// Tab "Pose 3D" — viewport Three.js, gizmo translate/rotate, drag dei polsi.
// Vanilla JS, ES modules.

import * as THREE from 'three';
import { OrbitControls } from 'three/addons/controls/OrbitControls.js';
import { TransformControls } from 'three/addons/controls/TransformControls.js';

const $ = (id) => document.getElementById(id);
const POLL_MS = 1000;

// ----- helpers geometria -----
function makeUCS(size = 0.1) {
  // 3 linee X(rosso) Y(verde) Z(blu) dalla origine
  const g = new THREE.Group();
  const mat = (color) => new THREE.LineBasicMaterial({ color, linewidth: 2 });
  const make = (dir, color) => {
    const geom = new THREE.BufferGeometry().setFromPoints([
      new THREE.Vector3(0, 0, 0),
      new THREE.Vector3(dir.x * size, dir.y * size, dir.z * size),
    ]);
    return new THREE.Line(geom, mat(color));
  };
  g.add(make(new THREE.Vector3(1, 0, 0), 0xe74c3c));
  g.add(make(new THREE.Vector3(0, 1, 0), 0x3ecf8e));
  g.add(make(new THREE.Vector3(0, 0, 1), 0x4da3ff));
  return g;
}

function makeWristMarker(color) {
  const group = new THREE.Group();
  const sphere = new THREE.Mesh(
    new THREE.SphereGeometry(0.025, 16, 12),
    new THREE.MeshStandardMaterial({ color, metalness: 0.2, roughness: 0.5 }),
  );
  group.add(sphere);
  group.add(makeUCS(0.07));
  group.userData.sphere = sphere;
  return group;
}

// ----- state -----
const state = {
  three: null,                    // {scene, camera, renderer, orbit, transform}
  arms: { right: null, left: null },         // wrist groups (real)
  ghosts: { right: null, left: null },       // wrist groups (target preview)
  links: { right: null, left: null },        // line shoulder→wrist
  current: { right: null, left: null },      // {position, quaternion}
  target: { right: null, left: null },       // null = nessuna modifica locale
  active_side: 'right',
  mode: 'editor',
  gizmo_mode: 'translate',
  precise: true,
  saved_poses: {},
  live_max_step_m: 0.15,
};

// Posizioni torso e spalle hardcoded (riferimento visivo, non IK)
const TORSO_POS = new THREE.Vector3(0, 0, 0.40);
const SHOULDER = {
  right: new THREE.Vector3(0, -0.20, 0.60),
  left:  new THREE.Vector3(0,  0.20, 0.60),
};

// ----- scene init -----
function initScene() {
  const canvas = $('p3Canvas');
  const renderer = new THREE.WebGLRenderer({ canvas, antialias: true });
  const rect = canvas.parentElement.getBoundingClientRect();
  renderer.setSize(rect.width, rect.height, false);
  renderer.setPixelRatio(window.devicePixelRatio || 1);

  const scene = new THREE.Scene();
  scene.background = new THREE.Color(0x0d1014);

  const camera = new THREE.PerspectiveCamera(45, rect.width / rect.height, 0.05, 20);
  camera.position.set(1, -1, 0.8);
  camera.up.set(0, 0, 1);  // Z up (coerente col base frame del robot)
  camera.lookAt(0, 0, 0.3);

  scene.add(new THREE.HemisphereLight(0xffffff, 0x202030, 0.6));
  const dir = new THREE.DirectionalLight(0xffffff, 0.8);
  dir.position.set(2, 2, 3);
  scene.add(dir);

  // Grid + base UCS
  const grid = new THREE.GridHelper(2, 20, 0x444444, 0x222222);
  grid.rotation.x = Math.PI / 2;  // piano XY (z=0)
  scene.add(grid);
  const baseUCS = makeUCS(0.2);
  scene.add(baseUCS);

  // Torso
  const torso = new THREE.Mesh(
    new THREE.BoxGeometry(0.20, 0.40, 0.50),
    new THREE.MeshStandardMaterial({ color: 0x4a5560, transparent: true, opacity: 0.7 }),
  );
  torso.position.copy(TORSO_POS);
  scene.add(torso);

  // Arms
  for (const side of ['right', 'left']) {
    const wrist = makeWristMarker(side === 'right' ? 0x4da3ff : 0xff5e7e);
    wrist.position.copy(SHOULDER[side]);  // posizione di partenza, sarà aggiornata dal polling
    wrist.userData.side = side;
    scene.add(wrist);
    state.arms[side] = wrist;

    // Linea shoulder → wrist
    const lineGeom = new THREE.BufferGeometry().setFromPoints([
      SHOULDER[side].clone(),
      wrist.position.clone(),
    ]);
    const line = new THREE.Line(lineGeom, new THREE.LineBasicMaterial({ color: 0xaaaaaa }));
    scene.add(line);
    state.links[side] = line;

    // Ghost (preview target), inizialmente nascosto
    const ghost = makeWristMarker(side === 'right' ? 0x4da3ff : 0xff5e7e);
    ghost.userData.sphere.material = ghost.userData.sphere.material.clone();
    ghost.userData.sphere.material.transparent = true;
    ghost.userData.sphere.material.opacity = 0.4;
    ghost.visible = false;
    scene.add(ghost);
    state.ghosts[side] = ghost;
  }

  const orbit = new OrbitControls(camera, renderer.domElement);
  orbit.target.set(0, 0, 0.3);
  orbit.update();

  const transform = new TransformControls(camera, renderer.domElement);
  transform.setMode('translate');
  // Disable orbit while dragging gizmo
  transform.addEventListener('dragging-changed', (e) => { orbit.enabled = !e.value; });
  scene.add(transform);

  state.three = { scene, camera, renderer, orbit, transform };

  // Resize handler
  const onResize = () => {
    const r = canvas.parentElement.getBoundingClientRect();
    renderer.setSize(r.width, r.height, false);
    camera.aspect = r.width / r.height;
    camera.updateProjectionMatrix();
  };
  window.addEventListener('resize', onResize);

  // Render loop
  function animate() {
    requestAnimationFrame(animate);
    renderer.render(scene, camera);
  }
  animate();
}

// ----- init triggered on first activation -----
let inited = false;
function ensureInit() {
  if (inited) return;
  if (!$('p3Canvas')) return;
  inited = true;
  initScene();
}

// Observe quando la tab diventa visibile per inizializzare
const tabObserver = new MutationObserver(() => {
  if ($('tab-pose-3d')?.classList.contains('active')) ensureInit();
});
if ($('tab-pose-3d')) {
  tabObserver.observe($('tab-pose-3d'), { attributes: true, attributeFilter: ['class'] });
  // Se è già attivo all'avvio
  if ($('tab-pose-3d').classList.contains('active')) ensureInit();
}