const websocket = require('websocket').server
const http = require('http')
const express = require('express')
const path = require('path')
const bonjour = require('bonjour')()

const app = express(),
      bodyParser = require('body-parser'),
      wsPort = 3080,
      httpPort = 18080,
      sockets = new Set(),
      services = {}

// Initialize HTTP websocket transport
const server = http.createServer(function(request, response) {
    console.log(`[${(new Date())}] Received request for ${request.url}`)
    response.writeHead(404)
    response.end()
})

server.listen(wsPort, '127.0.0.1', () => {
    console.log(`[${(new Date())}] Websocket transport listening on port ${wsPort}`)
})

// Initialize Express web service
app.use(bodyParser.json())
app.use(express.static(path.join(__dirname, '../webapp/dist')))

app.get('/', (req,res) => {
  res.sendFile(path.join(__dirname, '../webapp/dist/index.html'))
})

app.listen(httpPort, () => {
    console.log(`Web server listening on port ${httpPort}`)
})

// Initialize websocket service
wsServer = new websocket({
    httpServer: server,
    autoAcceptConnections: false,
})

function requestAllowed(request) {
    if (request.resource !== '/services') {
        console.log(`Unknown web socket resource: ${request.resource}`)
        return false
    }

    if (request.remoteAddress !== '127.0.0.1' && request.remoteAddress !== '::1') {
        console.log('Websocket requests are only allowed from localhost')
        return false
    }

    return true
}

wsServer.on('request', (request) => {
    if (!requestAllowed(request))
        return

    const connection = request.accept('', request.origin)
    console.log(`[${(new Date())}] Connection accepted.`)

    sockets.add(connection)
    sendServiceInfo(connection)

    connection.on('message', function(message) {
        if (message.type === 'utf8') {
            if (message.utf8Data === 'sync') {
                console.log('Received sync request')
                sendServiceInfo(connection)
            } else {
                console.log(`Unsupported command: ${message.utf8Data}`)
            }
        }
    })

    connection.on('close', function() {
        console.log(`[${(new Date())}] Peer ${connection.remoteAddress} disconnected.`)
    })
})

// Initialize the Zeroconf/Bonjour service
function discoverServices() {
    bonjour.find({type: 'platypush-http'}, (service) => {
        services[service.name] = service
        for (const socket of sockets) {
            sendServiceInfo(socket, service)
        }
    })
}

function sendServiceInfo(sock, service) {
    const srvs = service ? [service] : Object.values(services)
    for (const srv of srvs)
        sock.sendUTF(JSON.stringify(srv))
}

discoverServices()
setInterval(discoverServices, 10000)