{% extends "base.html" %}
{% block title %}Link Debug – GANDALF{% endblock %}

{% block content %}

<div class="page-header">
  <h1 class="page-title">Link Debug</h1>
  <p class="page-sub">
    Per-interface stats: speed, duplex, SFP optical levels, TX/RX rates, errors, and carrier changes.
    Data collected via Prometheus node_exporter + SSH ethtool (servers) and UniFi API (switches) every poll cycle.
    <span id="links-updated" style="margin-left:10px; color:var(--text-muted); font-size:.85em;"></span>
  </p>
</div>

<div id="links-container">
  <div class="link-loading">Loading link statistics</div>
</div>

{% endblock %}

{% block scripts %}
<script>
// ── Formatting helpers ────────────────────────────────────────────
function fmtRate(bytesPerSec) {
  if (bytesPerSec === null || bytesPerSec === undefined) return '–';
  const bps = bytesPerSec * 8;
  if (bps < 1e3)  return bps.toFixed(0) + ' bps';
  if (bps < 1e6)  return (bps/1e3).toFixed(1) + ' Kbps';
  if (bps < 1e9)  return (bps/1e6).toFixed(2) + ' Mbps';
  return (bps/1e9).toFixed(3) + ' Gbps';
}

function fmtRateBar(bytesPerSec, linkSpeedMbps) {
  if (!linkSpeedMbps || linkSpeedMbps <= 0) return 0;
  const mbps = (bytesPerSec * 8) / 1e6;
  return Math.min(100, (mbps / linkSpeedMbps) * 100);
}

function fmtSpeed(mbps) {
  if (mbps === null || mbps === undefined) return '–';
  if (mbps >= 1000) return (mbps/1000).toFixed(0) + ' Gbps';
  return mbps + ' Mbps';
}

function fmtDuplex(d) {
  if (!d) return '–';
  return d.charAt(0).toUpperCase() + d.slice(1);
}

function fmtTemp(c) {
  if (c === null || c === undefined) return '–';
  return c.toFixed(1) + '°C';
}

function fmtVoltage(v) {
  if (v === null || v === undefined) return '–';
  return v.toFixed(2) + 'V';
}

function fmtPower(dbm) {
  if (dbm === null || dbm === undefined) return '–';
  return dbm.toFixed(2) + ' dBm';
}

function fmtBias(ma) {
  if (ma === null || ma === undefined) return '–';
  return ma.toFixed(2) + ' mA';
}

function fmtErrors(rate) {
  if (rate === null || rate === undefined) return '–';
  if (rate < 0.001) return '<span class="counter-zero">0 /s</span>';
  return `<span class="counter-nonzero">${rate.toFixed(3)} /s</span>`;
}

function fmtCarrier(n) {
  if (n === null || n === undefined) return '–';
  const v = parseInt(n);
  if (v <= 2) return `<span class="val-good">${v}</span>`;
  if (v <= 10) return `<span class="val-warn">${v}</span>`;
  return `<span class="val-crit">${v}</span>`;
}

// Power level: returns {cls, pct} for -30..0 dBm scale
function rxPowerClass(dbm) {
  if (dbm === null || dbm === undefined) return {cls:'power-ok', pct:0};
  const pct = Math.max(0, Math.min(100, (dbm + 30) / 30 * 100));
  let cls = 'power-ok';
  if (dbm < -25 || dbm > 0) cls = 'power-crit';
  else if (dbm < -20)        cls = 'power-warn';
  return {cls, pct};
}

function txPowerClass(dbm) {
  if (dbm === null || dbm === undefined) return {cls:'power-ok', pct:0};
  const pct = Math.max(0, Math.min(100, (dbm + 20) / 20 * 100));
  let cls = 'power-ok';
  if (dbm < -15 || dbm > 2)  cls = 'power-crit';
  else if (dbm < -10)         cls = 'power-warn';
  return {cls, pct};
}

function tempClass(c) {
  if (c === null || c === undefined) return 'val-neutral';
  if (c > 80) return 'val-crit';
  if (c > 60) return 'val-warn';
  return 'val-good';
}

function voltageClass(v) {
  if (v === null || v === undefined) return 'val-neutral';
  if (v < 3.0 || v > 3.6) return 'val-crit';
  if (v < 3.1 || v > 3.5) return 'val-warn';
  return 'val-good';
}

function portTypeLabel(pt) {
  if (!pt) return {label:'–', cls:''};
  const u = pt.toUpperCase();
  if (u.includes('FIBRE') || u.includes('FIBER') || u.includes('SFP'))
    return {label: pt, cls: 'type-fibre'};
  if (u.includes('DA') || u.includes('DIRECT'))
    return {label: pt, cls: 'type-da'};
  return {label: pt, cls: 'type-copper'};
}

// ── Error alert badge ─────────────────────────────────────────────
function errorBadges(d) {
  const badges = [];
  if ((d.tx_errs_rate || 0) > 0.01 || (d.rx_errs_rate || 0) > 0.01)
    badges.push('<span class="link-alert-badge">ERR</span>');
  if ((d.tx_drops_rate || 0) > 0.1 || (d.rx_drops_rate || 0) > 0.1)
    badges.push('<span class="link-alert-badge link-alert-amber">DROP</span>');
  if ((d.carrier_changes || 0) > 10)
    badges.push('<span class="link-alert-badge link-alert-amber">FLAP</span>');
  return badges.join('');
}

// ── Render a single interface card ────────────────────────────────
function renderIfaceCard(ifaceName, d) {
  const speed = fmtSpeed(d.speed_mbps);
  const duplex = fmtDuplex(d.duplex);
  const ptype  = portTypeLabel(d.port_type);
  const autoneg= d.auto_neg !== undefined ? (d.auto_neg ? 'On' : 'Off') : '–';
  const linkDet= d.link_detected !== undefined ? (d.link_detected ? '<span class="val-good">Yes</span>' : '<span class="val-crit">No</span>') : '–';

  // Traffic bars
  const txRate = d.tx_bytes_rate;
  const rxRate = d.rx_bytes_rate;
  const txPct  = fmtRateBar(txRate, d.speed_mbps);
  const rxPct  = fmtRateBar(rxRate, d.speed_mbps);

  const txStr  = fmtRate(txRate);
  const rxStr  = fmtRate(rxRate);

  // SFP / optical section
  let sfpHtml = '';
  const sfp = d.sfp;
  if (sfp && Object.keys(sfp).length > 0) {
    const tx = txPowerClass(sfp.tx_power_dbm);
    const rx = rxPowerClass(sfp.rx_power_dbm);
    const tcls = tempClass(sfp.temp_c);
    const vcls = voltageClass(sfp.voltage_v);

    const vendorStr = [sfp.vendor, sfp.part_no].filter(Boolean).join(' / ') || '–';
    const sfpTypeStr= [sfp.sfp_type, sfp.connector, sfp.wavelength_nm ? sfp.wavelength_nm + 'nm' : ''].filter(Boolean).join(' · ') || '';

    sfpHtml = `
      <div class="sfp-panel">
        <div class="sfp-vendor-row">
          <span>${escHtml(vendorStr)}</span>
          ${sfpTypeStr ? `<span style="margin-left:8px;color:var(--text-muted)">${escHtml(sfpTypeStr)}</span>` : ''}
        </div>
        <div class="sfp-grid">
          <div class="sfp-stat">
            <span class="sfp-stat-label">Temp</span>
            <span class="sfp-stat-value ${tcls}">${fmtTemp(sfp.temp_c)}</span>
          </div>
          <div class="sfp-stat">
            <span class="sfp-stat-label">Voltage</span>
            <span class="sfp-stat-value ${vcls}">${fmtVoltage(sfp.voltage_v)}</span>
          </div>
          <div class="sfp-stat">
            <span class="sfp-stat-label">Bias</span>
            <span class="sfp-stat-value">${fmtBias(sfp.bias_ma)}</span>
          </div>
          <div class="sfp-stat">
            <span class="sfp-stat-label">TX Power</span>
            <span class="sfp-stat-value ${tx.cls === 'power-ok' ? 'val-good' : tx.cls === 'power-warn' ? 'val-warn' : 'val-crit'}">${fmtPower(sfp.tx_power_dbm)}</span>
            <div class="power-row">
              <div class="power-track"><div class="power-fill ${tx.cls}" style="width:${tx.pct}%"></div></div>
            </div>
          </div>
          <div class="sfp-stat">
            <span class="sfp-stat-label">RX Power</span>
            <span class="sfp-stat-value ${rx.cls === 'power-ok' ? 'val-good' : rx.cls === 'power-warn' ? 'val-warn' : 'val-crit'}">${fmtPower(sfp.rx_power_dbm)}</span>
            <div class="power-row">
              <div class="power-track"><div class="power-fill ${rx.cls}" style="width:${rx.pct}%"></div></div>
            </div>
          </div>
          <div class="sfp-stat">
            <span class="sfp-stat-label">RX – TX</span>
            <span class="sfp-stat-value ${sfp.rx_power_dbm !== undefined && sfp.tx_power_dbm !== undefined ? (Math.abs(sfp.rx_power_dbm - sfp.tx_power_dbm) > 8 ? 'val-warn' : 'val-neutral') : 'val-neutral'}">
              ${sfp.rx_power_dbm !== undefined && sfp.tx_power_dbm !== undefined
                ? (sfp.rx_power_dbm - sfp.tx_power_dbm).toFixed(2) + ' dBm'
                : '–'}
            </span>
          </div>
        </div>
      </div>`;
  }

  return `
    <div class="link-iface-card">
      <div class="link-iface-header">
        <span class="link-iface-name">${escHtml(ifaceName)}</span>
        ${speed !== '–' ? `<span class="link-iface-speed">${speed}</span>` : ''}
        ${ptype.label !== '–' ? `<span class="link-iface-type ${ptype.cls}">${escHtml(ptype.label)}</span>` : ''}
        ${errorBadges(d)}
      </div>
      <div class="link-stats-grid">
        <div class="link-stat">
          <span class="link-stat-label">Duplex</span>
          <span class="link-stat-value ${duplex==='Full'?'val-good':duplex==='Half'?'val-crit':'val-neutral'}">${duplex}</span>
        </div>
        <div class="link-stat">
          <span class="link-stat-label">Auto-neg</span>
          <span class="link-stat-value val-neutral">${autoneg}</span>
        </div>
        <div class="link-stat">
          <span class="link-stat-label">Link Det.</span>
          <span class="link-stat-value">${linkDet}</span>
        </div>
        <div class="link-stat">
          <span class="link-stat-label">Carrier Chg</span>
          <span class="link-stat-value">${fmtCarrier(d.carrier_changes)}</span>
        </div>
        <div class="link-stat">
          <span class="link-stat-label">TX Errors</span>
          <span class="link-stat-value">${fmtErrors(d.tx_errs_rate)}</span>
        </div>
        <div class="link-stat">
          <span class="link-stat-label">RX Errors</span>
          <span class="link-stat-value">${fmtErrors(d.rx_errs_rate)}</span>
        </div>
        <div class="link-stat">
          <span class="link-stat-label">TX Drops</span>
          <span class="link-stat-value">${fmtErrors(d.tx_drops_rate)}</span>
        </div>
        <div class="link-stat">
          <span class="link-stat-label">RX Drops</span>
          <span class="link-stat-value">${fmtErrors(d.rx_drops_rate)}</span>
        </div>
      </div>

      ${(txRate !== undefined || rxRate !== undefined) ? `
      <div class="traffic-section">
        <div class="traffic-row">
          <span class="traffic-label">TX</span>
          <div class="traffic-bar-track">
            <div class="traffic-bar-fill traffic-tx" style="width:${txPct}%"></div>
          </div>
          <span class="traffic-value">${txStr}</span>
        </div>
        <div class="traffic-row">
          <span class="traffic-label">RX</span>
          <div class="traffic-bar-track">
            <div class="traffic-bar-fill traffic-rx" style="width:${rxPct}%"></div>
          </div>
          <span class="traffic-value">${rxStr}</span>
        </div>
      </div>` : ''}

      ${sfpHtml}
    </div>`;
}

// ── Render a single UniFi switch port card ────────────────────────
function renderPortCard(portName, d) {
  const up      = d.up;
  const speed   = up ? fmtSpeed(d.speed_mbps) : 'DOWN';
  const duplex  = d.full_duplex ? 'Full' : (up ? 'Half' : '–');
  const media   = d.media || '';

  const uplinkBadge = d.is_uplink
    ? '<span class="port-badge port-badge-uplink">UPLINK</span>' : '';
  const poeBadge = (d.poe_power != null && d.poe_power > 0)
    ? `<span class="port-badge port-badge-poe">PoE ${d.poe_power.toFixed(1)}W</span>` : '';
  const numBadge = d.port_idx
    ? `<span class="port-badge port-badge-num">#${d.port_idx}</span>` : '';

  const lldpHtml = (d.lldp && d.lldp.system_name)
    ? `<div class="port-lldp">→ ${escHtml(d.lldp.system_name)}${d.lldp.port_id ? ' (' + escHtml(d.lldp.port_id) + ')' : ''}</div>` : '';

  let poeMaxHtml = '';
  if (d.poe_class != null) {
    const poeDraw = d.poe_power || 0;
    const poeMax  = d.poe_max_power || 0;
    const poePct  = poeMax > 0 ? Math.min(100, (poeDraw / poeMax) * 100) : 0;
    const poeBarCls = poePct >= 80 ? 'poe-bar-crit' : poePct >= 60 ? 'poe-bar-warn' : 'poe-bar-ok';
    const poeMode = d.poe_mode ? ` · ${escHtml(d.poe_mode)}` : '';
    poeMaxHtml = `<div class="port-poe-info">
      PoE class ${d.poe_class}${poeMax > 0 ? ` · ${poeDraw.toFixed(1)}W / ${poeMax.toFixed(1)}W max${poeMode}` : poeMode}
      ${poeMax > 0 ? `<div class="poe-bar-track"><div class="poe-bar-fill ${poeBarCls}" style="width:${poePct.toFixed(1)}%"></div></div>` : ''}
    </div>`;
  }

  const txRate = d.tx_bytes_rate;
  const rxRate = d.rx_bytes_rate;
  const txPct  = fmtRateBar(txRate, d.speed_mbps);
  const rxPct  = fmtRateBar(rxRate, d.speed_mbps);
  const txStr  = fmtRate(txRate);
  const rxStr  = fmtRate(rxRate);

  return `
    <div class="link-iface-card${up ? '' : ' port-down'}">
      <div class="link-iface-header">
        <span class="link-iface-name">${escHtml(portName)}</span>
        <span class="link-iface-speed ${up ? '' : 'val-crit'}">${speed}</span>
        ${numBadge}${uplinkBadge}${poeBadge}
        ${media ? `<span class="link-iface-type type-${media.toLowerCase().includes('sfp') ? 'fibre' : 'copper'}">${escHtml(media)}</span>` : ''}
        ${errorBadges(d)}
      </div>
      ${lldpHtml}${poeMaxHtml}
      <div class="link-stats-grid">
        <div class="link-stat">
          <span class="link-stat-label">Duplex</span>
          <span class="link-stat-value ${duplex==='Full'?'val-good':duplex==='Half'?'val-crit':'val-neutral'}">${duplex}</span>
        </div>
        <div class="link-stat">
          <span class="link-stat-label">Auto-neg</span>
          <span class="link-stat-value val-neutral">${d.autoneg ? 'On' : 'Off'}</span>
        </div>
        <div class="link-stat">
          <span class="link-stat-label">TX Errors</span>
          <span class="link-stat-value">${fmtErrors(d.tx_errs_rate)}</span>
        </div>
        <div class="link-stat">
          <span class="link-stat-label">RX Errors</span>
          <span class="link-stat-value">${fmtErrors(d.rx_errs_rate)}</span>
        </div>
        <div class="link-stat">
          <span class="link-stat-label">TX Drops</span>
          <span class="link-stat-value">${fmtErrors(d.tx_drops_rate)}</span>
        </div>
        <div class="link-stat">
          <span class="link-stat-label">RX Drops</span>
          <span class="link-stat-value">${fmtErrors(d.rx_drops_rate)}</span>
        </div>
      </div>
      ${(up && (txRate != null || rxRate != null)) ? `
      <div class="traffic-section">
        <div class="traffic-row">
          <span class="traffic-label">TX</span>
          <div class="traffic-bar-track">
            <div class="traffic-bar-fill traffic-tx" style="width:${txPct}%"></div>
          </div>
          <span class="traffic-value">${txStr}</span>
        </div>
        <div class="traffic-row">
          <span class="traffic-label">RX</span>
          <div class="traffic-bar-track">
            <div class="traffic-bar-fill traffic-rx" style="width:${rxPct}%"></div>
          </div>
          <span class="traffic-value">${rxStr}</span>
        </div>
      </div>` : ''}
    </div>`;
}

// ── Render UniFi switches section ─────────────────────────────────
function renderUnifiSwitches(unifiSwitches) {
  if (!unifiSwitches || !Object.keys(unifiSwitches).length) return '';

  const panels = Object.entries(unifiSwitches).map(([swName, sw]) => {
    const ports   = sw.ports || {};
    const allPorts= Object.entries(ports)
      .sort(([,a],[,b]) => (a.port_idx||0) - (b.port_idx||0));
    const upCount = allPorts.filter(([,d]) => d.up).length;
    const downCount = allPorts.length - upCount;

    const portCards = allPorts
      .map(([pname, d]) => renderPortCard(pname, d))
      .join('');

    const meta = [
      sw.model,
      `${upCount} up`,
      downCount ? `${downCount} down` : '',
    ].filter(Boolean).join(' · ');

    return `
      <div class="link-host-panel" id="unifi-${escHtml(swName)}">
        <div class="link-host-title" onclick="togglePanel(this.closest('.link-host-panel'))">
          <span class="link-host-name">${escHtml(swName)}</span>
          ${sw.ip ? `<span class="link-host-ip">${escHtml(sw.ip)}</span>` : ''}
          <span class="link-host-upd">${escHtml(meta)}</span>
          <span class="panel-toggle" title="Collapse / expand">[–]</span>
        </div>
        <div class="link-ifaces-grid">
          ${portCards || '<div class="link-no-data">No port data available.</div>'}
        </div>
      </div>`;
  }).join('');

  return `
    <div class="unifi-section-header">UniFi Switches</div>
    <div class="link-host-list">${panels}</div>`;
}

// ── Collapse / expand panels ───────────────────────────────────────
function togglePanel(panel) {
  panel.classList.toggle('collapsed');
  const btn = panel.querySelector('.panel-toggle');
  if (btn) btn.textContent = panel.classList.contains('collapsed') ? '[+]' : '[–]';
  const id = panel.id;
  if (id) {
    const saved = JSON.parse(localStorage.getItem('gandalfCollapsed') || '{}');
    saved[id] = panel.classList.contains('collapsed');
    localStorage.setItem('gandalfCollapsed', JSON.stringify(saved));
  }
}

function restoreCollapseState() {
  const saved = JSON.parse(localStorage.getItem('gandalfCollapsed') || '{}');
  for (const [id, collapsed] of Object.entries(saved)) {
    if (!collapsed) continue;
    const panel = document.getElementById(id);
    if (panel) {
      panel.classList.add('collapsed');
      const btn = panel.querySelector('.panel-toggle');
      if (btn) btn.textContent = '[+]';
    }
  }
}

function collapseAll() {
  document.querySelectorAll('.link-host-panel').forEach(panel => {
    panel.classList.add('collapsed');
    const btn = panel.querySelector('.panel-toggle');
    if (btn) btn.textContent = '[+]';
    const id = panel.id;
    if (id) {
      const saved = JSON.parse(localStorage.getItem('gandalfCollapsed') || '{}');
      saved[id] = true;
      localStorage.setItem('gandalfCollapsed', JSON.stringify(saved));
    }
  });
}

function expandAll() {
  document.querySelectorAll('.link-host-panel').forEach(panel => {
    panel.classList.remove('collapsed');
    const btn = panel.querySelector('.panel-toggle');
    if (btn) btn.textContent = '[–]';
    const id = panel.id;
    if (id) {
      const saved = JSON.parse(localStorage.getItem('gandalfCollapsed') || '{}');
      saved[id] = false;
      localStorage.setItem('gandalfCollapsed', JSON.stringify(saved));
    }
  });
}

// ── Link health summary ───────────────────────────────────────────
function buildLinkSummary(hosts, unifiSwitches) {
  let svrTotal = 0, svrErrors = 0, svrFlap = 0;
  let swTotal = 0, swUp = 0, swDown = 0, swErrors = 0;
  let poeDrawW = 0, poeMaxW = 0;

  for (const ifaces of Object.values(hosts)) {
    for (const d of Object.values(ifaces)) {
      svrTotal++;
      if ((d.tx_errs_rate || 0) > 0.01 || (d.rx_errs_rate || 0) > 0.01) svrErrors++;
      if ((d.carrier_changes || 0) > 10) svrFlap++;
    }
  }
  for (const sw of Object.values(unifiSwitches || {})) {
    for (const d of Object.values(sw.ports || {})) {
      swTotal++;
      if (d.up) swUp++; else swDown++;
      if ((d.tx_errs_rate || 0) > 0.01 || (d.rx_errs_rate || 0) > 0.01) swErrors++;
      if (d.poe_power != null) poeDrawW += d.poe_power;
      if (d.poe_max_power != null) poeMaxW += d.poe_max_power;
    }
  }

  const poePct = poeMaxW > 0 ? (poeDrawW / poeMaxW * 100) : null;
  const poeBarCls = poePct >= 80 ? 'poe-bar-crit' : poePct >= 60 ? 'poe-bar-warn' : 'poe-bar-ok';
  const totalErrors = svrErrors + swErrors;
  const hasAlerts = totalErrors > 0 || svrFlap > 0 || swDown > 0;

  return `
    <div class="link-summary-panel${hasAlerts ? ' link-summary-has-alerts' : ''}">
      <div class="link-summary-grid">
        <div class="link-summary-stat">
          <span class="lss-label">Server Ifaces</span>
          <span class="lss-value">${svrTotal}</span>
        </div>
        ${svrErrors > 0 ? `<div class="link-summary-stat lss-alert">
          <span class="lss-label">Iface Errors</span>
          <span class="lss-value val-crit">${svrErrors}</span>
        </div>` : ''}
        ${svrFlap > 0 ? `<div class="link-summary-stat lss-alert">
          <span class="lss-label">Flapping</span>
          <span class="lss-value val-warn">${svrFlap}</span>
        </div>` : ''}
        ${swTotal > 0 ? `<div class="link-summary-stat">
          <span class="lss-label">Switch Ports</span>
          <span class="lss-value">${swUp}<span class="lss-sub">/${swTotal}</span></span>
        </div>` : ''}
        ${swDown > 0 ? `<div class="link-summary-stat lss-alert">
          <span class="lss-label">Ports Down</span>
          <span class="lss-value val-crit">${swDown}</span>
        </div>` : ''}
        ${swErrors > 0 ? `<div class="link-summary-stat lss-alert">
          <span class="lss-label">Port Errors</span>
          <span class="lss-value val-crit">${swErrors}</span>
        </div>` : ''}
        ${poePct !== null ? `<div class="link-summary-stat">
          <span class="lss-label">PoE Load</span>
          <span class="lss-value ${poeBarCls === 'poe-bar-crit' ? 'val-crit' : poeBarCls === 'poe-bar-warn' ? 'val-warn' : 'val-good'}">${poeDrawW.toFixed(0)}W<span class="lss-sub">/${poeMaxW.toFixed(0)}W</span></span>
          <div class="poe-bar-track" style="margin-top:3px"><div class="poe-bar-fill ${poeBarCls}" style="width:${poePct.toFixed(1)}%"></div></div>
        </div>` : ''}
        ${totalErrors === 0 && svrFlap === 0 && swDown === 0 ? `<div class="link-summary-stat">
          <span class="lss-label">Status</span>
          <span class="lss-value val-good">All OK ✔</span>
        </div>` : ''}
      </div>
    </div>`;
}

// ── Render all hosts ──────────────────────────────────────────────
function renderLinks(data) {
  const hosts  = data.hosts  || {};
  const unifi  = data.unifi_switches || {};

  if (!Object.keys(hosts).length && !Object.keys(unifi).length) {
    document.getElementById('links-container').innerHTML =
      '<p class="empty-state">No link data collected yet. Monitor may still be initialising.</p>';
    return;
  }

  const upd = data.updated ? `Updated: ${data.updated}` : '';
  const updEl = document.getElementById('links-updated');
  if (updEl) updEl.textContent = upd;

  const serverHtml = Object.entries(hosts).map(([hostName, ifaces]) => {
    const ifaceCards = Object.entries(ifaces)
      .sort(([a],[b]) => a.localeCompare(b))
      .map(([ifaceName, d]) => renderIfaceCard(ifaceName, d))
      .join('');

    const hostIp = ifaces[Object.keys(ifaces)[0]]?.host_ip || '';
    return `
      <div class="link-host-panel" id="${escHtml(hostName)}">
        <div class="link-host-title" onclick="togglePanel(this.closest('.link-host-panel'))">
          <span class="link-host-name">${escHtml(hostName)}</span>
          ${hostIp ? `<span class="link-host-ip">${escHtml(hostIp)}</span>` : ''}
          <span class="panel-toggle" title="Collapse / expand">[–]</span>
        </div>
        <div class="link-ifaces-grid">
          ${ifaceCards || '<div class="link-no-data">No interface data available.</div>'}
        </div>
      </div>`;
  }).join('');

  document.getElementById('links-container').innerHTML =
    buildLinkSummary(hosts, unifi) +
    `<div class="link-collapse-bar">
       <button class="btn btn-secondary btn-sm" onclick="collapseAll()">Collapse all</button>
       <button class="btn btn-secondary btn-sm" onclick="expandAll()">Expand all</button>
     </div>` +
    `<div class="link-host-list">${serverHtml}</div>` +
    renderUnifiSwitches(unifi);

  restoreCollapseState();

  // Jump to anchor if URL has #hostname
  if (location.hash) {
    const el = document.querySelector(location.hash);
    if (el) {
      if (el.classList.contains('collapsed')) togglePanel(el);
      el.scrollIntoView({behavior:'smooth', block:'start'});
    }
  }
}

// ── Stale data check ─────────────────────────────────────────────
function checkLinksStale(updatedStr) {
  let banner = document.getElementById('links-stale-banner');
  if (!updatedStr) return;
  const ageMs = Date.now() - new Date(updatedStr.replace(' UTC', 'Z').replace(' ', 'T'));
  if (ageMs > 120000) { // >2 minutes
    if (!banner) {
      banner = document.createElement('div');
      banner.id = 'links-stale-banner';
      banner.className = 'stale-banner';
      document.getElementById('links-container').insertAdjacentElement('beforebegin', banner);
    }
    const mins = Math.floor(ageMs / 60000);
    banner.textContent = `⚠ Link data is stale — last update was ${mins} minute${mins !== 1 ? 's' : ''} ago.`;
    banner.style.display = '';
  } else if (banner) {
    banner.style.display = 'none';
  }
}

// ── Fetch and render ──────────────────────────────────────────────
async function loadLinks() {
  try {
    const resp = await fetch('/api/links');
    if (!resp.ok) throw new Error(`HTTP ${resp.status}`);
    const data = await resp.json();
    renderLinks(data);
    checkLinksStale(data.updated);
  } catch(e) {
    document.getElementById('links-container').innerHTML =
      `<div class="error-state"><p>Failed to load link data: ${escHtml(e.message)}</p></div>`;
  }
}

loadLinks();
setInterval(loadLinks, 60000);
</script>
{% endblock %}