import {
  AnimationMixer,
  DirectionalLight,
  Clock,
  Color,
  Fog,
  HemisphereLight,
  Mesh,
  MeshPhongMaterial,
  PlaneGeometry,
  Vector3,
} from "three";
import { MapControls } from "three/examples/jsm/controls/MapControls.js";
import { GLTFLoader } from "three/examples/jsm/loaders/GLTFLoader.js";
import { clone } from "three/examples/jsm/utils/SkeletonUtils.js";

import Instance from "@giro3d/giro3d/core/Instance.js";
import Inspector from "@giro3d/giro3d/gui/Inspector.js";

function bindNumericalDropDown(id, onChange) {
  const element = document.getElementById(id);
  if (!(element instanceof HTMLSelectElement)) {
    throw new Error(
      "invalid binding element: expected HTMLSelectElement, got: " +
        element.constructor.name,
    );
  }

  element.onchange = () => {
    onChange(parseInt(element.value));
  };

  const callback = (v) => {
    element.value = v.toString();
    onChange(parseInt(element.value));
  };

  return [callback, parseInt(element.value), element];
}

const instance = new Instance({
  target: "view",
  crs: "EPSG:3857",
});

const camera = instance.view.camera;

instance.renderer.shadowMap.enabled = true;

const controls = new MapControls(instance.view.camera, instance.domElement);
controls.enableDamping = true;
controls.dampingFactor = 0.2;
instance.view.setControls(controls);

const clock = new Clock();

// we can access the THREE.js scene directly
instance.scene.background = new Color(0xa0a0a0);
instance.scene.fog = new Fog(0xa0a0a0, 10, 50);

// adding lights directly to scene is ok
const hemiLight = new HemisphereLight(0xffffff, 0x444444, 2);
hemiLight.position.set(0, 0, 20);
hemiLight.updateMatrixWorld();
instance.scene.add(hemiLight);

const dirLight = new DirectionalLight(0xffffff, 3);
dirLight.position.set(-3, 10, 10);
dirLight.castShadow = true;
dirLight.shadow.camera.top = 4;
dirLight.shadow.camera.bottom = -4;
dirLight.shadow.camera.left = -4;
dirLight.shadow.camera.right = 4;
dirLight.shadow.camera.near = 0.1;
dirLight.shadow.camera.far = 40;
instance.scene.add(dirLight);
instance.scene.add(dirLight.target);
dirLight.updateMatrixWorld();

// Let's now setup a "ground" to receive the shadows
const mesh = new Mesh(
  new PlaneGeometry(200, 200),
  new MeshPhongMaterial({ color: 0xcbcbcb, depthWrite: false }),
);
mesh.receiveShadow = true;
// Contrary to lights, every meshes should be added through `instance.add`, in order for Giro3D to
// be aware of them. Otherwise the objects will just disappear.
// For technical details, see how MainLoop.js calculates camera near and far.
instance.add(mesh);

// Let's load objects using one of the THREE loaders.
const loader = new GLTFLoader();
loader.load("https://threejs.org/examples/models/gltf/Soldier.glb", (gltf) => {
  gltf.scene.traverse((object) => {
    if (object.isMesh) {
      object.castShadow = true;
    }
  });

  // this code is virtually identical to this example:
  // https://threejs.org/examples/webgl_animation_multiple
  const model1 = clone(gltf.scene);
  const model2 = clone(gltf.scene);
  const model3 = clone(gltf.scene);
  const models = [model1, model2, model3];

  const mixer1 = new AnimationMixer(model1);
  const mixer2 = new AnimationMixer(model2);
  const mixer3 = new AnimationMixer(model3);
  const mixers = [mixer1, mixer2, mixer3];

  mixer1.clipAction(gltf.animations[0]).play(); // idle
  mixer2.clipAction(gltf.animations[1]).play(); // run
  mixer3.clipAction(gltf.animations[3]).play(); // walk

  model1.position.x = 1;
  model1.rotation.x = Math.PI / 2;
  model1.updateMatrixWorld();
  model2.position.x = 0;
  model2.rotation.x = Math.PI / 2;
  model2.updateMatrixWorld();
  model3.position.x = 2;
  model3.rotation.x = Math.PI / 2;
  model3.updateMatrixWorld();

  // except for this part, we add directly to instance to make Giro3D aware of these models
  instance.add(model1);
  instance.add(model2);
  instance.add(model3);

  // let's move our camera and control target
  // We add 1 to z to look at the waist. The 0, 0, 0 is located at the soldier's feet.
  const lookAt = new Vector3(0, 0, 1).add(model1.position);
  camera.position.set(2, 6, 3);
  camera.lookAt(lookAt);
  controls.target.copy(lookAt);
  controls.saveState();

  // you can hook yourself to event of the rendering loop.
  instance.addEventListener("after-camera-update", () => {
    const delta = clock.getDelta();

    for (const mixer of mixers) {
      mixer.update(delta);
    }
    for (const model of models) {
      model.updateMatrixWorld();
      instance.notifyChange(model);
    }
  });

  instance.notifyChange();

  let where = models;
  bindNumericalDropDown("pick_source", (newMode) => {
    if (newMode === 1) {
      where = [model1];
    } else if (newMode === 2) {
      where = [model2];
    } else if (newMode === 3) {
      where = [model3];
    } else {
      where = models;
    }
  });

  const formatter = new Intl.NumberFormat();

  function format(point) {
    return `x: ${formatter.format(point.x)}\n
                y: ${formatter.format(point.y)}\n
                z: ${formatter.format(point.z)}`;
  }

  instance.domElement.addEventListener("dblclick", (e) => {
    const picked = instance.pickObjectsAt(e, { limit: 1, where });
    if (picked.length === 0) {
      document.getElementById("selectedDiv").innerText = "No object found";
    } else {
      document.getElementById("selectedDiv").innerHTML = `
                Picked ${picked[0].object.name} at:<br>
                ${format(picked[0].point)}!`;
    }
  });
});

Inspector.attach("inspector", instance);

<!doctype html>
<html lang="en">
  <head>
    <title>Three.js loaders</title>
    <meta charset="UTF-8" />
    <meta name="name" content="three_loader" />
    <meta
      name="description"
      content="Load models directly from a Three.js loader (skinned mesh in this instance)."
    />
    <meta name="viewport" content="width=device-width, initial-scale=1.0" />

    <link rel="icon" href="https://giro3d.org/images/favicon.svg" />
    <link
      href="https://giro3d.org/assets/bootstrap-custom.css"
      rel="stylesheet"
    />
    <script src="https://giro3d.org/assets/bootstrap.bundle.min.js"></script>
    <link
      rel="stylesheet"
      type="text/css"
      href="https://giro3d.org/next/css/example.css"
    />
  </head>

  <body>
    <div id="view" class="m-0 p-0 w-100 h-100"></div>
    <div
      id="inspector"
      class="position-absolute top-0 start-0 mh-100 overflow-auto"
    ></div>

    <div class="side-pane-with-status-bar">
      <div class="card">
        <div class="card-body">
          <div class="input-group">
            <label class="input-group-text" for="pick_source">Pick from</label>
            <select class="form-select" id="pick_source">
              <option value="0" selected>All models</option>
              <option value="1">Vanguard idle</option>
              <option value="3">Vanguard walking</option>
              <option value="2">Vanguard running</option>
            </select>
          </div>
          <div id="selectedDiv"></div>
        </div>
      </div>
    </div>

    <script type="module" src="index.js"></script>
    <script>
      /* activate popovers */
      const popoverTriggerList = [].slice.call(
        document.querySelectorAll('[data-bs-toggle="popover"]'),
      );
      popoverTriggerList.map(
        // bootstrap is used as script in the template, disable warning about undef
        // eslint-disable-next-line no-undef
        (popoverTriggerEl) =>
          new bootstrap.Popover(popoverTriggerEl, {
            trigger: "hover",
            placement: "left",
            content: document.getElementById(
              popoverTriggerEl.getAttribute("data-bs-content"),
            ).innerHTML,
            html: true,
          }),
      );
    </script>
  </body>
</html>

{
    "name": "three_loader",
    "dependencies": {
        "@giro3d/giro3d": "git+https://gitlab.com/giro3d/giro3d.git"
    },
    "devDependencies": {
        "vite": "^3.2.3"
    },
    "scripts": {
        "start": "vite",
        "build": "vite build"
    }
}