'use strict'

const trim = require('lodash/trim')
const uniqBy = require('lodash/uniqBy')
const slugg = require('slugg')
const without = require('lodash/without')
const {parseHook} = require('../../lib/profile-hooks')

const _parseJourney = require('../../parse/journey')
const _parseJourneyLeg = require('../../parse/journey-leg')
const _parseLine = require('../../parse/line')
const _parseArrival = require('../../parse/arrival')
const _parseDeparture = require('../../parse/departure')
const _parseHint = require('../../parse/hint')
const _parseLocation = require('../../parse/location')
const _formatStation = require('../../format/station')
const {bike} = require('../../format/filters')

const products = require('./products')
const formatLoyaltyCard = require('./loyalty-cards').format

const transformReqBody = (ctx, body) => {
	const req = body.svcReqL[0] || {}

	// see https://pastebin.com/qZ9WS3Cx
	req.cfg = {...req.cfg, rtMode: 'HYBRID'} // todo: use `REALTIME`?

	body.client = {id: 'DB', v: '16040000', type: 'IPH', name: 'DB Navigator'}
	body.ext = 'DB.R19.04.a'
	body.ver = '1.15'
	body.auth = {type: 'AID', aid: 'n91dB8Z77MLdoR0K'}

	return body
}

const slices = (n, arr) => {
	const initialState = {slices: [], count: Infinity}
	return arr.reduce(({slices, count}, item) => {
		if (count >= n) {
			slices.push([item])
			count = 1
		} else {
			slices[slices.length - 1].push(item)
			count++
		}
		return {slices, count}
	}, initialState).slices
}

const parseGrid = (g) => {
	// todo: g.type, e.g. `S`
	return {
		title: g.title,
		rows: slices(g.nCols, g.itemL.map(item => item.msgL[0]))
	}
}

const ausstattungKeys = Object.assign(Object.create(null), {
	'3-s-zentrale': '3SZentrale',
	'parkplatze': 'parkingLots',
	'fahrrad-stellplatze': 'bicycleParkingRacks',
	'opnv-anbindung': 'localPublicTransport',
	'wc': 'toilets',
	'schliessfacher': 'lockers',
	'reisebedarf': 'travelShop',
	'stufenfreier-zugang': 'stepFreeAccess',
	'ein-umsteigehilfe': 'boardingAid',
	'taxi-am-bahnhof': 'taxis'
})
const parseAusstattungVal = (val) => {
	val = val.toLowerCase()
	return val === 'ja' ? true : (val === 'nein' ? false : val)
}

const parseAusstattungGrid = (g) => {
	// filter duplicate hint rows
	const rows = uniqBy(g.rows, ([key, val]) => key + ':' + val)

	const res = {}
	Object.defineProperty(res, 'raw', {value: rows})
	for (let [key, val] of rows) {
		key = ausstattungKeys[slugg(key)]
		if (key) res[key] = parseAusstattungVal(val)
	}
	return res
}

const parseReisezentrumÖffnungszeiten = (g) => {
	const res = {}
	for (const [dayOfWeek, val] of g.rows) res[dayOfWeek] = val
	res.raw = g.rows
	return res
}

const parseLocWithDetails = ({parsed, common}, l) => {
	if (!parsed) return parsed
	if (parsed.type !== 'stop' && parsed.type !== 'station') return parsed

	if (Array.isArray(l.gridL)) {
		const resolveCell = cell => 'hint' in cell ? cell.hint.text : cell
		const resolveCells = grid => ({
			...grid,
			rows: grid.rows.map(row => row.map(resolveCell))
		})

		let grids = l.gridL
		.map(grid => parseGrid(grid, common))
		.map(resolveCells)

		const ausstattung = grids.find(g => slugg(g.title) === 'ausstattung')
		if (ausstattung) {
			parsed.facilities = parseAusstattungGrid(ausstattung)
		}
		const öffnungszeiten = grids.find(g => slugg(g.title) === 'offnungszeiten-reisezentrum')
		if (öffnungszeiten) {
			parsed.reisezentrumOpeningHours = parseReisezentrumÖffnungszeiten(öffnungszeiten)
		}

		grids = without(grids, ausstattung, öffnungszeiten)
		if (grids.length > 0) parsed.grids = grids
	}

	return parsed
}

// https://www.bahn.de/p/view/service/buchung/auslastungsinformation.shtml
const loadFactors = []
loadFactors[1] = 'low-to-medium'
loadFactors[2] = 'high'
loadFactors[3] = 'very-high'
loadFactors[4] = 'exceptionally-high'

const parseLoadFactor = (opt, tcocL, tcocX) => {
	const cls = opt.firstClass ? 'FIRST' : 'SECOND'
	const load = tcocX.map(i => tcocL[i]).find(lf => lf.c === cls)
	return load && loadFactors[load.r] || null
}

const parseArrOrDepWithLoadFactor = ({parsed, res, opt}, d) => {
	if (d.stbStop.dTrnCmpSX && Array.isArray(d.stbStop.dTrnCmpSX.tcocX)) {
		const load = parseLoadFactor(opt, res.common.tcocL || [], d.stbStop.dTrnCmpSX.tcocX)
		if (load) parsed.loadFactor = load
	}
	return parsed
}

const transformJourneysQuery = ({opt}, query) => {
	const filters = query.jnyFltrL
	if (opt.bike) filters.push(bike)

	query.trfReq = {
		jnyCl: opt.firstClass === true ? 1 : 2,
		tvlrProf: [{
			type: 'E',
			redtnCard: opt.loyaltyCard
				? formatLoyaltyCard(opt.loyaltyCard)
				: null
		}],
		cType: 'PK'
	}

	return query
}

const parseLineWithAdditionalName = ({parsed}, l) => {
	if (l.nameS && ['bus', 'tram', 'ferry'].includes(l.product)) {
		parsed.name = l.nameS
	}
	if (l.addName) {
		parsed.additionalName = parsed.name
		parsed.name = l.addName
	}
	return parsed
}

// todo: sotRating, conSubscr, isSotCon, showARSLink, sotCtxt
// todo: conSubscr, showARSLink, useableTime
const parseJourneyWithPrice = ({parsed}, raw) => {
	parsed.price = null
	// todo: find cheapest, find discounts
	// todo: write a parser like vbb-parse-ticket
	// [ {
	// 	prc: 15000,
	// 	isFromPrice: true,
	// 	isBookable: true,
	// 	isUpsell: false,
	// 	targetCtx: 'D',
	// 	buttonText: 'To offer selection'
	// } ]
	if (
		raw.trfRes &&
		Array.isArray(raw.trfRes.fareSetL) &&
		raw.trfRes.fareSetL[0] &&
		Array.isArray(raw.trfRes.fareSetL[0].fareL) &&
		raw.trfRes.fareSetL[0].fareL[0]
	) {
		const tariff = raw.trfRes.fareSetL[0].fareL[0]
		if (tariff.prc >= 0) { // wat
			parsed.price = {
				amount: tariff.prc / 100,
				currency: 'EUR',
				hint: null
			}
		}
	}

	return parsed
}

const parseJourneyLegWithLoadFactor = ({parsed, res, opt}, raw) => {
	const tcocX = raw.jny && raw.jny.dTrnCmpSX && raw.jny.dTrnCmpSX.tcocX
	if (Array.isArray(tcocX) && Array.isArray(res.common.tcocL)) {
		const load = parseLoadFactor(opt, res.common.tcocL, tcocX)
		if (load) parsed.loadFactor = load
	}
	return parsed
}

// todo:
// [ { type: 'hint',
//     code: 'P5',
//     text: 'Es gilt ein besonderer Fahrpreis' }
const hintsByCode = Object.assign(Object.create(null), {
	fb: {
		type: 'hint',
		code: 'bicycle-conveyance',
		summary: 'bicycles conveyed'
	},
	fr: {
		type: 'hint',
		code: 'bicycle-conveyance-reservation',
		summary: 'bicycles conveyed, subject to reservation'
	},
	nf: {
		type: 'hint',
		code: 'no-bicycle-conveyance',
		summary: 'bicycles not conveyed'
	},
	k2: {
		type: 'hint',
		code: '2nd-class-only',
		summary: '2. class only'
	},
	eh: {
		type: 'hint',
		code: 'boarding-ramp',
		summary: 'vehicle-mounted boarding ramp available'
	},
	ro: {
		type: 'hint',
		code: 'wheelchairs-space',
		summary: 'space for wheelchairs'
	},
	oa: {
		type: 'hint',
		code: 'wheelchairs-space-reservation',
		summary: 'space for wheelchairs, subject to reservation'
	},
	wv: {
		type: 'hint',
		code: 'wifi',
		summary: 'WiFi available'
	},
	wi: {
		type: 'hint',
		code: 'wifi',
		summary: 'WiFi available'
	},
	sn: {
		type: 'hint',
		code: 'snacks',
		summary: 'snacks available for purchase'
	},
	mb: {
		type: 'hint',
		code: 'snacks',
		summary: 'snacks available for purchase'
	},
	mp: {
		type: 'hint',
		code: 'snacks',
		summary: 'snacks available for purchase at the seat'
	},
	bf: {
		type: 'hint',
		code: 'barrier-free',
		summary: 'barrier-free'
	},
	rg: {
		type: 'hint',
		code: 'barrier-free-vehicle',
		summary: 'barrier-free vehicle'
	},
	bt: {
		type: 'hint',
		code: 'on-board-bistro',
		summary: 'Bordbistro available'
	},
	br: {
		type: 'hint',
		code: 'on-board-restaurant',
		summary: 'Bordrestaurant available'
	},
	ki: {
		type: 'hint',
		code: 'childrens-area',
		summary: `children's area available`
	},
	kk: {
		type: 'hint',
		code: 'parents-childrens-compartment',
		summary: `parent-and-children compartment available`
	},
	kr: {
		type: 'hint',
		code: 'kids-service',
		summary: 'DB Kids Service available'
	},
	ls: {
		type: 'hint',
		code: 'power-sockets',
		summary: 'power sockets available'
	},
	ev: {
		type: 'hint',
		code: 'replacement-service',
		summary: 'replacement service'
	},
	kl: {
		type: 'hint',
		code: 'air-conditioned',
		summary: 'air-conditioned vehicle'
	},
	r0: {
		type: 'hint',
		code: 'upward-escalator',
		summary: 'upward escalator'
	},
	au: {
		type: 'hint',
		code: 'elevator',
		summary: 'elevator available'
	},
	ck: {
		type: 'hint',
		code: 'komfort-checkin',
		summary: 'Komfort-Checkin available'
	},
	it: {
		type: 'hint',
		code: 'ice-sprinter',
		summary: 'ICE Sprinter service'
	},
	rp: {
		type: 'hint',
		code: 'compulsory-reservation',
		summary: 'compulsory seat reservation'
	},
	rm: {
		type: 'hint',
		code: 'optional-reservation',
		summary: 'optional seat reservation'
	},
	scl: {
		type: 'hint',
		code: 'all-2nd-class-seats-reserved',
		summary: 'all 2nd class seats reserved'
	},
	acl: {
		type: 'hint',
		code: 'all-seats-reserved',
		summary: 'all seats reserved'
	},
	sk: {
		type: 'hint',
		code: 'oversize-luggage-forbidden',
		summary: 'oversize luggage not allowed'
	},
	hu: {
		type: 'hint',
		code: 'animals-forbidden',
		summary: 'animals not allowed, except guide dogs'
	},
	ik: {
		type: 'hint',
		code: 'baby-cot-required',
		summary: 'baby cot/child seat required'
	},
	ee: {
		type: 'hint',
		code: 'on-board-entertainment',
		summary: 'on-board entertainment available'
	},
	toilet: {
		type: 'hint',
		code: 'toilet',
		summary: 'toilet available'
	},
	oc: {
		type: 'hint',
		code: 'wheelchair-accessible-toilet',
		summary: 'wheelchair-accessible toilet available'
	},
	iz: {
		type: 'hint',
		code: 'intercity-2',
		summary: 'Intercity 2'
	}
})

const codesByText = Object.assign(Object.create(null), {
	'journey cancelled': 'journey-cancelled', // todo: German variant
	'stop cancelled': 'stop-cancelled', // todo: change to `stopover-cancelled`, German variant
	'signal failure': 'signal-failure',
	'signalstörung': 'signal-failure',
	'additional stop': 'additional-stopover', // todo: German variant
	'platform change': 'changed platform', // todo: use dash, German variant
})

const parseHintByCode = ({parsed}, raw) => {
	// plain-text hints used e.g. for stop metadata
	if (raw.type === 'K') {
		return {type: 'hint', text: raw.txtN}
	}

	if (raw.type === 'A') {
		const hint = hintsByCode[raw.code && raw.code.trim().toLowerCase()]
		if (hint) {
			return Object.assign({text: raw.txtN}, hint)
		}
	}

	if (parsed && raw.txtN) {
		const text = trim(raw.txtN.toLowerCase(), ' ()')
		if (codesByText[text]) parsed.code = codesByText[text]
	}

	return parsed
}

const isIBNR = /^\d{6,}$/
const formatStation = (id) => {
	if (!isIBNR.test(id)) throw new Error('station ID must be an IBNR.')
	return _formatStation(id)
}

// todo: find option for absolute number of results

const dbProfile = {
	locale: 'de-DE',
	timezone: 'Europe/Berlin',
	endpoint: 'https://reiseauskunft.bahn.de/bin/mgate.exe',

	salt: Buffer.from('bdI8UVj40K5fvxwf', 'utf8'),
	addChecksum: true,

	transformReqBody,
	transformJourneysQuery,

	products: products,

	parseLocation: parseHook(_parseLocation, parseLocWithDetails),
	parseJourney: parseHook(_parseJourney, parseJourneyWithPrice),
	parseJourneyLeg: parseHook(_parseJourneyLeg, parseJourneyLegWithLoadFactor),
	parseLine: parseHook(_parseLine, parseLineWithAdditionalName),
	parseArrival: parseHook(_parseArrival, parseArrOrDepWithLoadFactor),
	parseDeparture: parseHook(_parseDeparture, parseArrOrDepWithLoadFactor),
	parseHint: parseHook(_parseHint, parseHintByCode),

	formatStation,

	trip: true, // todo: #49
	radar: true,
	reachableFrom: true,
	remarks: false, // seems like ver >= 1.20 is required
}

module.exports = dbProfile