import * as THREE from 'three';
import {OrbitControls} from 'https://unpkg.com/three@0.142.0/examples/jsm/controls/OrbitControls.js';
import {GLTFLoader} from 'https://unpkg.com/three@0.142.0/examples/jsm/loaders/GLTFLoader.js';
import {DRACOLoader} from 'https://unpkg.com/three@0.142.0/examples/jsm/loaders/DRACOLoader.js';
import {RGBELoader} from 'https://unpkg.com/three@0.142.0/examples/jsm/loaders/RGBELoader.js';
import {LoadingBar} from 'https://niksgames.com/threejs-games-course/libs/LoadingBar.js';
import GUI from 'https://unpkg.com/three@0.142.0/examples/jsm/libs/lil-gui.module.min.js';

//Tip 20: Texture POT
//Tip 21: Smallest texture
//Tip 22: Disable stencil buffer - line 21

let camera, scene, renderer, envmap;
let light, clock, loadingBar;

init();

function init() {

  
  renderer = new THREE.WebGLRenderer({antialias: true, stencil: false});
  renderer.setPixelRatio( Math.min(2, window.devicePixelRatio ));
  renderer.setSize( window.innerWidth, window.innerHeight );
  document.body.appendChild( renderer.domElement );
  renderer.outputEncoding = THREE.sRGBEncoding;
  renderer.physicallyCorrectLights = true;

  //
  clock = new THREE.Clock();
  
  camera = new THREE.PerspectiveCamera( 45, window.innerWidth / window.innerHeight, 0.1, 50 );
  camera.position.set( 0, 0, 0.7 );
  
  const col = 0x201510;
	scene = new THREE.Scene();
	scene.background = new THREE.Color( col );
	
  const ambient = new THREE.HemisphereLight(0xffffff, 0xbbbbff, 1);
		scene.add(ambient);

  light = new THREE.DirectionalLight( );
  light.position.set( 4, 20, 20);
  scene.add( light );

  if (!('ontouchstart' in window)) window.addEventListener( 'resize', onWindowResize, false );
  
  const controls = new OrbitControls( camera, renderer.domElement );
  controls.target.y = 0.05;
  controls.update()
  
  controls.addEventListener( 'change', () => {
    renderer.render( scene, camera );
  })
  
  setEnvironment();
  loadModel();
  
}

function setAutoUpdate(value){
  factory.traverse( child => {
    if (child.isMesh && !child.name.includes('fan')){
      child.matrixAutoUpdate = value;
    }
  })
}

function setEnvironment(){
        const loader = new RGBELoader();
        const pmremGenerator = new THREE.PMREMGenerator( renderer );
        pmremGenerator.compileEquirectangularShader();
        
        loader.load( 'https://niksgames.com/courses/model-viewer/assets/hdr/venice_sunset_1k.hdr', ( texture ) => {
          envmap = pmremGenerator.fromEquirectangular( texture ).texture;
          pmremGenerator.dispose();

          scene.environment = envmap;

        }, undefined, (err)=>{
            console.error( 'An error occurred setting the environment');
          console.error(err);
        } );
    }

function loadModel(){
  const loader = new GLTFLoader( ).setPath('https://niksgames.com/courses/threejs-cookbook/assets/');
  const dracoLoader = new DRACOLoader();
  dracoLoader.setDecoderPath( 'https://unpkg.com/three@0.142.0/examples/js/libs/draco/' );
  loader.setDRACOLoader( dracoLoader );
        
  loadingBar = new LoadingBar();
  loadingBar.visible = true;
		
		// Load a glTF resource
		loader.load(
			// resource URL
			'apple.glb',
			// called when the resource is loaded
			gltf => {

        const apple = gltf.scene.children[0];
				scene.add( apple );
        
        let xPos = -0.3;
        const inc = 0.15;
        let loaded = 0;
        
        for(let i=0; i<4; i++){
          const apple1 = apple.clone();
          const texSize = Math.pow(2, i+7);
          const name = `apple_${texSize}.jpg`;
          const texLoader = new THREE.TextureLoader();
          texLoader.setPath('https://niksgames.com/courses/threejs-cookbook/assets/');
          apple1.material = apple.material.clone();
          texLoader.load(name, (tex) => {
            tex.encoding = THREE.sRGBEncoding;
            tex.flipY = false;
            apple1.material.map = tex;
            loaded++;
            if (loaded==4) renderer.render(scene, camera);
          })
          
          apple1.position.x = xPos;
          scene.add(apple1);
          xPos += inc;
        }
        
        apple.position.x = xPos;
        
				loadingBar.visible = false;
        renderer.render( scene, camera );
			},
			// called while loading is progressing
			xhr => {

				loadingBar.update('environment', xhr.loaded, xhr.total);
				
			},
			// called when loading has errors
			err => {

				console.error( err );

			}
		);
    }

function onWindowResize() {

  camera.aspect = window.innerWidth / window.innerHeight;
  camera.updateProjectionMatrix();

  renderer.setSize( window.innerWidth, window.innerHeight );
 
}

function render() {

  requestAnimationFrame( render );
  
  renderer.render(scene, camera);

}