rural-attractivness-service/index.js

const express = require('express');
const app = express();
const helpers = require('./helpers.js');
const nutsData = require('./nuts-data.js');
const cors = require('cors');

var _datasetsFilePath = 'data/datasets.csv';
var _dataFilePath = 'data/data.csv';
var _datasets = undefined;
var _ruralData = undefined;

// parse incoming POST requests body to JSON
app.use(express.json());
// handle CORS
app.use(cors())

/* Dummy web service call without the method specified */
app.get('/', (req, res) => {
    res.send('Rural attractivness web service');
});

/* Makes refresh of the data loaded to the server objects.
   Must be called after the CSV data has changed */
app.get('/refresh', (req, res, next) => {
    nutsData.loadDatasets(_datasetsFilePath, function (ds) {
        console.log('Datasets loaded succesfully');
        _datasets = ds;
        nutsData.loadRuralData(_dataFilePath, _datasets, function (rd) {
            console.log('Rural data loaded succesfully');
            _ruralData = rd;
        });
    });
});

/* Returns JSON array with the list of all the datasets */
app.get('/datasets', (req, res, next) => {
    if (_datasets) {
        helpers.formatResponse(_datasets, req, res);
    }
    else {
        nutsData.loadDatasets(_datasetsFilePath, function (ds) {
            console.log('Datasets loaded callback');
            _datasets = ds;
            helpers.formatResponse(_datasets, req, res);
        });
    }
});

/* Returns attractivity data for the region with ID equal to the 'nuts' parameter */
app.get('/scores/:nuts', (req, res, next) => {
    if (_ruralData) {
        returnReqionScores(req.params.nuts, req, res);
    }
    else {
        if (_datasets) { // datasets must be loaded prior to data loading
            nutsData.loadRuralData(_dataFilePath, _datasets, function (rd) {
                _ruralData = rd;
                returnReqionScores(req.params.nuts, req, res);
            });
        }
        else {
            nutsData.loadDatasets(_datasetsFilePath, function (ds) {
                _datasets = ds;

                nutsData.loadRuralData(_dataFilePath, _datasets, function (rd) {
                    _ruralData = rd;
                    returnReqionScores(req.params.nuts, req, res);
                });
            });
        }
    }
});

/* Returns attractivity data for all the regions in source CSV data. */
app.get('/scores', (req, res, next) => {
    if (_ruralData)
        helpers.formatResponse(_ruralData, req, res);
    else {
        if (_datasets) { // datasets must be loaded prior to data loading
            nutsData.loadRuralData(_dataFilePath, _datasets, function (rd) {
                _ruralData = rd;
                helpers.formatResponse(_ruralData, req, res);
            });
        }
        else {
            nutsData.loadDatasets(_datasetsFilePath, function (ds) {
                _datasets = ds;

                nutsData.loadRuralData(_dataFilePath, _datasets, function (rd) {
                    _ruralData = rd;
                    helpers.formatResponse(_ruralData, req, res);
                });
            });
        }
    }
});

/* Computes and returns attractivity data for all the NUTS regions based on the 
   incomming datasets and factor weights. */
app.post('/scores', (req, res, next) => {
    //console.log("query: " + JSON.stringify(req.body.factors, null, 4));

    if (_ruralData) {
        returnAllScores(req, res);
    }
    else {
        if (_datasets) { // datasets must be loaded prior to data loading
            nutsData.loadRuralData(_dataFilePath, _datasets, function (rd) {
                _ruralData = rd;
                returnAllScores(req, res);
            });
        }
        else {
            nutsData.loadDatasets(_datasetsFilePath, function (ds) {
                _datasets = ds;

                nutsData.loadRuralData(_dataFilePath, _datasets, function (rd) {
                    _ruralData = rd;
                    returnAllScores(req, res);
                });
            });
        }
    }
});

// start the service on the port xxxx
app.listen(3000, () => console.log('Rural attractivity WS listening on port 3000...'));


function returnAllScores(req, res) {
    var resData = [];
    _ruralData.forEach(region => {
    //var region = _ruralData[0];
        var sumWeight = 0;
        var sumValue = 0;
        let regionIndexes = { code: region.nuts };

        req.body.factors.forEach(f => {
            let fi = nutsData.getFactorIndex(region, f);
            //console.log("f: " + JSON.stringify(f));
            //console.log("fi: " + JSON.stringify(fi));

            regionIndexes[f.factor] = fi.index;
            sumValue += fi.sumValue * f.weight;
            sumWeight += fi.sumWeight;
        });

        regionIndexes.aggregate = sumValue / sumWeight;
        resData.push(regionIndexes);
    });

    helpers.formatResponse(resData, req, res);
}

function returnReqionScores(nuts, req, res) {
    var found = false;
    res.header("Content-Type", 'application/json');

    _ruralData.forEach(region => {
        if (region.nuts == nuts) {
            helpers.formatResponse(region, req, res);
           found = true;
        }
    });

    if (!found)
	    // NUTS region not found
	    res.status(404).send('NUTS region not found.');
}