/**
 * IfcLoader.js
 *
 * @author realor
 */

import { IFC } from './IFC.js'
import { IFCFile } from './IFCFile.js'
import { Cord } from '../../core/Cord.js'
import { CordGeometry } from '../../core/CordGeometry.js'
import { Profile } from '../../core/Profile.js'
import { ProfileGeometry } from '../../core/ProfileGeometry.js'
import { Solid } from '../../core/Solid.js'
import { SolidGeometry } from '../../core/SolidGeometry.js'
import { ObjectBuilder } from '../../builders/ObjectBuilder.js'
import { Cloner } from '../../builders/Cloner.js'
import { Extruder } from '../../builders/Extruder.js'
import { Revolver } from '../../builders/Revolver.js'
import { BooleanOperator } from '../../builders/BooleanOperator.js'
import { RectangleBuilder } from '../../builders/RectangleBuilder.js'
import { RectangleHollowBuilder } from '../../builders/RectangleHollowBuilder.js'
import { CircleBuilder } from '../../builders/CircleBuilder.js'
import { CircleHollowBuilder } from '../../builders/CircleHollowBuilder.js'
import { EllipseBuilder } from '../../builders/EllipseBuilder.js'
import { IProfileBuilder } from '../../builders/IProfileBuilder.js'
import { LProfileBuilder } from '../../builders/LProfileBuilder.js'
import { TProfileBuilder } from '../../builders/TProfileBuilder.js'
import { UProfileBuilder } from '../../builders/UProfileBuilder.js'
import { ZProfileBuilder } from '../../builders/ZProfileBuilder.js'
import { TrapeziumBuilder } from '../../builders/TrapeziumBuilder.js'
import { IFCVoider } from '../../builders/IFCVoider.js'
import { GeometryUtils } from '../../utils/GeometryUtils.js'
import { WebUtils } from '../../utils/WebUtils.js'
import { ObjectUtils } from '../../utils/ObjectUtils.js'
import { registerIfcHelperClass } from './BaseEntity.js'
import * as THREE from '../../lib/three.module.js'

class IFCLoader extends THREE.Loader {
    static options = {
        units: 'm', // default model units
        minCircleSegments: 16, // minimum circle segments
        circleSegmentsByRadius: 64, // circle segments by meter of radius
        halfSpaceSize: 30 // half space size in meters
    }

    constructor(manager) {
        super(manager)
    }

    load(url, onLoad, onProgress, onError, options) {
        const fileLoader = new THREE.FileLoader(this.manager)
        fileLoader.load(url, text => this.parse(text, onLoad, onProgress, onError, options), onProgress, onError)
    }

    parse(text, onCompleted, onProgress, onError, options) {
        this.options = Object.assign({}, IFCLoader.options, options)

        let ifcFile = new IFCFile()

        console.info('parsing file...')

        this.parseFile(ifcFile, text)

        console.info(ifcFile)

        return this.buildModel(ifcFile, onCompleted, onProgress, onError)
    }

    parseFile(ifcFile, text) {
        throw 'Not implemented'
    }

    buildModel(ifcFile, onCompleted, onProgress, onError) {
        const model = new THREE.Group()
        const types = new THREE.Group()
        types.name = 'Types'
        types.visible = false
        types.userData.selection = { type: 'none' }
        model.add(types)

        this.modelFactor = 1.0
        this.blockCount = 0
        this.blocks = new Set()

        const schema = ifcFile.schema

        /* process project info */
        const processProjectInfo = () => {
            if (ifcFile.entities.IfcProject) {
                let project = ifcFile.entities.IfcProject[0]

                model.name = project.Name || project.LongName || 'IFC'
                model._ifc = project
                model.userData.IFC = {
                    ifcClassName: 'IfcProject',
                    GlobalId: project.GlobalId,
                    Name: this.unBox(project.Name),
                    Description: this.unBox(project.Description)
                }
                let contextUnits = project.UnitsInContext
                if (contextUnits) {
                    let units = contextUnits.Units
                    if (units) {
                        for (let u = 0; u < units.length; u++) {
                            let unit = units[u]
                            if (unit instanceof schema.IfcSIUnit && unit.UnitType === '.LENGTHUNIT.') {
                                // unit name = METRE
                                let factor = 1

                                if (unit.Prefix) {
                                    let prefix = IFC.UNIT_PREFIXES[unit.Prefix]
                                    if (prefix) {
                                        // set factor respect metre unit
                                        factor = prefix.factor
                                        model.userData.units = prefix.symbol + 'm'
                                    }
                                } else {
                                    // meters
                                    model.userData.units = 'm'
                                }
                                project._loader.modelFactor = factor
                            }
                        }
                    }
                }
            }
        }

        /* applyStyles */
        const applyStyles = () => {
            let styledItems = ifcFile.entities.IfcStyledItem
            if (styledItems) {
                for (let i = 0; i < styledItems.length; i++) {
                    let styledItem = styledItems[i]
                    styledItem.helper.applyStyle()
                }
            }
        }

        /* create objects */
        const createObject = index => {
            let product = ifcFile.products[index]
            let object3D = product.helper.getObject3D()
            if (product.ObjectPlacement instanceof schema.IfcLocalPlacement) {
                let matrixWorld = product.ObjectPlacement.helper.getMatrixWorld()
                matrixWorld.decompose(object3D.position, object3D.quaternion, object3D.scale)
                object3D.matrix.copy(matrixWorld)
                object3D.matrixWorldNeedsUpdate = true
                model.add(object3D)
            } else {
                model.add(object3D)
            }
        }

        const createObjects = () => {
            let products = ifcFile.products
            for (let i = 0; i < products.length; i++) {
                createObject(i)
            }
        }

        /* process relationships */
        const processRelationships = () => {
            let relationships = ifcFile.relationships
            for (let relationship of relationships) {
                relationship.helper.relate()
            }
            model.updateMatrixWorld()
        }

        /* process layer assigments */
        const processLayerAssignments = () => {
            let assignments = ifcFile.entities.IfcPresentationLayerAssignment
            if (assignments) {
                for (let assignment of assignments) {
                    assignment.helper.assign()
                }
            }
            model.updateMatrixWorld()
        }

        /* voiding objects */
        const voidObject = index => {
            let product = ifcFile.products[index]
            let productObject3D = product.helper.getObject3D()
            if (productObject3D) {
                let productRepr = productObject3D.getObjectByName(IFC.RepresentationName)

                if (productRepr && productRepr.builder instanceof IFCVoider) {
                    ObjectBuilder.build(productRepr)
                }
            }
        }

        const voidObjects = () => {
            let products = ifcFile.products
            for (let i = 0; i < products.length; i++) {
                voidObject(i)
            }
        }

        const processTypeProducts = () => {
            let typeProducts = ifcFile.typeProducts
            for (let typeProduct of typeProducts) {
                if (typeProduct.RepresentationMaps && typeProduct.RepresentationMaps.length > 0) {
                    const reprMap = typeProduct.RepresentationMaps[0]
                    const mappedObject3D = reprMap.helper.getObject3D()
                    if (mappedObject3D && mappedObject3D.parent === null) {
                        let typeName = typeProduct.Name || typeProduct.GlobalId
                        if (typeName.startsWith(THREE.Object3D.HIDDEN_PREFIX)) {
                            typeName = typeName.substring(1)
                        }
                        let typeGroup = new THREE.Group()
                        typeGroup.name = typeName
                        typeGroup._ifc = typeProduct
                        typeGroup.add(mappedObject3D)
                        typeGroup.userData.IFC = {
                            ifcClassName: typeProduct.constructor.name,
                            GlobalId: typeProduct.GlobalId,
                            Name: this.unBox(typeProduct.Name)
                        }
                        types.add(typeGroup)

                        this.blocks.delete(mappedObject3D)
                    }
                }
            }
            // rest of blocks
            for (let mappedObject3D of this.blocks) {
                types.add(mappedObject3D)
            }
        }

        /* setup objects */
        const setupObjects = () => {
            model.traverse(object => {
                if (object.userData.IFC) {
                    var ifcClassName = object.userData.IFC.ifcClassName
                    if (ifcClassName === 'IfcOpeningElement' || ifcClassName === 'IfcSpace') {
                        object = object.getObjectByName(IFC.RepresentationName)
                        if (object) {
                            ObjectUtils.updateStyle(object, false, false)
                        }
                    } else if (ifcClassName === 'IfcSite' || ifcClassName === 'IfcBuilding' || ifcClassName === 'IfcBuildingStorey') {
                        object.userData.selection.type = 'box'
                    } else if (ifcClassName === 'IfcDoor') {
                        object.userData.collision = { enabled: false }
                    }
                }
            })
            if (types.children.length > 0) {
                ObjectUtils.updateVisibility(types, false)
            }
        }

        const paintObject = (object, material) => {
            object.traverse(function(object) {
                if (object instanceof Solid) {
                    if (object.material === Solid.FaceMaterial) {
                        object.material = material
                    }
                }
            })
        }

        const setCastShadowForObject = object => {
            object.traverse(function(object) {
                if (object instanceof Solid) {
                    if (object.material.transparent) {
                        object.castShadow = false
                    }
                }
            })
        }

        const paintObjects = () => {
            let products = ifcFile.products
            for (let i = 0; i < products.length; i++) {
                let product = products[i]
                let object3D = product.helper.getObject3D()
                if (object3D && object3D.userData && object3D.userData.IFC) {
                    let reprObject3D = object3D.getObjectByName(IFC.RepresentationName)
                    if (reprObject3D) {
                        let ifcClassName = object3D.userData.IFC.ifcClassName
                        let material = IFCLoader.MATERIALS[ifcClassName]
                        if (material) {
                            paintObject(reprObject3D, material)
                        }
                        setCastShadowForObject(reprObject3D)
                    }
                }
            }
        }

        // group objects
        const groupObjects = () => {
            const groupObject = object => {
                let groups = {}
                let children = object.children.slice(0) // clone children
                for (let child of children) {
                    let ifc = child.userData.IFC
                    if (ifc) {
                        let group = groups[ifc.ifcClassName]
                        if (group === undefined) {
                            group = new THREE.Group()
                            group.name = ifc.ifcClassName
                            groups[ifc.ifcClassName] = group
                        }
                        group.add(child)
                    }
                }
                let typeNames = Object.getOwnPropertyNames(groups)
                typeNames = typeNames.sort()
                for (let typeName of typeNames) {
                    let group = groups[typeName]
                    object.add(group)
                }
            }

            // group types
            groupObject(types)

            // group storeys
            let storeys = ifcFile.entities.IfcBuildingStorey
            if (storeys) {
                for (let i = 0; i < storeys.length; i++) {
                    let storey = storeys[i]
                    let storeyObject3D = storey.helper.getObject3D()
                    if (storeyObject3D) {
                        groupObject(storeyObject3D)
                    }
                }
            }
        }

        if (onCompleted) {
            // asynchronous operation

            const getIterations = function() {
                return ifcFile.products.length
            }

            WebUtils.executeTasks(
                [
                    { run: processProjectInfo, message: 'Processing project info...' },
                    { run: applyStyles, message: 'Applying styles...' },
                    { run: createObject, message: 'Creating objects...', iterations: getIterations },
                    { run: processRelationships, message: 'Processing relationships...' },
                    { run: processLayerAssignments, message: 'Processing layers...' },
                    { run: voidObject, message: 'Voiding objects...', iterations: getIterations },
                    { run: processTypeProducts, message: 'Processing types...' },
                    { run: setupObjects, message: 'Setting object properties...' },
                    { run: paintObjects, message: 'Painting objects...' },
                    { run: groupObjects, message: 'Grouping objects...' }
                ],
                () => onCompleted(model),
                onProgress,
                error => onError(error),
                100,
                10
            )
        } else {
            // synchronous operation
            processProjectInfo()
            applyStyles()
            createObjects()
            processRelationships()
            processLayerAssignments()
            voidObjects()
            processTypeProducts()
            setupObjects()
            paintObjects()
            groupObjects()
        }
        return model
    }

    unBox(value) {
        return value && value.Value !== undefined ? value.Value : value
    }

    getCircleSegments(radius) {
        let meterRadius = radius * this.modelFactor

        let segments = Math.max(this.options.minCircleSegments, Math.ceil(this.options.circleSegmentsByRadius * meterRadius))

        if (segments % 2 === 1) segments++

        return segments
    }

    cloneObject3D(object, full = false) {
        // clone preserving _ifc property
        let clonedObject = object.clone(false)
        clonedObject._ifc = object._ifc

        if (full) {
            const start = object instanceof Solid ? 2 : 0
            for (let i = start; i < object.children.length; i++) {
                let child = object.children[i]
                clonedObject.add(this.cloneObject3D(child, full))
            }
        }
        return clonedObject
    }

    /* default materials */

    static MATERIALS = {
        IfcWall: new THREE.MeshPhongMaterial({
            name: 'Wall',
            color: 0xc0c080,
            shininess: 1,
            flatShading: false,
            side: THREE.DoubleSide,
            polygonOffset: true,
            polygonOffsetFactor: 1.0,
            polygonOffsetUnits: 0.5
        }),

        IfcWallStandardCase: new THREE.MeshPhongMaterial({
            name: 'Wall',
            color: 0xc0c080,
            shininess: 1,
            flatShading: false,
            side: THREE.DoubleSide,
            polygonOffset: true,
            polygonOffsetFactor: 1.0,
            polygonOffsetUnits: 0.5
        }),

        IfcSlab: new THREE.MeshPhongMaterial({
            name: 'Slab',
            color: 0xc0c0c0,
            shininess: 1,
            flatShading: false,
            side: THREE.DoubleSide,
            polygonOffset: true,
            polygonOffsetFactor: 1.0,
            polygonOffsetUnits: 0.5
        }),

        IfcRailing: new THREE.MeshPhongMaterial({
            name: 'Railing',
            flatShading: false,
            color: 0x606060,
            shininess: 1,
            side: THREE.DoubleSide
        }),

        IfcWindow: new THREE.MeshPhongMaterial({
            name: 'Window',
            flatShading: false,
            color: 0x8080ff,
            opacity: 0.3,
            transparent: true,
            side: THREE.DoubleSide
        }),

        IfcDoor: new THREE.MeshPhongMaterial({
            name: 'Door',
            flatShading: false,
            color: 0xc0c040,
            side: THREE.DoubleSide
        }),

        IfcCovering: new THREE.MeshPhongMaterial({
            name: 'Covering',
            flatShading: false,
            color: 0xc0c0c0,
            side: THREE.FrontSide
        }),

        IfcBeam: new THREE.MeshPhongMaterial({
            name: 'Beam',
            flatShading: false,
            color: 0x606070,
            side: THREE.FrontSide
        }),

        IfcColumn: new THREE.MeshPhongMaterial({
            name: 'Column',
            flatShading: false,
            color: 0x808080,
            side: THREE.FrontSide
        }),

        IfcOpeningElement: new THREE.MeshPhongMaterial({
            name: 'Opening',
            flatShading: false,
            color: 0x8080ff,
            opacity: 0.2,
            transparent: true,
            side: THREE.DoubleSide
        }),

        IfcSpace: new THREE.MeshPhongMaterial({
            name: 'Space',
            flatShading: false,
            color: 0xc0c0f0,
            opacity: 0.2,
            transparent: true,
            side: THREE.DoubleSide
        }),

        IfcFlowTerminal: new THREE.MeshPhongMaterial({
            name: 'FlowTerminal',
            flatShading: false,
            color: 0xffffff,
            side: THREE.DoubleSide
        }),

        IfcFurnishingElement: new THREE.MeshPhongMaterial({
            name: 'FurnishingElement',
            flatShading: false,
            color: 0xdeb887,
            side: THREE.DoubleSide
        }),

        IfcStair: new THREE.MeshPhongMaterial({
            name: 'FurnishingElement',
            flatShading: false,
            color: 0xa0522d,
            side: THREE.DoubleSide
        }),

        IfcStairFlight: new THREE.MeshPhongMaterial({
            name: 'FurnishingElement',
            flatShading: false,
            color: 0xa0522d,
            side: THREE.DoubleSide
        })
    }
}

/* helper classes*/

class IfcHelper {
    constructor(instance) {
        this.instance = instance
    }
}
registerIfcHelperClass(IfcHelper)

class IfcProductHelper extends IfcHelper {
    constructor(instance) {
        super(instance)
        this.object3D = null
    }

    getObject3D() {
        if (this.object3D === null) {
            const product = this.instance
            const schema = this.instance.constructor.schema
            const loader = product._loader

            var object3D = new THREE.Object3D()
            object3D.userData.selection = { group: true }

            let name = product.Name ? product.Name : product.constructor.name

            if (name.length >= 2 && name[0] === THREE.Object3D.HIDDEN_PREFIX) {
                name = name.substring(1)
            }

            object3D.name = name
            object3D.userData.IFC = {
                ifcClassName: product.constructor.name,
                GlobalId: product.GlobalId,
                Name: loader.unBox(product.Name),
                Description: loader.unBox(product.Description)
            }
            object3D._ifc = product

            let objectPlacement = product.ObjectPlacement
            if (objectPlacement instanceof schema.IfcLocalPlacement) {
                let matrix = objectPlacement.helper.getMatrix()
                matrix.decompose(object3D.position, object3D.quaternion, object3D.scale)
                object3D.matrix.copy(matrix)
                object3D.matrixWorldNeedsUpdate = true
            }

            let productRepr = product.Representation
            if (productRepr instanceof schema.IfcProductRepresentation) {
                let reprObject3D = productRepr.helper.getObject3D('Body')
                if (reprObject3D) {
                    if (reprObject3D.parent) {
                        reprObject3D = loader.cloneObject3D(reprObject3D, true)
                    }

                    reprObject3D.name = IFC.RepresentationName

                    let ifcClassName = null
                    if (reprObject3D.userData.IFC) {
                        ifcClassName = reprObject3D.userData.IFC.ifcClassName
                    }

                    if (
                        product instanceof schema.IfcElement &&
                        !(product instanceof schema.IfcOpeningElement) &&
                        (ifcClassName === 'IfcExtrudedAreaSolid' || ifcClassName === 'IfcBooleanResult' || ifcClassName === 'IfcBooleanClippingResult')
                    ) {
                        // set IFCVoider representation
                        if (reprObject3D instanceof Solid) {
                            let voider = new Solid()
                            voider.name = IFC.RepresentationName
                            voider.material = reprObject3D.material
                            voider.userData = reprObject3D.userData
                            voider.position.copy(reprObject3D.position)
                            voider.rotation.copy(reprObject3D.rotation)
                            voider.scale.copy(reprObject3D.scale)
                            voider.updateMatrix()
                            voider.builder = new IFCVoider()
                            voider.add(reprObject3D)
                            reprObject3D.name = 'Unvoided'
                            reprObject3D.visible = false
                            reprObject3D.facesVisible = false
                            reprObject3D.edgesVisible = false
                            reprObject3D.position.set(0, 0, 0)
                            reprObject3D.rotation.set(0, 0, 0)
                            reprObject3D.scale.set(1, 1, 1)
                            reprObject3D.updateMatrix()
                            object3D.add(voider)
                        } else if (reprObject3D instanceof THREE.Group) {
                            reprObject3D.builder = new IFCVoider()
                            object3D.add(reprObject3D)
                        } else throw 'Unexpected representacion object'
                    } else {
                        object3D.add(reprObject3D)
                    }
                }
            }
            this.object3D = object3D
        }
        return this.object3D
    }
}
registerIfcHelperClass(IfcProductHelper)

class IfcProductRepresentationHelper extends IfcHelper {
    constructor(instance) {
        super(instance)
    }

    getObject3D(representationIdentifier) {
        var reprObject3D = null
        var productRepr = this.instance

        var repCount = productRepr.Representations.length
        for (var i = 0; i < repCount; i++) {
            var repr = productRepr.Representations[i] // IfcRepresentation
            if (repr.RepresentationIdentifier === representationIdentifier) {
                reprObject3D = repr.helper.getObject3D()
                if (reprObject3D === null) {
                    console.warn('Unsupported representation', representationIdentifier, repr)
                }
                break
            }
        }
        return reprObject3D
    }
}
registerIfcHelperClass(IfcProductRepresentationHelper)

class IfcRepresentationHelper extends IfcHelper {
    constructor(instance) {
        super(instance)
        this.object3D = null
    }

    getObject3D() {
        if (this.object3D === null) {
            var representation = this.instance

            var group = new THREE.Group()
            for (var i = 0; i < representation.Items.length; i++) {
                var item = representation.Items[i]
                if (item && item.helper.getObject3D) {
                    var itemObject3D = item.helper.getObject3D()
                    if (itemObject3D) {
                        itemObject3D.name = 'Item' + i
                        itemObject3D.userData.IFC = { ifcClassName: item.constructor.name }
                        group.add(itemObject3D)
                        if (itemObject3D instanceof Solid && item.helper.material) {
                            itemObject3D.material = item.helper.material
                        }
                    }
                }
            }
            if (group.children.length === 1) {
                this.object3D = group.children[0]
                group.remove(this.object3D)
            } else {
                this.object3D = group
            }
            this.object3D._ifc = representation
        }
        return this.object3D
    }
}
registerIfcHelperClass(IfcRepresentationHelper)

/* Geometric representation item helpers */

class IfcGeometricRepresentationItemHelper extends IfcHelper {
    constructor(instance) {
        super(instance)
        this.object3D = null
    }

    getObject3D() {
        let ifcClassName = this.instance.constructor.name
        console.warn('Unsupported item: ' + ifcClassName, this)
        return null
    }
}
registerIfcHelperClass(IfcGeometricRepresentationItemHelper)

class IfcHalfSpaceSolidHelper extends IfcGeometricRepresentationItemHelper {
    constructor(instance) {
        super(instance)
    }

    getObject3D() {
        if (this.object3D === null) {
            const halfSpace = this.instance

            const size = halfSpace._loader.options.halfSpaceSize / halfSpace._loader.modelFactor

            const surface = halfSpace.BaseSurface
            const flag = halfSpace.AgreementFlag === '.T.'
            const plane = surface.Position

            const geometry = new SolidGeometry()
            let vertices = geometry.vertices
            vertices.push(new THREE.Vector3(-size, -size, 0))
            vertices.push(new THREE.Vector3(size, -size, 0))
            vertices.push(new THREE.Vector3(size, size, 0))
            vertices.push(new THREE.Vector3(-size, size, 0))

            vertices.push(new THREE.Vector3(-size, -size, size))
            vertices.push(new THREE.Vector3(size, -size, size))
            vertices.push(new THREE.Vector3(size, size, size))
            vertices.push(new THREE.Vector3(-size, size, size))

            geometry.addFace(3, 2, 1, 0)
            geometry.addFace(4, 5, 6, 7)
            geometry.addFace(0, 1, 5, 4)
            geometry.addFace(1, 2, 6, 5)
            geometry.addFace(2, 3, 7, 6)
            geometry.addFace(3, 0, 4, 7)

            var matrix = plane.helper.getMatrix()
            if (flag) {
                matrix = matrix.clone()
                var rotMatrix = new THREE.Matrix4()
                rotMatrix.makeRotationX(Math.PI)
                matrix.multiply(rotMatrix)
            }
            geometry.applyMatrix4(matrix)
            const planeSolid = new Solid(geometry)
            planeSolid.name = 'halfSpace'

            this.object3D = planeSolid
            this.object3D._ifc = halfSpace
        }
        return this.object3D
    }
}
registerIfcHelperClass(IfcHalfSpaceSolidHelper)

class IfcPolygonalBoundedHalfSpaceHelper extends IfcGeometricRepresentationItemHelper {
    constructor(instance) {
        super(instance)
    }

    getObject3D() {
        if (this.object3D === null) {
            const halfSpace = this.instance
            const schema = this.instance.constructor.schema

            const surface = halfSpace.BaseSurface
            const base = halfSpace.Position
            const flag = halfSpace.AgreementFlag === '.T.'
            const boundary = halfSpace.PolygonalBoundary

            if (surface instanceof schema.IfcPlane) {
                try {
                    const size = halfSpace._loader.options.halfSpaceSize / halfSpace._loader.modelFactor
                    const extruder = new Extruder(size)

                    // polygon solid
                    const curvePoints = boundary.helper.getPoints()
                    let shape = new THREE.Shape()
                    shape.moveTo(curvePoints[0].x, curvePoints[0].y)
                    for (let i = 1; i < curvePoints.length; i++) {
                        shape.lineTo(curvePoints[i].x, curvePoints[i].y)
                    }
                    shape.closePath()

                    const polygonProfile = new Profile(new ProfileGeometry(shape))
                    polygonProfile.name = 'polygon'
                    polygonProfile.visible = false
                    polygonProfile._ifc = boundary
                    const polygonSolid = new Solid()
                    polygonSolid.add(polygonProfile)
                    polygonSolid.builder = extruder

                    let matrix = base.helper.getMatrix()
                    matrix.decompose(polygonSolid.position, polygonSolid.rotation, polygonSolid.scale)
                    polygonSolid.updateMatrix()

                    // plane solid
                    const plane = surface.Position

                    shape = new THREE.Shape()
                    shape.moveTo(-size, -size)
                    shape.lineTo(size, -size)
                    shape.lineTo(size, size)
                    shape.lineTo(-size, size)
                    shape.closePath()

                    let planeProfile = new Profile(new ProfileGeometry(shape))
                    planeProfile.name = 'plane'
                    planeProfile.visible = false
                    let planeSolid = new Solid()
                    planeSolid.add(planeProfile)
                    planeSolid.builder = extruder

                    matrix = plane.helper.getMatrix()
                    if (!flag) {
                        matrix = matrix.clone()
                        let rotMatrix = new THREE.Matrix4()
                        rotMatrix.makeRotationX(Math.PI)
                        matrix.multiply(rotMatrix)
                    }
                    matrix.decompose(planeSolid.position, planeSolid.rotation, planeSolid.scale)
                    planeSolid.updateMatrix()

                    let halfSpaceSolid = new Solid()
                    halfSpaceSolid.name = 'polygonalHalfSpace'
                    halfSpaceSolid.add(polygonSolid)
                    halfSpaceSolid.add(planeSolid)
                    halfSpaceSolid.builder = new BooleanOperator(BooleanOperator.SUBTRACT)
                    ObjectBuilder.build(halfSpaceSolid)

                    this.object3D = halfSpaceSolid
                    this.object3D._ifc = halfSpace
                } catch (ex) {
                    console.warn(ex)
                }
            }
        }
        return this.object3D
    }
}
registerIfcHelperClass(IfcPolygonalBoundedHalfSpaceHelper)

class IfcBooleanResultHelper extends IfcGeometricRepresentationItemHelper {
    constructor(instance) {
        super(instance)
    }

    getObject3D() {
        if (this.object3D === null) {
            var result = this.instance

            var operator = result.Operator
            var firstOperand = result.FirstOperand
            var secondOperand = result.SecondOperand

            var firstObject = firstOperand.helper.getObject3D()
            var secondObject = secondOperand.helper.getObject3D()
            if (firstObject instanceof Solid && firstOperand.helper.material) {
                firstObject.material = firstOperand.helper.material
            }

            if (firstObject instanceof Solid && secondObject instanceof Solid) {
                let oper = 'subtract'
                switch (operator) {
                    case '.UNION.':
                        oper = BooleanOperator.UNION
                        break
                    case '.INTERSECTION.':
                        oper = BooleanOperator.INTERSECT
                        break
                    case '.DIFFERENCE.':
                        oper = BooleanOperator.SUBTRACT
                        break
                    default:
                        console.warn('Invalid operator: ' + operator.constant)
                }
                let object3D = new Solid()
                object3D.name = oper
                object3D.builder = new BooleanOperator(oper)
                firstObject.visible = false
                firstObject.facesVisible = false
                firstObject.edgesVisible = false
                secondObject.visible = false
                secondObject.facesVisible = false
                secondObject.edgesVisible = false
                object3D.attach(firstObject)
                object3D.attach(secondObject)
                ObjectBuilder.build(object3D)
                if (object3D.isValid()) {
                    this.object3D = object3D
                    this.object3D.material = firstObject.material
                    this.object3D._ifc = result
                } else {
                    console.warn('boolean operation failed', result)
                    this.object3D = firstObject
                }
            } else {
                this.object3D = firstObject || secondObject
            }
        }
        return this.object3D
    }
}
registerIfcHelperClass(IfcBooleanResultHelper)

class IfcTriangulatedFaceSetHelper extends IfcGeometricRepresentationItemHelper {
    constructor(instance) {
        super(instance)
    }

    getObject3D() {
        if (this.object3D === null) {
            const faceSet = this.instance

            let geometry = new SolidGeometry()

            geometry.vertices = faceSet.Coordinates.helper.getPoints()

            let coordIndex = faceSet.CoordIndex
            for (let t = 0; t < coordIndex.length; t++) {
                let triangle = coordIndex[t]
                let a = triangle[0] - 1
                let b = triangle[1] - 1
                let c = triangle[2] - 1
                geometry.addFace(a, b, c)
            }
            let solid = new Solid()
            solid.updateGeometry(geometry, true)
            this.object3D = solid
            this.object3D._ifc = faceSet
        }
        return this.object3D
    }
}
registerIfcHelperClass(IfcTriangulatedFaceSetHelper)

class IfcPolygonalFaceSetHelper extends IfcGeometricRepresentationItemHelper {
    constructor(instance) {
        super(instance)
    }

    getObject3D() {
        if (this.object3D === null) {
            const faceSet = this.instance

            let geometry = new SolidGeometry()

            geometry.vertices = faceSet.Coordinates.helper.getPoints()

            let faces = faceSet.Faces
            for (let f = 0; f < faces.length; f++) {
                let face = faces[f]
                let coordIndex = face.CoordIndex

                let faceIndices = []
                for (let i = 0; i < coordIndex.length; i++) {
                    let vertexIndex = coordIndex[i] - 1 // 1-base index
                    faceIndices.push(vertexIndex)
                }
                let geomFace = geometry.addFace(...faceIndices)

                let innerCoordIndices = face.InnerCoordIndices
                if (innerCoordIndices) {
                    for (let h = 0; h < innerCoordIndices.length; h++) {
                        let hole = innerCoordIndices[h]
                        let holeIndices = []
                        for (let hv = 0; hv < hole.length; hv++) {
                            let vertexIndex = hole[hv] - 1 // 1-base index
                            holeIndices.push(vertexIndex)
                        }
                        geomFace.addHole(...holeIndices)
                    }
                }
            }
            this.object3D = new Solid(geometry)
            this.object3D._ifc = faceSet
        }
        return this.object3D
    }
}
registerIfcHelperClass(IfcPolygonalFaceSetHelper)

class IfcSweptAreaSolidHelper extends IfcGeometricRepresentationItemHelper {
    constructor(instance) {
        super(instance)
    }

    createSolid(builder) {
        const swept = this.instance
        const schema = this.instance.constructor.schema
        const profileDef = swept.SweptArea

        if (profileDef instanceof schema.IfcProfileDef) {
            let profile = profileDef.helper.getProfile()
            if (profile) {
                try {
                    if (profile.parent) {
                        profile = profile.clone()
                    }
                    profile._ifc = profileDef

                    let solid = new Solid()
                    solid.add(profile)
                    solid.builder = builder
                    ObjectBuilder.build(solid)
                    solid._ifc = swept

                    if (swept.Position) {
                        const matrix = swept.Position.helper.getMatrix()
                        matrix.decompose(solid.position, solid.quaternion, solid.scale)
                        solid.updateMatrix()
                    }
                    this.object3D = solid
                } catch (ex) {
                    console.warn(ex)
                }
            } else console.warn('Unsupported profile', profileDef)
        }
    }
}
registerIfcHelperClass(IfcSweptAreaSolidHelper)

class IfcExtrudedAreaSolidHelper extends IfcSweptAreaSolidHelper {
    constructor(instance) {
        super(instance)
    }

    getObject3D() {
        if (this.object3D === null) {
            const swept = this.instance
            const direction = swept.ExtrudedDirection.helper.getDirection()
            const depth = swept.Depth

            this.createSolid(new Extruder(depth, direction))
        }
        return this.object3D
    }
}
registerIfcHelperClass(IfcExtrudedAreaSolidHelper)

class IfcRevolvedAreaSolidHelper extends IfcSweptAreaSolidHelper {
    constructor(instance) {
        super(instance)
    }

    getObject3D() {
        if (this.object3D === null) {
            const swept = this.instance
            const location = swept.Axis.helper.getLocation()
            const axis = swept.Axis.helper.getAxis()
            const angle = THREE.MathUtils.radToDeg(swept.Angle)

            const radius = location.length() + 10 // radius estimate

            const segments = swept._loader.getCircleSegments(radius)

            this.createSolid(new Revolver(angle, location, axis, segments))
        }
        return this.object3D
    }
}
registerIfcHelperClass(IfcRevolvedAreaSolidHelper)

class IfcSurfaceCurveSweptAreaSolidHelper extends IfcGeometricRepresentationItemHelper {
    constructor(instance) {
        super(instance)
    }

    getObject3D() {
        if (this.object3D === null) {
            const swept = this.instance
            const profileDef = swept.SweptArea // IfcProfileDef
            const position = swept.Position // IfcAxis2Placement3D
            const matrix = position.helper.getMatrix()
            const directrix = swept.Directrix // IfcCurve
            const startParam = swept.StartParam // IfcParameterValue : number
            const endParam = swept.EndParam // IfcParameterValue : number
            const surface = swept.ReferenceSurface // IfcSurface: ignored

            const cordPoints = directrix.helper.getPoints()
            if (cordPoints) {
                const profile = profileDef.helper.getProfile()
                if (profile) {
                    try {
                        const solid = new Solid()

                        solid.name = 'swept'
                        solid._ifc = swept
                        solid.builder = new Extruder()
                        solid.add(profile)

                        const cord = new Cord(new CordGeometry(cordPoints))
                        solid.add(cord)

                        ObjectBuilder.build(solid)

                        if (matrix) {
                            matrix.decompose(solid.position, solid.quaternion, solid.scale)
                            solid.updateMatrix()
                        }
                        this.object3D = solid
                    } catch (ex) {
                        console.warn(ex)
                    }
                } else {
                    console.warn('Unsupported profile', profileDef)
                }
            } else {
                console.warn('Unsupported curve', directrix)
            }
        }
        return this.object3D
    }
}
registerIfcHelperClass(IfcSurfaceCurveSweptAreaSolidHelper)

class IfcSweptDiskSolidHelper extends IfcGeometricRepresentationItemHelper {
    constructor(instance) {
        super(instance)
    }

    getObject3D() {
        if (this.object3D === null) {
            const swept = this.instance
            const directrix = swept.Directrix // IfcCurve
            const radius = swept.Radius
            const innerRadius = swept.InnerRadius
            const segments = swept._loader.getCircleSegments(radius)

            try {
                this.object3D = new Solid()
                const object3D = this.object3D

                object3D.name = 'disk'
                object3D._ifc = swept
                object3D.builder = new Extruder()

                const profile = new Profile()

                if (typeof innerRadius === 'number') {
                    profile.builder = new CircleHollowBuilder(radius, radius - innerRadius, segments)
                } else {
                    profile.builder = new CircleBuilder(radius, segments)
                }
                object3D.add(profile)

                const cordPoints = directrix.helper.getPoints()
                const cord = new Cord(new CordGeometry(cordPoints))
                object3D.add(cord)

                ObjectBuilder.build(object3D)
            } catch (ex) {
                console.warn(ex)
            }
        }
        return this.object3D
    }
}
registerIfcHelperClass(IfcSweptDiskSolidHelper)

class IfcManifoldSolidBrepHelper extends IfcGeometricRepresentationItemHelper {
    constructor(instance) {
        super(instance)
    }

    getObject3D() {
        if (this.object3D === null) {
            var brep = this.instance

            var outerShell = brep.Outer
            this.object3D = outerShell.helper.getObject3D()
            this.object3D._ifc = brep
        }
        return this.object3D
    }
}
registerIfcHelperClass(IfcManifoldSolidBrepHelper)

class IfcFaceBasedSurfaceModelHelper extends IfcGeometricRepresentationItemHelper {
    constructor(instance) {
        super(instance)
    }

    getObject3D() {
        if (this.object3D === null) {
            this.object3D = new THREE.Group()
            var surface = this.instance
            var faceSets = surface.FbsmFaces // IfcConnectedFaceSet[...]
            for (var i = 0; i < faceSets.length; i++) {
                var faceSet = faceSets[i] // IfcConnectedFaceSet
                var faceSetObject3D = faceSet.helper.getObject3D()
                faceSetObject3D.name = 'FaceSet' + i
                this.object3D.add(faceSetObject3D)
                this.object3D._ifc = surface
            }
        }
        return this.object3D
    }
}
registerIfcHelperClass(IfcFaceBasedSurfaceModelHelper)

class IfcShellBasedSurfaceModelHelper extends IfcGeometricRepresentationItemHelper {
    constructor(instance) {
        super(instance)
    }

    getObject3D() {
        if (this.object3D === null) {
            this.object3D = new THREE.Group()
            var surface = this.instance
            var shells = surface.SbsmBoundary // IfcShell[...]
            for (var i = 0; i < shells.length; i++) {
                var shell = shells[i] // IfcConnectedFaceSet
                var shellObject3D = shell.helper.getObject3D()
                shellObject3D.name = 'Shell' + i
                shellObject3D._ifc = shell
                this.object3D.add(shellObject3D)
                this.object3D._ifc = surface
            }
        }
        return this.object3D
    }
}
registerIfcHelperClass(IfcShellBasedSurfaceModelHelper)

class IfcRepresentationMapHelper extends IfcHelper {
    constructor(instance) {
        super(instance)
        this.object3D = null
    }

    getObject3D() {
        if (this.object3D === null) {
            const reprMap = this.instance

            const repr = reprMap.MappedRepresentation // IfcRepresentation
            const origin = reprMap.MappingOrigin
            const loader = reprMap._loader

            let object3D = repr.helper.getObject3D()
            if (object3D.parent) {
                // already added to scene, clone it
                object3D = loader.cloneObject3D(object3D, true)
            }

            object3D.name = 'block-' + ++loader.blockCount
            object3D.userData.IFC = { ifcClassName: 'IfcRepresentationMap' }
            object3D._ifc = reprMap
            loader.blocks.add(object3D)

            if (origin) {
                let matrix = origin.helper.getMatrix()
                object3D.matrix.multiplyMatrices(matrix, object3D.matrix)
                object3D.matrix.decompose(object3D.position, object3D.quaternion, object3D.scale)
                object3D.matrixWorldNeedsUpdate = true
            }
            this.object3D = object3D
        }
        return this.object3D
    }
}
registerIfcHelperClass(IfcRepresentationMapHelper)

class IfcMappedItemHelper extends IfcGeometricRepresentationItemHelper {
    constructor(instance) {
        super(instance)
    }

    getObject3D() {
        if (this.object3D === null) {
            const mappedItem = this.instance

            const source = mappedItem.MappingSource // IfcRepresentationMap
            const target = mappedItem.MappingTarget
            const loader = mappedItem._loader

            const mappedObject3D = source.helper.getObject3D()

            if (mappedObject3D) {
                const instanceGroup = new THREE.Group()

                if (target) {
                    let matrix = target.helper.getMatrix()
                    matrix.decompose(instanceGroup.position, instanceGroup.quaternion, instanceGroup.scale)
                    instanceGroup.updateMatrix()
                }
                instanceGroup.builder = new Cloner(mappedObject3D)
                ObjectBuilder.build(instanceGroup)

                this.object3D = instanceGroup
                this.object3D._ifc = mappedItem
            }
        }
        return this.object3D
    }
}
registerIfcHelperClass(IfcMappedItemHelper)

/* Profile helpers */

class IfcProfileDefHelper extends IfcHelper {
    constructor(instance) {
        super(instance)
        this.profile = null
    }

    getProfile() {
        return this.profile
    }
}
registerIfcHelperClass(IfcProfileDefHelper)

class IfcParameterizedProfileDefHelper extends IfcProfileDefHelper {
    constructor(instance) {
        super(instance)
    }

    getProfile() {
        if (this.profile === null) {
            const builder = this.getProfileBuilder()
            if (builder) {
                const profileDef = this.instance

                const profile = new Profile()

                let name = builder.constructor.name
                let index = name.indexOf('Builder')
                if (index !== -1) name = name.substring(0, index)
                profile.name = name
                profile.builder = builder

                ObjectBuilder.build(profile)

                if (profileDef.Position) {
                    const profMat = profileDef.Position.helper.getMatrix()
                    profMat.decompose(profile.position, profile.quaternion, profile.scale)
                    profile.updateMatrix()
                }

                this.profile = profile
            }
        }
        return this.profile
    }

    getProfileBuilder() {
        return null
    }
}
registerIfcHelperClass(IfcParameterizedProfileDefHelper)

class IfcRectangleProfileDefHelper extends IfcParameterizedProfileDefHelper {
    constructor(instance) {
        super(instance)
    }

    getProfileBuilder() {
        const profileDef = this.instance

        return new RectangleBuilder(profileDef.XDim, profileDef.YDim)
    }
}
registerIfcHelperClass(IfcRectangleProfileDefHelper)

class IfcRectangleHollowProfileDefHelper extends IfcRectangleProfileDefHelper {
    constructor(instance) {
        super(instance)
    }

    getProfileBuilder() {
        const profileDef = this.instance

        return new RectangleHollowBuilder(profileDef.XDim, profileDef.YDim, profileDef.WallThickness)
    }
}
registerIfcHelperClass(IfcRectangleHollowProfileDefHelper)

class IfcCircleProfileDefHelper extends IfcParameterizedProfileDefHelper {
    constructor(instance) {
        super(instance)
    }

    getProfileBuilder() {
        const profileDef = this.instance
        const radius = profileDef.Radius
        const segments = profileDef._loader.getCircleSegments(radius)

        return new CircleBuilder(radius, segments)
    }
}
registerIfcHelperClass(IfcCircleProfileDefHelper)

class IfcCircleHollowProfileDefHelper extends IfcCircleProfileDefHelper {
    constructor(instance) {
        super(instance)
    }

    getProfileBuilder() {
        const profileDef = this.instance
        const radius = profileDef.Radius
        const thickness = profileDef.WallThickness
        const segments = profileDef._loader.getCircleSegments(radius)

        return new CircleHollowBuilder(radius, thickness, segments)
    }
}
registerIfcHelperClass(IfcCircleHollowProfileDefHelper)

class IfcEllipseProfileDefHelper extends IfcParameterizedProfileDefHelper {
    constructor(instance) {
        super(instance)
    }

    getProfileBuilder() {
        const profileDef = this.instance
        const xradius = profileDef.SemiAxis1
        const yradius = profileDef.SemiAxis2
        const maxRadius = Math.max(xradius, yradius)
        const segments = profileDef._loader.getCircleSegments(maxRadius)

        return new EllipseBuilder(xradius, yradius, segments)
    }
}
registerIfcHelperClass(IfcEllipseProfileDefHelper)

class IfcIShapeProfileDefHelper extends IfcParameterizedProfileDefHelper {
    constructor(instance) {
        super(instance)
    }

    getProfileBuilder() {
        const profileDef = this.instance
        const width = profileDef.OverallWidth
        const height = profileDef.OverallDepth
        const webThickness = profileDef.WebThickness
        const flangeThickness = profileDef.FlangeThickness

        return new IProfileBuilder(width, height, webThickness, flangeThickness)
    }
}
registerIfcHelperClass(IfcIShapeProfileDefHelper)

class IfcLShapeProfileDefHelper extends IfcParameterizedProfileDefHelper {
    constructor(instance) {
        super(instance)
    }

    getProfileBuilder() {
        const profileDef = this.instance
        const width = profileDef.Width
        const height = profileDef.Depth
        const thickness = profileDef.Thickness

        return new LProfileBuilder(width, height, thickness)
    }
}
registerIfcHelperClass(IfcLShapeProfileDefHelper)

class IfcTShapeProfileDefHelper extends IfcParameterizedProfileDefHelper {
    constructor(instance) {
        super(instance)
    }

    getProfileBuilder() {
        const profileDef = this.instance
        const flangeWidth = profileDef.FlangeWidth
        const height = profileDef.Depth
        const webThickness = profileDef.WebThickness
        const flangeThickness = profileDef.FlangeThickness

        return new TProfileBuilder(flangeWidth, height, webThickness, flangeThickness)
    }
}
registerIfcHelperClass(IfcTShapeProfileDefHelper)

class IfcUShapeProfileDefHelper extends IfcParameterizedProfileDefHelper {
    constructor(instance) {
        super(instance)
    }

    getProfileBuilder() {
        const profileDef = this.instance
        const flangeWidth = profileDef.FlangeWidth
        const height = profileDef.Depth
        const webThickness = profileDef.WebThickness
        const flangeThickness = profileDef.FlangeThickness

        return new UProfileBuilder(flangeWidth, height, webThickness, flangeThickness)
    }
}
registerIfcHelperClass(IfcUShapeProfileDefHelper)

class IfcZShapeProfileDefHelper extends IfcParameterizedProfileDefHelper {
    constructor(instance) {
        super(instance)
    }

    getProfileBuilder() {
        const profileDef = this.instance
        const flangeWidth = profileDef.FlangeWidth
        const height = profileDef.Depth
        const webThickness = profileDef.WebThickness
        const flangeThickness = profileDef.FlangeThickness

        return new ZProfileBuilder(flangeWidth, height, webThickness, flangeThickness)
    }
}
registerIfcHelperClass(IfcZShapeProfileDefHelper)

class IfcTrapeziumProfileDefHelper extends IfcParameterizedProfileDefHelper {
    constructor(instance) {
        super(instance)
    }

    getProfileBuilder() {
        const profileDef = this.instance
        const bottomXDim = profileDef.BottomXDim
        const height = profileDef.YDim
        const topXDim = profileDef.TopXDim
        const topXOffset = profileDef.TopXOffset

        return new TrapeziumBuilder(bottomXDim, height, topXDim, topXOffset)
    }
}
registerIfcHelperClass(IfcTrapeziumProfileDefHelper)

class IfcArbitraryClosedProfileDefHelper extends IfcProfileDefHelper {
    constructor(instance) {
        super(instance)
        this.profile = null
    }

    getProfile() {
        if (this.profile === null) {
            const profileDef = this.instance

            const curve = profileDef.OuterCurve // IfcCurve
            const curvePoints = curve.helper.getPoints()
            if (curvePoints) {
                const shape = new THREE.Shape()
                this.addPointsToPath(shape, curvePoints)
                this.profile = new Profile(new ProfileGeometry(shape))
            } else {
                console.warn('Unsupported curve', curve)
            }
        }
        return this.profile
    }

    addPointsToPath(path, curvePoints) {
        path.moveTo(curvePoints[0].x, curvePoints[0].y)
        for (let i = 1; i < curvePoints.length; i++) {
            path.lineTo(curvePoints[i].x, curvePoints[i].y)
        }
        path.closePath()
    }
}
registerIfcHelperClass(IfcArbitraryClosedProfileDefHelper)

class IfcArbitraryProfileDefWithVoidsHelper extends IfcArbitraryClosedProfileDefHelper {
    constructor(instance) {
        super(instance)
        this.profile = null
    }

    getProfile() {
        if (this.profile === null) {
            const profileDef = this.instance
            const curve = profileDef.OuterCurve // IfcCurve
            let curvePoints = curve.helper.getPoints()
            if (curvePoints) {
                const shape = new THREE.Shape()
                this.addPointsToPath(shape, curvePoints)

                const innerCurves = profileDef.InnerCurves // IfcCurve[]
                for (let innerCurve of innerCurves) {
                    curvePoints = innerCurve.helper.getPoints()
                    if (curvePoints) {
                        let hole = new THREE.Path()
                        this.addPointsToPath(hole, curvePoints)
                        shape.holes.push(hole)
                    } else {
                        console.warn('Unsupported inner curve', innerCurve)
                    }
                }
                this.profile = new Profile(new ProfileGeometry(shape))
            }
        }
        return this.profile
    }
}
registerIfcHelperClass(IfcArbitraryProfileDefWithVoidsHelper)

/* Curve helpers */

class IfcCurveHelper extends IfcHelper {
    constructor(instance) {
        super(instance)
        this.points = null
    }

    getPoints() {
        return this.points
    }
}
registerIfcHelperClass(IfcCurveHelper)

class IfcPolylineHelper extends IfcCurveHelper {
    constructor(instance) {
        super(instance)
    }

    getPoints() {
        if (this.points === null) {
            const polyline = this.instance

            this.points = []
            const points = polyline.Points
            for (let i = 0; i < points.length; i++) {
                let point = points[i].helper.getPoint()
                this.points.push(point)
            }
        }
        return this.points
    }
}
registerIfcHelperClass(IfcPolylineHelper)

class IfcIndexedPolyCurveHelper extends IfcCurveHelper {
    constructor(instance) {
        super(instance)
    }

    getPoints() {
        const polyCurve = this.instance
        return polyCurve.Points.helper.getPoints()
    }
}
registerIfcHelperClass(IfcIndexedPolyCurveHelper)

class IfcTrimmedCurveHelper extends IfcCurveHelper {
    constructor(instance) {
        super(instance)
    }

    getPoints() {
        if (this.points === null) {
            const curve = this.instance
            const schema = this.instance.constructor.schema

            const basisCurve = curve.BasisCurve
            const trim1 = curve.Trim1[0]
            const trim2 = curve.Trim2[0]
            if (basisCurve instanceof schema.IfcConic && trim1 instanceof schema.IfcParameterValue && trim2 instanceof schema.IfcParameterValue) {
                let startAngle = trim1.Value
                let endAngle = trim2.Value
                let sense = curve.SenseAgreement === '.T.'
                this.points = basisCurve.helper.getTrimmedPoints(startAngle, endAngle, sense)
            } else {
                console.info('unsupported trimmed curve segment', curve)
            }
        }
        return this.points
    }
}
registerIfcHelperClass(IfcTrimmedCurveHelper)

class IfcCompositeCurveHelper extends IfcCurveHelper {
    constructor(instance) {
        super(instance)
    }

    getPoints() {
        if (this.points === null) {
            const compositeCurve = this.instance
            const schema = this.instance.constructor.schema

            let points = []
            let segments = compositeCurve.Segments
            for (let i = 0; i < segments.length; i++) {
                let segment = segments[i] // IfcCompositeCurveSegment
                let curve = segment.ParentCurve
                let curvePoints = curve.helper.getPoints()
                if (curvePoints) {
                    if (segment.SameSense === '.T.') {
                        for (let j = 0; j < curvePoints.length; j++) {
                            points.push(curvePoints[j])
                        }
                    } else {
                        for (let j = curvePoints.length - 1; j >= 0; j--) {
                            points.push(curvePoints[j])
                        }
                    }
                } else {
                    console.info('unsupported curve segment', curve)
                }
            }
            if (points.length > 0) {
                this.points = points
            }
        }
        return this.points
    }
}
registerIfcHelperClass(IfcCompositeCurveHelper)

class IfcConicHelper extends IfcCurveHelper {
    constructor(instance) {
        super(instance)
    }

    getTrimmedPoints(param1, param2, sense) {
        return this.points
    }

    generatePoints(startAngle, endAngle, sense, segments, addPoint) {
        let angle
        if (sense) {
            // anti-clockwise
            if (endAngle < startAngle) endAngle += 2 * Math.PI
            let dif = endAngle - startAngle
            let divs = Math.ceil((dif * segments) / (2 * Math.PI))
            let angleStep = dif / divs

            angle = startAngle
            while (divs > 0) {
                addPoint(angle)
                angle += angleStep
                divs--
            }
            addPoint(endAngle)
        } // clockwise
        else {
            if (endAngle > startAngle) startAngle += 2 * Math.PI

            let dif = startAngle - endAngle
            let divs = Math.ceil((dif * segments) / (2 * Math.PI))
            let angleStep = dif / divs

            angle = startAngle
            while (divs > 0) {
                addPoint(angle)
                angle -= angleStep
                divs--
            }
            addPoint(endAngle)
        }
    }
}
registerIfcHelperClass(IfcConicHelper)

class IfcCircleHelper extends IfcConicHelper {
    constructor(instance) {
        super(instance)
    }

    getPoints() {
        if (this.points === null) {
            this.points = []
            const circle = this.instance
            const matrix = circle.Position.helper.getMatrix()
            const radius = circle.Radius
            const segments = circle._loader.getCircleSegments(radius)
            const angleStep = (2 * Math.PI) / segments
            for (let i = 0; i < segments; i++) {
                let angle = i * angleStep
                let point = new THREE.Vector3()
                point.x = Math.cos(angle) * radius
                point.y = Math.sin(angle) * radius
                point.z = 0
                point.applyMatrix4(matrix)
                this.points.push(point)
            }
        }
        return this.points
    }

    getTrimmedPoints(param1, param2, sense) {
        let points = []
        const circle = this.instance
        const matrix = circle.Position.helper.getMatrix()
        const radius = circle.Radius
        const startAngle = THREE.MathUtils.degToRad(param1)
        const endAngle = THREE.MathUtils.degToRad(param2)
        const segments = circle._loader.getCircleSegments(radius)

        const addPoint = angle => {
            let point = new THREE.Vector3()
            point.x = Math.cos(angle) * radius
            point.y = Math.sin(angle) * radius
            point.z = 0
            point.applyMatrix4(matrix)
            points.push(point)
        }

        this.generatePoints(startAngle, endAngle, sense, segments, addPoint)

        return points
    }
}
registerIfcHelperClass(IfcCircleHelper)

class IfcEllipseHelper extends IfcConicHelper {
    constructor(instance) {
        super(instance)
    }

    getPoints() {
        if (this.points === null) {
            this.points = []
            const ellipse = this.instance
            const matrix = ellipse.Position.helper.getMatrix()
            const semiAxis1 = ellipse.SemiAxis1
            const semiAxis2 = ellipse.SemiAxis2
            const maxAxis = Math.max(semiAxis1, semiAxis2)
            const segments = ellipse._loader.getCircleSegments(maxAxis)
            const angleStep = (2 * Math.PI) / segments
            for (let i = 0; i < segments; i++) {
                let angle = i * angleStep
                let point = new THREE.Vector3()
                point.x = Math.cos(angle) * semiAxis1
                point.y = Math.sin(angle) * semiAxis2
                point.z = 0
                point.applyMatrix4(matrix)
                this.points.push(point)
            }
        }
        return this.points
    }

    getTrimmedPoints(param1, param2, sense) {
        let points = []
        const ellipse = this.instance
        const matrix = ellipse.Position.helper.getMatrix()
        const semiAxis1 = ellipse.SemiAxis1
        const semiAxis2 = ellipse.SemiAxis2
        const maxAxis = Math.max(semiAxis1, semiAxis2)
        const startAngle = THREE.MathUtils.degToRad(param1)
        const endAngle = THREE.MathUtils.degToRad(param2)
        const segments = ellipse._loader.getCircleSegments(maxAxis)

        const addPoint = angle => {
            let point = new THREE.Vector3()
            point.x = Math.cos(angle) * semiAxis1
            point.y = Math.sin(angle) * semiAxis2
            point.z = 0
            point.applyMatrix4(matrix)
            points.push(point)
        }

        this.generatePoints(startAngle, endAngle, sense, segments, addPoint)

        return points
    }
}
registerIfcHelperClass(IfcEllipseHelper)

/* Geometry helpers */

class IfcConnectedFaceSetHelper extends IfcHelper {
    constructor(instance) {
        super(instance)
        this.object3D = null
    }

    getObject3D() {
        if (this.object3D === null) {
            const faceSet = this.instance
            const schema = this.instance.constructor.schema

            let faces = faceSet.CfsFaces

            let geometry = new SolidGeometry()

            for (let f = 0; f < faces.length; f++) {
                let face = faces[f] // IfcFace
                let bounds = face.Bounds // IfcFaceBound[...]

                let faceVertices = null
                let holes = []
                for (let b = 0; b < bounds.length; b++) {
                    let bound = bounds[b] // IfcFaceBound
                    let loop = bound.Bound // IfcLoop:
                    // (IfcPolyLoop, IfcEdgeLoop, IfcVertexLoop)
                    let loopVertices = loop.helper.getPoints()
                    let loopOrientation = bound.Orientation
                    if (loopOrientation === '.F.') {
                        // reverse loop sense
                        loopVertices = loopVertices.slice().reverse()
                    }
                    if (bound instanceof schema.IfcFaceOuterBound) {
                        faceVertices = loopVertices
                    } else {
                        holes.push(loopVertices)
                    }
                }

                if (faceVertices && faceVertices.length >= 3) {
                    let face = geometry.addFace(...faceVertices)
                    for (let holeVertices of holes) {
                        if (holeVertices.length >= 3) face.addHole(...holeVertices)
                    }
                }
            }
            let solid = new Solid()
            solid.updateGeometry(geometry, true)
            this.object3D = solid
            this.object3D._ifc = faceSet
        }
        return this.object3D
    }
}
registerIfcHelperClass(IfcConnectedFaceSetHelper)

class IfcPolyLoopHelper extends IfcHelper {
    constructor(instance) {
        super(instance)
        this.points = null
    }

    getPoints() {
        if (this.points === null) {
            const loop = this.instance
            const polygon = loop.Polygon

            this.points = []
            for (let i = 0; i < polygon.length; i++) {
                let point = polygon[i].helper.getPoint()
                this.points.push(point)
            }
        }
        return this.points
    }
}
registerIfcHelperClass(IfcPolyLoopHelper)

class IfcEdgeLoopHelper extends IfcHelper {
    constructor(instance) {
        super(instance)
        this.points = null
    }

    getPoints() {
        if (this.points === null) {
            const edges = this.instance.EdgeList // IfcOrientedEdge[]

            this.points = []
            for (let i = 0; i < edges.length; i++) {
                let edge = edges[i]
                let point = edge.Orientation === '.T.' ? edge.EdgeElement.EdgeStart.VertexGeometry.helper.getPoint() : edge.EdgeElement.EdgeEnd.VertexGeometry.helper.getPoint()
                this.points.push(point)
            }
        }
        return this.points
    }
}
registerIfcHelperClass(IfcEdgeLoopHelper)

class IfcVertexLoopHelper extends IfcHelper {
    constructor(instance) {
        super(instance)
        this.points = null
    }

    getPoints() {
        if (this.points === null) {
            const vertex = this.instance.LoopVertex // IfcVertexPoint
            const point = vertex.VertexGeometry.helper.getPoint()
            this.points = [point]
        }
        return this.points
    }
}
registerIfcHelperClass(IfcVertexLoopHelper)

class IfcCartesianPointList2DHelper extends IfcHelper {
    constructor(instance) {
        super(instance)
        this.points = null
    }

    getPoints() {
        if (this.points === null) {
            var list = this.instance

            this.points = []
            for (var i = 0; i < list.CoordList.length; i++) {
                var coord = list.CoordList[i]
                var point = new THREE.Vector3()
                point.x = coord[0]
                point.y = coord[1]
                this.points.push(point)
            }
        }
        return this.points
    }
}
registerIfcHelperClass(IfcCartesianPointList2DHelper)

class IfcCartesianPointList3DHelper extends IfcHelper {
    constructor(instance) {
        super(instance)
        this.points = null
    }

    getPoints() {
        if (this.points === null) {
            var list = this.instance

            this.points = []
            for (var i = 0; i < list.CoordList.length; i++) {
                var coord = list.CoordList[i]
                var point = new THREE.Vector3()
                point.x = coord[0]
                point.y = coord[1]
                point.z = coord[2]
                this.points.push(point)
            }
        }
        return this.points
    }
}
registerIfcHelperClass(IfcCartesianPointList3DHelper)

/* Matrix helpers */

class IfcLocalPlacementHelper extends IfcHelper {
    constructor(instance) {
        super(instance)
        this.matrix = null // relative matrix
        this.matrixWorld = null // matrixWorld
    }

    getMatrix() {
        if (this.matrix === null) {
            var placement = this.instance
            var relativePlacement = placement.RelativePlacement
            this.matrix = relativePlacement ? relativePlacement.helper.getMatrix() : new THREE.Matrix4()
        }
        return this.matrix
    }

    getMatrixWorld() {
        if (this.matrixWorld === null) {
            const placement = this.instance
            const schema = this.instance.constructor.schema

            var placementRelTo = placement.PlacementRelTo
            if (placementRelTo instanceof schema.IfcLocalPlacement) {
                this.matrixWorld = placementRelTo.helper.getMatrixWorld().clone()
                this.matrixWorld.multiply(this.getMatrix())
            } else this.matrixWorld = this.getMatrix()
        }
        return this.matrixWorld
    }
}
registerIfcHelperClass(IfcLocalPlacementHelper)

class IfcCartesianTransformationOperatorHelper extends IfcHelper {
    constructor(instance) {
        super(instance)
        this.matrix = null
    }

    getMatrix() {
        // TODO: process all parameters
        if (this.matrix === null) {
            var operator = this.instance

            this.matrix = new THREE.Matrix4()
            var origin = operator.LocalOrigin
            if (origin) {
                var point = origin.helper.getPoint()
                this.matrix.makeTranslation(point.x, point.y, point.z)
            }
        }
        return this.matrix
    }
}
registerIfcHelperClass(IfcCartesianTransformationOperatorHelper)

class IfcPlacementHelper extends IfcHelper {
    constructor(instance) {
        super(instance)
        this.matrix = null
        this.location = null
    }

    getLocation() {
        if (this.location === null) {
            var placement = this.instance
            var loc = placement.Location
            this.location = loc ? loc.helper.getPoint() : new THREE.Vector3(0, 0, 0)
        }
        return this.location
    }

    getMatrix() {
        if (this.matrix === null) {
            var placement = this.instance
            this.matrix = new THREE.Matrix4()
            this.matrix.setPosition(this.getLocation())
        }
        return this.matrix
    }
}
registerIfcHelperClass(IfcPlacementHelper)

class IfcAxis1PlacementHelper extends IfcPlacementHelper {
    constructor(instance) {
        super(instance)
        this.axis = null
    }

    getAxis() {
        if (this.axis === null) {
            var placement = this.instance
            var axis = placement.Axis
            this.axis = axis ? axis.helper.getDirection() : new THREE.Vector3(0, 0, 1)
        }
        return this.axis
    }

    getMatrix() {
        if (this.matrix === null) {
            var placement = this.instance

            var loc = this.getLocation()
            var vz = this.getAxis()
            var vy = GeometryUtils.orthogonalVector(vz)
            var vx = new THREE.Vector3()
            vx.crossVectors(vy, vz)

            this.matrix = new THREE.Matrix4()
            this.matrix.set(vx.x, vy.x, vz.x, loc.x, vx.y, vy.y, vz.y, loc.y, vx.z, vy.z, vz.z, loc.z, 0, 0, 0, 1)
        }
        return this.matrix
    }
}
registerIfcHelperClass(IfcAxis1PlacementHelper)

class IfcAxis2Placement2DHelper extends IfcPlacementHelper {
    constructor(instance) {
        super(instance)
        this.refDirection = null
    }

    getRefDirection() {
        if (this.refDirection === null) {
            var placement = this.instance
            var refd = placement.RefDirection
            this.refDirection = refd ? refd.helper.getDirection() : new THREE.Vector3(1, 0, 0)
        }
        return this.refDirection
    }

    getMatrix() {
        if (this.matrix === null) {
            var loc = this.getLocation()
            var vx = this.getRefDirection()
            var vz = new THREE.Vector3(0, 0, 1)
            var vy = new THREE.Vector3()
            vy.crossVectors(vz, vx)

            this.matrix = new THREE.Matrix4()
            this.matrix.set(vx.x, vy.x, vz.x, loc.x, vx.y, vy.y, vz.y, loc.y, vx.z, vy.z, vz.z, loc.z, 0, 0, 0, 1)
        }
        return this.matrix
    }
}
registerIfcHelperClass(IfcAxis2Placement2DHelper)

class IfcAxis2Placement3DHelper extends IfcPlacementHelper {
    constructor(instance) {
        super(instance)
        this.axis = null
        this.refDirection = null
    }

    getAxis() {
        if (this.axis === null) {
            var placement = this.instance
            var axis = placement.Axis
            this.axis = axis ? axis.helper.getDirection() : new THREE.Vector3(0, 0, 1)
        }
        return this.axis
    }

    getRefDirection() {
        if (this.refDirection === null) {
            var placement = this.instance
            var refd = placement.RefDirection
            this.refDirection = refd ? refd.helper.getDirection() : new THREE.Vector3(1, 0, 0)
        }
        return this.refDirection
    }

    getMatrix() {
        if (this.matrix === null) {
            var loc = this.getLocation()
            var vz = this.getAxis()
            var vx = this.getRefDirection()
            var vy = new THREE.Vector3()
            vy.crossVectors(vz, vx)

            this.matrix = new THREE.Matrix4()
            this.matrix.set(vx.x, vy.x, vz.x, loc.x, vx.y, vy.y, vz.y, loc.y, vx.z, vy.z, vz.z, loc.z, 0, 0, 0, 1)
        }
        return this.matrix
    }
}
registerIfcHelperClass(IfcAxis2Placement3DHelper)

/* Relationship helpers */

class IfcRelationshipHelper extends IfcHelper {
    constructor(instance) {
        super(instance)
    }

    relate() {}
}
registerIfcHelperClass(IfcRelationshipHelper)

class IfcRelDefinesByTypeHelper extends IfcRelationshipHelper {
    constructor(instance) {
        super(instance)
    }

    relate() {
        const rel = this.instance
        const schema = this.instance.constructor.schema

        let objects = rel.RelatedObjects
        let ifcType = rel.RelatingType
        const typeData = { ifcClassName: ifcType.constructor.name }

        for (let key in ifcType) {
            let value = ifcType[key]
            let valueType = typeof value
            if (valueType === 'string' || valueType === 'number' || valueType === 'boolean') {
                typeData[key] = value
            }
        }

        for (let i = 0; i < objects.length; i++) {
            if (objects[i].helper.getObject3D) {
                let object3D = objects[i].helper.getObject3D()
                object3D.userData['IFC_type'] = typeData
            }
        }
    }
}
registerIfcHelperClass(IfcRelDefinesByTypeHelper)

class IfcRelAssociatesClassificationHelper extends IfcRelationshipHelper {
    constructor(instance) {
        super(instance)
    }

    relate() {
        const rel = this.instance
        const schema = this.instance.constructor.schema

        var ifcObjects = rel.RelatedObjects
        var ifcClassifRef = rel.RelatingClassification
        if (ifcClassifRef instanceof schema.IfcClassificationReference) {
            for (var i = 0; i < ifcObjects.length; i++) {
                var ifcObject = ifcObjects[i]
                if (ifcObject.helper && ifcObject.helper.getObject3D) {
                    let object3D = ifcObject.helper.getObject3D()

                    let ifcClassification = ifcClassifRef.ReferencedSource || {}
                    let classifName = 'Unnamed'
                    if (ifcClassification.Name) {
                        classifName = ifcClassification.Name
                        if (ifcClassification.Edition) {
                            classifName += '_' + ifcClassification.Edition
                        }
                    }
                    let classifData = {}

                    object3D.userData['IFC_classification_' + classifName] = classifData

                    for (let key in ifcClassifRef) {
                        let value = ifcClassifRef[key]
                        let valueType = typeof value
                        if (valueType === 'string' || valueType === 'number' || valueType === 'boolean') {
                            classifData[key] = value
                        }
                    }
                }
            }
        }
    }
}
registerIfcHelperClass(IfcRelAssociatesClassificationHelper)

class IfcRelAssignsToGroupHelper extends IfcRelationshipHelper {
    constructor(instance) {
        super(instance)
    }

    relate() {
        const rel = this.instance
        const schema = this.instance.constructor.schema

        var ifcObjects = rel.RelatedObjects
        var ifcObjectsType = rel.RelatedObjectsType
        var ifcGroup = rel.RelatingGroup
        let groupData = { ifcClassName: ifcGroup.constructor.name }

        for (let key in ifcGroup) {
            let value = ifcGroup[key]
            let valueType = typeof value
            if (valueType === 'string' || valueType === 'number' || valueType === 'boolean') {
                groupData[key] = value
            }
        }

        let groupName = ifcGroup.Name || ifcGroup.GlobalId
        groupName = ifcGroup.constructor.name + '_' + groupName

        for (let i = 0; i < ifcObjects.length; i++) {
            let ifcObject = ifcObjects[i]
            if (ifcObject.helper && ifcObject.helper.getObject3D) {
                let object3D = ifcObject.helper.getObject3D()
                object3D.userData['IFC_group_' + groupName] = groupData
            }
        }
    }
}
registerIfcHelperClass(IfcRelAssignsToGroupHelper)

class IfcRelAggregatesHelper extends IfcRelationshipHelper {
    constructor(instance) {
        super(instance)
    }

    relate() {
        const rel = this.instance
        const schema = this.instance.constructor.schema

        var ifcObject = rel.RelatingObject
        if (ifcObject instanceof schema.IfcProduct) {
            var containerObject3D = ifcObject.helper.getObject3D()
            if (containerObject3D) {
                for (var i = 0; i < rel.RelatedObjects.length; i++) {
                    var ifcRelatedObject = rel.RelatedObjects[i]
                    if (ifcRelatedObject instanceof schema.IfcProduct) {
                        var object3D = ifcRelatedObject.helper.getObject3D()
                        if (object3D) {
                            if (object3D.parent !== containerObject3D) {
                                containerObject3D.attach(object3D)
                            }
                        }
                    }
                }
            }
        }
    }
}
registerIfcHelperClass(IfcRelAggregatesHelper)

class IfcRelContainedInSpatialStructureHelper extends IfcRelationshipHelper {
    constructor(instance) {
        super(instance)
    }

    relate() {
        const rel = this.instance
        const schema = this.instance.constructor.schema

        var ifcProduct = rel.RelatingStructure
        if (ifcProduct) {
            var containerObject3D = ifcProduct.helper.getObject3D()
            if (containerObject3D) {
                for (var i = 0; i < rel.RelatedElements.length; i++) {
                    var ifcRelatedProduct = rel.RelatedElements[i]
                    if (ifcRelatedProduct instanceof schema.IfcProduct) {
                        var object3D = ifcRelatedProduct.helper.getObject3D()
                        if (object3D) {
                            if (object3D.parent !== containerObject3D) {
                                var parentIFC = object3D.parent.userData.IFC || {}
                                if (parentIFC.ifcClassName === 'IfcOpeningElement') {
                                    // do not change hierarchy
                                } else {
                                    containerObject3D.attach(object3D)
                                }
                            }
                        }
                    }
                }
            }
        }
    }
}
registerIfcHelperClass(IfcRelContainedInSpatialStructureHelper)

class IfcRelVoidsElementHelper extends IfcRelationshipHelper {
    constructor(instance) {
        super(instance)
    }

    relate() {
        var rel = this.instance
        var element = rel.RelatingBuildingElement
        var opening = rel.RelatedOpeningElement
        if (element && opening) {
            var object3D = element.helper.getObject3D()
            if (object3D) {
                var openingObject3D = opening.helper.getObject3D()
                if (openingObject3D) {
                    if (object3D !== openingObject3D.parent) {
                        object3D.attach(openingObject3D)
                    }
                }
            }
        }
    }
}
registerIfcHelperClass(IfcRelVoidsElementHelper)

class IfcRelFillsElementHelper extends IfcRelationshipHelper {
    constructor(instance) {
        super(instance)
    }

    relate() {
        var rel = this.instance
        var opening = rel.RelatingOpeningElement
        var element = rel.RelatedBuildingElement
        if (element && opening) {
            var object3D = element.helper.getObject3D()
            if (object3D) {
                var openingObject3D = opening.helper.getObject3D()
                if (openingObject3D) {
                    if (object3D.parent !== openingObject3D) {
                        openingObject3D.attach(object3D)
                    }
                }
            }
        }
    }
}
registerIfcHelperClass(IfcRelFillsElementHelper)

class IfcRelConnectsPortToElementHelper extends IfcRelationshipHelper {
    constructor(instance) {
        super(instance)
    }

    relate() {
        var rel = this.instance
        var port = rel.RelatingPort
        var element = rel.RelatedElement
        if (port && element) {
            var object3D = element.helper.getObject3D()
            if (object3D) {
                var portObject3D = port.helper.getObject3D()
                if (portObject3D) {
                    if (object3D !== portObject3D.parent) {
                        object3D.attach(portObject3D)
                    }
                }
            }
        }
    }
}
registerIfcHelperClass(IfcRelConnectsPortToElementHelper)

class IfcRelDefinesByPropertiesHelper extends IfcRelationshipHelper {
    constructor(instance) {
        super(instance)
    }

    relate() {
        const rel = this.instance
        const schema = this.instance.constructor.schema

        var propertySet = rel.RelatingPropertyDefinition
        if (propertySet instanceof schema.IfcPropertySet) {
            var psetName = propertySet.Name
            var properties = propertySet.helper.getProperties()
            var relatedObjects = rel.RelatedObjects
            for (var i = 0; i < relatedObjects.length; i++) {
                var relatedObject = relatedObjects[i]
                if (relatedObject instanceof schema.IfcProduct) {
                    var object3D = relatedObject.helper.getObject3D()
                    if (object3D) {
                        object3D.userData['IFC_' + psetName] = properties
                    }
                }
            }
        }
    }
}
registerIfcHelperClass(IfcRelDefinesByPropertiesHelper)

/* Other helpers */

class IfcPointHelper extends IfcHelper {
    constructor(instance) {
        super(instance)
        this.point = null
    }

    getPoint() {
        if (this.point === null) {
            this.point = new THREE.Vector3()
        }
        return this.point
    }
}
registerIfcHelperClass(IfcPointHelper)

class IfcCartesianPointHelper extends IfcPointHelper {
    constructor(instance) {
        super(instance)
    }

    getPoint() {
        if (this.point === null) {
            var point = this.instance

            this.point = new THREE.Vector3()
            this.point.x = point.Coordinates[0]
            if (point.Coordinates.length > 1) {
                this.point.y = point.Coordinates[1]
                if (point.Coordinates.length > 2) {
                    this.point.z = point.Coordinates[2]
                }
            }
        }
        return this.point
    }
}
registerIfcHelperClass(IfcCartesianPointHelper)

class IfcDirectionHelper extends IfcHelper {
    constructor(instance) {
        super(instance)
        this.direction = null
    }

    getDirection() {
        if (this.direction === null) {
            var direction = this.instance

            this.direction = new THREE.Vector3()
            this.direction.x = direction.DirectionRatios[0]
            if (direction.DirectionRatios.length > 1) {
                this.direction.y = direction.DirectionRatios[1]
                if (direction.DirectionRatios.length > 2) {
                    this.direction.z = direction.DirectionRatios[2]
                }
            }
        }
        return this.direction
    }
}
registerIfcHelperClass(IfcDirectionHelper)

class IfcPresentationLayerAssignmentHelper extends IfcHelper {
    constructor(instance) {
        super(instance)
    }

    assign() {
        const assignment = this.instance
        const schema = this.instance.constructor.schema

        const layerName = assignment.Name
        const layerDescription = assignment.Description
        const assignedItems = assignment.AssignedItems
        const identifier = assignment.Identifier

        for (let assignedItem of assignedItems) {
            if (assignedItem instanceof schema.IfcShapeRepresentation) {
                let items = assignedItem.Items
                for (let item of items) {
                    if (item.helper.getObject3D) {
                        try {
                            let object = item.helper.getObject3D()
                            if (object) {
                                object.userData.IFC_layer = {
                                    Name: layerName,
                                    Description: layerDescription,
                                    Identifier: identifier
                                }
                            }
                        } catch (ex) {
                            console.info(ex)
                            console.info(item.helper)
                        }
                    }
                }
            }
        }
    }
}
registerIfcHelperClass(IfcPresentationLayerAssignmentHelper)

class IfcStyledItemHelper extends IfcHelper {
    constructor(instance) {
        super(instance)
        this.properties = null
    }

    applyStyle() {
        const styledItem = this.instance
        const schema = this.instance.constructor.schema

        var item = styledItem.Item // item to apply style
        var styles = styledItem.Styles // style to apply
        if (item === null || styles === null) return

        var style = styles[0] // apply only first style
        if (style instanceof schema.IfcPresentationStyleAssignment) {
            style = style.Styles[0]
        }
        if (style instanceof schema.IfcSurfaceStyle) {
            const material = style.helper.getMaterial()
            if (item.helper && material) {
                item.helper.material = material
            }
        }
    }
}
registerIfcHelperClass(IfcStyledItemHelper)

class IfcSurfaceStyleHelper extends IfcHelper {
    constructor(instance) {
        super(instance)
        this.material = null
    }

    getMaterial() {
        if (this.material === null) {
            const style = this.instance
            const schema = this.instance.constructor.schema

            const name = style.Name
            const side = style.Side
            const styleItem = style.Styles[0] // consider only first style item
            if (styleItem instanceof schema.IfcSurfaceStyleShading) {
                const color = styleItem.SurfaceColour
                const transparency = styleItem.Transparency
                const red = color.Red
                const green = color.Green
                const blue = color.Blue

                let transparent = transparency > 0
                let opacity = 1 - transparency

                this.material = new THREE.MeshPhongMaterial({
                    name: name,
                    color: new THREE.Color(red, green, blue),
                    flatShading: false,
                    opacity: opacity,
                    transparent: transparent,
                    side: side === '.BOTH.' ? THREE.DoubleSide : THREE.FrontSide
                })
            }
        }
        return this.material
    }
}
registerIfcHelperClass(IfcSurfaceStyleHelper)

class IfcPropertySetHelper extends IfcHelper {
    constructor(instance) {
        super(instance)
        this.properties = null
    }

    getProperties() {
        if (this.properties === null) {
            const pset = this.instance
            const schema = this.instance.constructor.schema
            const loader = pset._loader

            this.properties = {}
            for (var i = 0; i < pset.HasProperties.length; i++) {
                var prop = pset.HasProperties[i]
                if (prop instanceof schema.IfcPropertySingleValue) {
                    var name = loader.unBox(prop.Name)
                    var value = loader.unBox(prop.NominalValue)
                    if (value === '.T.') {
                        value = true
                    } else if (value === '.F.') {
                        value = false
                    }
                    this.properties[name] = value
                }
            }
        }
        return this.properties
    }
}
registerIfcHelperClass(IfcPropertySetHelper)

export { IFCLoader }