/stations/:id route

index.js

@@ -7,6 +7,7 @@ const hsts = require('hsts')
 const pkg = require('./package.json')
 const stations = require('./lib/stations')
 const allStations = require('./lib/all-stations')
+const station = require('./lib/station')
 
 const config = {
 	hostname: process.env.HOSTNAME || '2.db.transport.rest',
@@ -19,6 +20,7 @@ const config = {
 const api = createApi(hafas, config, (api) => {
 	api.get('/stations', stations)
 	api.get('/stations/all', allStations)
+	api.get('/stations/:id', station)
 })
 
 api.listen(config.port, (err) => {

lib/station.js

@@ -0,0 +1,40 @@
+'use strict'
+
+const stations = require('db-stations')
+
+const err400 = (msg) => {
+	const err = new Error(msg)
+	err.statusCode = 400
+	return err
+}
+
+// This is terribly inefficient, because we read all stations for every request.
+// todo: optimize it
+const route = (req, res, next) => {
+	const id = req.params.id.trim()
+	const stream = stations.full()
+
+	let found = false
+	const onStation = (station) => {
+		if (station.id !== id) return
+		found = true
+		stream.removeListener('data', onStation)
+
+		res.json(station)
+		next()
+	}
+	stream.on('data', onStation)
+
+	const onEnd = () => {
+		if (!found) return next(err400('Station not found.'))
+	}
+	stream.once('end', onEnd)
+
+	stream.once('error', (err) => {
+		stream.removeListener('data', onStation)
+		stream.removeListener('end', onEnd)
+		next(nerr)
+	})
+}
+
+module.exports = route