'use strict'

const Promise = require('pinkie-promise')
const {fetch} = require('fetch-ponyfill')({Promise})
const {stringify} = require('query-string')

const hafasError = (err) => {
	err.isHafasError = true
	return err
}

const request = (profile, data) => {
	const body = profile.transformReqBody({lang: 'en', svcReqL: [data]})
	const req = profile.transformReq({
		method: 'post',
		// todo: CORS? referrer policy?
		body: JSON.stringify(body),
		headers: {
			'Content-Type': 'application/json',
			'Accept-Encoding': 'gzip, deflate',
			'user-agent': 'https://github.com/derhuerst/hafas-client'
		},
		query: null
	})
	const url = profile.endpoint + (req.query ? '?' + stringify(req.query) : '')

	return fetch(url, req)
	.then((res) => {
		if (!res.ok) {
			const err = new Error(res.statusText)
			err.statusCode = res.status
			throw hafasError(err)
		}
		return res.json()
	})
	.then((b) => {
		if (b.err) throw hafasError(new Error(b.err))
		if (!b.svcResL || !b.svcResL[0]) throw new Error('invalid response')
		if (b.svcResL[0].err !== 'OK') {
			throw hafasError(new Error(b.svcResL[0].errTxt))
		}
		const d = b.svcResL[0].res
		const c = d.common || {}

		if (Array.isArray(c.locL)) {
			d.locations = c.locL.map(loc => profile.parseLocation(profile, loc))
		}
		if (Array.isArray(c.remL)) {
			d.remarks = c.remL.map(rem => profile.parseRemark(profile, rem))
		}
		if (Array.isArray(c.opL)) {
			d.operators = c.opL.map(op => profile.parseOperator(profile, op))
		}
		if (Array.isArray(c.prodL)) {
			const parse = profile.parseLine(profile, d.operators)
			d.lines = c.prodL.map(parse)
		}
		return d
	})
}

module.exports = request