Files
TFI-Live-G2/scripts/build-stop-index.mjs
2026-06-01 16:48:03 +01:00

132 lines
3.6 KiB
JavaScript

import { createReadStream, mkdirSync, readFileSync, writeFileSync } from 'node:fs'
import { dirname, join } from 'node:path'
import { fileURLToPath } from 'node:url'
import { createInterface } from 'node:readline'
export async function buildStopIndex(gtfsDir, outputPath = 'public/stops.json') {
const stops = readCsv(join(gtfsDir, 'stops.txt'))
const routes = readCsv(join(gtfsDir, 'routes.txt'))
const trips = readCsv(join(gtfsDir, 'trips.txt'))
const routeById = new Map(routes.map((route) => [route.route_id, route]))
const tripRouteById = new Map(trips.map((trip) => [trip.trip_id, trip.route_id]))
const routesByStop = new Map()
const modesByStop = new Map()
await eachCsvRow(join(gtfsDir, 'stop_times.txt'), (row) => {
const stopId = row.stop_id
const routeId = tripRouteById.get(row.trip_id)
if (!stopId || !routeId) {
return
}
const route = routeById.get(routeId)
const routeName = route?.route_short_name || route?.route_long_name || routeId
pushUnique(routesByStop, stopId, routeName)
pushUnique(modesByStop, stopId, modeFromRouteType(route?.route_type))
})
const index = stops
.map((stop) => ({
id: stop.stop_id,
code: stop.stop_code || stop.stop_id,
name: stop.stop_name,
lat: Number(stop.stop_lat),
lon: Number(stop.stop_lon),
modes: modesByStop.get(stop.stop_id) || ['unknown'],
routes: routesByStop.get(stop.stop_id) || [],
}))
.filter((stop) => stop.id && stop.name && Number.isFinite(stop.lat) && Number.isFinite(stop.lon))
mkdirSync(dirname(outputPath), { recursive: true })
writeFileSync(outputPath, `${JSON.stringify({ stops: index })}\n`)
return index.length
}
if (process.argv[1] === fileURLToPath(import.meta.url)) {
const [gtfsDir, outputPath = 'public/stops.json'] = process.argv.slice(2)
if (!gtfsDir) {
console.error('Usage: node scripts/build-stop-index.mjs <extracted-gtfs-dir> [output.json]')
process.exit(1)
}
const count = await buildStopIndex(gtfsDir, outputPath)
console.log(`Wrote ${count} stops to ${outputPath}`)
}
function readCsv(path) {
const [headerLine, ...lines] = readFileSync(path, 'utf8').trim().split(/\r?\n/)
const headers = parseCsvLine(headerLine)
return lines.map((line) => rowFromValues(headers, parseCsvLine(line)))
}
async function eachCsvRow(path, callback) {
const reader = createInterface({
input: createReadStream(path),
crlfDelay: Infinity,
})
let headers = []
for await (const line of reader) {
if (!headers.length) {
headers = parseCsvLine(line)
continue
}
callback(rowFromValues(headers, parseCsvLine(line)))
}
}
function rowFromValues(headers, values) {
return Object.fromEntries(headers.map((header, index) => [header, values[index] ?? '']))
}
function parseCsvLine(line) {
const values = []
let value = ''
let quoted = false
for (let index = 0; index < line.length; index += 1) {
const char = line[index]
const next = line[index + 1]
if (char === '"' && quoted && next === '"') {
value += '"'
index += 1
} else if (char === '"') {
quoted = !quoted
} else if (char === ',' && !quoted) {
values.push(value)
value = ''
} else {
value += char
}
}
values.push(value)
return values
}
function pushUnique(map, key, value) {
if (!value) {
return
}
const values = map.get(key) || []
if (!values.includes(value)) {
values.push(value)
map.set(key, values)
}
}
function modeFromRouteType(routeType) {
switch (String(routeType)) {
case '0':
return 'tram'
case '2':
return 'rail'
case '3':
return 'bus'
default:
return 'unknown'
}
}