MapComplete/UI/ShowDataLayer/ShowDataLayer.ts

import {UIEventSource} from "../../Logic/UIEventSource";
import LayerConfig from "../../Models/ThemeConfig/LayerConfig";
import {ShowDataLayerOptions} from "./ShowDataLayerOptions";
import {ElementStorage} from "../../Logic/ElementStorage";
import RenderingMultiPlexerFeatureSource from "../../Logic/FeatureSource/Sources/RenderingMultiPlexerFeatureSource";
import ScrollableFullScreen from "../Base/ScrollableFullScreen";
/*
// import 'leaflet-polylineoffset'; 
We don't actually import it here. It is imported in the 'MinimapImplementation'-class, which'll result in a patched 'L' object.
 Even though actually importing this here would seem cleaner, we don't do this as this breaks some scripts:
 - Scripts are ran in ts-node
 - ts-node doesn't define the 'window'-object
 - Importing this will execute some code which needs the window object

 */

/**
 * The data layer shows all the given geojson elements with the appropriate icon etc
 */
export default class ShowDataLayer {

    private static dataLayerIds = 0
    private readonly _leafletMap: UIEventSource<L.Map>;
    private readonly _enablePopups: boolean;
    private readonly _features: RenderingMultiPlexerFeatureSource
    private readonly _layerToShow: LayerConfig;
    private readonly _selectedElement: UIEventSource<any>
    private readonly allElements: ElementStorage
    // Used to generate a fresh ID when needed
    private _cleanCount = 0;
    private geoLayer = undefined;

    /**
     * A collection of functions to call when the current geolayer is unregistered
     */
    private unregister: (() => void)[] = [];
    private isDirty = false;
    /**
     * If the selected element triggers, this is used to lookup the correct layer and to open the popup
     * Used to avoid a lot of callbacks on the selected element
     *
     * Note: the key of this dictionary is 'feature.properties.id+features.geometry.type' as one feature might have multiple presentations
     * @private
     */
    private readonly leafletLayersPerId = new Map<string, { feature: any, leafletlayer: any }>()
    private readonly showDataLayerid: number;
    private readonly createPopup: (tags: UIEventSource<any>, layer: LayerConfig) => ScrollableFullScreen

    /**
     * Creates a datalayer.
     * 
     * If 'createPopup' is set, this function is called every time that 'popupOpen' is called
     * @param options
     */
    constructor(options: ShowDataLayerOptions & { layerToShow: LayerConfig }) {
        this._leafletMap = options.leafletMap;
        this.showDataLayerid = ShowDataLayer.dataLayerIds;
        ShowDataLayer.dataLayerIds++
        if (options.features === undefined) {
            console.error("Invalid ShowDataLayer invocation: options.features is undefed")
            throw "Invalid ShowDataLayer invocation: options.features is undefed"
        }
        this._features = new RenderingMultiPlexerFeatureSource(options.features, options.layerToShow);
        this._layerToShow = options.layerToShow;
        this._selectedElement = options.selectedElement
        this.allElements = options.state?.allElements;
        this.createPopup = undefined;
        this._enablePopups = options.popup !== undefined;
        if (options.popup !== undefined) {
            this.createPopup = options.popup
        }
        const self = this;

        options.leafletMap.addCallback(_ => {
                return self.update(options)
            }
        );

        this._features.features.addCallback(_ => self.update(options));
        options.doShowLayer?.addCallback(doShow => {
            const mp = options.leafletMap.data;
            if (mp === null) {
                self.Destroy()
                return true;
            }
            if (mp == undefined) {
                return;
            }

            if (doShow) {
                if (self.isDirty) {
                    return self.update(options)
                } else {
                    mp.addLayer(this.geoLayer)
                }
            } else {
                if (this.geoLayer !== undefined) {
                    mp.removeLayer(this.geoLayer)
                    this.unregister.forEach(f => f())
                    this.unregister = []
                }
            }

        })


        this._selectedElement?.addCallbackAndRunD(selected => {
            self.openPopupOfSelectedElement(selected)
        })

        this.update(options)

    }

    private Destroy() {
        this.unregister.forEach(f => f())
    }

    private openPopupOfSelectedElement(selected) {
        if (selected === undefined) {
            return
        }
        if (this._leafletMap.data === undefined) {
            return;
        }
        const v = this.leafletLayersPerId.get(selected.properties.id + selected.geometry.type)
        if (v === undefined) {
            return;
        }
        const leafletLayer = v.leafletlayer
        const feature = v.feature
        if (leafletLayer.getPopup().isOpen()) {
            return;
        }
        if (selected.properties.id !== feature.properties.id) {
            return;
        }

        if (feature.id !== feature.properties.id) {
            // Probably a feature which has renamed
            // the feature might have as id 'node/-1' and as 'feature.properties.id' = 'the newly assigned id'. That is no good too
            console.log("Not opening the popup for", feature, "as probably renamed")
            return;
        }
        if (selected.geometry.type === feature.geometry.type  // If a feature is rendered both as way and as point, opening one popup might trigger the other to open, which might trigger the one to open again
        ) {
            leafletLayer.openPopup()
        }
    }

    private update(options: ShowDataLayerOptions): boolean {
        if (this._features.features.data === undefined) {
            return;
        }
        this.isDirty = true;
        if (options?.doShowLayer?.data === false) {
            return;
        }
        const mp = options.leafletMap.data;

        if (mp === null) {
            return true; // Unregister as the map has been destroyed
        }
        if (mp === undefined) {
            return;
        }

        this._cleanCount++
        // clean all the old stuff away, if any
        if (this.geoLayer !== undefined) {
            mp.removeLayer(this.geoLayer);
        }

        const self = this;
        const data = {
            type: "FeatureCollection",
            features: []
        }
        // @ts-ignore
        this.geoLayer = L.geoJSON(data, {
            style: feature => self.createStyleFor(feature),
            pointToLayer: (feature, latLng) => self.pointToLayer(feature, latLng),
            onEachFeature: (feature, leafletLayer) => self.postProcessFeature(feature, leafletLayer)
        });

        const selfLayer = this.geoLayer;
        const allFeats = this._features.features.data;
        for (const feat of allFeats) {
            if (feat === undefined) {
                continue
            }
            try {
                if (feat.geometry.type === "LineString") {
                    const coords = L.GeoJSON.coordsToLatLngs(feat.geometry.coordinates)
                    const tagsSource = this.allElements?.addOrGetElement(feat) ?? new UIEventSource<any>(feat.properties);
                    let offsettedLine;
                    tagsSource
                        .map(tags => this._layerToShow.lineRendering[feat.lineRenderingIndex].GenerateLeafletStyle(tags), [], undefined, true)
                        .withEqualityStabilized((a, b) => {
                            if (a === b) {
                                return true
                            }
                            if (a === undefined || b === undefined) {
                                return false
                            }
                            return a.offset === b.offset && a.color === b.color && a.weight === b.weight && a.dashArray === b.dashArray
                        })
                        .addCallbackAndRunD(lineStyle => {
                            if (offsettedLine !== undefined) {
                                self.geoLayer.removeLayer(offsettedLine)
                            }
                            // @ts-ignore
                            offsettedLine = L.polyline(coords, lineStyle);
                            this.postProcessFeature(feat, offsettedLine)
                            offsettedLine.addTo(this.geoLayer)

                            // If 'self.geoLayer' is not the same as the layer the feature is added to, we can safely remove this callback
                            return self.geoLayer !== selfLayer
                        })
                } else {
                    this.geoLayer.addData(feat);
                }
            } catch (e) {
                console.error("Could not add ", feat, "to the geojson layer in leaflet due to", e, e.stack)
            }
        }

        if (options.zoomToFeatures ?? false) {
            if (this.geoLayer.getLayers().length > 0) {
                try {
                    const bounds = this.geoLayer.getBounds()
                    mp.fitBounds(bounds, {animate: false})
                } catch (e) {
                    console.debug("Invalid bounds", e)
                }
            }
        }

        if (options.doShowLayer?.data ?? true) {
            mp.addLayer(this.geoLayer)
        }
        this.isDirty = false;
        this.openPopupOfSelectedElement(this._selectedElement?.data)
    }


    private createStyleFor(feature) {
        const tagsSource = this.allElements?.addOrGetElement(feature) ?? new UIEventSource<any>(feature.properties);
        // Every object is tied to exactly one layer
        const layer = this._layerToShow

        const pointRenderingIndex = feature.pointRenderingIndex
        const lineRenderingIndex = feature.lineRenderingIndex

        if (pointRenderingIndex !== undefined) {
            const style = layer.mapRendering[pointRenderingIndex].GenerateLeafletStyle(tagsSource, this._enablePopups)
            return {
                icon: style
            }
        }
        if (lineRenderingIndex !== undefined) {
            return layer.lineRendering[lineRenderingIndex].GenerateLeafletStyle(tagsSource.data)
        }

        throw "Neither lineRendering nor mapRendering defined for " + feature
    }

    private pointToLayer(feature, latLng): L.Layer {
        // Leaflet cannot handle geojson points natively
        // We have to convert them to the appropriate icon
        // Click handling is done in the next step

        const layer: LayerConfig = this._layerToShow
        if (layer === undefined) {
            return;
        }
        let tagSource = this.allElements?.getEventSourceById(feature.properties.id) ?? new UIEventSource<any>(feature.properties)
        const clickable = !(layer.title === undefined && (layer.tagRenderings ?? []).length === 0) && this._enablePopups
        let style: any = layer.mapRendering[feature.pointRenderingIndex].GenerateLeafletStyle(tagSource, clickable);
        const baseElement = style.html;
        if (!this._enablePopups) {
            baseElement.SetStyle("cursor: initial !important")
        }
        style.html = style.html.ConstructElement()
        return L.marker(latLng, {
            icon: L.divIcon(style)
        });
    }

    /**
     * Post processing - basically adding the popup
     * @param feature
     * @param leafletLayer
     * @private
     */
    private postProcessFeature(feature, leafletLayer: L.Layer) {
        const layer: LayerConfig = this._layerToShow
        if (layer.title === undefined || !this._enablePopups) {
            // No popup action defined -> Don't do anything
            // or probably a map in the popup - no popups needed!
            return;
        }

        const popup = L.popup({
            autoPan: true,
            closeOnEscapeKey: true,
            closeButton: false,
            autoPanPaddingTopLeft: [15, 15],

        }, leafletLayer);

        leafletLayer.bindPopup(popup);

        let infobox: ScrollableFullScreen = undefined;
        const id = `popup-${feature.properties.id}-${feature.geometry.type}-${this.showDataLayerid}-${this._cleanCount}-${feature.pointRenderingIndex ?? feature.lineRenderingIndex}-${feature.multiLineStringIndex ?? ""}`
        popup.setContent(`<div style='height: 65vh' id='${id}'>Popup for ${feature.properties.id} ${feature.geometry.type} ${id} is loading</div>`)
        const createpopup = this.createPopup;
        leafletLayer.on("popupopen", () => {
            if (infobox === undefined) {
                const tags = this.allElements?.getEventSourceById(feature.properties.id) ?? new UIEventSource<any>(feature.properties);
                infobox = createpopup(tags, layer);

                infobox.isShown.addCallback(isShown => {
                    if (!isShown) {
                        leafletLayer.closePopup()
                    }
                });
            }
            infobox.AttachTo(id)
            infobox.Activate();
            this.unregister.push(() => {
                console.log("Destroying infobox")
                infobox.Destroy();
            })
            if (this._selectedElement?.data?.properties?.id !== feature.properties.id) {
                this._selectedElement?.setData(feature)
            }

        });


        // Add the feature to the index to open the popup when needed
        this.leafletLayersPerId.set(feature.properties.id + feature.geometry.type, {
            feature: feature,
            leafletlayer: leafletLayer
        })

    }

}