normals-for-threadex-stations.js

const fs = require('fs')
const client = require('mongodb').MongoClient
const turf = require('@turf/turf')
const rimraf = require('rimraf')
const mkdirp = require('mkdirp')

const ncdcConnection = 'mongodb://localhost:27017/ncdc'
const ncdcCollection = 'normals'

let geojsonThreadex = 'json/threadex.geojson'
let stationsThreadex = JSON.parse(fs.readFileSync(geojsonThreadex))
let stationCount = stationsThreadex.features.length
let queried = 0
let outFields = { 'properties.min-values': true, 'properties.max-values': true, 'properties.avg-values': true }
let allDistances = []
let outFolder = 'json/normals-for-threadex-stations/'

rimraf(outFolder, (err) => {
  if (err) return console.log('rimraf error...', error)
  mkdirp(outFolder, (err) => {
    if (err) return console.log('mkdir error', error)
    processData()
  })
})

let getNormals = (station, cb) => {
  // console.log(station)
  client.connect(ncdcConnection, (err, db) => {
    // console.log(`station... ${station.properties.name}`)
    let collection = db.collection(ncdcCollection)
    let [lon, lat] = station.geometry.coordinates
    collection.geoNear(lon, lat, { num: 1, spherical: true}, (err, docs) => {
      db.close()
      if ( docs ) {
        let { properties } = docs.results[0].obj
        // console.log(properties)
        let measurements = ['min-values', 'max-values', 'avg-values']
        let lengths = measurements.map(p => properties[p].length)
        let distance = parseInt(turf.distance(station, docs.results[0].obj, 'miles') * 100) / 100
        allDistances.push(distance)
        console.log(`${queried}, ${station.properties.place}/${properties.name} lengths:  ${lengths.join(', ')}, ${distance}`)
        let outFile = `${outFolder}${station.properties.place}.json`
        let outData = { 
          place: station.properties.place, 
          station: station.properties.station, 
          normals: {} 
        }
        outData['miles-to-threadex'] = distance
        outData.normals.min = properties[measurements[0]]
        outData.normals.max = properties[measurements[1]]
        outData.normals.avg = properties[measurements[2]]
        fs.writeFileSync(outFile, JSON.stringify(outData, null, 2))
        console.log(`...wrote JSON for ${station.properties.place}`)
      } else {
        console.log(`${queried}, \tno results for ${station}`)
      }

      queried += 1
      if ( queried < stationCount ) {
        processData()
      } else {
        let maxDistance = Math.max.apply(null, allDistances)
        console.log(`\nMax distance:  ${maxDistance}\nFinished.`)
      }
    })
  })
}

let processData = () => {
  let next = stationsThreadex.features[queried]
  getNormals(next, processData);
}