mapcomplete/scripts/generateCache.ts

/**
 * Generates a collection of geojson files based on an overpass query for a given theme
 */
import {TileRange, Utils} from "../Utils";

Utils.runningFromConsole = true
import {Overpass} from "../Logic/Osm/Overpass";
import {existsSync, readFileSync, writeFileSync} from "fs";
import {TagsFilter} from "../Logic/Tags/TagsFilter";
import {Or} from "../Logic/Tags/Or";
import LayoutConfig from "../Customizations/JSON/LayoutConfig";
import {AllKnownLayouts} from "../Customizations/AllKnownLayouts";
import ScriptUtils from "./ScriptUtils";
import ExtractRelations from "../Logic/Osm/ExtractRelations";
import * as OsmToGeoJson from "osmtogeojson";
import MetaTagging from "../Logic/MetaTagging";


function createOverpassObject(theme: LayoutConfig) {
    let filters: TagsFilter[] = [];
    let extraScripts: string[] = [];
    for (const layer of theme.layers) {
        if (typeof (layer) === "string") {
            throw "A layer was not expanded!"
        }
        if (layer.doNotDownload) {
            continue;
        }
        if (layer.source.geojsonSource !== undefined) {
            // We download these anyway - we are building the cache after all!
            //continue;
        }


        // Check if data for this layer has already been loaded
        if (layer.source.overpassScript !== undefined) {
            extraScripts.push(layer.source.overpassScript)
        } else {
            filters.push(layer.source.osmTags);
        }
    }
    filters = Utils.NoNull(filters)
    extraScripts = Utils.NoNull(extraScripts)
    if (filters.length + extraScripts.length === 0) {
        throw "Nothing to download! The theme doesn't declare anything to download"
    }
    return new Overpass(new Or(filters), extraScripts);
}

function saveResponse(chunks: string[], targetDir: string): boolean {
    const contents = chunks.join("")
    if (contents.startsWith("<?xml")) {
        // THis is an error message
        console.error("Failed to create ", targetDir, "probably over quota: ", contents)
        return false;
    }
    writeFileSync(targetDir, contents)
    return true
}

function rawJsonName(targetDir: string, x: number, y: number, z: number): string {
    return targetDir + "_" + z + "_" + x + "_" + y + ".json"
}

function geoJsonName(targetDir: string, x: number, y: number, z: number): string {
    return targetDir + "_" + z + "_" + x + "_" + y + ".geojson"
}

async function downloadRaw(targetdir: string, r: TileRange, overpass: Overpass)/* : {failed: number, skipped :number} */ {
    let downloaded = 0
    let failed = 0
    let skipped = 0
    for (let x = r.xstart; x <= r.xend; x++) {
        for (let y = r.ystart; y <= r.yend; y++) {
            downloaded++;
            const filename = rawJsonName(targetdir, x, y, r.zoomlevel)
            if (existsSync(filename)) {
                console.log("Already exists: ", filename)
                skipped++
                continue;
            }
            console.log("x:", (x - r.xstart), "/", (r.xend - r.xstart), "; y:", (y - r.ystart), "/", (r.yend - r.ystart), "; total: ", downloaded, "/", r.total, "failed: ", failed, "skipped: ", skipped)

            const boundsArr = Utils.tile_bounds(r.zoomlevel, x, y)
            const bounds = {
                north: Math.max(boundsArr[0][0], boundsArr[1][0]),
                south: Math.min(boundsArr[0][0], boundsArr[1][0]),
                east: Math.max(boundsArr[0][1], boundsArr[1][1]),
                west: Math.min(boundsArr[0][1], boundsArr[1][1])
            }
            const url = overpass.buildQuery("[bbox:" + bounds.south + "," + bounds.west + "," + bounds.north + "," + bounds.east + "]")

            let gotResponse = false
            let success = false;
            ScriptUtils.DownloadJSON(url,
                chunks => {
                    gotResponse = true;
                    success = saveResponse(chunks, filename)
                })

            while (!gotResponse) {
                await ScriptUtils.sleep(10000)
                console.debug("Waking up")
                if (!gotResponse) {
                    console.log("Didn't get an answer yet - waiting more")
                }
            }

            if (!success) {
                failed++;
                console.log("Hit the rate limit - waiting 90s")
                for (let i = 0; i < 90; i++) {
                    console.log(90 - i)
                    await ScriptUtils.sleep(1000)
                }
            }


        }
    }

    return {failed: failed, skipped: skipped}
}

async function postProcess(targetdir: string, r: TileRange, theme: LayoutConfig) {
    let processed = 0;
    for (let x = r.xstart; x <= r.xend; x++) {
        for (let y = r.ystart; y <= r.yend; y++) {
            processed++;
            const filename = rawJsonName(targetdir, x, y, r.zoomlevel)
            console.log(" Post processing", processed, "/", r.total, filename)
            if (!existsSync(filename)) {
                throw "Not found - and not downloaded. Run this script again!: " + filename
            }

            // We read the raw OSM-file and convert it to a geojson
            const rawOsm = JSON.parse(readFileSync(filename, "UTF8"))

            // Create and save the geojson file - which is the main chunk of the data
            const geojson = OsmToGeoJson.default(rawOsm);
            const osmTime = new Date(rawOsm.osm3s.timestamp_osm_base);

            for (const feature of geojson.features) {

                for (const layer of theme.layers) {
                    if (layer.source.osmTags.matchesProperties(feature.properties)) {
                        feature["_matching_layer_id"] = layer.id;
                        break;
                    }
                }
            }
            const featuresFreshness = geojson.features.map(feature => {
                feature["_timestamp"] = rawOsm.osm3s.timestamp_osm_base;
                return ({
                    freshness: osmTime,
                    feature: feature
                });
            });
            // Extract the relationship information
            const relations = ExtractRelations.BuildMembershipTable(ExtractRelations.GetRelationElements(rawOsm))
            MetaTagging.addMetatags(featuresFreshness, relations, theme.layers);


            writeFileSync(geoJsonName(targetdir, x, y, r.zoomlevel), JSON.stringify(geojson, null, " "))

        }
    }
}

async function splitPerLayer(targetdir: string, r: TileRange, theme: LayoutConfig) {
    let processed = 0;
    const z = r.zoomlevel;
    for (let x = r.xstart; x <= r.xend; x++) {
        for (let y = r.ystart; y <= r.yend; y++) {
            const file = readFileSync(geoJsonName(targetdir, x, y, z), "UTF8")

            for (const layer of theme.layers) {
                const geojson = JSON.parse(file)
                geojson.features = geojson.features.filter(f => f._matching_layer_id === layer.id)
                if(geojson.features.length == 0){
                    continue;
                }
                const new_path = geoJsonName(targetdir+"_"+layer.id, x, y, z);
                writeFileSync(new_path, JSON.stringify(geojson, null, " "))
            }
        
            
        }
    }
}


async function main(args: string[]) {

    if (args.length == 0) {
        console.error("Expected arguments are: theme zoomlevel targetdirectory lat0 lon0 lat1 lon1")
        return;
    }
    const themeName = args[0]
    const zoomlevel = Number(args[1])
    const targetdir = args[2] + "/" + themeName
    const lat0 = Number(args[3])
    const lon0 = Number(args[4])
    const lat1 = Number(args[5])
    const lon1 = Number(args[6])

    const tileRange = Utils.TileRangeBetween(zoomlevel, lat0, lon0, lat1, lon1)

    const theme = AllKnownLayouts.allKnownLayouts.get(themeName)
    if (theme === undefined) {
        const keys = []
        AllKnownLayouts.allKnownLayouts.forEach((_, key) => {
            keys.push(key)
        })
        console.error("The theme " + theme + " was not found; try one of ", keys);
        return
    }

    const overpass = createOverpassObject(theme)

    let failed = 0;
    do {
        const cachingResult = await downloadRaw(targetdir, tileRange, overpass)
        failed = cachingResult.failed
        if (failed > 0) {
            ScriptUtils.sleep(30000)
        }
    } while (failed > 0)

    await postProcess(targetdir, tileRange, theme)
    await splitPerLayer(targetdir, tileRange, theme)
}


let args = [...process.argv]
args.splice(0, 2)
main(args);