weather/dark-sky.js

const log = console.log
const fs = require('fs')
const {table, getBorderCharacters} = require('table')
// const argv = require('yargs').argv

const TABLE_CONFIG = {
  // columns: {
    // 0: { alignment: 'center' },
    // 1: { alignment: 'center' },
    // 2: { alignment: 'center' },
  // },
  border: getBorderCharacters(`ramac`)
}
const HIDE_PRECIP_LESS_THAN = 10
// const CREDIT_MSG = "Powered by Dark Sky: https://darksky.net/poweredby/"
// const CREDIT_MSG = "https://darksky.net/poweredby • https://smol.gq/wthr-src\n"
const CREDIT_MSG = "darksky.net/poweredby • smol.gq/wthr-src\n\n"

// https://medium.com/@osiolabs/read-write-json-files-with-node-js-92d03cc82824
const jsonReader = (filePath, cb) => {
  fs.readFile(filePath, (err, fileData) => {
    if (err) {
      log(err)
      return cb && cb(err)
    }
    try {
      const object = JSON.parse(fileData)
      // log(filePath, object['latitude'])
      return cb && cb(null, object)
    } catch(err) {
      log(err)
      return cb && cb(err)
    }
  })
}

const round5 = x => { return Math.ceil(x / 5) * 5 }

const updateTempHigh = (temp, index, tempHigh) => { 
  // +1 to offset header
  return (temp > tempHigh[0]) ? [temp, index + 1] : tempHigh
}

const updateTempLow = (temp, index, tempLow) => { 
  return (temp < tempLow[0]) ? [temp, index + 1] : tempLow
}

const getWeatherTable = (jsonFile, loc, orientation) => { 
  return new Promise((resolve, reject) => { 
    jsonReader(jsonFile, (err, weatherInfo) => {
      if (err) {
        reject(err)
      }
      
      let output = loc + '\n'
      // value, index
      let tempHigh = [-100, -1]
      let tempLow = [100, -1]

      weatherInfo['hourly']['data'][0] = weatherInfo['currently']
      if (orientation == 'v') {
        const infoList = [['H', '°C', 'R','%P']]
        for (let i = 0; i < 12; i++) {
          const hourInfo = weatherInfo['hourly']['data'][i]
          const date = new Date(hourInfo['time'] * 1000)
          const temp = Math.floor(hourInfo['apparentTemperature'])
          tempHigh = updateTempHigh(temp, i, tempHigh)
          tempLow = updateTempLow(temp, i, tempHigh)
          const precipProbability = round5(hourInfo['precipProbability'] * 100)
          const precipText = ((precipProbability < HIDE_PRECIP_LESS_THAN)
            ? '' : precipProbability)
          infoList.push([
            date.getHours(),
            temp,
            ((hourInfo['summary'].includes('Rain')) ? 'Y' : ''),
            precipText,
          ])
        }
        infoList[tempHigh[1]][1] = `${infoList[tempHigh[1]][1]}+`
        infoList[tempLow[1]][1] = `${infoList[tempLow[1]][1]}-`
        output += table(infoList, TABLE_CONFIG)
      } else {
        // horizontal
        const hoursList = ['H']
        const tempsList = ['°C']
        const rainList = ['R']
        const precipList = ['%P']
        for (let i = 0; i < 16; i += 2) {
          const hourInfo = weatherInfo['hourly']['data'][i]
          const date = new Date(hourInfo['time'] * 1000)
          const temp = Math.floor(hourInfo['apparentTemperature'])
          tempHigh = updateTempHigh(temp, i/2, tempHigh)
          tempLow = updateTempLow(temp, i/2, tempHigh)
          hoursList.push(date.getHours())
          tempsList.push(temp)
          rainList.push((hourInfo['summary'].includes('Rain')) ? 'Y' : '')
          const precipProbability = round5(hourInfo['precipProbability'] * 100)
          precipList.push((precipProbability < HIDE_PRECIP_LESS_THAN)
            ? '' : precipProbability)
        }
        tempsList[tempHigh[1]] = `${tempsList[tempHigh[1]]}+`
        tempsList[tempLow[1]] = `${tempsList[tempLow[1]]}-`
        output += table([hoursList, tempsList, rainList, precipList],
          TABLE_CONFIG)
      }
      resolve(output)
    })
  })
}

const formatTimeUnit = unit => { return ((unit < 10) ? '0' : '') + unit }

const getTablePromises = [
  getWeatherTable('./markham.json', 'Markham', 'h'),
  getWeatherTable('./markham.json', 'Markham', 'v'),
  getWeatherTable('./toronto.json', 'Toronto', 'h'),
  getWeatherTable('./toronto.json', 'Toronto', 'v'),
]
Promise.all(getTablePromises).then(tables => {
  const mText = tables[0]
  const mvText = tables[1]
  const tText = tables[2]
  const tvText = tables[3]
  const writeErrorHandler = error => { if (error) { throw error } }
  fs.writeFile('mt.txt', CREDIT_MSG + mText + '\n' + tText, writeErrorHandler)
  fs.writeFile('mtv.txt', CREDIT_MSG + mvText + '\n' + tvText, writeErrorHandler)
  fs.writeFile('m.txt', CREDIT_MSG + mText, writeErrorHandler)
  fs.writeFile('mv.txt', CREDIT_MSG + mvText, writeErrorHandler)
  fs.writeFile('t.txt', CREDIT_MSG + tText, writeErrorHandler)
  fs.writeFile('tv.txt', CREDIT_MSG + tvText, writeErrorHandler)
})