# src/toolbar/SectionTool.js

    import {Controller} from "../Controller.js";
    import {SectionToolContextMenu} from "./../contextMenus/SectionToolContextMenu.js";
    import {math, SectionPlanesPlugin} from "@xeokit/xeokit-sdk/dist/xeokit-sdk.es.js";

    /** @private */
    class SectionTool extends Controller { // XX

        constructor(parent, cfg) {

            super(parent, cfg);

            if (!cfg.buttonElement) {
                throw "Missing config: buttonElement";
            }

            if (!cfg.menuButtonElement) {
                throw "Missing config: menuButtonElement";
            }

            this._buttonElement = cfg.buttonElement;
            this._counterElement = cfg.counterElement;
            this._menuButtonElement = cfg.menuButtonElement;
            this._menuButtonArrowElement = cfg.menuButtonArrowElement;

            this._sectionPlanesPlugin = new SectionPlanesPlugin(this.viewer, {});

            this._sectionToolContextMenu = new SectionToolContextMenu({
                sectionPlanesPlugin: this._sectionPlanesPlugin,
                hideOnMouseDown: false,
                hideOnAction: false
            });

            this._sectionPlanesPlugin.setOverviewVisible(false);

            this.on("enabled", (enabled) => {
                if (!enabled) {
                    this._buttonElement.classList.add("disabled");
                    if (this._counterElement) {
                        this._counterElement.classList.add("disabled");
                    }
                    this._menuButtonElement.classList.add("disabled");
                    this._menuButtonArrowElement.classList.add("disabled");
                } else {
                    this._buttonElement.classList.remove("disabled");
                    if (this._counterElement) {
                        this._counterElement.classList.remove("disabled");
                    }
                    this._menuButtonElement.classList.remove("disabled");
                    this._menuButtonArrowElement.classList.remove("disabled");
                }
            });

            this.on("active", (active) => {
                if (active) {
                    this._buttonElement.classList.add("active");
                    if (this._counterElement) {
                        this._counterElement.classList.add("active");
                    }
                    this._menuButtonElement.classList.add("active");
                    this._menuButtonArrowElement.classList.add("active");
                } else {
                    this._buttonElement.classList.remove("active");
                    if (this._counterElement) {
                        this._counterElement.classList.remove("active");
                    }
                    this._menuButtonElement.classList.remove("active");
                    this._menuButtonArrowElement.classList.remove("active");
                }
            });

            this.on("active", (active) => {
                if (!active) {
                    this._sectionPlanesPlugin.hideControl();
                }
            });

            this._buttonElement.addEventListener("click", (e) => {
                if (!this.getEnabled()) {
                    return;
                }
                if (e.target === this._menuButtonElement || e.target.parentNode === this._menuButtonElement) {
                    return;
                }
                const active = this.getActive();
                this.setActive(!active);
                e.preventDefault();
            });

            document.addEventListener("mousedown", (e) => {

                if (e.target.classList.contains("xeokit-context-menu-item")) {
                    // Allow click on menu item
                    return;
                }

                if (e.target === this._menuButtonElement || e.target.parentNode === this._menuButtonElement) {
                    e.preventDefault();
                    if (this._sectionToolContextMenu.shown) {
                        this._sectionToolContextMenu.hide();
                    } else {
                        this._sectionToolContextMenu.context = {
                            bimViewer: this.bimViewer,
                            viewer: this.viewer,
                            sectionTool: this
                        };

                        const rect = this._menuButtonElement.getBoundingClientRect();

                        this._sectionToolContextMenu.show(rect.left, rect.bottom + 5);
                    }
                } else {
                    this._sectionToolContextMenu.hide();
                }
            });

            this._sectionToolContextMenu.on("shown", () => {
                this._menuButtonArrowElement.classList.remove("xeokit-arrow-down");
                this._menuButtonArrowElement.classList.add("xeokit-arrow-up");
            });

            this._sectionToolContextMenu.on("hidden", () => {
                this._menuButtonArrowElement.classList.remove("xeokit-arrow-up");
                this._menuButtonArrowElement.classList.add("xeokit-arrow-down");
            });

            this.bimViewer.on("reset", () => {
                this.clear();
                this.setActive(false);
            });

            this.viewer.scene.on("sectionPlaneCreated", () => {
                this._updateSectionPlanesCount();
            });

            this.viewer.scene.on("sectionPlaneDestroyed", () => {
                this._updateSectionPlanesCount();
            });

            this._initSectionMode();
        }

        _initSectionMode() {

            this.viewer.scene.input.on("mouseclicked", (coords) => {

                if (!this.getActive() || !this.getEnabled()) {
                    return;
                }

                const pickResult = this.viewer.scene.pick({
                    canvasPos: coords,
                    pickSurface: true  // <<------ This causes picking to find the intersection point on the entity
                });

                if (pickResult) {

                    const sectionPlane = this._sectionPlanesPlugin.createSectionPlane({
                        pos: pickResult.worldPos,
                        dir: math.mulVec3Scalar(pickResult.worldNormal, -1)
                    });

                    this._sectionPlanesPlugin.showControl(sectionPlane.id);
                }
            });

            this._updateSectionPlanesCount();
        }

        _updateSectionPlanesCount() {
            if (this._counterElement) {
                this._counterElement.innerText = ("" + this.getNumSections());
            }
        }

        getNumSections() {
            return Object.keys(this.viewer.scene.sectionPlanes).length;
        }

        clear() {
            this._sectionPlanesPlugin.clear();
            this._updateSectionPlanesCount();
        }

        flipSections() {
            this._sectionPlanesPlugin.flipSectionPlanes();
        }

        enableSections() {
            const sectionPlanes = this.viewer.scene.sectionPlanes;
            for (let id in sectionPlanes) {
                const sectionPlane = sectionPlanes[id];
                sectionPlane.active = true;
            }
        }

        disableSections() {
            const sectionPlanes = this.viewer.scene.sectionPlanes;
            for (let id in sectionPlanes) {
                const sectionPlane = sectionPlanes[id];
                sectionPlane.active = false;
            }
        }

        hideControl() {
            this._sectionPlanesPlugin.hideControl();
        }

        destroy() {
            this._sectionPlanesPlugin.destroy();
            this._sectionToolContextMenu.destroy();
            super.destroy();
        }
    }

    export {SectionTool};