mapcomplete/scripts/slice.ts

import * as fs from "fs"
import TiledFeatureSource from "../Logic/FeatureSource/TiledFeatureSource/TiledFeatureSource"
import StaticFeatureSource from "../Logic/FeatureSource/Sources/StaticFeatureSource"
import * as readline from "readline"
import ScriptUtils from "./ScriptUtils"
import { Utils } from "../Utils"
import Script from "./Script"
import { BBox } from "../Logic/BBox"
import { GeoOperations } from "../Logic/GeoOperations"

/**
 * This script slices a big newline-delimeted geojson file into tiled geojson
 * It was used to convert the CRAB-data into geojson tiles
 */

class Slice extends Script {
    constructor() {
        super("Break data into tiles")
    }

    async readFeaturesFromLineDelimitedJsonFile(inputFile: string): Promise<any[]> {
        const fileStream = fs.createReadStream(inputFile)

        const rl = readline.createInterface({
            input: fileStream,
            crlfDelay: Infinity,
        })
        // Note: we use the crlfDelay option to recognize all instances of CR LF
        // ('\r\n') in input.txt as a single line break.

        const allFeatures: any[] = []
        // @ts-ignore
        for await (const line of rl) {
            try {
                allFeatures.push(JSON.parse(line))
            } catch (e) {
                console.error("Could not parse", line)
                break
            }
            if (allFeatures.length % 10000 === 0) {
                ScriptUtils.erasableLog("Loaded ", allFeatures.length, "features up till now")
            }
        }
        return allFeatures
    }

    async readGeojsonLineByLine(inputFile: string): Promise<any[]> {
        const fileStream = fs.createReadStream(inputFile)

        const rl = readline.createInterface({
            input: fileStream,
            crlfDelay: Infinity,
        })
        // Note: we use the crlfDelay option to recognize all instances of CR LF
        // ('\r\n') in input.txt as a single line break.

        const allFeatures: any[] = []
        let featuresSeen = false
        // @ts-ignore
        for await (let line: string of rl) {
            if (!featuresSeen && line.startsWith('"features":')) {
                featuresSeen = true
                continue
            }
            if (!featuresSeen) {
                continue
            }
            if (line.endsWith(",")) {
                line = line.substring(0, line.length - 1)
            }

            try {
                allFeatures.push(JSON.parse(line))
            } catch (e) {
                console.error("Could not parse", line)
                break
            }
            if (allFeatures.length % 10000 === 0) {
                ScriptUtils.erasableLog("Loaded ", allFeatures.length, "features up till now")
            }
        }
        return allFeatures
    }

    async readFeaturesFromGeoJson(inputFile: string): Promise<any[]> {
        try {
            return JSON.parse(fs.readFileSync(inputFile, { encoding: "utf-8" })).features
        } catch (e) {
            // We retry, but with a line-by-line approach
            return await this.readGeojsonLineByLine(inputFile)
        }
    }

    async main(args: string[]) {
        console.log("GeoJSON slicer")
        if (args.length < 3) {
            console.log(
                "USAGE: <input-file.geojson> <target-zoom-level> <output-directory> [--clip]"
            )
            return
        }

        const inputFile = args[0]
        const zoomlevel = Number(args[1])
        const outputDirectory = args[2]
        const doSlice = args[3] === "--clip"

        if (!fs.existsSync(outputDirectory)) {
            fs.mkdirSync(outputDirectory)
            console.log("Directory created")
        }
        console.log("Using directory ", outputDirectory)

        let allFeatures: any[]
        if (inputFile.endsWith(".geojson")) {
            console.log("Detected geojson")
            allFeatures = await this.readFeaturesFromGeoJson(inputFile)
        } else {
            console.log("Loading as newline-delimited features")
            allFeatures = await this.readFeaturesFromLineDelimitedJsonFile(inputFile)
        }
        allFeatures = Utils.NoNull(allFeatures)

        console.log("Loaded all", allFeatures.length, "points")

        const keysToRemove = ["STRAATNMID", "GEMEENTE", "POSTCODE"]
        for (const f of allFeatures) {
            if (f.properties === null) {
                console.log("Got a feature without properties!", f)
                continue
            }
            for (const keyToRm of keysToRemove) {
                delete f.properties[keyToRm]
            }
            delete f.bbox
        }
        const maxNumberOfTiles = Math.pow(2, zoomlevel) * Math.pow(2, zoomlevel)
        let handled = 0
        TiledFeatureSource.createHierarchy(StaticFeatureSource.fromGeojson(allFeatures), {
            minZoomLevel: zoomlevel,
            maxZoomLevel: zoomlevel,
            maxFeatureCount: Number.MAX_VALUE,
            registerTile: (tile) => {
                handled = handled + 1
                const path = `${outputDirectory}/tile_${tile.z}_${tile.x}_${tile.y}.geojson`
                const box = BBox.fromTile(tile.z, tile.x, tile.y)
                let features = tile.features.data.map((ff) => ff.feature)
                if (doSlice) {
                    features = Utils.NoNull(
                        features.map((f) => {
                            const bbox = box.asGeoJson({})
                            const properties = {
                                ...f.properties,
                                id:
                                    (f.properties?.id ?? "") +
                                    "_" +
                                    tile.z +
                                    "_" +
                                    tile.x +
                                    "_" +
                                    tile.y,
                            }

                            if (GeoOperations.completelyWithin(bbox, f)) {
                                bbox.properties = properties
                                return bbox
                            }
                            const intersection = GeoOperations.intersect(f, box.asGeoJson({}))
                            if (intersection) {
                                intersection.properties = properties
                            }
                            return intersection
                        })
                    )
                }
                features.forEach((f) => {
                    delete f.bbox
                })
                if (features.length === 0) {
                    ScriptUtils.erasableLog(
                        handled + "/" + maxNumberOfTiles,
                        "Not writing ",
                        path,
                        ": no features"
                    )
                    return
                }
                fs.writeFileSync(
                    path,
                    JSON.stringify(
                        {
                            type: "FeatureCollection",
                            features: features,
                        },
                        null,
                        "  "
                    )
                )
                ScriptUtils.erasableLog(
                    handled + "/" + maxNumberOfTiles,
                    "Written ",
                    path,
                    "which has ",
                    tile.features.data.length,
                    "features"
                )
            },
        })
    }
}

new Slice().run()