mapcomplete/Logic/State/FeaturePipelineState.ts

import LayoutConfig from "../../Models/ThemeConfig/LayoutConfig";
import FeaturePipeline from "../FeatureSource/FeaturePipeline";
import {Tiles} from "../../Models/TileRange";
import ShowDataLayer from "../../UI/ShowDataLayer/ShowDataLayer";
import {TileHierarchyAggregator} from "../../UI/ShowDataLayer/TileHierarchyAggregator";
import ShowTileInfo from "../../UI/ShowDataLayer/ShowTileInfo";
import {UIEventSource} from "../UIEventSource";
import MapState from "./MapState";
import SelectedFeatureHandler from "../Actors/SelectedFeatureHandler";
import Hash from "../Web/Hash";
import {BBox} from "../BBox";

export default class FeaturePipelineState extends MapState {

    /**
     * The piece of code which fetches data from various sources and shows it on the background map
     */
    public readonly featurePipeline: FeaturePipeline;
    private readonly featureAggregator: TileHierarchyAggregator;

    constructor(layoutToUse: LayoutConfig) {
        super(layoutToUse);

        const clustering = layoutToUse.clustering
        this.featureAggregator = TileHierarchyAggregator.createHierarchy(this);
        const clusterCounter = this.featureAggregator
        const self = this;
        this.featurePipeline = new FeaturePipeline(
            source => {

                clusterCounter.addTile(source)

                const sourceBBox = source.features.map(allFeatures => BBox.bboxAroundAll(allFeatures.map(f => BBox.get(f.feature))))
                
                // Do show features indicates if the respective 'showDataLayer' should be shown. It can be hidden by e.g. clustering
                const doShowFeatures = source.features.map(
                    f => {
                        const z = self.locationControl.data.zoom

                        if (!source.layer.isDisplayed.data) {
                            return false;
                        }

                        const bounds = self.currentBounds.data
                        if (bounds === undefined) {
                            // Map is not yet displayed
                            return false;
                        }

                        if (!sourceBBox.data.overlapsWith(bounds)) {
                            // Not within range -> features are hidden
                            return false
                        }


                        if (z < source.layer.layerDef.minzoom) {
                            // Layer is always hidden for this zoom level
                            return false;
                        }

                        if (z > clustering.maxZoom) {
                            return true
                        }

                        if (f.length > clustering.minNeededElements) {
                            // This tile alone already has too much features
                            return false
                        }

                        let [tileZ, tileX, tileY] = Tiles.tile_from_index(source.tileIndex);
                        if (tileZ >= z) {

                            while (tileZ > z) {
                                tileZ--
                                tileX = Math.floor(tileX / 2)
                                tileY = Math.floor(tileY / 2)
                            }

                            if (clusterCounter.getTile(Tiles.tile_index(tileZ, tileX, tileY))?.totalValue > clustering.minNeededElements) {
                                // To much elements
                                return false
                            }
                        }


                        return true
                    }, [this.currentBounds, source.layer.isDisplayed, sourceBBox]
                )

                new ShowDataLayer(
                    {
                        features: source,
                        leafletMap: self.leafletMap,
                        layerToShow: source.layer.layerDef,
                        doShowLayer: doShowFeatures,
                        allElements: self.allElements,
                        selectedElement: self.selectedElement
                    }
                );
            }, this
        );
        new SelectedFeatureHandler(Hash.hash, this)

        this.AddClusteringToMap(this.leafletMap)

    }

    /**
     * Adds the cluster-tiles to the given map
     * @param leafletMap: a UIEventSource possible having a leaflet map
     * @constructor
     */
    public AddClusteringToMap(leafletMap: UIEventSource<any>) {
        const clustering = this.layoutToUse.clustering
        new ShowDataLayer({
            features: this.featureAggregator.getCountsForZoom(clustering, this.locationControl, clustering.minNeededElements),
            leafletMap: leafletMap,
            layerToShow: ShowTileInfo.styling,
            enablePopups: this.featureSwitchIsDebugging.data,
        })
    }


}