + 16, y = box.top + p.y + 16;
    tip.style.left = x + 'px'; tip.style.top = y + 'px';
  }
  function hideTip() { el('l2-tip').style.display = 'none'; }

  /* ---------------- search ---------------- */
  function buildIndex(snap) {
    var idx = [];
    (snap.nodes || []).forEach(function (n) { idx.push({id: n.id, label: n.name, sub: n.ip, kind: 'sw'}); });
    (snap.terminals || []).forEach(function (tm) { idx.push({id: 't_' + tm.mac, label: tm.ip || tm.mac, sub: tm.mac + ' · ' + (tm.sw_name || ''), kind: 'term', mac: tm.mac}); });
    return idx;
  }
  var INDEX = [];
  function doSearch(q) {
    var box = el('l2-sug');
    q = (q || '').trim().toLowerCase();
    if (!q) { box.style.display = 'none'; box.innerHTML = ''; return; }
    var hits = [];
    for (var i = 0; i < INDEX.length && hits.length < 14; i++) {
      var it = INDEX[i];
      if ((it.label && it.label.toLowerCase().indexOf(q) >= 0) || (it.sub && it.sub.toLowerCase().indexOf(q) >= 0)) hits.push(it);
    }
    if (!hits.length) { box.innerHTML = '<div class="sug-empty">—</div>'; box.style.display = 'block'; return; }
    box.innerHTML = hits.map(function (h) {
      return '<div class="sug-row" data-id="' + esc(h.id) + '"><span class="sug-kind ' + h.kind + '">' + (h.kind === 'sw' ? 'SW' : 'PC') + '</span>' +
        '<span class="sug-lbl">' + esc(h.label) + '</span><span class="sug-sub">' + esc(h.sub || '') + '</span></div>';
    }).join('');
    box.style.display = 'block';
    box.querySelectorAll('.sug-row').forEach(function (r) {
      r.addEventListener('click', function () {
        var id = r.getAttribute('data-id');
        revealById(id);
        box.style.display = 'none';
      });
    });
  }

  /* ---------------- toolbar wiring ---------------- */
  function setupControls() {
    dark = el('l2-wrap').classList.contains('l2-dark');
    el('l2-dark').checked = dark;
    var back = el('l2-back');
    if (back) {
      back.textContent = t('l2.back_overview', '← Overview');
      back.addEventListener('click', function () { viewGroup = null; render(lastSnap); });
    }

    el('l2-dark').addEventListener('change', function () {
      dark = el('l2-dark').checked;
      el('l2-wrap').classList.toggle('l2-dark', dark);
      render(lastSnap);
    });
    el('l2-showterm').addEventListener('change', function () { showTerm = el('l2-showterm').checked; render(lastSnap); });
    el('l2-onlyoff').addEventListener('change', function () {
      onlyOff = el('l2-onlyoff').checked;
      if (onlyOff && !showTerm) { showTerm = true; el('l2-showterm').checked = true; }
      render(lastSnap);
    });
    el('l2-zin').addEventListener('click', function () { if (cy) cy.zoom({level: cy.zoom() * 1.25, renderedPosition: {x: cy.width() / 2, y: cy.height() / 2}}); });
    el('l2-zout').addEventListener('click', function () { if (cy) cy.zoom({level: cy.zoom() / 1.25, renderedPosition: {x: cy.width() / 2, y: cy.height() / 2}}); });
    el('l2-fit').addEventListener('click', function () { if (cy) cy.fit(undefined, 50); });
    el('l2-refresh-btn').addEventListener('click', function () { reload(true); });

    var s = el('l2-search');
    s.addEventListener('input', function () { doSearch(s.value); });
    document.addEventListener('click', function (ev) {
      if (!ev.target.closest('.l2-search-wrap')) el('l2-sug').style.display = 'none';
    });

    el('l2-ts').addEventListener('change', function () {
      var v = el('l2-ts').value;
      var u = '/zabbix.php?action=l2.topology.view';
      if (v) u += '&ts=' + encodeURIComponent(v);
      window.location = u;
    });

    el('l2-pause').addEventListener('click', function () {
      paused = !paused;
      el('l2-pause').classList.toggle('on', paused);
      el('l2-pause').textContent = paused ? '▶' : '❚❚';
      el('l2-pause').title = paused ? t('l2.resume', 'Resume') : t('l2.pause', 'Pause');
    });
  }

  function reload(manual) {
    if (!META.isLive) return;
    fetch(META.snapshotUrl + '?t=' + Date.now(), {cache: 'no-store'})
      .then(function (r) { return r.json(); })
      .then(function (j) { if (j && j.nodes) { SNAP = j; INDEX = buildIndex(j); render(j); } })
      .catch(function () {})
      .then(function () { if (manual) resetCountdown(); });
  }

  function resetCountdown() { countdown = META.refreshSeconds || 300; }
  function startTimer() {
    if (!META.isLive) return;
    resetCountdown();
    timer = setInterval(function () {
      if (paused) { el('l2-countdown').textContent = '⏸'; return; }
      countdown--;
      if (countdown <= 0) { countdown = META.refreshSeconds || 300; reload(false); }
      var m = Math.floor(countdown / 60), s = countdown % 60;
      el('l2-countdown').textContent = '↻ ' + m + ':' + (s < 10 ? '0' + s : s);
    }, 1000);
  }

  /* ---------------- boot ---------------- */
  function boot() {
    setupControls();
    try {
      var qg = new URLSearchParams(window.location.search).get('g');
      if (qg) viewGroup = qg;
    } catch (e) {}
    if (!SNAP || !SNAP.nodes) {
      el('l2-cy').innerHTML = '<div class="l2-empty">' + t('l2.no_data', 'No data') + '</div>';
    } else {
      INDEX = buildIndex(SNAP);
      render(SNAP);
    }
    if (META.isLive) startTimer();
    else { el('l2-pause').disabled = true; el('l2-countdown').textContent = t('l2.snapshot', 'Snapshot'); }
  }

  if (document.readyState === 'loading') document.addEventListener('DOMContentLoaded', boot);
  else boot();
})();