import { RenderSide, Vector3, Matrix3, Vector2, Encoding } from "@gl-widget/gl-widget";
import { PhysicalShaderOptions } from "./ShaderOptions";
import physicalVertex from './shader-lib/physical-vertex.glsl'
import physicalFragment from './shader-lib/physical-fragment.glsl'
import { replaceLightNums, unrollLoops, replaceTonemapping, replaceColorspace, replaceClippingPlanes, getToneMappingFunction, getTexelDecodingFunction, getTexelEncodingFunction } from "./utils";
import { ToneMapping } from "./Constants";
import { Lights } from "./Lights";
class PhysicalShader {
  lightVersion: any;
  lights: Lights;
  vertexShader: string
  fragmentShader: string
  uniforms: any
  side: RenderSide;
  transparent: boolean = false 
  defines: Array<string> = [];
  parameters: any
  options: PhysicalShaderOptions

  rotation: number;
  center: Vector2;
  repeat: Vector2;
  offset: Vector2;
  uvTransform: Matrix3;
  
  updateUniforms(options, force) {
    let needsRecompile = false
    for(let option in options) {
      if (this.uniforms[option]) {
        if (this.uniforms[option].needsRecompile && this.uniforms[option].value != options[option]) {
          needsRecompile = true
        }
        this.uniforms[option].value = options[option]
      }
    }
    if (options.lights) {
      Object.assign(this.uniforms, options.lights.uniforms)
      let lightVersion = this.getLightVersion(options.lights.uniforms)
      if (this.lightVersion != lightVersion) {
        needsRecompile = true
        this.lightVersion = lightVersion
      }
    }

    if (force || needsRecompile) {
      this.compile()
    }
    this.updateUvTransform()
    
  }
  getLightVersion(lights) {
    let version = ''
    for(let lightType in lights) {
      let light = lights[lightType]
      version += lightType + <string>light.value.length
    }
    return version
  }
  compile () {
    this.getParameters()
      this.vertexShader = this.getVertexShader()
      this.fragmentShader = this.getFragmentShader()
  }
  constructor (options: PhysicalShaderOptions = {}) {
    this.options = Object.assign({
      offset: new Vector2( 0, 0 ),
      repeat: new Vector2( 1, 1 ),
      center: new Vector2( 0, 0 ),
      rotation: 0,
      toneMapping: ToneMapping.LinearToneMapping,
      outputEncoding: Encoding.sRGBEncoding
    }, options)

    this.uniforms = {
      diffuse: {
        value: new Vector3(1, 1, 1)
      },
      ambientLightColor: {
        value: new Vector3(0, 0, 0)
      },
      diffuseMap: {
        value: null,
        needsRecompile: true
      },
      envMap: {
        value: null,
        needsRecompile: true
      },
      normalMap: {
        value: null,
        needsRecompile: true
      },
      aoMap: {
        value: null,
        needsRecompile: true
      },
      aoMapIntensity: {
        value: 1
      },
      specularMap: {
        value: null,
        needsRecompile: true
      },
      roughnessMap: {
        value: null,
        needsRecompile: true
      },
      metalnessMap: {
        value: null,
        needsRecompile: true
      },
      emissive: {
        value: new Vector3(0, 0, 0)
      },
      emissiveMap: {
        value: null,
        needsRecompile: true
      },
      normalScale: {
        value: new Vector2(1, 1)
      },
      envMapIntensity: {
        value: 1
      },
      opacity: {
        value: 1
      },
      transparency: {
        value: 0
      },
      reflectivity: {
        value: 0
      },
      roughness: {
        value: 0.5
      },
      metalness: {
        value: 0
      },
      flipEnvMap: {
        value: -1,
        needsRecompile: true
      },
      maxMipLevel: {
        value: 10
      },
      toneMappingExposure: {
        value: 1
      },
      toneMappingWhitePoint: {
        value: 1
      },
      directionalLights: {
        value:[
        ]
      },
      pointLights: {
        value: [
        ]
      },
      uvTransform: {
        value: new Matrix3()
      },
      sheen: {
        value: null
      }
    }



    
    this.update(this.options, true)
  }
  setLights (lights: Lights) {
    this.lights = lights
    Object.assign(this.uniforms, lights.uniforms)
    this.compile()
  }
  updateUvTransform () {
    this.uniforms.uvTransform.value.setUvTransform( 
      this.options.offset.x, 
      this.options.offset.y, 
      this.options.repeat.x, 
      this.options.repeat.y, 
      this.options.rotation, 
      this.options.center.x, 
      this.options.center.y )
  }
  update (options: PhysicalShaderOptions = {}, force: boolean = false) {
    Object.assign(this.options, options)
    this.updateUniforms(options, force)

  }
  getTextureEncodingFromMap (map) {
    return map ? map.encoding : ''
  }
  getParameters () {
    let options = this.options
		this.parameters = {
			defines: this.defines,

			precision: 'highp',

			instancing: options.isInstanced === true,

			diffuseMap: !! this.uniforms.diffuseMap.value,
			mapEncoding: this.getTextureEncodingFromMap(  this.uniforms.diffuseMap.value ),

			envMap: !! this.uniforms.envMap.value,
			// envMapMode: envMap && envMap.mapping,
			envMapEncoding: this.getTextureEncodingFromMap( this.uniforms.envMap.value ),
			envMapCubeUV: false,
      outputEncoding: this.options.outputEncoding,
			normalMap: !! this.uniforms.normalMap.value,

			// clearcoatNormalMap: !! this.uniforms.clearcoatNormalMap.value,
			// displacementMap: !! this.uniforms.displacementMap.value,
			roughnessMap: !! this.uniforms.roughnessMap.value,
			metalnessMap: !! this.uniforms.metalnessMap.value,
      specularMap: !! this.uniforms.specularMap.value,
      aoMap: !! this.uniforms.aoMap.value,
      emissiveMap: !! this.uniforms.emissiveMap.value,
			// alphaMap: !! this.uniforms.alphaMap.value,

			// gradientMap: !! this.uniforms.gradientMap.value,

			sheen: !! this.uniforms.sheen.value,

	
      
      fog: !! options.fog,
			useFog: options.fog,
			fogExp2: true,

			flatShading: options.flatShading,

			// sizeAttenuation: material.sizeAttenuation,
			logarithmicDepthBuffer: false,


			// numDirLights: lights.directional.length,
			// numPointLights: lights.point.length,
			// numSpotLights: lights.spot.length,
			// numRectAreaLights: lights.rectArea.length,
			// numHemiLights: lights.hemi.length,

			// numDirLightShadows: lights.directionalShadowMap.length,
			// numPointLightShadows: lights.pointShadowMap.length,
			// numSpotLightShadows: lights.spotShadowMap.length,

			// numClippingPlanes: nClipPlanes,
			// numClipIntersection: nClipIntersection,

			dithering: false,

			shadowMapEnabled: false,
			// shadowMapType: renderer.shadowMap.type,

			toneMapping: !!this.options.toneMapping,
			physicallyCorrectLights: false,

			premultipliedAlpha: false,

			alphaTest: false,
			doubleSided: this.options.side == RenderSide.DOUBLE,
			flipSided: false,

			depthPacking: false,

			index0AttributeName: undefined,
    };
    this.parameters.vertexUvs = this.parameters.diffuseMap 
    || this.parameters.normalMap
    || this.parameters.emissiveMap
    || this.parameters.aoMap
    || this.parameters.roughnessMap
    || this.parameters.metalnessMap


	};
  getFragmentShader() {
    let envMapTypeDefine = 'ENVMAP_TYPE_CUBE'
    let envMapModeDefine = 'ENVMAP_MODE_REFLECTION'
    let envMapBlendingDefine = 'ENVMAP_BLENDING_NONE'
    let parameters = this.parameters
    let shaderDefines = [
      '#extension GL_OES_standard_derivatives : enable',
      '#extension GL_EXT_shader_texture_lod : enable',
      'precision highp float;',
      'precision highp int;',
      '#define STANDARD',
      '#define PHYSICAL',
      '#define GAMMA_FACTOR 2',
      '#define TEXTURE_LOD_EXT',
      parameters.toneMapping ? '#define TONE_MAPPING' : '',
      parameters.doubleSided ? '#define DOUBLE_SIDED' : '',
      parameters.vertexUvs ? '#define USE_UV' : '',
      parameters.diffuseMap ? '#define USE_MAP' : '',
			parameters.envMap ? '#define USE_ENVMAP' : '',
			parameters.envMap ? '#define ' + envMapTypeDefine : '',
			parameters.envMap ? '#define ' + envMapModeDefine : '',
      parameters.envMap ? '#define ' + envMapBlendingDefine : '',

      parameters.lightMap ? '#define USE_LIGHTMAP' : '',
			parameters.aoMap ? '#define USE_AOMAP' : '',
			parameters.emissiveMap ? '#define USE_EMISSIVEMAP' : '',
			parameters.bumpMap ? '#define USE_BUMPMAP' : '',
      parameters.normalMap ? '#define USE_NORMALMAP' : '',
      parameters.normalMap ? '#define TANGENTSPACE_NORMALMAP' : '',
			parameters.clearcoatNormalMap ? '#define USE_CLEARCOAT_NORMALMAP' : '',
			parameters.displacementMap && parameters.supportsVertexTextures ? '#define USE_DISPLACEMENTMAP' : '',
			parameters.specularMap ? '#define USE_SPECULARMAP' : '',
			parameters.roughnessMap ? '#define USE_ROUGHNESSMAP' : '',
			parameters.metalnessMap ? '#define USE_METALNESSMAP' : '',
      parameters.alphaMap ? '#define USE_ALPHAMAP' : '',
      
      parameters.sheen ? '#define USE_SHEEN' : '',
    ]
    let defineString = shaderDefines.join('\n')
    let fragmentShader = physicalFragment
    fragmentShader = replaceLightNums(fragmentShader, {
      numPointLights: this.uniforms.pointLights.value.length,
      numDirLights: this.uniforms.directionalLights.value.length,
    })
    fragmentShader = unrollLoops(fragmentShader)
    let toneMappingFunction = getToneMappingFunction(this.options.toneMapping)
    fragmentShader = replaceTonemapping(fragmentShader, toneMappingFunction)

    fragmentShader = replaceColorspace(fragmentShader, `
      // ${getTexelDecodingFunction('matcapTexelToLinear', parameters.envMapEncoding)}
			${getTexelDecodingFunction( 'mapTexelToLinear', parameters.mapEncoding )}
      ${getTexelDecodingFunction('envMapTexelToLinear', parameters.envMapEncoding)}
      ${getTexelDecodingFunction('emissiveMapTexelToLinear', parameters.envMapEncoding)}
      // ${getTexelDecodingFunction('lightMapTexelToLinear', parameters.envMapEncoding)}
      ${getTexelEncodingFunction('linearToOutputTexel', parameters.outputEncoding)}
    `)
    
    fragmentShader = replaceClippingPlanes(fragmentShader, 0, 0)
    return defineString + fragmentShader
  }
  getVertexShader() {
    let parameters = this.parameters
    let envMapModeDefine = 'ENVMAP_MODE_REFLECTION'

    let shaderDefines = [
      'precision highp float;',
      'precision highp int;',
      '#define HIGH_PRECISION',
      '#define STANDARD',
      '#define PHYSICAL',
  
      parameters.doubleSided ? '#define DOUBLE_SIDED' : '',
      parameters.vertexUvs ? '#define USE_UV' : '',
      parameters.diffuseMap ? '#define USE_MAP' : '',
      parameters.envMap ? '#define USE_ENVMAP' : '',
      parameters.envMap ? '#define ' + envMapModeDefine : '',

      parameters.lightMap ? '#define USE_LIGHTMAP' : '',
			parameters.aoMap ? '#define USE_AOMAP' : '',
			parameters.emissiveMap ? '#define USE_EMISSIVEMAP' : '',
			parameters.bumpMap ? '#define USE_BUMPMAP' : '',
			parameters.normalMap ? '#define USE_NORMALMAP' : '',
			parameters.normalMap ? '#define TANGENTSPACE_NORMALMAP' : '',
			parameters.clearcoatNormalMap ? '#define USE_CLEARCOAT_NORMALMAP' : '',
			parameters.displacementMap && parameters.supportsVertexTextures ? '#define USE_DISPLACEMENTMAP' : '',
			parameters.specularMap ? '#define USE_SPECULARMAP' : '',
			parameters.roughnessMap ? '#define USE_ROUGHNESSMAP' : '',
			parameters.metalnessMap ? '#define USE_METALNESSMAP' : '',
      parameters.alphaMap ? '#define USE_ALPHAMAP' : '',
      
      parameters.sheen ? '#define USE_SHEEN' : '',
    ]
    let defineString = shaderDefines.join('\n')
    let vertexShader = physicalVertex
    vertexShader = replaceLightNums(vertexShader, {
      numPointLights: this.uniforms.pointLights.value.length,
      numDirLights: this.uniforms.directionalLights.value.length,
    })
    vertexShader = unrollLoops(vertexShader)

    return defineString + vertexShader
  }
  
}
export {
  PhysicalShader
}