index.js

import fs from 'fs'
import express from 'express'
import path from 'path'
import bodyParser from 'body-parser'
import axios from 'axios'
import { has, castArray } from 'lodash'
import expressStaticGzip from 'express-static-gzip'
import { createBackendSearchConfig } from './sparql/Utils'
import {
  getResultCount,
  getPaginatedResults,
  getAllResults,
  getByURI
} from './sparql/FacetResults'
import { getFacet } from './sparql/FacetValues'
import { queryJenaIndex } from './sparql/JenaQuery'
import { getFederatedResults } from './sparql/FederatedSearch'
import { fetchGeoJSONLayer } from './wfs/WFSApi'
import swaggerUi from 'swagger-ui-express'
import * as OpenApiValidator from 'express-openapi-validator'
import yaml from 'js-yaml'
import querystring from 'querystring'

const DEFAULT_PORT = 3001
const app = express()
app.set('port', process.env.PORT || DEFAULT_PORT)
app.use(bodyParser.json())

// NODE_ENV is defined in package.json when running in localhost
const isDevelopment = process.env.NODE_ENV === 'development'

// CORS middleware
app.use(function (req, res, next) {
  res.header('Access-Control-Allow-Origin', '*')
  res.header('Access-Control-Allow-Methods', 'GET,POST,OPTIONS')
  res.header('Access-Control-Allow-Headers', 'Origin, X-Requested-With, Content-Type, Accept')
  // handle pre-flight request
  if (req.method === 'OPTIONS') {
    return res.status(200).end()
  }
  next()
})

// Generate API docs from YAML file with Swagger UI
let swaggerDocument
try {
  swaggerDocument = yaml.safeLoad(fs.readFileSync(path.join(__dirname, './openapi.yaml'), 'utf8'))
} catch (e) {
  console.log(e)
}
app.use('/api-docs', swaggerUi.serve, swaggerUi.setup(swaggerDocument))

// Express server is used to serve the React app only in production
let publicPath = null
if (!isDevelopment) {
  // The root directory from which to serve static assets
  publicPath = path.join(__dirname, './../public/')
  // app.use(express.static(publicPath))
  app.use('/', expressStaticGzip(publicPath))
}

// React app makes requests to these api urls
const apiPath = '/api/v1'

const validator = OpenApiValidator.middleware({
  apiSpec: swaggerDocument,
  validateResponses: true
})
app.use(validator)

// https://medium.com/@Abazhenov/using-async-await-in-express-with-node-8-b8af872c0016
app.post(`${apiPath}/faceted-search/:resultClass/paginated`, async (req, res, next) => {
  const { params, body } = req
  try {
    const backendSearchConfig = await createBackendSearchConfig()
    const data = await getPaginatedResults({
      backendSearchConfig,
      resultClass: params.resultClass,
      page: body.page,
      pagesize: parseInt(body.pagesize),
      sortBy: body.sortBy,
      sortDirection: body.sortDirection,
      constraints: body.constraints,
      resultFormat: 'json'
    })
    res.json(data)
  } catch (error) {
    console.log(error)
    next(error)
  }
})

app.post(`${apiPath}/faceted-search/:resultClass/all`, async (req, res, next) => {
  const { params, body } = req
  const resultFormat = 'json'
  try {
    const backendSearchConfig = await createBackendSearchConfig()
    const data = await getAllResults({
      backendSearchConfig,
      perspectiveID: body.perspectiveID,
      resultClass: params.resultClass,
      facetClass: body.facetClass,
      uri: body.uri,
      constraints: body.constraints,
      resultFormat: resultFormat,
      limit: body.limit,
      optimize: body.optimize,
      fromID: body.fromID,
      toID: body.toID
    })
    if (resultFormat === 'csv') {
      res.writeHead(200, {
        'Content-Type': 'text/csv',
        'Content-Disposition': 'attachment; filename=results.csv'
      })
      res.end(data)
    } else {
      res.json(data)
    }
  } catch (error) {
    next(error)
  }
})

// GET endpoint for supporting CSV button
app.get(`${apiPath}/faceted-search/:resultClass/all`, async (req, res, next) => {
  try {
    const backendSearchConfig = await createBackendSearchConfig()
    const resultFormat = req.query.resultFormat == null ? 'json' : req.query.resultFormat
    const data = await getAllResults({
      backendSearchConfig,
      perspectiveID: req.body.perspectiveID,
      resultClass: req.params.resultClass,
      facetClass: req.query.facetClass || null,
      constraints: req.query.constraints == null ? null : req.query.constraints,
      resultFormat: resultFormat
    })
    if (resultFormat === 'csv') {
      res.writeHead(200, {
        'Content-Type': 'text/csv',
        'Content-Disposition': 'attachment; filename=results.csv'
      })
      res.end(data)
    } else {
      res.json(data)
    }
  } catch (error) {
    next(error)
  }
})

app.post(`${apiPath}/faceted-search/:resultClass/count`, async (req, res, next) => {
  const { params, body } = req
  try {
    const backendSearchConfig = await createBackendSearchConfig()
    const data = await getResultCount({
      backendSearchConfig,
      resultClass: params.resultClass,
      constraints: body.constraints,
      resultFormat: 'json'
    })
    res.json(data)
  } catch (error) {
    next(error)
  }
})

app.post(`${apiPath}/:resultClass/page/:uri`, async (req, res, next) => {
  const { params, body } = req
  try {
    const backendSearchConfig = await createBackendSearchConfig()
    const data = await getByURI({
      backendSearchConfig,
      perspectiveID: body.perspectiveID,
      resultClass: params.resultClass,
      uri: params.uri,
      facetClass: body.facetClass,
      constraints: body.constraints,
      resultFormat: 'json'
    })
    res.json(data)
  } catch (error) {
    next(error)
  }
})

app.post(`${apiPath}/faceted-search/:facetClass/facet/:id`, async (req, res, next) => {
  const { params, body } = req
  try {
    const backendSearchConfig = await createBackendSearchConfig()
    const data = await getFacet({
      backendSearchConfig,
      facetClass: params.facetClass,
      facetID: params.id,
      sortBy: body.sortBy,
      sortDirection: body.sortDirection,
      constraints: body.constraints,
      resultFormat: 'json',
      constrainSelf: body.constrainSelf
    })
    res.json(data)
  } catch (error) {
    next(error)
  }
})

app.get(`${apiPath}/full-text-search`, async (req, res, next) => {
  try {
    const backendSearchConfig = await createBackendSearchConfig()
    const data = await queryJenaIndex({
      backendSearchConfig,
      queryTerm: req.query.q,
      resultClass: 'fullTextSearch',
      resultFormat: 'json'
    })
    res.json(data)
  } catch (error) {
    next(error)
  }
})

app.get(`${apiPath}/federated-search`, async (req, res, next) => {
  const perspectiveID = req.query.perspectiveID
  let queryTerm = ''
  let latMin = 0
  let longMin = 0
  let latMax = 0
  let longMax = 0
  if (has(req.query, 'q')) {
    queryTerm = req.query.q
  }
  if (has(req.query, 'latMin')) {
    latMin = req.query.latMin
    longMin = req.query.longMin
    latMax = req.query.latMax
    longMax = req.query.longMax
  }
  try {
    const backendSearchConfig = await createBackendSearchConfig()
    // console.log(backendSearchConfig[perspectiveID])
    const data = await getFederatedResults({
      perspectiveID,
      federatedSearchDatasets: backendSearchConfig[perspectiveID].datasets,
      queryTerm,
      latMin,
      longMin,
      latMax,
      longMax,
      datasets: castArray(req.query.dataset),
      resultFormat: req.query.resultFormat == null ? 'json' : req.query.resultFormat
    })
    res.json(data)
  } catch (error) {
    next(error)
  }
})

app.get(`${apiPath}/wfs`, async (req, res, next) => {
  const layerIDs = castArray(req.query.layerID)
  try {
    const data = await Promise.all(layerIDs.map(layerID => fetchGeoJSONLayer({ layerID })))
    res.json(data)
  } catch (error) {
    next(error)
  }
})

// https://www.maanmittauslaitos.fi/karttakuvapalvelu/tekninen-kuvaus-wmts
app.get(`${apiPath}/nls-wmts`, async (req, res, next) => {
  const url = `https://karttakuva.maanmittauslaitos.fi/maasto/wmts/1.0.0/${req.query.layerID}/default/WGS84_Pseudo-Mercator/${req.query.z}/${req.query.y}/${req.query.x}.png`
  const headers = {
    'Content-Type': 'image/png',
    Authorization: `Basic ${process.env.NLS_WMTS_BASIC_AUTH}`
  }
  try {
    const response = await axios({
      method: 'get',
      url,
      responseType: 'arraybuffer',
      headers
    })
    res.end(response.data, 'base64')
  } catch (error) {
    next(error)
  }
})

// https://www.maanmittauslaitos.fi/karttakuvapalvelu/tekninen-kuvaus-wmts
app.get(`${apiPath}/nls-wmts-open`, async (req, res, next) => {
  const url = `https://avoin-karttakuva.maanmittauslaitos.fi/avoin/wmts/1.0.0/${req.query.layerID}/default/WGS84_Pseudo-Mercator/${req.query.z}/${req.query.y}/${req.query.x}.png`
  const headers = {
    'Content-Type': 'image/png',
    Authorization: `Basic ${process.env.NLS_API_KEY_BASE64}`
  }
  try {
    const response = await axios({
      method: 'get',
      url,
      responseType: 'arraybuffer',
      headers
    })
    res.end(response.data, 'base64')
  } catch (error) {
    next(error)
  }
})

// // https://www.maanmittauslaitos.fi/karttakuvapalvelu/tekninen-kuvaus-vektoritiilet
app.get(`${apiPath}/nls-vectortiles-open`, async (req, res, next) => {
  const url = 'https://avoin-karttakuva.maanmittauslaitos.fi/vectortiles/stylejson/v20/taustakartta.json?TileMatrixSet=WGS84_Pseudo-Mercator'
  const headers = {
    Authorization: `Basic ${process.env.NLS_API_KEY_BASE64}`
  }
  try {
    const response = await axios({
      method: 'get',
      url,
      headers
    })
    res.json(response.data)
  } catch (error) {
    next(error)
  }
})

app.get(`${apiPath}/fha-wms`, async (req, res, next) => {
  const headers = {
    Authorization: `Basic ${process.env.FHA_WMS_BASIC_AUTH}`
  }
  const { service, request, layers, styles, format, transparent, version, width, height, crs, bbox } = req.query
  const mapServerParams = {
    service,
    request,
    layers,
    styles,
    format,
    transparent,
    version,
    width,
    height,
    crs,
    bbox
  }
  const url = `http://137.116.207.73/geoserver/ows?${querystring.stringify(mapServerParams)}`
  try {
    const response = await axios({
      method: 'get',
      url,
      responseType: 'arraybuffer',
      headers
    })
    res.end(response.data, 'base64')
  } catch (error) {
    console.log(error)
    next(error)
  }
})

app.get(`${apiPath}/wfs`, async (req, res, next) => {
  const layerIDs = castArray(req.query.layerID)
  try {
    const data = await Promise.all(layerIDs.map(layerID => fetchGeoJSONLayer({ layerID })))
    res.json(data)
  } catch (error) {
    next(error)
  }
})

app.get(`${apiPath}/void/:resultClass`, async (req, res, next) => {
  const { params } = req
  try {
    const backendSearchConfig = await createBackendSearchConfig()
    const data = await getAllResults({
      backendSearchConfig,
      resultClass: params.resultClass,
      resultFormat: 'json'
    })
    res.json(data)
  } catch (error) {
    next(error)
  }
})

// Express server is used to serve the React app only in production
if (!isDevelopment) {
  /*  Routes are matched to a url in order of their definition
      Redirect all the the rest for react-router to handle */
  app.get('*', function (request, response) {
    response.sendFile(path.join(publicPath, 'index.html'))
  })
}

const servingInfo = isDevelopment
  ? 'NODE_ENV=development, so Webpack serves the React app'
  : `Static files (e.g. the React app) will be served from ${publicPath}`

const port = app.get('port')

app.listen(port, () =>
  console.log(`
        Express server listening on port ${port}
        API path is ${apiPath}
        ${servingInfo}
      `)
)