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262// call the packages we need
var express = require('express'); // call express
var app = express(); // define our app using express
var bodyParser = require('body-parser');
var request = require('request');
var http = require('http');
var redis = require('redis');
var config = require('./config_student.json');
var arr = Object.keys(config).map(function(k) { return config[k] });
var pg = require('pg');
var connectionString = 'postgres://postgres:postgres@localhost:5432/infinity_rules_db';
var client = new pg.Client(connectionString);
client.connect();
// configure app to use bodyParser()
// this will let us get the data from a POST
app.use(bodyParser.urlencoded({ extended: true }));
app.use(bodyParser.json());
var port = process.env.PORT || 16385; // set our port
// ROUTES FOR OUR API
// =============================================================================
var router = express.Router(); // get an instance of the express Router
// middle-ware to use for all requests
router.use(function(req, res, next) {
// do logging
console.log('Something is happening.');
next(); // make sure we go to the next routes and don't stop here
});
// test route to make sure everything is working (accessed at GET http://localhost:8080/api)
router.get('/', function(req, res) {
invokeandProcessResponse(req , function(err, result){
if(err){
res.send(500, { error: 'something blew up' });
} else {
res.send(result);
}
});
});
var invokeandProcessResponse = function(req, callback){
var query = client.query("select * from tbl_rules");
var rows = [];
query.on('row', function(row) {
rows.push(row);
console.log(row);
console.log("Row successfully retrieved.");
});
query.on('end', function(res){
console.log(rows[0]);
var instanceToRouteTo;
console.log(req.method);
var firstCharacterString, firstCharacter;
var reqMethod;
var bodyParameters;
reqMethod = req.method;
bodyParameters = req.body;
if(req.method == "POST" )
{
firstCharacterString = bodyParameters['lastname'];
}
else if (req.method == "GET" || req.method == "PUT" || req.method == "DELETE")
{
firstCharacterString = req.url.split('/')[2];
}
firstCharacter = firstCharacterString[0];
console.log(firstCharacter);
if(firstCharacter >= 'A' && firstCharacter <= 'F')
{
instanceToRouteTo = rows[0].instancetorouteto;
instanceToRouteTo += req.url;
}
else if (firstCharacter >= "G" && firstCharacter <= 'Q')
{
instanceToRouteTo = rows[1].instancetorouteto;
instanceToRouteTo += req.url;
}
else if (firstCharacter >= 'R' && firstCharacter <= 'Z') {
instanceToRouteTo = rows[2].instancetorouteto;
instanceToRouteTo += req.url;
}
console.log('Sending ' +req.method+ ' request to ' + instanceToRouteTo);
request({ url : instanceToRouteTo,
method : req.method,
json : bodyParameters
}, function (error, response, body) {
if (!error && response.statusCode == 200) {
callback(null, response.body);
} else {
callback(error);
}
})
});
}
// m
// more routes for our API will happen here
router.route('/studentRouter/:ruleId')
// create a new student (accessed at POST http://localhost:8080/api/student)
.put(function(req, res) {
console.log("Updating " + req.body['instanceurl'] + " with rule id " + req.url.split('/')[2]);
var query = client.query("update tbl_rules set instancetorouteto=$1 where ruleid=$2", [req.body['instanceurl'],req.url.split('/')[2]]);
query.on('end', function(result) {
console.log("Updated " + req.body['instanceurl'] + " with rule id " + req.url.split('/')[2]);
res.json({message : 'Updated'});
});
// res.json({ message: 'Student created!' });
//Logic to save the student to db
});
/************************************************************
*
* Student API Endpoints
*
*************************************************************/
//API endpoint to add student to the students table
router.route('/student')
// create a new student (accessed at POST http://localhost:8080/api/student)
.post(function(req, res) {
invokeandProcessResponse(req , function(err, result){
if(err){
res.send(500, { error: 'something blew up' });
} else {
res.send(result);
}
});
// res.json({ message: 'Student created!' });
//Logic to save the student to db
});
//API end point to get student details (accessed at POST http://localhost:8080/api/student/id)
router.route('/student/:student_id')
// get the student with that id (accessed at GET http://localhost:8080/api/student/:student_id)
.get(function(req, res) {
invokeandProcessResponse(req , function(err, result){
if(err){
res.send(500, { error: 'something blew up' });
} else {
res.send(result);
}
});
})
// update the student with this id (accessed at PUT http://localhost:8080/api/student/:student_id)
.put(function(req, res) {
invokeandProcessResponse(req , function(err, result){
if(err){
res.send(500, { error: 'something blew up' });
} else {
res.send(result);
}
});
})
.delete(function(req, res) {
invokeandProcessResponse(req , function(err, result){
if(err){
res.send(500, { error: 'something blew up' });
} else {
res.send(result);
}
});
});
//API end point to get student details (accessed at POST http://localhost:8080/api/student/id)
var subscriber = redis.createClient(6379, 'localhost' , {no_ready_check: true});
subscriber.on('connect', function() {
console.log('Connected to Subscriber Redis');
});
var publisher = redis.createClient(6379, 'localhost' , {no_ready_check: true});
publisher.on('connect', function() {
console.log('Connected to Publisher Redis');
});
subscriber.on("message", function(channel, message) {
console.log("Message '" + message + "' on channel '" + channel + "' arrived!")
var parsedMessage = JSON.parse(message);
console.log(parsedMessage);
//message event, origin, studentname and coursename
var messageEvent = parsedMessage.event;
var messageOrigin = parsedMessage.origin;
var lname = parsedMessage.lname;
var courseno = parsedMessage.courseno;
var url;
for(var key in arr){
if(messageEvent == arr[key].event){
console.log("Event:" + arr[key].event);
if (arr[key].req_method == "DELETE") {
console.log(arr[key].req_method);
url = arr[key].publicurl + "/" + courseno + "/" + lname;
}
else {
url = arr[key].publicurl;
}
request( { url : url,
method : arr[key].req_method,
json : parsedMessage
}, function (error, response, body) {
if (!error && response.statusCode == 200) {
console.log(response.statusCode);
} else {
console.log(response.statusCode);
}
});
}
}
});
// REGISTER OUR ROUTES -------------------------------
// all of our routes will be prefixed with /api
app.use('/api', router);
// START THE SERVER
// =============================================================================
app.listen(port);
console.log('Magic happens on port ' + port);
//subscriber.subscribe("student");