/**
 * VITEC SSR cockpit (module web_vitecssr).
 * Draws the gauges, the availability strip, the traffic chart and the
 * sparkline from the JSON the controller puts on #ssr-cockpit
 * (SsrController::cockpitData), and keeps the live parts current by
 * polling the vitec_ssr_health ajax route (GET /__health of the node):
 * every 2 s while a warm run is active, every 15 s otherwise.
 * Chart.js is the copy TYPO3 ships with EXT:dashboard.
 */
import AjaxRequest from '@typo3/core/ajax/ajax-request.js';
import { Chart, registerables } from '@typo3/dashboard/contrib/chartjs.js';

const root = document.getElementById('ssr-cockpit');
if (root) {
  Chart.register(...registerables);

  let data = {};
  try {
    data = JSON.parse(root.dataset.json || '{}');
  } catch (e) {
    data = {};
  }

  const C = 2 * Math.PI * 40;
  const $ = (id) => document.getElementById(id);
  const nf = new Intl.NumberFormat('en-GB');
  const num = (v) => (typeof v === 'number' && isFinite(v) ? v : 0);
  const hhmm = (ts) => new Date(ts * 1000).toLocaleTimeString('en-GB', { hour: '2-digit', minute: '2-digit' });
  const css = getComputedStyle(root);
  const tok = (name) => css.getPropertyValue(name).trim();
  const col = {
    navy: tok('--vc-navy-hi'), sky: tok('--vc-sky'), warn: tok('--vc-warn'), bad: tok('--vc-bad'),
    orange: tok('--vc-orange'), ok: tok('--vc-ok'), faint: tok('--vc-faint'), panel: tok('--vc-panel'),
    text: tok('--vc-text'), muted: tok('--vc-muted'),
  };

  const setRing = (el, frac) => {
    if (!el) {
      return;
    }
    el.style.strokeDasharray = String(C);
    el.style.strokeDashoffset = String(C * (1 - Math.max(0, Math.min(1, frac))));
  };

  /* Hit rate gauge */
  const hit = data.hitRate;
  if (typeof hit === 'number') {
    $('vc-hit').textContent = hit.toFixed(1);
    requestAnimationFrame(() => setRing($('vc-ring-hit'), hit / 100));
    if (typeof data.hitRatePrev === 'number') {
      const d = Math.round((hit - data.hitRatePrev) * 10) / 10;
      const cls = d >= 0 ? 'is-up' : 'is-down';
      $('vc-hit-trend').innerHTML = '<span class="' + cls + '">' + (d >= 0 ? '▲ ' : '▼ ') + Math.abs(d).toFixed(1)
        + ' pts</span> vs. the 24 h before';
    }
  } else {
    $('vc-hit-trend').textContent = 'no traffic counters yet';
  }

  /* Response time */
  if (data.msMedian !== null && data.msMedian !== undefined) {
    $('vc-ms-median').textContent = data.msMedian + ' ms';
    $('vc-ms-p95').textContent = data.msP95 + ' ms';
  }
  const drawSpark = () => {
    const sp = (data.spark || []).map((p) => p[1]);
    const el = $('vc-spark');
    if (!el || sp.length < 2) {
      return;
    }
    const w = 300;
    const h = 46;
    const max = Math.max(...sp) * 1.08;
    const min = Math.min(...sp) * 0.85;
    const span = Math.max(1, max - min);
    const pts = sp.map((v, i) => [(i / (sp.length - 1)) * w, h - ((v - min) / span) * h]);
    const d = pts.map((p, i) => (i ? 'L' : 'M') + p[0].toFixed(1) + ' ' + p[1].toFixed(1)).join(' ');
    const last = pts[pts.length - 1];
    el.innerHTML = '<defs><linearGradient id="vc-sg" x1="0" y1="0" x2="0" y2="1">'
      + '<stop offset="0" stop-color="' + col.orange + '" stop-opacity=".45"/>'
      + '<stop offset="1" stop-color="' + col.orange + '" stop-opacity="0"/></linearGradient></defs>'
      + '<path d="' + d + ' L' + w + ' ' + h + ' L0 ' + h + 'Z" fill="url(#vc-sg)"/>'
      + '<path d="' + d + '" fill="none" stroke="' + col.orange + '" stroke-width="2" vector-effect="non-scaling-stroke"/>'
      + '<circle cx="' + last[0].toFixed(1) + '" cy="' + last[1].toFixed(1) + '" r="3.5" fill="' + col.orange
      + '" stroke="' + col.panel + '" stroke-width="2"/>';
  };
  drawSpark();

  /* Cache fill */
  const renderCache = (pages, mb) => {
    const limit = num(data.cacheLimitMb);
    if (typeof pages === 'number') {
      $('vc-cache-pages').textContent = nf.format(pages);
    }
    if (typeof mb === 'number') {
      $('vc-cache-mb').textContent = nf.format(mb);
      if (limit > 0) {
        setRing($('vc-ring-cache'), mb / limit);
        $('vc-cache-pct').textContent = ' · ' + Math.round((mb / limit) * 100) + ' % used';
      }
    }
  };
  requestAnimationFrame(() => renderCache(data.cachedPages, data.cacheMb));

  /* Client errors per hour */
  const mini = $('vc-mini');
  const eh = data.errHours || [];
  const ehMax = Math.max(1, ...eh);
  eh.forEach((v, i) => {
    const b = document.createElement('i');
    b.style.height = (v ? Math.max(14, (v / ehMax) * 100) : 5) + '%';
    if (v > 0 && v >= ehMax && v >= 3) {
      b.className = 'is-hot';
    }
    b.title = (23 - i === 0 ? 'this hour' : (23 - i) + ' h ago') + ': ' + v + ' report' + (v === 1 ? '' : 's');
    mini.appendChild(b);
  });

  /* Availability strip */
  const strip = data.strip || { w: [], end: data.now, slot: 900 };
  const bars = $('vc-bars');
  const stripStart = strip.end - 96 * strip.slot;
  (strip.w || []).forEach((w, i) => {
    const b = document.createElement('i');
    const t = stripStart + i * strip.slot;
    let label = 'no sample';
    if (w === null) {
      b.className = 'is-none';
    } else if (w.s === 2) {
      b.className = 'is-down';
      label = 'down';
    } else if (w.s === 1) {
      b.className = 'is-slow';
      label = 'slow, ' + w.ms + ' ms';
    } else {
      label = 'ok, ' + w.ms + ' ms';
      b.style.height = Math.round(78 + Math.min(22, (w.ms / 200) * 22)) + '%';
    }
    b.title = hhmm(t) + '–' + hhmm(t + strip.slot) + ' · ' + label;
    bars.appendChild(b);
  });
  const axis = $('vc-uptime-axis');
  [0, 24, 48, 72, 96].forEach((i, k) => {
    const s = document.createElement('span');
    s.textContent = k === 4 ? 'now' : hhmm(stripStart + i * strip.slot);
    axis.appendChild(s);
  });
  if (typeof data.uptimePct === 'number') {
    const slow = num(data.slowWindows);
    const down = num(data.downWindows);
    $('vc-uptime-sum').innerHTML = '<b>' + data.uptimePct.toFixed(1) + ' %</b> up · ' + slow + ' slow window'
      + (slow === 1 ? '' : 's') + ' · ' + down + ' outage' + (down === 1 ? '' : 's');
  } else {
    $('vc-uptime-sum').textContent = 'no samples yet';
  }

  /* Traffic chart */
  let chart = null;
  const label = (ts, size) => {
    const d = new Date(ts * 1000);
    const hm = d.toLocaleTimeString('en-GB', { hour: '2-digit', minute: '2-digit' });
    return size >= 14400 ? d.toLocaleDateString('en-GB', { weekday: 'short' }) + ' ' + hm : hm;
  };
  const draw = (key) => {
    const range = (data.range || {})[key];
    if (!range) {
      return;
    }
    const b = range.b;
    const sum = (k) => b.reduce((a, x) => a + num(x[k]), 0);
    const h = sum('hit');
    const st = sum('stale');
    const m = sum('miss');
    const total = h + st + m;
    $('vc-st-req').textContent = total ? nf.format(total + sum('bypass')) : '–';
    $('vc-st-hit').textContent = total ? (((h + st) / total) * 100).toFixed(1) + ' %' : '–';
    $('vc-st-err').textContent = nf.format(sum('errors'));
    $('vc-st-purge').textContent = nf.format(sum('purges'));
    const hasMs = b.some((x) => x.ms !== null);
    $('vc-traffic-empty').hidden = total > 0 || hasMs;

    const maxY = Math.max(1, ...b.map((x) => num(x.hit) + num(x.stale) + num(x.miss)));
    const maxMs = Math.max(100, ...b.map((x) => num(x.ms)));
    const tick = { color: col.faint, font: { size: 11 } };
    const cfg = {
      type: 'bar',
      data: {
        labels: b.map((x) => label(x.t, range.size)),
        datasets: [
          { label: 'Served from cache', data: b.map((x) => x.hit), backgroundColor: col.navy, stack: 'r', yAxisID: 'y', order: 3 },
          { label: 'Stale, refreshed in background', data: b.map((x) => x.stale), backgroundColor: col.sky, stack: 'r', yAxisID: 'y', order: 3 },
          { label: 'Rendered fresh', data: b.map((x) => x.miss), backgroundColor: col.warn, stack: 'r', borderRadius: { topLeft: 3, topRight: 3 }, yAxisID: 'y', order: 3 },
          {
            type: 'line', label: 'Response time', data: b.map((x) => x.ms), borderColor: col.orange, borderWidth: 2,
            pointRadius: 0, pointHoverRadius: 4, pointBackgroundColor: col.orange, tension: 0.35, spanGaps: true, yAxisID: 'y1', order: 1,
          },
          {
            type: 'line', label: 'Purge', data: b.map((x) => (x.purges ? maxY * 1.06 : null)), showLine: false,
            pointStyle: 'triangle', pointRadius: 7, pointHoverRadius: 9, pointBackgroundColor: col.bad, pointBorderColor: col.panel,
            yAxisID: 'y', order: 0,
          },
        ],
      },
      options: {
        responsive: true,
        maintainAspectRatio: false,
        animation: { duration: 600 },
        interaction: { mode: 'index', intersect: false },
        plugins: {
          legend: { display: false },
          tooltip: {
            backgroundColor: '#0b1131', borderColor: 'rgba(140,156,255,.3)', borderWidth: 1,
            titleColor: col.text, bodyColor: '#c4cbf0', padding: 10,
            filter: (it) => it.raw !== null,
            callbacks: {
              label: (c) => {
                if (c.dataset.label === 'Purge') {
                  const x = b[c.dataIndex];
                  return ' ' + x.purges + ' purge' + (x.purges === 1 ? '' : 's') + (x.purgeAll ? ', ' + x.purgeAll + ' of them everything' : '');
                }
                if (c.dataset.label === 'Response time') {
                  return ' Response time: ' + c.raw + ' ms';
                }
                return ' ' + c.dataset.label + ': ' + nf.format(c.raw);
              },
            },
          },
        },
        scales: {
          x: { stacked: true, grid: { display: false }, ticks: { ...tick, maxRotation: 0, autoSkip: true, maxTicksLimit: 8 }, border: { color: 'rgba(140,156,255,.2)' } },
          y: {
            stacked: true, beginAtZero: true, suggestedMax: maxY * 1.12, grid: { color: 'rgba(140,156,255,.08)' }, ticks: tick,
            border: { display: false }, title: { display: true, text: 'requests', color: col.faint },
          },
          y1: {
            position: 'right', beginAtZero: true, suggestedMax: Math.ceil(maxMs * 1.3), grid: { display: false },
            ticks: { ...tick, color: col.orange, callback: (v) => v + ' ms' }, border: { display: false },
          },
        },
      },
    };
    if (chart) {
      chart.destroy();
    }
    chart = new Chart($('vc-traffic'), cfg);
  };
  Chart.defaults.font.family = getComputedStyle(document.body).fontFamily;
  // Draw once the stylesheet has laid out the grid, and follow the box
  // afterwards: Chart.js alone kept the width it saw on first paint.
  const box = $('vc-traffic').parentElement;
  const start = () => {
    draw('24h');
    if (window.ResizeObserver) {
      let size = box.clientWidth + 'x' + box.clientHeight;
      new ResizeObserver(() => {
        const now = box.clientWidth + 'x' + box.clientHeight;
        if (chart && now !== size) {
          size = now;
          chart.resize();
        }
      }).observe(box);
    }
  };
  if (document.readyState === 'complete') {
    requestAnimationFrame(start);
  } else {
    window.addEventListener('load', () => requestAnimationFrame(start), { once: true });
  }
  root.querySelectorAll('.vc-seg button[data-range]').forEach((btn) => {
    btn.addEventListener('click', () => {
      root.querySelectorAll('.vc-seg button[data-range]').forEach((x) => x.setAttribute('aria-pressed', x === btn ? 'true' : 'false'));
      draw(btn.dataset.range);
    });
  });

  /* Warm cache + live status */
  const warmBtn = $('ssr-warm-button');
  const warmLabel = $('vc-warm-label');
  const warmPct = $('vc-warm-pct');
  const warmMeta = $('vc-warm-meta');
  const warmPill = $('vc-warm-pill');
  const warmRing = $('vc-ring-warm');
  const pill = (cls, text) => {
    warmPill.hidden = !text;
    warmPill.className = 'vc-pill ' + cls;
    warmPill.textContent = text || '';
  };
  const renderWarm = (w) => {
    w = w || {};
    const queued = num(w.queued);
    const handled = num(w.done) + num(w.skipped) + num(w.failed);
    const failed = num(w.failed);
    const failedHtml = failed ? '<span class="vc-bad-text">' + failed + ' failed</span>' : '0 failed';
    if (w.running) {
      const f = queued > 0 ? handled / queued : 0;
      setRing(warmRing, f);
      warmPct.textContent = Math.round(f * 100) + ' %';
      warmMeta.innerHTML = '<b>' + nf.format(handled) + '</b> of ' + nf.format(queued) + ' pages<br>'
        + num(w.skipped) + ' still fresh · ' + failedHtml + '<br>live, every 2 seconds';
      pill('is-sky', 'running');
    } else if (w.startedAt) {
      setRing(warmRing, queued > 0 ? handled / queued : 1);
      warmPct.textContent = failed || w.aborted ? '!' : '✓';
      const started = new Date(w.startedAt);
      const secs = w.finishedAt ? Math.round((new Date(w.finishedAt) - started) / 1000) : null;
      const took = secs === null ? '' : '<br>took ' + (secs >= 120 ? Math.round(secs / 60) + ' min' : secs + ' s');
      warmMeta.innerHTML = 'Last run ' + started.toLocaleString('en-GB', { weekday: 'short', hour: '2-digit', minute: '2-digit' })
        + '<br><b>' + nf.format(num(w.done)) + '</b> of ' + nf.format(queued) + ' rendered · '
        + num(w.skipped) + ' still fresh · ' + failedHtml + took;
      pill(w.aborted ? 'is-warn' : (failed ? 'is-bad' : 'is-ok'), w.aborted ? 'aborted by restart' : (failed ? 'with errors' : 'done'));
    } else {
      setRing(warmRing, 0);
      warmPct.textContent = '–';
      warmMeta.textContent = 'No run since the server started.';
      pill('', '');
    }
    if (warmBtn) {
      warmBtn.disabled = !!w.running;
      warmLabel.textContent = w.running ? 'Warming …' : 'Warm cache';
    }
    return !!w.running;
  };
  requestAnimationFrame(() => renderWarm(data.warming));

  const renderOnline = (online) => {
    const p = $('vc-pulse');
    const t = $('vc-live-title');
    if (!p || !t) {
      return;
    }
    p.classList.toggle('is-down', !online);
    t.innerHTML = online ? 'SSR <span class="vc-ok-text">online</span>' : 'SSR <span class="vc-bad-text">not reachable</span>';
  };

  let timer = null;
  const schedule = (ms) => {
    clearTimeout(timer);
    timer = setTimeout(poll, ms);
  };
  const poll = () => {
    new AjaxRequest(TYPO3.settings.ajaxUrls.vitec_ssr_health).get()
      .then((response) => response.resolve())
      .then((res) => {
        const h = res && res.health;
        renderOnline(!!h);
        let running = false;
        if (h) {
          running = renderWarm(h.warming);
          renderCache(h.cachedPages, h.cacheMB);
          if (typeof h.responseMs === 'number') {
            $('vc-ms').textContent = h.responseMs;
          }
        }
        schedule(running ? 2000 : 15000);
      })
      .catch(() => schedule(15000));
  };
  schedule(data.warming && data.warming.running ? 1000 : 15000);
  document.addEventListener('visibilitychange', () => {
    if (document.hidden) {
      clearTimeout(timer);
    } else {
      poll();
    }
  });
}