/**
 * Dashboard Chart Animator
 * Continuously animates SVG bar charts, line graph, and pie chart.
 * Uses requestAnimationFrame, pauses off-screen via IntersectionObserver.
 */
(function () {
  'use strict';

  /* ── Configuration ──────────────────────────────────── */
  var SPEED   = 0.0025;   // phase increment per ms  (~4-6 s visible cycle)
  var BAR_H   = 120;      // max bar height in SVG units
  var BAR_MIN = 0.12;     // minimum bar height ratio (12 %)
  var LINE_PTS = 8;       // number of points on the line graph

  /* ── Colour sets (matches theme tokens) ─────────────── */
  var DARK  = { text: '#E0E0E0', muted: '#9E9E9E', border: '#333', center: '#222' };
  var LIGHT = { text: '#333333', muted: '#666666', border: '#E0E0E0', center: '#fff' };

  function isDark() {
    return document.documentElement.getAttribute('data-theme') === 'dark';
  }
  function palette() { return isDark() ? DARK : LIGHT; }

  /** Stacked sine waves => smooth organic value in 0..1 range */
  function wave(t, offset) {
    return Math.max(0, Math.min(1,
      0.55 +
      Math.sin(t * 1.0 + offset)         * 0.30 +
      Math.sin(t * 2.3 + offset * 1.4)   * 0.25 +
      Math.sin(t * 0.7 + offset * 0.6)   * 0.20
    ));
  }

  /* ── Per-chart state ────────────────────────────────── */
  function makeState(svg) {
    return {
      svg:      svg,
      bars1:    svg.querySelectorAll('#bars-group-1 .bar'),
      bars2:    svg.querySelectorAll('#bars-group-2 .bar'),
      vals1:    svg.querySelectorAll('#values-group-1 text'),
      vals2:    svg.querySelectorAll('#values-group-2 text'),
      linePath: svg.querySelector('#line-path'),
      lineFill: svg.querySelector('#line-fill'),
      pieSegs:  svg.querySelectorAll('.pie-segment'),
      phase:    Math.random() * Math.PI * 2,
      paused:   false,
      raf:      null,
      themeN:   0
    };
  }

  /* ── Update routines ────────────────────────────────── */
  function updateBars(bars, vals, st, pct) {
    var i, v, h;
    for (i = 0; i < bars.length; i++) {
      v = wave(st.phase, i * 1.1);
      v = Math.max(BAR_MIN, v);
      h = v * BAR_H;
      bars[i].setAttribute('height', h);
      bars[i].setAttribute('y', BAR_H - h);
    }
    for (i = 0; i < Math.min(bars.length, vals.length); i++) {
      v = wave(st.phase, i * 1.1);
      v = Math.max(BAR_MIN, v);
      vals[i].textContent = pct ? Math.round(v * 100) + '%' : Math.round(v * 5000);
    }
  }

  function updateLine(st) {
    if (!st.linePath) return;
    var d = 'M', i, x, y, v;
    for (i = 0; i < LINE_PTS; i++) {
      x = (i / (LINE_PTS - 1)) * 200;
      v = wave(st.phase * 0.8, i * 0.9);
      y = 25 + (1 - v) * 110;
      d += (i ? ' L' : '') + x.toFixed(1) + ',' + y.toFixed(1);
    }
    st.linePath.setAttribute('d', d);
    if (st.lineFill) st.lineFill.setAttribute('d', d + ' L200,145 L0,145 Z');
  }

  function updatePie(st) {
    if (!st.pieSegs.length) return;
    var base = (st.phase * 40) % 360;
    for (var i = 0; i < st.pieSegs.length; i++) {
      var w = Math.sin(st.phase * 0.6 + i * 1.5) * 4;
      st.pieSegs[i].setAttribute('transform', 'rotate(' + (base + i * 90 + w) + ')');
    }
  }

  function applyTheme(st) {
    var c = palette();
    var q = st.svg.querySelectorAll.bind(st.svg);
    var all, j;

    all = q('.ct');  for (j = 0; j < all.length; j++) all[j].setAttribute('fill', c.text);
    all = q('.cl');  for (j = 0; j < all.length; j++) all[j].setAttribute('fill', c.muted);
    all = q('.cv');  for (j = 0; j < all.length; j++) all[j].setAttribute('fill', c.text);
    all = q('.grid-line'); for (j = 0; j < all.length; j++) all[j].setAttribute('stroke', c.border);

    var cc = st.svg.querySelector('#pie-center');
    if (cc) { cc.setAttribute('fill', c.center); cc.setAttribute('stroke', c.border); }
    var pt = st.svg.querySelector('#pie-center-text');
    if (pt) pt.setAttribute('fill', c.text);
  }

  /* ── Animation loop ─────────────────────────────────── */
  function tick(st) {
    if (!st.paused) {
      st.phase += SPEED * 16;   // ~16 ms per frame at 60 fps
      updateBars(st.bars1, st.vals1, st, true);
      updateBars(st.bars2, st.vals2, st, false);
      updateLine(st);
      updatePie(st);

      // Re-apply theme colours every ~30 frames (~0.5 s)
      if (++st.themeN > 30) { st.themeN = 0; applyTheme(st); }
    }
    st.raf = requestAnimationFrame(function () { tick(st); });
  }

  /* ── Hover pause / resume ───────────────────────────── */
  function attachHover(st) {
    var el = st.svg.closest('[data-dashboard-container]') || st.svg.parentElement;
    if (!el) return;
    el.addEventListener('mouseenter', function () { st.paused = true; });
    el.addEventListener('mouseleave', function () { st.paused = false; });
    el.addEventListener('touchstart',  function () { st.paused = true; },  { passive: true });
    el.addEventListener('touchend',    function () { st.paused = false; }, { passive: true });
  }

  /* ── IntersectionObserver (pause off-screen) ────────── */
  function observe(st) {
    if (!('IntersectionObserver' in window)) return;
    new IntersectionObserver(function (entries) {
      for (var i = 0; i < entries.length; i++) st.paused = !entries[i].isIntersecting;
    }, { rootMargin: '200px', threshold: 0.05 }).observe(st.svg);
  }

  /* ── Bootstrap ──────────────────────────────────────── */
  function boot() {
    var svgs = document.querySelectorAll('.dashboard-chart');
    if (!svgs.length) return;
    var reduced = window.matchMedia('(prefers-reduced-motion: reduce)').matches;

    for (var i = 0; i < svgs.length; i++) {
      if (svgs[i]._dbAnim) continue;
      var st = makeState(svgs[i]);
      svgs[i]._dbAnim = st;
      applyTheme(st);
      if (!reduced) { tick(st); attachHover(st); observe(st); }
    }
  }

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