Files
traintracker/functions/index.js
2023-03-03 18:49:01 +00:00

115 lines
4.1 KiB
JavaScript

// Firebase imports
const functions = require("firebase-functions");
const admin = require('firebase-admin');
const cors = require('cors')({ origin: true });
admin.initializeApp();
// external imports
const axios = require('axios');
const parseString = require('xml2js').parseString;
// function to fetch live train data from the Firestore database
exports.getLiveTrainData = functions.https.onRequest((request, response) => {
response.set('Access-Control-Allow-Origin', '*');
response.set('Access-Control-Allow-Credentials', 'true');
let jsonData = [];
cors(request, response, () => {
// fetch the "liveTrainData" collection
admin.firestore().collection('liveTrainData').get().then((snapshot) => {
if (snapshot.empty) {
response.status(404).send({data: "Error fetching live train data from the database"});
return;
}
// iterate through each of the collection's documents
snapshot.forEach(doc => {
jsonData.push(doc.data());
});
response.json({data: jsonData});
})
});
})
// function to fetch station data from the Firestore database
exports.getStationData = functions.https.onRequest((request, response) => {
response.set('Access-Control-Allow-Origin', '*');
response.set('Access-Control-Allow-Credentials', 'true');
let jsonData = [];
cors(request, response, () => {
// fetch the "stations" collection
admin.firestore().collection('stations').get().then((snapshot) => {
if (snapshot.empty) {
response.status(404).send({data: "Error fetching station data from the database"})
return;
}
// iterate through each of the collection's documents
snapshot.forEach(doc => {
jsonData.push(doc.data());
});
response.json({data: jsonData});
})
});
})
// helper function to fetch data from Irish Rail given a train type (mainland, suburban, dart)
function callIrishRail(request, response, db, trainTypeCode) {
cors(request, response, () => {
let url = 'https://api.irishrail.ie/realtime/realtime.asmx/getCurrentTrainsXML_WithTrainType?TrainType=' + trainTypeCode
axios.get(url)
.then((res) => {
var batchWrite = db.batch();
// XML to JSON
parseString(res.data, function(err, result) {
let jsonStr = JSON.stringify(result);
let jsonObj = JSON.parse(jsonStr);
let jsonData = jsonObj.ArrayOfObjTrainPositions.objTrainPositions;
jsonData.forEach((doc) => {
// ignore trains with longitudes or latitudes equal zero
if (!(doc["TrainLongitude"] == 0 || doc["TrainLatitude"] == 0)) {
doc["TrainType"] = [trainTypeCode]
// set the train's code as the document ID
var docID = db.collection('liveTrainData').doc(doc["TrainCode"][0]);
batchWrite.set(docID, doc);
}
});
batchWrite.commit()
.catch((error) => {
return false;
})
})
})
.catch((error) => {
return false;
})
})
}
// function to populate the Firestore database with live train data from Irish Rail
exports.postLiveTrainData = functions.https.onRequest((request, response) => {
response.set('Access-Control-Allow-Origin', '*');
response.set('Access-Control-Allow-Credentials', 'true');
cors(request, response, () => {
// batch delete all of the "liveTrainData" collections's documents
var db = admin.firestore();
admin.firestore().collection('liveTrainData').get().then((snapshot) => {
var batchDelete = db.batch();
snapshot.forEach(doc => {
batchDelete.delete(doc.ref);
});
// fetch data using codes M (mainland), S (suburban), D (dart)
batchDelete.commit().then(function() {
if (callIrishRail(request, response, db, "M") == false ||
callIrishRail(request, response, db, "S") == false ||
callIrishRail(request, response, db, "D") == false) {
response.send({data: "Error fetching data from the IrishRail API"});
}
response.send({data: "Successfully fetched and uploaded live train data from Irish Rail"});
})
})
})
})