MapComplete/Logic/FeatureSource/TiledFeatureSource/DynamicGeoJsonTileSource.ts

import FilteredLayer from "../../../Models/FilteredLayer";
import {FeatureSourceForLayer, Tiled} from "../FeatureSource";
import {UIEventSource} from "../../UIEventSource";
import DynamicTileSource from "./DynamicTileSource";
import {Utils} from "../../../Utils";
import GeoJsonSource from "../Sources/GeoJsonSource";
import {BBox} from "../../BBox";

export default class DynamicGeoJsonTileSource extends DynamicTileSource {

    private static whitelistCache = new Map<string, any>()

    constructor(layer: FilteredLayer,
                registerLayer: (layer: FeatureSourceForLayer & Tiled) => void,
                state: {
                    locationControl?: UIEventSource<{zoom?: number}>
                    currentBounds: UIEventSource<BBox>
                }) {
        const source = layer.layerDef.source
        if (source.geojsonZoomLevel === undefined) {
            throw "Invalid layer: geojsonZoomLevel expected"
        }
        if (source.geojsonSource === undefined) {
            throw "Invalid layer: geojsonSource expected"
        }

        let whitelist = undefined
        if (source.geojsonSource.indexOf("{x}_{y}.geojson") > 0) {

            const whitelistUrl = source.geojsonSource
                .replace("{z}", "" + source.geojsonZoomLevel)
                .replace("{x}_{y}.geojson", "overview.json")
                .replace("{layer}", layer.layerDef.id)

            if (DynamicGeoJsonTileSource.whitelistCache.has(whitelistUrl)) {
                whitelist = DynamicGeoJsonTileSource.whitelistCache.get(whitelistUrl)
            } else {
                Utils.downloadJsonCached(whitelistUrl, 1000 * 60 * 60).then(
                    json => {
                        const data = new Map<number, Set<number>>();
                        for (const x in json) {
                            if (x === "zoom") {
                                continue
                            }
                            data.set(Number(x), new Set(json[x]))
                        }
                        console.log("The whitelist is", data, "based on ", json, "from", whitelistUrl)
                        whitelist = data
                        DynamicGeoJsonTileSource.whitelistCache.set(whitelistUrl, whitelist)
                    }
                ).catch(err => {
                    console.warn("No whitelist found for ", layer.layerDef.id, err)
                })
            }
        }

        const blackList = (new Set<string>())
        super(
            layer,
            source.geojsonZoomLevel,
            (zxy) => {
                if (whitelist !== undefined) {
                    const isWhiteListed = whitelist.get(zxy[1])?.has(zxy[2])
                    if (!isWhiteListed) {
                        console.debug("Not downloading tile", ...zxy, "as it is not on the whitelist")
                        return undefined;
                    }
                }

                const src = new GeoJsonSource(
                    layer,
                    zxy,
                    {
                        featureIdBlacklist: blackList
                    }
                )
     
                registerLayer(src)
                return src
            },
            state
        );

    }

    public static RegisterWhitelist(url: string, json: any) {
        const data = new Map<number, Set<number>>();
        for (const x in json) {
            if (x === "zoom") {
                continue
            }
            data.set(Number(x), new Set(json[x]))
        }
        DynamicGeoJsonTileSource.whitelistCache.set(url, data)
    }

}