const path = require('path');
const express = require('express');
const app = express();
const staticPath = path.join(__dirname, "/public");
var bodyParser = require('body-parser')
const cassandra = require('cassandra-driver');
const client = new cassandra.Client({
contactPoints: ['127.0.0.1:9042'],
localDataCenter: 'datacenter1',
keyspace: 'glink'
});
let id = 1; /* Ideally should initialize id to be nextFromDB or write to file and read */
const port = 63342; // Port that the server listens on */
const RADIUS_OF_EARTH_IN_MILES = 3958.7614580848;
app.use( bodyParser.json() );
app.use(bodyParser.urlencoded({
extended: true
}));
app.use(express.static(staticPath));
const GLINK_SIZE = 6;
function getRandomGLink() {
let glink = "";
glink = newString(GLINK_SIZE);
validateLink(glink);
return glink;
}
function validateLink(glink) {
let qry = "SELECT id FROM data WHERE glink = ? allow filtering";
client.execute(qry, [glink], {}, (err, result) => {
if(err) {
console.log(err.message);
glink = null;
}
if (result.rows.length === 0) {
console.log("Done");
} else {
console.log(glink);
glink = getRandomGLink();
}
});
return glink;
}
function newString(n) {
let str = "";
let symbols = "ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz";
for (let i = 0; i < n; i ++) {
str += symbols.charAt(Math.floor(Math.random() * 52));
}
return str;
}
function nextId() {
let next = id;
id = id + 1;
return next;
}
function filter(path) {
if (path.match(new RegExp("^/[a-zA-Z]+/*$"))) {
if (path.charAt(0) === '/') {
path = path.substring(1);
}
return path;
} else {
console.log("failed check. path is " + path);
return null;
}
}
function calculateDistance(lat1, lat2, long1, long2) {
console.log(lat1 + " " + lat2 + " " + long1 + " " + long2);
lat1 = lat1 * (Math.PI / 180);
lat2 = lat2 * (Math.PI / 180);
long1 = long1 * (Math.PI / 180);
long2 = long2 * (Math.PI / 180);
/* 2 asin(((lat2 - lat1)/2) ^ 2)*/
return (2 * Math.asin(Math.sqrt(Math.pow(Math.sin((lat2 - lat1)/2), 2) + Math.pow(Math.sin((long2 - long1)/2), 2) * Math.cos(lat1) * Math.cos(lat2))) * RADIUS_OF_EARTH_IN_MILES);
}
// app.get('/', (request, response) => {
// response.render("index.html");
// })
app.get('/node_modules/', (request, response) => {
response.redirect("./error.html");
})
app.get('/public/', (request, response) => {
response.redirect("./error.html");
})
const query = "INSERT INTO data (id, url, glink, time, isGeo, radius, latitude, longitude) VALUES (?, ?, ?, toTimestamp(now()), ?, ?, ?, ?)";
app.post('/__add', function(req, res) {
let input_url = req.body.url;
let input_glink = req.body.glink;
let input_checkbox = req.body.restricted;
let input_radius = req.body.radiusSelect;
let input_latitude = req.body.latitude;
let input_longitude = req.body.longitude;
let geoBool = false;
let geoString = "off";
//console.log("Received query " + input_url + " and " + input_glink);
if (input_checkbox) {
geoString = "on";
geoBool = true;
} else {
input_radius = null;
input_latitude = null;
input_longitude = null;
}
if (input_glink === "") {
input_glink = getRandomGLink();
let currID = nextId();
console.log(currID, input_url, input_glink, geoBool, input_radius, input_latitude, input_longitude)
client.execute(query, [currID, input_url, input_glink, geoBool, input_radius, input_latitude, input_longitude], {prepare: true}, function(err,result) {
if (err) {
res.send("
" + err.message + "
");
} else {
res.send("
New entry has been added with url = " + req.body.url + " and glink = " + input_glink + " with geolocation turned " + geoString + "
");
}
});
} else {
let selectQuery = "SELECT id FROM data where glink = ? allow filtering";
console.log(input_glink);
client.execute(selectQuery, [input_glink],{} ,function(err, result) {
if (result.rows.length === 0) {
let currID = nextId();
console.log("values are: " + currID, input_url, input_glink, geoBool, input_radius, input_latitude, input_longitude);
client.execute(query, [currID, input_url, input_glink, geoBool, input_radius, input_latitude, input_longitude], {prepare: true}, function(err,result) {
if (err) {
res.send("
" + err.message + "
");
} else {
res.send("" +
"
" +
"New entry has been added with geolocation turned " + geoString + " and url = " + req.body.url + " and glink = " +
"
" +
"" +
"
" +
"" +
"
" +
"" +
"");
}
});
} else {
res.send("
This glink has already been registered. Please try a different glink
");
}
});
}
})
app.post('/__check', function(req, res) {
let user_latitude = req.body.latitude;
let user_longitude = req.body.longitude;
let req_path = req.body.glink;
let selQry = "select url, latitude, longitude, radius from data where glink = ? allow filtering";
client.execute(selQry, [req_path], {}, function(err, result) {
if (result.rows.length === 0) {
res.redirect("/error.html");
} else {
let page = result.rows[0]["url"];
let latitude = result.rows[0]["latitude"];
let longitude = result.rows[0]["longitude"];
let radius = result.rows[0]["radius"];
console.log(user_latitude + user_longitude);
let distance = calculateDistance(user_latitude, latitude, user_longitude, longitude);
console.log(distance + " " + radius);
if (distance < radius) {
console.log("inside radius");
res.writeHead(301, {Location: page});
res.end();
} else {
res.redirect("./error.html ");
console.log("Outside radius");
}
}
})
})
/* Redirect requests to corresponding entry in database */
app.get('/*', (request, response, cb) => {
let original_request = request.path;
if (original_request.charAt(original_request.length - 1) === '/' && original_request.length > 1) {
original_request = original_request.substring(0, original_request.length - 1);
}
let req_path = filter(original_request);
if (!req_path) {
console.log(staticPath + original_request);
response.redirect("./error.html");
return cb("");
} else {
let geoQry = "select isGeo from data where glink = ? allow filtering";
client.execute(geoQry, [req_path], {}, function (err, result) {
if (result.rows.length === 0) {
response.redirect("/error.html");
} else {
let isGeo = result.rows[0]["isgeo"];
if (isGeo) {
response.send("
Redirecting you to the website! Please wait ...
");
response.end();
} else {
let selQry = "select url from data where glink = ? allow filtering";
client.execute(selQry, [req_path], {}, function (err, result) {
if (result.rows.length === 0) {
response.redirect("/error.html");
} else {
let page = result.rows[0]["url"];
response.writeHead(301, {Location: page});
response.end();
}
})
}
}
})
}
})
app.listen(port, function(){
console.log("server listening on port 63342");
})
/** Validate url and glink on client side as well */
/** Put the glink in a span or label and make it copyable */