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';
const vertexShader=`

precision mediump float;
precision mediump int;

uniform mat4 modelViewMatrix; // optional
uniform mat4 projectionMatrix; // optional

attribute vec3 position;
attribute vec4 color;

varying vec3 vPosition;
varying vec4 vColor;

void main()	{

  vPosition = position;
  vColor = color;

  gl_Position = projectionMatrix * modelViewMatrix * vec4( position, 1.0 );

}
`

const fragmentShader = `

precision mediump float;
precision mediump int;

uniform float time;

varying vec3 vPosition;
varying vec4 vColor;

void main()	{

  vec4 color = vec4( vColor );
  color.r += sin( vPosition.x * 10.0 + time ) * 0.5;

  gl_FragColor = color;

}
`
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 container, stats;

			let camera, scene, renderer;

			init();
			animate();

			function init() {

				container = document.getElementById( 'container' );

				camera = new THREE.PerspectiveCamera( 50, window.innerWidth / window.innerHeight, 1, 10 );
				camera.position.z = 2;

				scene = new THREE.Scene();
				scene.background = new THREE.Color( 0x101010 );

				// geometry
				// nr of triangles with 3 vertices per triangle
				const vertexCount = 200 * 3;

				const geometry = new THREE.BufferGeometry();

				const positions = [];
				const colors = [];

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

					// adding x,y,z
					positions.push( Math.random() - 0.5 );
					positions.push( Math.random() - 0.5 );
					positions.push( Math.random() - 0.5 );

					// adding r,g,b,a
					colors.push( Math.random() * 255 );
					colors.push( Math.random() * 255 );
					colors.push( Math.random() * 255 );
					colors.push( Math.random() * 255 );

				}

				const positionAttribute = new THREE.Float32BufferAttribute( positions, 3 );
				const colorAttribute = new THREE.Uint8BufferAttribute( colors, 4 );

				colorAttribute.normalized = true; // this will map the buffer values to 0.0f - +1.0f in the shader

				geometry.setAttribute( 'position', positionAttribute );
				geometry.setAttribute( 'color', colorAttribute );

				// material

				const material = new THREE.RawShaderMaterial( {

					uniforms: {
						time: { value: 1.0 }
					},
					vertexShader,
					fragmentShader,
					side: THREE.DoubleSide,
					transparent: true

				} );

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

				renderer = new THREE.WebGLRenderer();
				renderer.setPixelRatio( window.devicePixelRatio );
				renderer.setSize( window.innerWidth, window.innerHeight );
				container.appendChild( renderer.domElement );

				stats = new Stats();
				container.appendChild( stats.dom );

				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 = performance.now();

				const object = scene.children[ 0 ];

				object.rotation.y = time * 0.0005;
				object.material.uniforms.time.value = time * 0.005;

				renderer.render( scene, camera );

			}
  }
})