mapcomplete/scripts/filter.ts

import * as fs from "fs"
import { TagUtils } from "../Logic/Tags/TagUtils"
import { writeFileSync } from "fs"
import { TagsFilter } from "../Logic/Tags/TagsFilter"

function main(args) {
    if (args.length < 2) {
        console.log(
            "Given a single geojson file and a filter specification, will print all the entries to std-out which pass the property"
        )
        console.log("USAGE: perProperty `file.geojson` `key=value` [outputfile]")
        return
    }
    const path = args[0]
    const spec = args[1]
    const output = args[2]

    const data = JSON.parse(fs.readFileSync(path, { encoding: "utf8" }))
    let filter: TagsFilter
    try {
        filter = TagUtils.Tag(JSON.parse(spec))
    } catch (e) {
        filter = TagUtils.Tag(spec)
    }
    const features = data.features.filter((f) => filter.matchesProperties(f.properties))

    if (features.length === 0) {
        console.log("Warning: no features matched the filter. Exiting now")
        return
    }

    const collection = {
        type: "FeatureCollection",
        features,
    }
    const stringified = JSON.stringify(collection, null, "  ")
    if (output === undefined) {
        console.log(stringified)
    } else {
        console.log(
            "Filtered " +
                path +
                ": kept " +
                features.length +
                " out of " +
                data.features.length +
                " objects"
        )
        writeFileSync(output, stringified)
    }
}

main(process.argv.slice(2))