// WEBklar Analyse: Heatmap-Overlay (wird von w.js nur mit gueltigem ?__wk_heat=Token geladen).
import { escapeHtml } from './core.js';

function main() {
  const me = document.currentScript;
  const token = me && me.getAttribute('data-token');
  const src = String((me && (me.src || me.getAttribute('src'))) || '').replace(/[?#].*$/, '');
  const base = src.replace(/[^/]*$/, '');
  if (!token || !base) return;

  const de = document.documentElement;
  const host = document.createElement('div');
  host.style.position = 'fixed'; host.style.left = '0'; host.style.right = '0'; host.style.top = '0'; host.style.zIndex = '2147483647';
  const root = host.attachShadow({ mode: 'open' });
  const style = document.createElement('style');
  style.textContent = ':host{all:initial}.bar{display:flex;align-items:center;justify-content:space-between;gap:12px;padding:10px 16px;background:#111;color:#fff;font:14px/1.4 system-ui,-apple-system,Segoe UI,Roboto,sans-serif}button{font:600 14px/1 system-ui,sans-serif;padding:8px 14px;border:2px solid #fff;border-radius:6px;background:#fff;color:#111;cursor:pointer}button:focus-visible{outline:3px solid #1a73e8;outline-offset:2px}';
  const bar = document.createElement('div');
  bar.className = 'bar';
  const msg = document.createElement('span');
  msg.innerHTML = escapeHtml('Heatmap wird geladen ...');
  const close = document.createElement('button');
  close.setAttribute('type', 'button');
  close.textContent = 'Schließen';
  bar.appendChild(msg); bar.appendChild(close);
  root.appendChild(style); root.appendChild(bar);
  document.body.appendChild(host);

  const canvas = document.createElement('canvas');
  const cs = canvas.style;
  cs.position = 'absolute'; cs.left = '0'; cs.top = '0'; cs.pointerEvents = 'none'; cs.zIndex = '2147483646';
  document.body.appendChild(canvas);

  let points = [];
  let lastW = 0, lastH = 0, timer = 0;

  // Farbverlauf: transparent -> blau -> gruen -> gelb -> rot
  const ramp = (function () {
    const c = document.createElement('canvas'); c.width = 256; c.height = 1;
    const g = c.getContext('2d');
    const lg = g.createLinearGradient(0, 0, 256, 0);
    lg.addColorStop(0.25, 'rgb(0,0,255)'); lg.addColorStop(0.55, 'rgb(0,255,0)'); lg.addColorStop(0.85, 'rgb(255,255,0)'); lg.addColorStop(1, 'rgb(255,0,0)');
    g.fillStyle = lg; g.fillRect(0, 0, 256, 1);
    return g.getImageData(0, 0, 256, 1).data;
  })();

  function draw() {
    const w = Math.max(de.scrollWidth, de.clientWidth, 1);
    const h = Math.max(de.scrollHeight, de.clientHeight, 1);
    lastW = w; lastH = h;
    // Zeichenflaeche begrenzen (Speicher): hoechstens ca. 4 Mio. Pixel
    const scale = Math.min(1, Math.sqrt(4e6 / (w * h)));
    const cw = Math.max(1, Math.floor(w * scale)), ch = Math.max(1, Math.floor(h * scale));
    canvas.width = cw; canvas.height = ch;
    cs.width = w + 'px'; cs.height = h + 'px';
    const g = canvas.getContext('2d');
    g.clearRect(0, 0, cw, ch);
    const r = Math.max(6, 30 * scale);
    for (const p of points) {
      const x = p.x * cw, y = p.y * ch;
      const rg = g.createRadialGradient(x, y, 0, x, y, r);
      rg.addColorStop(0, 'rgba(0,0,0,0.25)'); rg.addColorStop(1, 'rgba(0,0,0,0)');
      g.fillStyle = rg; g.fillRect(x - r, y - r, r * 2, r * 2);
    }
    // Deckkraft-Stufen in Farben umsetzen
    const img = g.getImageData(0, 0, cw, ch);
    const d = img.data;
    for (let i = 3; i < d.length; i += 4) {
      const a = d[i];
      if (!a) continue;
      const k = Math.min(255, a * 3) * 4;
      d[i - 3] = ramp[k]; d[i - 2] = ramp[k + 1]; d[i - 1] = ramp[k + 2];
      d[i] = Math.min(200, 60 + a);
    }
    g.putImageData(img, 0, 0);
  }

  function redrawIfChanged() {
    if (Math.max(de.scrollWidth, de.clientWidth) !== lastW || Math.max(de.scrollHeight, de.clientHeight) !== lastH) draw();
  }
  function stop() {
    clearInterval(timer);
    window.removeEventListener('resize', draw);
    host.remove(); canvas.remove();
  }
  close.addEventListener('click', stop);
  window.addEventListener('resize', draw);

  fetch(base + 'heat?token=' + encodeURIComponent(token), { credentials: 'omit' })
    .then(function (r) { if (!r.ok) throw new Error('heat'); return r.json(); })
    .then(function (j) {
      points = (j && Array.isArray(j.points) ? j.points : []).filter(function (p) { return p && p.x >= 0 && p.x <= 1 && p.y >= 0 && p.y <= 1; });
      msg.innerHTML = escapeHtml('Heatmap – ' + points.length + ' Klicks (letzte 30 Tage)');
      draw();
      timer = setInterval(redrawIfChanged, 1000);
    })
    .catch(function () { msg.innerHTML = escapeHtml('Heatmap-Link abgelaufen oder ungültig'); });
}

try { main(); } catch (e) { /* nie die Seite stoeren */ }