app.js

const express = require('express')
const https = require('https')
const bodyParser = require('body-parser')
process.env.NODE_ENV = 'development';
const app = express()
app.use(bodyParser.json())

//source :   http://covid19.sante.gov.dz/carte/
let GOV_API = "https://services8.arcgis.com/yhz7DEAMzdabE4ro/arcgis/rest/services/Cas_confirme_view/FeatureServer/0/query?f=json&where=1%3D1&returnGeometry=false&outFields=*&orderByFields=Cas_confirm%20desc&resultRecordCount=48";
let GOV_API_TOTAL = 'https://services8.arcgis.com/yhz7DEAMzdabE4ro/arcgis/rest/services/Cas_confirme_view/FeatureServer/0/query?f=json&where=1%3D1&returnGeometry=false&spatialRel=esriSpatialRelIntersects&outFields=*&outStatistics=%5B%7B%22statisticType%22%3A%22sum%22%2C%22onStatisticField%22%3A%22D%C3%A9c%C3%A9s%22%2C%22outStatisticFieldName%22%3A%22D%C3%A9c%C3%A9s%22%7D%2C%7B%22statisticType%22%3A%22sum%22%2C%22onStatisticField%22%3A%22R%C3%A9cup%C3%A9r%22%2C%22outStatisticFieldName%22%3A%22R%C3%A9cup%C3%A9r%22%7D%2C%7B%22statisticType%22%3A%22sum%22%2C%22onStatisticField%22%3A%22active%22%2C%22outStatisticFieldName%22%3A%22active%22%7D%5D&cacheHint=true'


app.get('/', (request, response) => {
  response.json({
    msg: "this is covid19 statistics of algeria",
    APIs: {
      0: '/api/province/all    --- get all provinces stats',
      1: '/api/province/:provinceCode  -- get province stats eg: /api/covid19/9 fro BLIDA',
      2: '/api/total/  -- get total stats (deaths, active,recovered, total)'
    }
  })
})



//get overal stats
app.get('/api/total', (request, response) => {

  https.get(GOV_API_TOTAL, (res) => {

    // Async, append chunks of data as it comes
    let body = "";
    res.on("data", data => {
      body += data;
    });

    //When finished, treat it
    res.on('end', () => {


      //The data is in attributes field
      let { Décés, Récupér, active } = JSON.parse(body).features[0].attributes
      response.json({
        active,
        recovered: Récupér,
        dead: Décés,
        total: Récupér + Décés + active
      })
    })

    res.on("error", (error) => {
      response.json(error)
    })
  })
})
//get all provinces statistics
app.get('/api/province/all', (request, response) => {
  https.get(GOV_API, (res) => {

    // Async, append chunks of data as it comes
    let body = "";
    res.on("data", data => {
      body += data;
    });

    //When finished, treat it
    res.on('end', () => {

      //may through 48 feature
      //The data is in attributes field
      //Bizzare naming here, don't mind them
      let allProvinceStatistics = JSON.parse(body).features.map(({ attributes: {
        NOM_WILAYA, wilayat, WILAYA,
        Décés, Récupér, active, Cas_confirm, Femelle, Males,
        Date_rapport,
        A1_25, A25_34, a35_44, a45_59, A_60, cinqantneuf, soixantedix, plus } }) => {
        return ({
          province: {
            codeName: WILAYA,
            french: NOM_WILAYA,
            arabic: wilayat,
          },
          deaths: Décés,
          recovered: Récupér,
          activeCases: active ? active : 0,
          totalConfirmedCases: Cas_confirm,
          females: Femelle,
          males: Males,
          lastUpdated: new Date(Date_rapport),
          ageStatistics: [
            {
              from: 0,
              to: 5,
              count: A1_25 || 0
            }, {
              from: 5,
              to: 15,
              count: A25_34 || 0
            }, {
              from: 15,
              to: 25,
              count: a35_44 || 0
            }, {
              from: 25,
              to: 35,
              count: a45_59 || 0
            }, {
              from: 35,
              to: 45,
              count: A_60 || 0
            }, {
              from: 45,
              to: 60,
              count: cinqantneuf || 0
            }, {
              from: 60,
              to: 70,
              count: soixantedix || 0
            }, {
              from: 70,
              to: 100,
              count: plus || 0
            },
          ],
        });
      })

      response.json(allProvinceStatistics)
    })

    res.on("error", (error) => {
      response.json(error)
    })
  })
});
//get one province statistics
app.get('/api/province/:provinceCode', (request, response) => {

  let provinceCode = Number(request.params.provinceCode)

  // Must be an 0 < interger < 49 
  if (!Number.isInteger(provinceCode) || provinceCode > 48 || provinceCode < 1) {
    response.json({ msg: "Please give an Integer number from 1 to 48" })
    return
  }
  //fixing issue: https://github.com/bilobom/covid19API/issues/2
  provinceCode += 1
  // change the orderByFields to WILAYA , put resultRecordCount = provinceCode , you get all wilayas
  // up till the last resultRecordCount, and then pop the array to get last result
  let GOV_API_WILAYA = 'https://services8.arcgis.com/yhz7DEAMzdabE4ro/arcgis/rest/services/Cas_confirme_view/FeatureServer/0/query?f=json&where=1%3D1&returnGeometry=false&outFields=*&orderByFields=WILAYA&resultRecordCount=' + provinceCode;

  https.get(GOV_API_WILAYA, (res) => {
    let body = "";
    res.on("data", data => {
      body += data;
    });
    res.on('end', () => {
      //The data is in attributes field poped from features returned
      let ProvinceRawStatistics = JSON.parse(body).features.pop().attributes

      //Bizzare naming here, don't mind them    
      let {
        NOM_WILAYA, wilayat, WILAYA,
        Décés, Récupér, active, Cas_confirm, Femelle, Males,
        Date_rapport,
        A1_25, A25_34, a35_44, a45_59, A_60, cinqantneuf, soixantedix, plus } = ProvinceRawStatistics

      let ProvinceStatistics = {
        province: {
          codeName: WILAYA,
          french: NOM_WILAYA,
          arabic: wilayat,
        },
        deaths: Décés,
        recovered: Récupér,
        activeCases: active ? active : 0,
        totalConfirmedCases: Cas_confirm,
        females: Femelle,
        males: Males,
        lastUpdated: new Date(Date_rapport),
        ageStatistics: [
          {
            from: 0,
            to: 5,
            count: A1_25 || 0
          }, {
            from: 5,
            to: 15,
            count: A25_34 || 0
          }, {
            from: 15,
            to: 25,
            count: a35_44 || 0
          }, {
            from: 25,
            to: 35,
            count: a45_59 || 0
          }, {
            from: 35,
            to: 45,
            count: A_60 || 0
          }, {
            from: 45,
            to: 60,
            count: cinqantneuf || 0
          }, {
            from: 60,
            to: 70,
            count: soixantedix || 0
          }, {
            from: 70,
            to: 100,
            count: plus || 0
          },
        ],
      }


      response.json(ProvinceStatistics)
    })

    res.on("error", (error) => {
      response.json(error)
    })
  })
})


function normalizePort(val) {
  var port = parseInt(val, 10);

  if (isNaN(port)) {
    // named pipe
    return val;
  }

  if (port >= 0) {
    // port number
    return port;
  }

  return false;
}
var port = normalizePort(process.env.PORT || '4000');

app.listen(port, () => {
  console.log("listening on port", port)
})