const express = require('express');
const app = express();
const mongoose = require('mongoose');
const Schema = mongoose.Schema;
const database = 'mongodb://' + process.env.mongousr + ':' + process.env.mongopwd + '@mongo:27017/test';
const today = new Date();
var counter = 0;
const Prometheus = require('prom-client');
const fs = require('file-system');
const marked = require('marked');
const jwt = require('jsonwebtoken');
const bodyParser= require('body-parser');
const secret = 'wowmuchsecretveryhiddenwow'; 
const cookieParser = require('cookie-parser');

app.use(cookieParser());

// const morgan = require('morgan');
// // use morgan to log requests to the console
// app.use(morgan('dev'));

// global controller
// app.get('/*',function(req,res,next){
//   res.header.token = 'sample-token';
//   next(); // http://expressjs.com/guide.html#passing-route control
// });

// a middleware with no mount path; gets executed for every request to the app
// app.use(function(req, res, next) {
//   res.setHeader('charset', 'utf-8')
//   next();
// });

// database connection (with retries)
const options = {
  autoIndex: false, // Don't build indexes
  reconnectTries:30, // Retry up to 30 times
  reconnectInterval: 500, // Reconnect every 500ms
  poolSize: 10, // Maintain up to 10 socket connections
  // If not connected, return errors immediately rather than waiting for reconnect
  bufferMaxEntries: 0,
  useNewUrlParser: true
}

const connectWithRetry = () => {
  console.log('MongoDB connection with retry')
  mongoose.connect(database, options).then(()=>{
    console.log('MongoDB is connected')
  }).catch(err=>{
    console.log('MongoDB connection unsuccessful, retry after 5 seconds.')
    setTimeout(connectWithRetry, 5000)
  })
}

const libCounter = new Prometheus.Counter({
  name: 'lib_invocation_count',
  help: 'A simple counter for app access during runtime created with prometheus nodejs library'
});

const libUptime = new Prometheus.Counter({
  name: 'lib_upTime',
  help: 'uptime A counter of the application\'s uptime in seconds created with prometheus nodejs library.'
})

console.log('mongousr: ', process.env.mongousr);
console.log('mongopwd: ', process.env.mongopwd);

// Prometheus Default Metrics collector
const collectDefaultMetrics = Prometheus.collectDefaultMetrics;
// Probe every 5th second.
collectDefaultMetrics({ timeout: 5000 });

// new schema model object based on the structure of what I want to put on MongoDB collection
var testSchema = new Schema({
  thingies: {
    type: String
  }
},{
  collection: 'test'
});

// new object that will hold the data using model structure made above
var thingies = mongoose.model('thingieName', testSchema);

// Default message for testing
app.get('/', (req, res, next)=>{
  res.json([{message:'yes, your nodejs app is really running'}]);
  counter++; // for prometheus invocation_count metric
  libCounter.inc(); // for prometheus lib_invocation_count metric
  console.log('Hello, I\'m inside endpoint \'/\'');
  console.log('HTTP headers below:');
  console.log(req.headers);
  console.log('Cookies: ', req.cookies);
  next();
});

app.get('/cookie', function(req, res, next) {
  res.cookie('some_cross_domain_cookie', 'http://mysubdomain.example.com',{domain:'example.com'});
  res.send('I am inside endpoint /cookie');
  console.log('Cookies: ', req.cookies);
  console.log('Cookies: ', res.cookies);
});

// Test endpoint for md files rendering
app.get('/test', function(req, res) {
  var path = '/app/README.md';
  var file = fs.readFileSync(path, 'utf8');
  res.send(marked(file.toString()));
});

// Prometheus metrics endpoint - Library
app.get('/metrics', function(req, res){
  libUptime.inc(Math.floor(process.uptime()));
  res.set('Content-Type', Prometheus.register.contentType)
  res.end(Prometheus.register.metrics())
  libUptime.reset();
});

// Prometheus metrics endpoint - Handmade
app.get('/metrics2', function(req, res){
  var now = new Date();
  var passedTime = now - today;
  res.writeHead(200, {'Content-Type':'text/plain'});
  res.write('# HELP uptime A counter of the application\'s uptime in millisenconds.' + '\n');
  res.write('# TYPE uptime counter' + '\n');
  res.write('uptime ' + passedTime + '\n');
  res.write('# HELP invocation_count A simple counter for app access during runtime' + '\n');
  res.write('# TYPE invocation_count counter'+ '\n');
  res.write('invocation_count ' + counter + '\n');
  res.end();
})

// JWT generation
app.use(bodyParser.urlencoded({ extended: false }));

app.post('/token', function(req, res) {

  const claims_power = { 
    username: req.body.username,
    password: req.body.password,
    subject: 'power#1234',
    issuer: 'http://youcantrustme.io',
    scope: 'admin' 
  };
  
  const claims_user = { 
    username: req.body.username,
    password: req.body.password,
    subject: 'normal_user',
    issuer: 'http://youcantrustme.io',
    scope: 'user' 
  };

  switch(req.body.username) {
      case 'user1':
      if (req.body.password === 'pass1') {
          token = jwt.sign(claims_user, secret);
          console.log('JWT Token: ' + token);
          console.log(jwt.decode(token));
          res.redirect('http://localhost/yay.html');
      } else {
          res.redirect('http://localhost/nay.html');
      }
      break;
      case 'power':
      if (req.body.password === 'weak') {
          token = jwt.sign(claims_power, secret);
          console.log('JWT Token: ' + token);
          console.log(jwt.decode(token));
          res.redirect('http://localhost/yay.html');
      } else {
      res.redirect('http://localhost/nay.html');
      }
      break;
      default:
      res.status(500).send('User not found');
  } 
  console.log('http headers below:')
  console.log(req.headers);
});


// Restricted route root
const restrictedRoutes = express.Router();
app.use('/restricted', restrictedRoutes);

restrictedRoutes.use(function (req, res, next) {
  let sentToken = req.headers['token'];
  if (sentToken) {
    jwt.verify(sentToken, secret, function (err, decoded) {
      if (err) {
        return res.json({ message: 'invalid token' });
      } else {
        req.decoded = decoded;
        console.log(decoded);
        next();
      }
    });
  } else {
    res.status(500).send({ message: 'no token found' });
  };
});

// // Restricted route root stupid
// const restrictedRoutes = express.Router();
// app.use('/restricted', restrictedRoutes);

// restrictedRoutes.use( function(req, res, next){
//   let sentToken = req.headers['token'];
//   console.log('hello there, do not mind me.');
//   console.log('next line will show the JWT token:');
//   console.log(sentToken);
//   console.log('okay, so, next line will show the decoded JWT token:');
//   let decodedToken = jwt.decode(sentToken);
//   console.log(decodedToken);
//   console.log('yay, so now I am going to verify it and show again the decoded token if successful.');
//   console.log('if NOT successful I will not let you see the secret message');
//   console.log('here we go...');
//   let verifiedToken = jwt.verify(sentToken, secret);
//   console.log(verifiedToken);
//   if (verifiedToken) {
//     console.log('success! secret message will be shown.');
//     next();
//   } else {
//     res.status(401).json({message: 'nope, you are not authorized'});
//   }
// });

// Restricted endpoint
restrictedRoutes.get('/access', (req, res) => {
  res.status(200).json([{secret:'You have access to restricted contents!'}])
});

// Restricted route root test (KISS)
const router = express.Router();
app.use('/api', router);

router.use( function(req, res, next){
  console.log('yo, this should always be called whenever /api or anything inside is called');
  next();
});

// Restricted route endpoint test (KISS)
router.get('/inside', (req, res) => {
  console.log('I am inside /api, hopefully');
  res.status(200).json({message: 'it worked'});
})

// JWT decode test
app.get('/decode', function(req, res){
  let sentToken = req.headers['token'];
  if (sentToken) {
    var decode = jwt.verify(sentToken, secret);
    console.log(decode);
    res.status(200).send('success');
  }
})

// Mongo query
app.get('/info', function(req, res){
  thingies.find({}).then(function (thingies) {
    res.json(thingies);
  });
});


// Mongo insert
app.post('/info/add/:name', function(req, res){
  var item = {thingies: req.params.name};
  var data = new thingies(item);
  data.save();
  res.send('thingie ' + req.params.name + ' added to database' + '\n');
});

connectWithRetry();

app.listen(3001, () => {
  console.log('Server running on port 3001');
  console.log('process.env.PORT: ' + process.env.PORT);
});