/**
 * @author spidersharma / http://eduperiment.com/
 */

import {
	AdditiveBlending,
	Color,
	DoubleSide,
	LinearFilter,
	Matrix4,
	MeshBasicMaterial,
	MeshDepthMaterial,
	NoBlending,
	RGBADepthPacking,
	RGBAFormat,
	ShaderMaterial,
	UniformsUtils,
	Vector2,
	Vector3,
	WebGLRenderTarget
} from "../../../build/three.module.js";
import { Pass } from "../postprocessing/Pass.js";
import { CopyShader } from "../shaders/CopyShader.js";

var OutlinePass = function ( resolution, scene, camera, selectedObjects ) {

	this.renderScene = scene;
	this.renderCamera = camera;
	this.selectedObjects = selectedObjects !== undefined ? selectedObjects : [];
	this.visibleEdgeColor = new Color( 1, 1, 1 );
	this.hiddenEdgeColor = new Color( 0.1, 0.04, 0.02 );
	this.edgeGlow = 0.0;
	this.usePatternTexture = false;
	this.edgeThickness = 1.0;
	this.edgeStrength = 3.0;
	this.downSampleRatio = 2;
	this.pulsePeriod = 0;

	Pass.call( this );

	this.resolution = ( resolution !== undefined ) ? new Vector2( resolution.x, resolution.y ) : new Vector2( 256, 256 );

	var pars = { minFilter: LinearFilter, magFilter: LinearFilter, format: RGBAFormat };

	var resx = Math.round( this.resolution.x / this.downSampleRatio );
	var resy = Math.round( this.resolution.y / this.downSampleRatio );

	this.maskBufferMaterial = new MeshBasicMaterial( { color: 0xffffff } );
	this.maskBufferMaterial.side = DoubleSide;
	this.renderTargetMaskBuffer = new WebGLRenderTarget( this.resolution.x, this.resolution.y, pars );
	this.renderTargetMaskBuffer.texture.name = "OutlinePass.mask";
	this.renderTargetMaskBuffer.texture.generateMipmaps = false;

	this.depthMaterial = new MeshDepthMaterial();
	this.depthMaterial.side = DoubleSide;
	this.depthMaterial.depthPacking = RGBADepthPacking;
	this.depthMaterial.blending = NoBlending;

	this.prepareMaskMaterial = this.getPrepareMaskMaterial();
	this.prepareMaskMaterial.side = DoubleSide;
	this.prepareMaskMaterial.fragmentShader = replaceDepthToViewZ( this.prepareMaskMaterial.fragmentShader, this.renderCamera );

	this.renderTargetDepthBuffer = new WebGLRenderTarget( this.resolution.x, this.resolution.y, pars );
	this.renderTargetDepthBuffer.texture.name = "OutlinePass.depth";
	this.renderTargetDepthBuffer.texture.generateMipmaps = false;

	this.renderTargetMaskDownSampleBuffer = new WebGLRenderTarget( resx, resy, pars );
	this.renderTargetMaskDownSampleBuffer.texture.name = "OutlinePass.depthDownSample";
	this.renderTargetMaskDownSampleBuffer.texture.generateMipmaps = false;

	this.renderTargetBlurBuffer1 = new WebGLRenderTarget( resx, resy, pars );
	this.renderTargetBlurBuffer1.texture.name = "OutlinePass.blur1";
	this.renderTargetBlurBuffer1.texture.generateMipmaps = false;
	this.renderTargetBlurBuffer2 = new WebGLRenderTarget( Math.round( resx / 2 ), Math.round( resy / 2 ), pars );
	this.renderTargetBlurBuffer2.texture.name = "OutlinePass.blur2";
	this.renderTargetBlurBuffer2.texture.generateMipmaps = false;

	this.edgeDetectionMaterial = this.getEdgeDetectionMaterial();
	this.renderTargetEdgeBuffer1 = new WebGLRenderTarget( resx, resy, pars );
	this.renderTargetEdgeBuffer1.texture.name = "OutlinePass.edge1";
	this.renderTargetEdgeBuffer1.texture.generateMipmaps = false;
	this.renderTargetEdgeBuffer2 = new WebGLRenderTarget( Math.round( resx / 2 ), Math.round( resy / 2 ), pars );
	this.renderTargetEdgeBuffer2.texture.name = "OutlinePass.edge2";
	this.renderTargetEdgeBuffer2.texture.generateMipmaps = false;

	var MAX_EDGE_THICKNESS = 4;
	var MAX_EDGE_GLOW = 4;

	this.separableBlurMaterial1 = this.getSeperableBlurMaterial( MAX_EDGE_THICKNESS );
	this.separableBlurMaterial1.uniforms[ "texSize" ].value = new Vector2( resx, resy );
	this.separableBlurMaterial1.uniforms[ "kernelRadius" ].value = 1;
	this.separableBlurMaterial2 = this.getSeperableBlurMaterial( MAX_EDGE_GLOW );
	this.separableBlurMaterial2.uniforms[ "texSize" ].value = new Vector2( Math.round( resx / 2 ), Math.round( resy / 2 ) );
	this.separableBlurMaterial2.uniforms[ "kernelRadius" ].value = MAX_EDGE_GLOW;

	// Overlay material
	this.overlayMaterial = this.getOverlayMaterial();

	// copy material
	if ( CopyShader === undefined )
		console.error( "OutlinePass relies on CopyShader" );

	var copyShader = CopyShader;

	this.copyUniforms = UniformsUtils.clone( copyShader.uniforms );
	this.copyUniforms[ "opacity" ].value = 1.0;

	this.materialCopy = new ShaderMaterial( {
		uniforms: this.copyUniforms,
		vertexShader: copyShader.vertexShader,
		fragmentShader: copyShader.fragmentShader,
		blending: NoBlending,
		depthTest: false,
		depthWrite: false,
		transparent: true
	} );

	this.enabled = true;
	this.needsSwap = false;

	this.oldClearColor = new Color();
	this.oldClearAlpha = 1;

	this.fsQuad = new Pass.FullScreenQuad( null );

	this.tempPulseColor1 = new Color();
	this.tempPulseColor2 = new Color();
	this.textureMatrix = new Matrix4();

	function replaceDepthToViewZ( string, camera ) {

		var type = camera.isPerspectiveCamera ? 'perspective' : 'orthographic';

		return string.replace( /DEPTH_TO_VIEW_Z/g, type + 'DepthToViewZ' );

	}

};

OutlinePass.prototype = Object.assign( Object.create( Pass.prototype ), {

	constructor: OutlinePass,

	dispose: function () {

		this.renderTargetMaskBuffer.dispose();
		this.renderTargetDepthBuffer.dispose();
		this.renderTargetMaskDownSampleBuffer.dispose();
		this.renderTargetBlurBuffer1.dispose();
		this.renderTargetBlurBuffer2.dispose();
		this.renderTargetEdgeBuffer1.dispose();
		this.renderTargetEdgeBuffer2.dispose();

	},

	setSize: function ( width, height ) {

		this.renderTargetMaskBuffer.setSize( width, height );

		var resx = Math.round( width / this.downSampleRatio );
		var resy = Math.round( height / this.downSampleRatio );
		this.renderTargetMaskDownSampleBuffer.setSize( resx, resy );
		this.renderTargetBlurBuffer1.setSize( resx, resy );
		this.renderTargetEdgeBuffer1.setSize( resx, resy );
		this.separableBlurMaterial1.uniforms[ "texSize" ].value = new Vector2( resx, resy );

		resx = Math.round( resx / 2 );
		resy = Math.round( resy / 2 );

		this.renderTargetBlurBuffer2.setSize( resx, resy );
		this.renderTargetEdgeBuffer2.setSize( resx, resy );

		this.separableBlurMaterial2.uniforms[ "texSize" ].value = new Vector2( resx, resy );

	},

	changeVisibilityOfSelectedObjects: function ( bVisible ) {

		function gatherSelectedMeshesCallBack( object ) {

			if ( object.isMesh ) {

				if ( bVisible ) {

					object.visible = object.userData.oldVisible;
					delete object.userData.oldVisible;

				} else {

					object.userData.oldVisible = object.visible;
					object.visible = bVisible;

				}

			}

		}

		for ( var i = 0; i < this.selectedObjects.length; i ++ ) {

			var selectedObject = this.selectedObjects[ i ];
			selectedObject.traverse( gatherSelectedMeshesCallBack );

		}

	},

	changeVisibilityOfNonSelectedObjects: function ( bVisible ) {

		var selectedMeshes = [];

		function gatherSelectedMeshesCallBack( object ) {

			if ( object.isMesh ) selectedMeshes.push( object );

		}

		for ( var i = 0; i < this.selectedObjects.length; i ++ ) {

			var selectedObject = this.selectedObjects[ i ];
			selectedObject.traverse( gatherSelectedMeshesCallBack );

		}

		function VisibilityChangeCallBack( object ) {

			if ( object.isMesh || object.isLine || object.isSprite ) {

				var bFound = false;

				for ( var i = 0; i < selectedMeshes.length; i ++ ) {

					var selectedObjectId = selectedMeshes[ i ].id;

					if ( selectedObjectId === object.id ) {

						bFound = true;
						break;

					}

				}

				if ( ! bFound ) {

					var visibility = object.visible;

					if ( ! bVisible || object.bVisible ) object.visible = bVisible;

					object.bVisible = visibility;

				}

			}

		}

		this.renderScene.traverse( VisibilityChangeCallBack );

	},

	updateTextureMatrix: function () {

		this.textureMatrix.set( 0.5, 0.0, 0.0, 0.5,
			0.0, 0.5, 0.0, 0.5,
			0.0, 0.0, 0.5, 0.5,
			0.0, 0.0, 0.0, 1.0 );
		this.textureMatrix.multiply( this.renderCamera.projectionMatrix );
		this.textureMatrix.multiply( this.renderCamera.matrixWorldInverse );

	},

	render: function ( renderer, writeBuffer, readBuffer, deltaTime, maskActive ) {

		if ( this.selectedObjects.length > 0 ) {

			this.oldClearColor.copy( renderer.getClearColor() );
			this.oldClearAlpha = renderer.getClearAlpha();
			var oldAutoClear = renderer.autoClear;

			renderer.autoClear = false;

			if ( maskActive ) renderer.state.buffers.stencil.setTest( false );

			renderer.setClearColor( 0xffffff, 1 );

			// Make selected objects invisible
			this.changeVisibilityOfSelectedObjects( false );

			var currentBackground = this.renderScene.background;
			this.renderScene.background = null;

			// 1. Draw Non Selected objects in the depth buffer
			this.renderScene.overrideMaterial = this.depthMaterial;
			renderer.setRenderTarget( this.renderTargetDepthBuffer );
			renderer.clear();
			renderer.render( this.renderScene, this.renderCamera );

			// Make selected objects visible
			this.changeVisibilityOfSelectedObjects( true );

			// Update Texture Matrix for Depth compare
			this.updateTextureMatrix();

			// Make non selected objects invisible, and draw only the selected objects, by comparing the depth buffer of non selected objects
			this.changeVisibilityOfNonSelectedObjects( false );
			this.renderScene.overrideMaterial = this.prepareMaskMaterial;
			this.prepareMaskMaterial.uniforms[ "cameraNearFar" ].value = new Vector2( this.renderCamera.near, this.renderCamera.far );
			this.prepareMaskMaterial.uniforms[ "depthTexture" ].value = this.renderTargetDepthBuffer.texture;
			this.prepareMaskMaterial.uniforms[ "textureMatrix" ].value = this.textureMatrix;
			renderer.setRenderTarget( this.renderTargetMaskBuffer );
			renderer.clear();
			renderer.render( this.renderScene, this.renderCamera );
			this.renderScene.overrideMaterial = null;
			this.changeVisibilityOfNonSelectedObjects( true );

			this.renderScene.background = currentBackground;

			// 2. Downsample to Half resolution
			this.fsQuad.material = this.materialCopy;
			this.copyUniforms[ "tDiffuse" ].value = this.renderTargetMaskBuffer.texture;
			renderer.setRenderTarget( this.renderTargetMaskDownSampleBuffer );
			renderer.clear();
			this.fsQuad.render( renderer );

			this.tempPulseColor1.copy( this.visibleEdgeColor );
			this.tempPulseColor2.copy( this.hiddenEdgeColor );

			if ( this.pulsePeriod > 0 ) {

				var scalar = ( 1 + 0.25 ) / 2 + Math.cos( performance.now() * 0.01 / this.pulsePeriod ) * ( 1.0 - 0.25 ) / 2;
				this.tempPulseColor1.multiplyScalar( scalar );
				this.tempPulseColor2.multiplyScalar( scalar );

			}

			// 3. Apply Edge Detection Pass
			this.fsQuad.material = this.edgeDetectionMaterial;
			this.edgeDetectionMaterial.uniforms[ "maskTexture" ].value = this.renderTargetMaskDownSampleBuffer.texture;
			this.edgeDetectionMaterial.uniforms[ "texSize" ].value = new Vector2( this.renderTargetMaskDownSampleBuffer.width, this.renderTargetMaskDownSampleBuffer.height );
			this.edgeDetectionMaterial.uniforms[ "visibleEdgeColor" ].value = this.tempPulseColor1;
			this.edgeDetectionMaterial.uniforms[ "hiddenEdgeColor" ].value = this.tempPulseColor2;
			renderer.setRenderTarget( this.renderTargetEdgeBuffer1 );
			renderer.clear();
			this.fsQuad.render( renderer );

			// 4. Apply Blur on Half res
			this.fsQuad.material = this.separableBlurMaterial1;
			this.separableBlurMaterial1.uniforms[ "colorTexture" ].value = this.renderTargetEdgeBuffer1.texture;
			this.separableBlurMaterial1.uniforms[ "direction" ].value = OutlinePass.BlurDirectionX;
			this.separableBlurMaterial1.uniforms[ "kernelRadius" ].value = this.edgeThickness;
			renderer.setRenderTarget( this.renderTargetBlurBuffer1 );
			renderer.clear();
			this.fsQuad.render( renderer );
			this.separableBlurMaterial1.uniforms[ "colorTexture" ].value = this.renderTargetBlurBuffer1.texture;
			this.separableBlurMaterial1.uniforms[ "direction" ].value = OutlinePass.BlurDirectionY;
			renderer.setRenderTarget( this.renderTargetEdgeBuffer1 );
			renderer.clear();
			this.fsQuad.render( renderer );

			// Apply Blur on quarter res
			this.fsQuad.material = this.separableBlurMaterial2;
			this.separableBlurMaterial2.uniforms[ "colorTexture" ].value = this.renderTargetEdgeBuffer1.texture;
			this.separableBlurMaterial2.uniforms[ "direction" ].value = OutlinePass.BlurDirectionX;
			renderer.setRenderTarget( this.renderTargetBlurBuffer2 );
			renderer.clear();
			this.fsQuad.render( renderer );
			this.separableBlurMaterial2.uniforms[ "colorTexture" ].value = this.renderTargetBlurBuffer2.texture;
			this.separableBlurMaterial2.uniforms[ "direction" ].value = OutlinePass.BlurDirectionY;
			renderer.setRenderTarget( this.renderTargetEdgeBuffer2 );
			renderer.clear();
			this.fsQuad.render( renderer );

			// Blend it additively over the input texture
			this.fsQuad.material = this.overlayMaterial;
			this.overlayMaterial.uniforms[ "maskTexture" ].value = this.renderTargetMaskBuffer.texture;
			this.overlayMaterial.uniforms[ "edgeTexture1" ].value = this.renderTargetEdgeBuffer1.texture;
			this.overlayMaterial.uniforms[ "edgeTexture2" ].value = this.renderTargetEdgeBuffer2.texture;
			this.overlayMaterial.uniforms[ "patternTexture" ].value = this.patternTexture;
			this.overlayMaterial.uniforms[ "edgeStrength" ].value = this.edgeStrength;
			this.overlayMaterial.uniforms[ "edgeGlow" ].value = this.edgeGlow;
			this.overlayMaterial.uniforms[ "usePatternTexture" ].value = this.usePatternTexture;


			if ( maskActive ) renderer.state.buffers.stencil.setTest( true );

			renderer.setRenderTarget( readBuffer );
			this.fsQuad.render( renderer );

			renderer.setClearColor( this.oldClearColor, this.oldClearAlpha );
			renderer.autoClear = oldAutoClear;

		}

		if ( this.renderToScreen ) {

			this.fsQuad.material = this.materialCopy;
			this.copyUniforms[ "tDiffuse" ].value = readBuffer.texture;
			renderer.setRenderTarget( null );
			this.fsQuad.render( renderer );

		}

	},

	getPrepareMaskMaterial: function () {

		return new ShaderMaterial( {

			uniforms: {
				"depthTexture": { value: null },
				"cameraNearFar": { value: new Vector2( 0.5, 0.5 ) },
				"textureMatrix": { value: new Matrix4() }
			},

			vertexShader: [
				'varying vec4 projTexCoord;',
				'varying vec4 vPosition;',
				'uniform mat4 textureMatrix;',

				'void main() {',

				'	vPosition = modelViewMatrix * vec4( position, 1.0 );',
				'	vec4 worldPosition = modelMatrix * vec4( position, 1.0 );',
				'	projTexCoord = textureMatrix * worldPosition;',
				'	gl_Position = projectionMatrix * modelViewMatrix * vec4( position, 1.0 );',

				'}'
			].join( '\n' ),

			fragmentShader: [
				'#include <packing>',
				'varying vec4 vPosition;',
				'varying vec4 projTexCoord;',
				'uniform sampler2D depthTexture;',
				'uniform vec2 cameraNearFar;',

				'void main() {',

				'	float depth = unpackRGBAToDepth(texture2DProj( depthTexture, projTexCoord ));',
				'	float viewZ = - DEPTH_TO_VIEW_Z( depth, cameraNearFar.x, cameraNearFar.y );',
				'	float depthTest = (-vPosition.z > viewZ) ? 1.0 : 0.0;',
				'	gl_FragColor = vec4(0.0, depthTest, 1.0, 1.0);',

				'}'
			].join( '\n' )

		} );

	},

	getEdgeDetectionMaterial: function () {

		return new ShaderMaterial( {

			uniforms: {
				"maskTexture": { value: null },
				"texSize": { value: new Vector2( 0.5, 0.5 ) },
				"visibleEdgeColor": { value: new Vector3( 1.0, 1.0, 1.0 ) },
				"hiddenEdgeColor": { value: new Vector3( 1.0, 1.0, 1.0 ) },
			},

			vertexShader:
				"varying vec2 vUv;\n\
				void main() {\n\
					vUv = uv;\n\
					gl_Position = projectionMatrix * modelViewMatrix * vec4( position, 1.0 );\n\
				}",

			fragmentShader:
				"varying vec2 vUv;\
				uniform sampler2D maskTexture;\
				uniform vec2 texSize;\
				uniform vec3 visibleEdgeColor;\
				uniform vec3 hiddenEdgeColor;\
				\
				void main() {\n\
					vec2 invSize = 1.0 / texSize;\
					vec4 uvOffset = vec4(1.0, 0.0, 0.0, 1.0) * vec4(invSize, invSize);\
					vec4 c1 = texture2D( maskTexture, vUv + uvOffset.xy);\
					vec4 c2 = texture2D( maskTexture, vUv - uvOffset.xy);\
					vec4 c3 = texture2D( maskTexture, vUv + uvOffset.yw);\
					vec4 c4 = texture2D( maskTexture, vUv - uvOffset.yw);\
					float diff1 = (c1.r - c2.r)*0.5;\
					float diff2 = (c3.r - c4.r)*0.5;\
					float d = length( vec2(diff1, diff2) );\
					float a1 = min(c1.g, c2.g);\
					float a2 = min(c3.g, c4.g);\
					float visibilityFactor = min(a1, a2);\
					vec3 edgeColor = 1.0 - visibilityFactor > 0.001 ? visibleEdgeColor : hiddenEdgeColor;\
					gl_FragColor = vec4(edgeColor, 1.0) * vec4(d);\
				}"
		} );

	},

	getSeperableBlurMaterial: function ( maxRadius ) {

		return new ShaderMaterial( {

			defines: {
				"MAX_RADIUS": maxRadius,
			},

			uniforms: {
				"colorTexture": { value: null },
				"texSize": { value: new Vector2( 0.5, 0.5 ) },
				"direction": { value: new Vector2( 0.5, 0.5 ) },
				"kernelRadius": { value: 1.0 }
			},

			vertexShader:
				"varying vec2 vUv;\n\
				void main() {\n\
					vUv = uv;\n\
					gl_Position = projectionMatrix * modelViewMatrix * vec4( position, 1.0 );\n\
				}",

			fragmentShader:
				"#include <common>\
				varying vec2 vUv;\
				uniform sampler2D colorTexture;\
				uniform vec2 texSize;\
				uniform vec2 direction;\
				uniform float kernelRadius;\
				\
				float gaussianPdf(in float x, in float sigma) {\
					return 0.39894 * exp( -0.5 * x * x/( sigma * sigma))/sigma;\
				}\
				void main() {\
					vec2 invSize = 1.0 / texSize;\
					float weightSum = gaussianPdf(0.0, kernelRadius);\
					vec4 diffuseSum = texture2D( colorTexture, vUv) * weightSum;\
					vec2 delta = direction * invSize * kernelRadius/float(MAX_RADIUS);\
					vec2 uvOffset = delta;\
					for( int i = 1; i <= MAX_RADIUS; i ++ ) {\
						float w = gaussianPdf(uvOffset.x, kernelRadius);\
						vec4 sample1 = texture2D( colorTexture, vUv + uvOffset);\
						vec4 sample2 = texture2D( colorTexture, vUv - uvOffset);\
						diffuseSum += ((sample1 + sample2) * w);\
						weightSum += (2.0 * w);\
						uvOffset += delta;\
					}\
					gl_FragColor = diffuseSum/weightSum;\
				}"
		} );

	},

	getOverlayMaterial: function () {

		return new ShaderMaterial( {

			uniforms: {
				"maskTexture": { value: null },
				"edgeTexture1": { value: null },
				"edgeTexture2": { value: null },
				"patternTexture": { value: null },
				"edgeStrength": { value: 1.0 },
				"edgeGlow": { value: 1.0 },
				"usePatternTexture": { value: 0.0 }
			},

			vertexShader:
				"varying vec2 vUv;\n\
				void main() {\n\
					vUv = uv;\n\
					gl_Position = projectionMatrix * modelViewMatrix * vec4( position, 1.0 );\n\
				}",

			fragmentShader:
				"varying vec2 vUv;\
				uniform sampler2D maskTexture;\
				uniform sampler2D edgeTexture1;\
				uniform sampler2D edgeTexture2;\
				uniform sampler2D patternTexture;\
				uniform float edgeStrength;\
				uniform float edgeGlow;\
				uniform bool usePatternTexture;\
				\
				void main() {\
					vec4 edgeValue1 = texture2D(edgeTexture1, vUv);\
					vec4 edgeValue2 = texture2D(edgeTexture2, vUv);\
					vec4 maskColor = texture2D(maskTexture, vUv);\
					vec4 patternColor = texture2D(patternTexture, 6.0 * vUv);\
					float visibilityFactor = 1.0 - maskColor.g > 0.0 ? 1.0 : 0.5;\
					vec4 edgeValue = edgeValue1 + edgeValue2 * edgeGlow;\
					vec4 finalColor = edgeStrength * maskColor.r * edgeValue;\
					if(usePatternTexture)\
						finalColor += + visibilityFactor * (1.0 - maskColor.r) * (1.0 - patternColor.r);\
					gl_FragColor = finalColor;\
				}",
			blending: AdditiveBlending,
			depthTest: false,
			depthWrite: false,
			transparent: true
		} );

	}

} );

OutlinePass.BlurDirectionX = new Vector2( 1.0, 0.0 );
OutlinePass.BlurDirectionY = new Vector2( 0.0, 1.0 );

export { OutlinePass };
