import { loadData, filterResults, selectBestResults, expandCpuRows, attachCpuBaselineFromCpuRecords, mergeDepthPairs } from './data.js';
import { initFilters, populateQuantOptions, getFilters, resetFilters } from './filters.js';
import { renderDecodeChart, renderPrefillChart, renderSizeChart, renderMachineChart, renderCpuGpuChart, renderSpeedupChart } from './charts.js';
import { renderResultsTable, renderErrorTable, renderMachineInfo, renderCpuGpuTable } from './tables.js';

let appData = null;

async function init() {
  try {
    appData = await loadData();
  } catch (e) {
    const loading = document.getElementById('loading');
    loading.className = 'loading-state';
    loading.innerHTML = `
      <div class="loading-content">
        <p class="loading-error">Failed to load data</p>
        <p class="loading-hint">Run: <code>node scripts/build-site.js</code></p>
      </div>
    `;
    return;
  }

  // Hide loading, show dashboard with entrance animation
  const loading = document.getElementById('loading');
  const dashboard = document.getElementById('dashboard');
  loading.style.display = 'none';
  dashboard.style.display = '';
  requestAnimationFrame(() => dashboard.classList.add('animate-in'));

  // Populate quant options from actual data
  populateQuantOptions(appData.results);

  // Surface the dataset's last-updated time so users know data freshness.
  renderHeroMeta(appData);

  // Init filter dropdowns
  initFilters(appData.meta, () => render());

  // Wire theme toggle
  document.getElementById('theme-toggle')?.addEventListener('click', () => {
    const next = document.documentElement.getAttribute('data-theme') === 'dark' ? 'light' : 'dark';
    document.documentElement.setAttribute('data-theme', next);
    localStorage.setItem('theme', next);
    if (appData) render();
  });

  // Wire reset button
  const resetBtn = document.getElementById('filter-reset');
  if (resetBtn) {
    resetBtn.addEventListener('click', () => {
      resetFilters();
      render();
    });
  }

  // Wire metric selector for CPU vs GPU section
  const metricSelect = document.getElementById('cpu-gpu-metric');
  if (metricSelect) {
    metricSelect.addEventListener('change', () => render());
  }

  // Init section navigation
  initSectionNav();

  // Initial render
  render();
}

function render() {
  // Sync Chart.js defaults with current theme
  const isDark = document.documentElement.getAttribute('data-theme') === 'dark';
  Chart.defaults.color = isDark ? '#a1a1aa' : '#71717a';
  Chart.defaults.plugins.tooltip.backgroundColor = isDark ? 'rgba(15,15,18,0.95)' : 'rgba(255,255,255,0.95)';
  Chart.defaults.plugins.tooltip.borderColor = isDark ? '#27272a' : '#e4e4e7';
  Chart.defaults.plugins.tooltip.titleColor = isDark ? '#e4e4e7' : '#09090b';
  Chart.defaults.plugins.tooltip.bodyColor = isDark ? '#a1a1aa' : '#71717a';

  const filters = getFilters();
  // Filter, attach CPU baseline values (folds CLI-flow CPU records onto
  // their GPU sibling so both submission paths produce one row per cell),
  // fold the (d=0, d=N) study pair into a single GPU row carrying both
  // depths, collapse to one canonical row per (machine, browser, model,
  // variant, backend), then drop the now-redundant CPU rows. CPU numbers
  // stay visible via the cpu_baseline_* columns on each GPU row.
  const filtered = selectBestResults(
    mergeDepthPairs(
      attachCpuBaselineFromCpuRecords(filterResults(appData.results, filters)),
    ),
  ).filter(r => r.nGpuLayers !== 0);

  // Summary cards — counts tween from previous value to new on filter changes
  // and from 0 on first paint (since `data-value` defaults to "0").
  const passed = filtered.filter(r => r.status === 'done');
  animateCount(document.getElementById('stat-machines'), appData.meta.machines.length, { decimals: 0 });
  animateCount(document.getElementById('stat-benchmarks'), filtered.length, { decimals: 0 });
  const passRate = filtered.length > 0 ? (passed.length / filtered.length) * 100 : 0;
  animateCount(document.getElementById('stat-pass-rate'), passRate, { decimals: 0 });

  const decodeVals = passed.map(r => r.decode_tok_s).filter(v => v != null);
  const bestDecode = decodeVals.length ? Math.max(...decodeVals) : 0;
  animateCount(document.getElementById('stat-best-decode'), bestDecode, { decimals: 1 });

  const sizes = passed.map(r => r.sizeMB).filter(v => v != null);
  const largest = sizes.length ? Math.max(...sizes) : 0;
  animateCount(document.getElementById('stat-largest'), largest, { decimals: 0 });

  // Results count
  const countEl = document.getElementById('results-count');
  if (countEl) {
    const total = appData.results.length;
    countEl.textContent = filtered.length === total
      ? `${total} total`
      : `${filtered.length} of ${total}`;
  }

  // Reset button — only present when at least one filter is active. Hiding
  // (rather than disabling) removes a permanent ghost button from the bar
  // and makes the appearance signal "you can undo your filter."
  const resetBtn = document.getElementById('filter-reset');
  if (resetBtn) {
    const activeCount = (filters.machine !== 'all' ? 1 : 0) + (filters.browser !== 'all' ? 1 : 0) +
      (filters.model !== 'all' ? 1 : 0) + (filters.backend !== 'all' ? 1 : 0) +
      (filters.status !== 'all' ? 1 : 0) + (filters.quants.size > 0 ? 1 : 0);
    resetBtn.disabled = activeCount === 0;
    resetBtn.hidden = activeCount === 0;
    const label = resetBtn.querySelector('.filter-reset-label') || resetBtn;
    if (label !== resetBtn) {
      label.textContent = activeCount ? `Reset (${activeCount})` : 'Reset';
    }
  }

  // Tables
  renderResultsTable(filtered);
  renderErrorTable(filtered);
  renderMachineInfo(appData.meta.machines);

  // Charts
  renderDecodeChart(filtered);
  renderPrefillChart(filtered);
  renderSizeChart(filtered);
  renderMachineChart(filtered, appData.meta.machines);

  // CPU vs GPU comparison
  const metric = document.getElementById('cpu-gpu-metric')?.value || 'decode_tok_s';
  renderCpuGpuSection(filtered, metric);
}

/* Consolidate the 3-part CPU-vs-GPU block (two charts + table). When there
   is no CPU baseline or no overlapping GPU data, render a single inline
   empty state and hide the charts+table so the user doesn't see the same
   message repeated three times. */
function renderCpuGpuSection(filtered, metric) {
  const chartsGrid = document.querySelector('#performance-section .charts-grid:nth-of-type(2)');
  const table = document.getElementById('cpu-gpu-table');
  const passed = filtered.filter(r => r.status === 'done');
  // Same expansion the chart/table renderers do — see expandCpuRows().
  const cpuResults = expandCpuRows(passed);
  const gpuResults = passed.filter(r => r.nGpuLayers !== 0);

  if (!chartsGrid || !table) {
    renderCpuGpuChart(filtered, metric);
    renderSpeedupChart(filtered, metric);
    renderCpuGpuTable(filtered);
    return;
  }

  if (cpuResults.length === 0 || gpuResults.length === 0) {
    chartsGrid.hidden = true;
    const reason = cpuResults.length === 0
      ? 'No CPU baseline in the current filter. Select "All Backends" or enable CPU baselines when benchmarking with <code>--consistency</code>.'
      : 'No WebGPU runs in the current filter. Adjust the Backend filter to include WebGPU.';
    table.innerHTML = `<div class="empty-state"><p>${reason}</p></div>`;
    return;
  }

  chartsGrid.hidden = false;
  renderCpuGpuChart(filtered, metric);
  renderSpeedupChart(filtered, metric);
  renderCpuGpuTable(filtered);
}

function renderHeroMeta(data) {
  const el = document.getElementById('hero-meta');
  const liveEl = document.getElementById('hero-live');
  const liveText = document.getElementById('hero-live-text');
  const generated = data?.meta?.generatedAt;
  const machineCount = data?.meta?.machines?.length || 0;
  const resultCount = data?.results?.length || 0;

  if (el) {
    const parts = [];
    if (machineCount > 0) parts.push(`${machineCount} machine${machineCount === 1 ? '' : 's'}`);
    if (resultCount > 0) parts.push(`${resultCount} benchmark${resultCount === 1 ? '' : 's'}`);
    if (generated) parts.push(`updated ${formatRelativeTime(new Date(generated))}`);
    if (parts.length > 0) {
      el.textContent = parts.join(' · ');
      el.hidden = false;
      if (generated) el.title = new Date(generated).toLocaleString();
    }
  }

  if (liveEl && liveText && generated) {
    liveText.textContent = `Live · ${formatRelativeTime(new Date(generated))}`;
    liveEl.hidden = false;
  }

  // Hero stat: top decode tok/s with machine + model context. Uses the
  // canonical set (best per cell) so a noisy 1-iteration outlier can't
  // hijack the headline number. Depth-merge first so a Study cell counts
  // once at its d=N number, not twice.
  const canonical = selectBestResults(mergeDepthPairs(data?.results || []));
  const passed = canonical.filter(r => r.status === 'done' && r.decode_tok_s != null);
  const heroStatEl = document.getElementById('hero-stat');
  const heroNumEl = document.getElementById('hero-top-decode');
  const heroMetaEl = document.getElementById('hero-top-meta');
  if (heroStatEl && heroNumEl && heroMetaEl && passed.length > 0) {
    const top = passed.reduce((a, b) => (a.decode_tok_s > b.decode_tok_s ? a : b));
    heroStatEl.hidden = false;
    heroMetaEl.textContent = `${top.machineSlug || top.machine || '—'} · ${top.model || ''} ${top.variant || ''}`.trim();
    animateCount(heroNumEl, top.decode_tok_s, { decimals: 1, duration: 800 });
  }
}

/* Tween numeric content from 0 to a target. CSS-only via @property would
   need server-side @property registration to work in older Safari; keep
   this 12-line JS tween for predictability. */
function animateCount(el, target, { decimals = 0, duration = 600 } = {}) {
  if (!el) return;
  const start = parseFloat(el.dataset.value || '0') || 0;
  const end = Number(target) || 0;
  if (start === end) {
    el.textContent = end.toFixed(decimals);
    return;
  }
  const startTime = performance.now();
  const ease = (t) => 1 - Math.pow(1 - t, 3);
  function step(now) {
    const t = Math.min(1, (now - startTime) / duration);
    const v = start + (end - start) * ease(t);
    el.textContent = v.toFixed(decimals);
    if (t < 1) requestAnimationFrame(step);
    else el.dataset.value = String(end);
  }
  requestAnimationFrame(step);
}

function formatRelativeTime(date) {
  const now = Date.now();
  const diff = Math.max(0, now - date.getTime());
  const min = 60_000, hr = 60 * min, day = 24 * hr;
  if (diff < min) return 'just now';
  if (diff < hr) return `${Math.floor(diff / min)} min ago`;
  if (diff < day) return `${Math.floor(diff / hr)} h ago`;
  const days = Math.floor(diff / day);
  if (days < 30) return `${days} day${days === 1 ? '' : 's'} ago`;
  return date.toISOString().slice(0, 10);
}

function initSectionNav() {
  const nav = document.getElementById('section-nav');
  if (!nav) return;

  const track = nav.querySelector('.section-nav-track');
  const buttons = nav.querySelectorAll('.section-nav-item');
  const sections = [];

  // Prefer the sticky wrapper height so the jumped-to section isn't
  // obscured by the sticky head.
  const stickyHead = document.querySelector('.sticky-head') || nav;

  buttons.forEach(btn => {
    const sectionId = btn.dataset.section;
    const section = document.getElementById(sectionId);
    if (section) sections.push({ btn, section });

    btn.addEventListener('click', (e) => {
      e.preventDefault();
      if (section) {
        const offset = stickyHead.offsetHeight + 8;
        const top = section.getBoundingClientRect().top + window.scrollY - offset;
        window.scrollTo({ top, behavior: 'smooth' });
      }
    });
  });

  // Drive the sliding indicator from the active button's geometry. Track
  // is the positioned ancestor; offsetLeft/offsetWidth are relative to it.
  const moveIndicator = (btn) => {
    if (!track || !btn) return;
    track.style.setProperty('--indicator-x', `${btn.offsetLeft}px`);
    track.style.setProperty('--indicator-w', `${btn.offsetWidth}px`);
  };

  // Scroll spy: instead of IntersectionObserver (which fires inconsistently
  // when multiple sections overlap the observer band), compute the
  // currently-active section on scroll by comparing each section's top to
  // the bottom of the sticky head. Cheaper and predictable.
  if (sections.length === 0) return;

  let ticking = false;
  const updateActive = () => {
    const anchor = stickyHead.offsetHeight + 16;
    let active = sections[0];
    for (const entry of sections) {
      const top = entry.section.getBoundingClientRect().top;
      if (top - anchor <= 0) active = entry;
      else break;
    }
    buttons.forEach(b => b.classList.toggle('active', b === active.btn));
    moveIndicator(active.btn);
  };
  const onScroll = () => {
    if (ticking) return;
    ticking = true;
    requestAnimationFrame(() => { updateActive(); ticking = false; });
  };
  window.addEventListener('scroll', onScroll, { passive: true });
  window.addEventListener('resize', onScroll);
  updateActive();
  // Re-measure once fonts settle — Bricolage Grotesque shifts widths.
  document.fonts?.ready?.then(() => updateActive()).catch(() => {});
}

init();