// modules/panels/heatmap.js — Commit heatmap floor overlay
import * as THREE from 'three';
import { state } from '../core/state.js';
import { HEATMAP_ZONES } from '../data/gitea.js';
import { GLASS_RADIUS } from '../terrain/island.js';

const HEATMAP_SIZE = 512;
const HEATMAP_ZONE_SPAN_RAD = Math.PI / 2;

const heatmapCanvas = document.createElement('canvas');
heatmapCanvas.width = HEATMAP_SIZE;
heatmapCanvas.height = HEATMAP_SIZE;
const heatmapTexture = new THREE.CanvasTexture(heatmapCanvas);

const heatmapMat = new THREE.MeshBasicMaterial({
  map: heatmapTexture, transparent: true, opacity: 0.9,
  depthWrite: false, blending: THREE.AdditiveBlending, side: THREE.DoubleSide,
});

let heatmapMesh;

export function drawHeatmap() {
  const ctx = heatmapCanvas.getContext('2d');
  const cx = HEATMAP_SIZE / 2;
  const cy = HEATMAP_SIZE / 2;
  const r = cx * 0.96;

  ctx.clearRect(0, 0, HEATMAP_SIZE, HEATMAP_SIZE);
  ctx.save();
  ctx.beginPath();
  ctx.arc(cx, cy, r, 0, Math.PI * 2);
  ctx.clip();

  for (const zone of HEATMAP_ZONES) {
    const intensity = state.zoneIntensity[zone.name] || 0;
    if (intensity < 0.01) continue;
    const [rr, gg, bb] = zone.color;
    const baseRad = zone.angleDeg * (Math.PI / 180);
    const startRad = baseRad - HEATMAP_ZONE_SPAN_RAD / 2;
    const endRad = baseRad + HEATMAP_ZONE_SPAN_RAD / 2;
    const gx = cx + Math.cos(baseRad) * r * 0.55;
    const gy = cy + Math.sin(baseRad) * r * 0.55;
    const grad = ctx.createRadialGradient(gx, gy, 0, gx, gy, r * 0.75);
    grad.addColorStop(0,   `rgba(${rr},${gg},${bb},${0.65 * intensity})`);
    grad.addColorStop(0.45, `rgba(${rr},${gg},${bb},${0.25 * intensity})`);
    grad.addColorStop(1,   `rgba(${rr},${gg},${bb},0)`);
    ctx.beginPath();
    ctx.moveTo(cx, cy);
    ctx.arc(cx, cy, r, startRad, endRad);
    ctx.closePath();
    ctx.fillStyle = grad;
    ctx.fill();
    if (intensity > 0.05) {
      const labelX = cx + Math.cos(baseRad) * r * 0.62;
      const labelY = cy + Math.sin(baseRad) * r * 0.62;
      ctx.font = `bold ${Math.round(13 * intensity + 7)}px "Courier New", monospace`;
      ctx.fillStyle = `rgba(${rr},${gg},${bb},${Math.min(intensity * 1.2, 0.9)})`;
      ctx.textAlign = 'center';
      ctx.textBaseline = 'middle';
      ctx.fillText(zone.name, labelX, labelY);
    }
  }

  ctx.restore();
  heatmapTexture.needsUpdate = true;
}

export function init(scene) {
  heatmapMesh = new THREE.Mesh(
    new THREE.CircleGeometry(GLASS_RADIUS, 64),
    heatmapMat
  );
  heatmapMesh.rotation.x = -Math.PI / 2;
  heatmapMesh.position.y = 0.005;
  heatmapMesh.userData.zoomLabel = 'Activity Heatmap';
  scene.add(heatmapMesh);
}

export function update(elapsed) {
  heatmapMat.opacity = 0.75 + Math.sin(elapsed * 0.6) * 0.2;
}