server.js

var http = require('http');
var express = require('express');
var app = express();
var fs = require("fs");
var mysql = require('mysql');
var utils = require('./utils.js');
var rest_client = require('./rest_client.js');
var config = require('./config.js');

// TESTING PURPOSE //
// var contents = fs.readFileSync("./data/kd_sample.json");
// var jsonContent = JSON.parse(contents);
// TESTING PURPOSE //

var con = mysql.createConnection({
  host: config.db.host,
  user: config.db.user,
  password: config.db.password,
  database: config.db.name,
  port: config.db.port
});

app.get('/findByIcoAndYear', function (req, res) {
  if (!req.query.ico || !req.query.year) {
    res.send("ICO or year is missing");
  } else {
    var ico = req.query.ico.replace(/^\D+/g, '');
    var year = req.query.year.replace(/^\D+/g, '');

    retval = [];
    if (ico.length != 0) {
      // con.connect(function(err) {
      //   if (err) throw err;
      con.query(`select * from apa_ziadosti where ICO = ${ico} AND Rok = ${year};`, function (err, result, fields) {
        if (err) throw err;
        var gis_lokalita_diely = [];

        // map from sql DB
        result.forEach(element => {
          retval.push(utils.fromSqlToKD(element));
        });

        // get unique LOKALITA values
        var lokality = Array.from(new Set(retval.map(function (value, index) { return value.lokalita; })));

        // build LOKALITA IN (...) AND ZDKOD IN (...) array
        lokality.forEach(l => {
          var concrete_lokalita = retval.filter(element => element.lokalita == l);
          var concrete_diel = Array.from(new Set(concrete_lokalita.map(function (value, index) { return value.diel; })));
          gis_lokalita_diely.push(utils.buildLokalitaDielQuery(l, concrete_diel));
        })

        // call VUPOP
        var vupop_data = [];
        var batch_size = config.batchSize;

        console.log("VUPOP: calling for " + gis_lokalita_diely.length);
        for (var i = 1; i < gis_lokalita_diely.length + 1; i += batch_size) {
          var batch_arr = rest_client.findPolygonsGet({ hist_layer_year: year, lokalita_diely: gis_lokalita_diely.slice(i - 1, i * batch_size) }, rest_client.TERM_ICO_YEAR);

          if (batch_arr && batch_arr.features) {
            batch_arr.features.forEach(e => {
              vupop_data.push(e);
            })
          }
        }
        console.log("VUPOP: Found " + vupop_data.length + " features");
        // join data with geometry
        if (vupop_data) {
          retval.forEach(element => {
            f = vupop_data.find(f => f.properties.ZKODKD == element.diel && f.properties.LOKALITA == element.lokalita);
            if (f != null) {
              element.feature = Array(f);
            } else {
              element.feature = [];
            }
          });
          setHeaders(res);
          res.send(retval);
          res.end();
        }
      });
    } else {
      setHeaders(res);
      res.send(retval);
      res.end();
    }
  }
});

app.get('/findByPlace', function (req, res) {
  if (!req.query.place || !req.query.year) {
    res.send("Place or year is missing");
  } else {

    var place = encodeURIComponent(req.query.place);
    var year = req.query.year.replace(/^\D+/g, '');

    retval = [];

    // console.log(place);
    var features = rest_client.findPolygonsGet(place, rest_client.TERM_PLACE);
    var retval = [];

    if (features && features.features) {
      features = features.features;
      var i = 0;
      features.forEach(feature => {
        retval.push(findParts(features, i, year));
        i += 1;
      });
    }

    var final_items_arr = [];

    retval.forEach(p => {
      p.then((body) => {
        if (body) {
          try {
            var json_body = JSON.parse(body);

            if (json_body && json_body.features) {
              json_body.features.forEach(feature => {
                var new_item = {
                  ziadatel: "",
                  rok: feature.properties['ROK'],
                  ico: "",
                  lokalita: feature.properties['LOKALITA'],
                  diel: feature.properties['ZKODKD'],
                  kultura: feature.properties['KULTURA'],
                  vymera: (Math.round(feature.properties['VYMERA'] * 100) / 100),
                  feature: [feature]
                }
                final_items_arr.push(new_item);
              });
            }
          } catch (error) {
            console.log("PARSING obce - error occurred.");
          }
        }
        setHeaders(res);
        res.send(final_items_arr);
      });
    });
  }
});

async function findParts(features, i, year) {
  if (features.length > 0 && features.length > i) {
    var municipality_name = features[i].attributes.NM2;

    console.log('Requesting parts for ' + municipality_name);

    let a = await rest_client.findPolygonsPost(features[i], year);

    return a;
  }
}

function setHeaders(res) {
  // Website you wish to allow to connect
  res.setHeader('Access-Control-Allow-Origin', config.server.allowedOrigins);

  // Request methods you wish to allow
  res.setHeader('Access-Control-Allow-Methods', 'GET, POST, OPTIONS, PUT, PATCH, DELETE');

  // Request headers you wish to allow
  res.setHeader('Access-Control-Allow-Headers', 'X-Requested-With,content-type');

  // Set to true if you need the website to include cookies in the requests sent
  // to the API (e.g. in case you use sessions)
  res.setHeader('Access-Control-Allow-Credentials', true);
}

/************ Init server ****************/
var server = app.listen(config.server.port, function () {
  var host = server.address().address
  var port = server.address().port

  console.log("KD map is listening at http://%s:%s\n", host, port)
})