import * as THREE from 'three';
const {
  document,
	window,
	HTMLCanvasElement,
	requestAnimationFrame,
	cancelAnimationFrame,
core,
	Event,
  Event0
} = THREE .DHTML

import Stats from 'three/examples/jsm/libs/stats.module.js';
import { GUI } from 'three/examples/jsm/libs/lil-gui.module.min.js';
var requestId
Page({
	onUnload() {
		cancelAnimationFrame(requestId, this.canvas)
		this.worker && this.worker.terminate()
if(this.canvas) this.canvas = null
		setTimeout(() => {
			if (this.renderer instanceof THREE.WebGLRenderer) {
				this.renderer.dispose()
				this.renderer.forceContextLoss()
				this.renderer.context = null
				this.renderer.domElement = null
				this.renderer = null
			}
		}, 10)
	},
  webgl_touch(e){
		const web_e = (window.platform=="devtools"?Event:Event0).fix(e)
		this.canvas.dispatchEvent(web_e)
  },
  onLoad() {
		document.createElementAsync("canvas", "webgl2",this).then(canvas => {
      this.canvas = canvas
      this.body_load(canvas).then()
    })
  },
  async body_load(canvas3d) {

    let camera, scene, renderer, stats;

    let mesh;

    init();
    animate();

    function init() {

      //

      camera = new THREE.PerspectiveCamera( 27, window.innerWidth / window.innerHeight, 1, 3500 );
      camera.position.z = 64;

      scene = new THREE.Scene();
      scene.background = new THREE.Color( 0x050505 );

      //

      const light = new THREE.HemisphereLight();
      light.intensity = 3;
      scene.add( light );

      //

      const geometry = new THREE.BufferGeometry();

      const indices = [];

      const vertices = [];
      const normals = [];
      const colors = [];

      const size = 20;
      const segments = 10;

      const halfSize = size / 2;
      const segmentSize = size / segments;

      const _color = new THREE.Color();

      // generate vertices, normals and color data for a simple grid geometry

      for ( let i = 0; i <= segments; i ++ ) {

        const y = ( i * segmentSize ) - halfSize;

        for ( let j = 0; j <= segments; j ++ ) {

          const x = ( j * segmentSize ) - halfSize;

          vertices.push( x, - y, 0 );
          normals.push( 0, 0, 1 );

          const r = ( x / size ) + 0.5;
          const g = ( y / size ) + 0.5;

          _color.setRGB( r, g, 1, THREE.SRGBColorSpace );

          colors.push( _color.r, _color.g, _color.b );

        }

      }

      // generate indices (data for element array buffer)

      for ( let i = 0; i < segments; i ++ ) {

        for ( let j = 0; j < segments; j ++ ) {

          const a = i * ( segments + 1 ) + ( j + 1 );
          const b = i * ( segments + 1 ) + j;
          const c = ( i + 1 ) * ( segments + 1 ) + j;
          const d = ( i + 1 ) * ( segments + 1 ) + ( j + 1 );

          // generate two faces (triangles) per iteration

          indices.push( a, b, d ); // face one
          indices.push( b, c, d ); // face two

        }

      }

      //

      geometry.setIndex( indices );
      geometry.setAttribute( 'position', new THREE.Float32BufferAttribute( vertices, 3 ) );
      geometry.setAttribute( 'normal', new THREE.Float32BufferAttribute( normals, 3 ) );
      geometry.setAttribute( 'color', new THREE.Float32BufferAttribute( colors, 3 ) );

      const material = new THREE.MeshPhongMaterial( {
        side: THREE.DoubleSide,
        vertexColors: true
      } );

      mesh = new THREE.Mesh( geometry, material );
      scene.add( mesh );

      //

      renderer = new THREE.WebGLRenderer( { antialias: true } );
      renderer.setPixelRatio( window.devicePixelRatio );
      renderer.setSize( window.innerWidth, window.innerHeight );
      document.body.appendChild( renderer.domElement );

      //

      stats = new Stats();
      document.body.appendChild( stats.dom );

      //

      const gui = new GUI();
      gui.add( material, 'wireframe' );

      //

      window.addEventListener( 'resize', onWindowResize );

    }

    function onWindowResize() {

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

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

    }

    //

    function animate() {

      requestId = requestAnimationFrame( animate );

      render();
      stats.update();

    }

    function render() {

      const time = Date.now() * 0.001;

      mesh.rotation.x = time * 0.25;
      mesh.rotation.y = time * 0.5;

      renderer.render( scene, camera );

    }

  }
})