// Per-agent stats page. Fetches /api/state for the title + dashboard link
// once on load, then /api/stats?window=... for the chart data — re-fetches
// when the operator clicks a window tab.

(function () {
  'use strict';

  const cssVar = (name) => getComputedStyle(document.documentElement).getPropertyValue(name).trim();
  const palette = {
    bg: cssVar('--bg'),
    bgElev: cssVar('--bg-elev'),
    fg: cssVar('--fg'),
    muted: cssVar('--muted'),
    purple: cssVar('--purple'),
    cyan: cssVar('--cyan'),
    pink: cssVar('--pink'),
    amber: cssVar('--amber'),
    green: cssVar('--green'),
    red: cssVar('--red'),
    border: cssVar('--border'),
  };
  // Distinct hues for categorical charts (top tools / wake mix / result mix).
  const wheel = [palette.purple, palette.cyan, palette.pink, palette.amber,
                 palette.green, palette.red, '#94e2d5', '#f9e2af',
                 '#74c7ec', '#b4befe'];

  // Apply Catppuccin defaults globally so each Chart inherits without per-call
  // overrides. Chart.js v4 reads these on chart construction.
  Chart.defaults.color = palette.fg;
  Chart.defaults.borderColor = palette.border;
  Chart.defaults.font.family = '"JetBrains Mono", "Fira Code", monospace';
  Chart.defaults.font.size = 11;
  Chart.defaults.plugins.legend.labels.color = palette.fg;

  const charts = {};
  let currentWindow = '24h';

  function fmtMs(ms) {
    if (!Number.isFinite(ms) || ms <= 0) return '0';
    if (ms < 1000) return ms.toFixed(0) + 'ms';
    return (ms / 1000).toFixed(ms < 10000 ? 2 : 1) + 's';
  }

  function fmtInt(n) {
    if (!Number.isFinite(n)) return '0';
    return new Intl.NumberFormat().format(Math.round(n));
  }

  function bucketLabel(ts, bucketSecs) {
    const d = new Date(ts * 1000);
    if (bucketSecs >= 86400) {
      return d.toISOString().slice(5, 10); // MM-DD
    }
    return d.toISOString().slice(11, 16); // HH:MM
  }

  function destroy(name) {
    if (charts[name]) {
      charts[name].destroy();
      delete charts[name];
    }
  }

  function paintEmpty(canvasId, msg) {
    destroy(canvasId);
    const cv = document.getElementById(canvasId);
    if (!cv) return;
    const ctx = cv.getContext('2d');
    ctx.clearRect(0, 0, cv.width, cv.height);
    ctx.fillStyle = palette.muted;
    ctx.font = '12px monospace';
    ctx.textAlign = 'center';
    ctx.textBaseline = 'middle';
    ctx.fillText(msg, cv.width / 2, cv.height / 2);
  }

  function renderSummary(s) {
    const root = document.getElementById('summary');
    root.replaceChildren();
    const chips = [
      ['turns', fmtInt(s.turn_count)],
      ['avg duration', fmtMs(s.duration_summary.avg_ms)],
      ['p50 duration', fmtMs(s.duration_summary.p50_ms)],
      ['p95 duration', fmtMs(s.duration_summary.p95_ms)],
      ['window', s.window],
    ];
    for (const [label, value] of chips) {
      const chip = document.createElement('span');
      chip.className = 'chip';
      const l = document.createElement('span');
      l.className = 'label';
      l.textContent = label;
      const v = document.createElement('span');
      v.className = 'value';
      v.textContent = value;
      chip.append(l, v);
      root.append(chip);
    }
  }

  function renderTurnsChart(s) {
    const id = 'chart-turns';
    destroy(id);
    const labels = s.buckets.map((b) => bucketLabel(b.ts, s.bucket_seconds));
    const data = s.buckets.map((b) => b.turn_count);
    charts[id] = new Chart(document.getElementById(id), {
      type: 'bar',
      data: {
        labels,
        datasets: [{
          label: 'turns',
          data,
          backgroundColor: palette.purple,
          borderColor: palette.purple,
          borderWidth: 1,
        }],
      },
      options: {
        responsive: true, maintainAspectRatio: false,
        plugins: { legend: { display: false } },
        scales: {
          x: { grid: { color: palette.border } },
          y: { beginAtZero: true, grid: { color: palette.border }, ticks: { precision: 0 } },
        },
      },
    });
  }

  function renderDurationChart(s) {
    const id = 'chart-duration';
    destroy(id);
    const labels = s.buckets.map((b) => bucketLabel(b.ts, s.bucket_seconds));
    const ds = (label, color, key) => ({
      label, data: s.buckets.map((b) => b[key]),
      borderColor: color, backgroundColor: color + '33',
      tension: 0.25, pointRadius: 0, borderWidth: 2, spanGaps: true,
    });
    charts[id] = new Chart(document.getElementById(id), {
      type: 'line',
      data: {
        labels,
        datasets: [
          ds('p50', palette.cyan, 'p50_duration_ms'),
          ds('p95', palette.pink, 'p95_duration_ms'),
          ds('avg', palette.amber, 'avg_duration_ms'),
        ],
      },
      options: {
        responsive: true, maintainAspectRatio: false,
        scales: {
          x: { grid: { color: palette.border } },
          y: {
            beginAtZero: true,
            grid: { color: palette.border },
            ticks: { callback: (v) => fmtMs(v) },
          },
        },
      },
    });
  }

  function renderCtxChart(s) {
    const id = 'chart-ctx';
    destroy(id);
    const labels = s.buckets.map((b) => bucketLabel(b.ts, s.bucket_seconds));
    charts[id] = new Chart(document.getElementById(id), {
      type: 'line',
      data: {
        labels,
        datasets: [
          {
            label: 'avg ctx',
            data: s.buckets.map((b) => b.avg_ctx_tokens),
            borderColor: palette.cyan,
            backgroundColor: palette.cyan + '33',
            tension: 0.25, pointRadius: 0, borderWidth: 2, spanGaps: true,
          },
          {
            label: 'max ctx',
            data: s.buckets.map((b) => b.max_ctx_tokens),
            borderColor: palette.amber,
            backgroundColor: palette.amber + '33',
            tension: 0.25, pointRadius: 0, borderWidth: 2, spanGaps: true,
          },
        ],
      },
      options: {
        responsive: true, maintainAspectRatio: false,
        scales: {
          x: { grid: { color: palette.border } },
          y: { beginAtZero: true, grid: { color: palette.border }, ticks: { callback: (v) => fmtInt(v) } },
        },
      },
    });
  }

  function renderCostChart(s) {
    const id = 'chart-cost';
    destroy(id);
    const labels = s.buckets.map((b) => bucketLabel(b.ts, s.bucket_seconds));
    // Stacked bars: cache_read (cheap) / cache_creation / input / output.
    // Highlights "what's actually getting billed at full rate" vs cache hits.
    charts[id] = new Chart(document.getElementById(id), {
      type: 'bar',
      data: {
        labels,
        datasets: [
          { label: 'cache_read', data: s.buckets.map((b) => b.cache_read_input_tokens),
            backgroundColor: palette.muted },
          { label: 'cache_creation', data: s.buckets.map((b) => b.cache_creation_input_tokens),
            backgroundColor: palette.cyan },
          { label: 'input', data: s.buckets.map((b) => b.input_tokens),
            backgroundColor: palette.amber },
          { label: 'output', data: s.buckets.map((b) => b.output_tokens),
            backgroundColor: palette.pink },
        ],
      },
      options: {
        responsive: true, maintainAspectRatio: false,
        scales: {
          x: { stacked: true, grid: { color: palette.border } },
          y: { stacked: true, beginAtZero: true,
               grid: { color: palette.border }, ticks: { callback: (v) => fmtInt(v) } },
        },
      },
    });
  }

  function renderModelChart(s) {
    const id = 'chart-model';
    destroy(id);
    const models = s.models || [];
    if (!models.length) { paintEmpty(id, 'no turns in window'); return; }
    const labels = s.buckets.map((b) => bucketLabel(b.ts, s.bucket_seconds));
    // One stacked series per model. Model choice drives token cost,
    // so this lines up against the cost chart above it.
    const datasets = models.map((m, i) => ({
      label: m,
      data: s.buckets.map((b) => (b.model_counts && b.model_counts[m]) || 0),
      backgroundColor: wheel[i % wheel.length],
    }));
    charts[id] = new Chart(document.getElementById(id), {
      type: 'bar',
      data: { labels, datasets },
      options: {
        responsive: true, maintainAspectRatio: false,
        plugins: { legend: { position: 'top', labels: { boxWidth: 12 } } },
        scales: {
          x: { stacked: true, grid: { color: palette.border } },
          y: { stacked: true, beginAtZero: true,
               grid: { color: palette.border }, ticks: { precision: 0 } },
        },
      },
    });
  }

  function renderKeyCount(canvasId, items, emptyMsg) {
    destroy(canvasId);
    if (!items || items.length === 0) {
      paintEmpty(canvasId, emptyMsg);
      return;
    }
    const labels = items.map((kc) => kc.key);
    const data = items.map((kc) => kc.count);
    const colors = items.map((_, i) => wheel[i % wheel.length]);
    charts[canvasId] = new Chart(document.getElementById(canvasId), {
      type: 'doughnut',
      data: { labels, datasets: [{ data, backgroundColor: colors, borderColor: palette.bg, borderWidth: 2 }] },
      options: {
        responsive: true, maintainAspectRatio: false,
        plugins: { legend: { position: 'right', labels: { boxWidth: 12 } } },
      },
    });
  }

  function render(s) {
    renderSummary(s);
    if (s.turn_count === 0) {
      paintEmpty('chart-turns', 'no turns in window');
      paintEmpty('chart-duration', 'no turns in window');
      paintEmpty('chart-ctx', 'no turns in window');
      paintEmpty('chart-cost', 'no turns in window');
      paintEmpty('chart-model', 'no turns in window');
      paintEmpty('chart-tools', 'no tool calls');
      paintEmpty('chart-wake', 'no wakes');
      paintEmpty('chart-result', 'no results');
      return;
    }
    renderTurnsChart(s);
    renderDurationChart(s);
    renderCtxChart(s);
    renderCostChart(s);
    renderModelChart(s);
    renderKeyCount('chart-tools', s.tool_breakdown, 'no tool calls');
    renderKeyCount('chart-wake', s.wake_mix, 'no wakes');
    renderKeyCount('chart-result', s.result_mix, 'no results');
  }

  async function loadStats() {
    try {
      const resp = await fetch('/api/stats?window=' + encodeURIComponent(currentWindow));
      if (!resp.ok) throw new Error('http ' + resp.status);
      const snap = await resp.json();
      render(snap);
    } catch (e) {
      document.getElementById('summary').textContent = 'stats fetch failed: ' + e;
    }
  }

  async function loadIdentity() {
    try {
      const resp = await fetch('/api/state');
      if (!resp.ok) return;
      const s = await resp.json();
      document.title = 'stats · ' + s.label;
      document.getElementById('title').textContent = '◆ ' + s.label + ' ◆';
      const dl = document.getElementById('dashboard-link');
      dl.href = 'http://' + window.location.hostname + ':' + s.dashboard_port + '/';
    } catch (_) { /* non-fatal */ }
  }

  function bindTabs() {
    const tabs = document.getElementById('window-tabs');
    tabs.addEventListener('click', (ev) => {
      const btn = ev.target.closest('button[data-w]');
      if (!btn) return;
      currentWindow = btn.dataset.w;
      for (const b of tabs.querySelectorAll('button')) b.classList.toggle('active', b === btn);
      loadStats();
    });
  }

  document.addEventListener('DOMContentLoaded', () => {
    bindTabs();
    loadIdentity();
    loadStats();
  });
})();