DB: support age-based tariffs

The supported age groups are now:
- 'B' (baby, infant)
- 'K' (kind, child)
- 'Y' (young)
- 'E' (Erwachsener, adult)
- 'S' (Senior)

p/db/ageGroup.js

@@ -0,0 +1,36 @@
+'use strict'
+
+const ageGroup = {
+	BABY: 'B',
+	CHILD: 'K',
+	YOUNG: 'Y',
+	ADULT: 'E',
+	SENIOR: 'S',
+	upperBoundOf: {
+		BABY: 6,
+		CHILD: 15,
+		YOUNG: 27,
+		ADULT: 65,
+		SENIOR: Infinity
+	}
+}
+
+const ageGroupFromAge = (age) => {
+	const {upperBoundOf} = ageGroup
+	if (age < upperBoundOf.BABY)
+		return ageGroup.BABY
+	if (age < upperBoundOf.CHILD)
+		return ageGroup.CHILD
+	if (age < upperBoundOf.YOUNG)
+		return ageGroup.YOUNG
+	if (age < upperBoundOf.ADULT)
+		return ageGroup.ADULT
+	if (age < upperBoundOf.SENIOR)
+		return ageGroup.SENIOR
+	throw new TypeError(`Invalid age '${age}'`)
+}
+
+module.exports = {
+	ageGroup,
+	ageGroupFromAge
+}

p/db/base.json

@@ -12,6 +12,6 @@
 	},
 	"endpoint": "https://reiseauskunft.bahn.de/bin/mgate.exe",
 	"ext": "DB.R20.12.b",
-	"ver": "1.34",
+	"ver": "1.46",
 	"defaultLanguage": "en"
 }

p/db/index.js

@@ -19,6 +19,7 @@ const {bike} = require('../../format/filters')
 const products = require('./products')
 const baseProfile = require('./base.json')
 const formatLoyaltyCard = require('./loyalty-cards').format
+const {ageGroup} = require('./ageGroup')
 
 const transformReqBody = (ctx, body) => {
 	const req = body.svcReqL[0] || {}
@@ -159,7 +160,7 @@ const transformJourneysQuery = ({opt}, query) => {
 		jnyCl: opt.firstClass === true ? 1 : 2,
 		// todo [breaking]: support multiple travelers
 		tvlrProf: [{
-			type: 'E',
+			type: opt.ageGroup || ageGroup.ADULT,
 			redtnCard: opt.loyaltyCard
 				? formatLoyaltyCard(opt.loyaltyCard)
 				: null