const EventEmitter = require('events') const $ = require('../lib/chibi') let demo try { demo = require('./demo') } catch (err) {} const RECONN_DELAY = 2000 const HEARTBEAT_TIME = 3000 /** Handle connections */ module.exports = class TermConnection extends EventEmitter { constructor (screen) { super() this.screen = screen this.ws = null this.heartbeatTimeout = null this.pingInterval = null this.xoff = false this.autoXoffTimeout = null this.reconnTimeout = null this.forceClosing = false try { this.blobReader = new FileReader() this.blobReader.onload = (evt) => { this.onDecodedWSMessage(this.blobReader.result) } this.blobReader.onerror = (evt) => { console.error(evt) } } catch (e) { this.blobReader = null } this.pageShown = false this.disconnectTimeout = null document.addEventListener('visibilitychange', () => { if (document.hidden === true) { console.info('Window lost focus, freeing socket') // Delayed, avoid disconnecting if the background time is short this.disconnectTimeout = setTimeout(() => { this.closeSocket() clearTimeout(this.heartbeatTimeout) }, 1000) } else { clearTimeout(this.disconnectTimeout) console.info('Window got focus, re-connecting') this.init() } }, false) } onWSOpen (evt) { console.log('CONNECTED') this.heartbeat() this.send('i') this.forceClosing = false this.emit('connect') } onWSClose (evt) { if (this.forceClosing) { this.forceClosing = false return } console.warn('SOCKET CLOSED, code ' + evt.code + '. Reconnecting...') if (evt.code < 1000) { console.error('Bad code from socket!') // this sometimes happens for unknown reasons, code < 1000 is invalid // location.reload() } clearTimeout(this.reconnTimeout) this.reconnTimeout = setTimeout(() => this.init(), RECONN_DELAY) this.emit('disconnect', evt.code) } onDecodedWSMessage (str) { switch (str.charAt(0)) { case '.': // heartbeat, no-op message break case '-': // console.log('xoff'); this.xoff = true this.autoXoffTimeout = setTimeout(() => { this.xoff = false }, 250) break case '+': // console.log('xon'); this.xoff = false clearTimeout(this.autoXoffTimeout) break default: this.screen.load(str) if (!this.pageShown) { window.showPage() this.pageShown = true } break } this.heartbeat() } onWSMessage (evt) { if (typeof evt.data === 'string') this.onDecodedWSMessage(evt.data) else { if (!this.blobReader) { console.error('No FileReader!') return } if (this.blobReader.readyState !== 1) { this.blobReader.readAsText(evt.data) } else { setTimeout(() => { this.onWSMessage(evt) }, 1) } } } canSend () { return !this.xoff } send (message) { if (window._demo) { if (typeof window.demoInterface !== 'undefined') { demo.input(message) } else { console.log(`TX: ${JSON.stringify(message)}`) } return true // Simulate success } if (this.xoff) { // TODO queue console.log("Can't send, flood control.") return false } if (!this.ws) return false // for dry testing if (this.ws.readyState !== 1) { console.error('Socket not ready') return false } if (typeof message !== 'string') { message = JSON.stringify(message) } this.ws.send(message) return true } /** Safely close the socket */ closeSocket () { if (this.ws) { this.forceClosing = true if (this.ws.readyState === 1) this.ws.close() this.ws = null } } init () { if (window._demo) { if (typeof window.demoInterface === 'undefined') { window.alert('Demoing non-demo build!') // this will catch mistakes when deploying to the website } else { demo.init(this.screen) } return } clearTimeout(this.reconnTimeout) clearTimeout(this.heartbeatTimeout) this.closeSocket() this.ws = new window.WebSocket('ws://' + window._root + '/term/update.ws') this.ws.addEventListener('open', (...args) => this.onWSOpen(...args)) this.ws.addEventListener('close', (...args) => this.onWSClose(...args)) this.ws.addEventListener('message', (...args) => this.onWSMessage(...args)) console.log('Opening socket.') this.heartbeat() this.emit('open') } heartbeat () { this.emit('heartbeat') clearTimeout(this.heartbeatTimeout) this.heartbeatTimeout = setTimeout(() => this.onHeartbeatFail(), HEARTBEAT_TIME) } sendPing () { console.log('> ping') this.emit('ping') $.get('http://' + window._root + '/api/v1/ping', (resp, status) => { if (status === 200) { clearInterval(this.pingInterval) console.info('Server ready, opening socket…') this.emit('ping-success') this.init() // location.reload() } else this.emit('ping-fail', status) }, { timeout: 100, loader: false // we have loader on-screen }) } onHeartbeatFail () { this.closeSocket() this.emit('silence') console.error('Heartbeat lost, probing server...') clearInterval(this.pingInterval) this.pingInterval = setInterval(() => { this.sendPing() }, 1000) // first ping, if this gets through, it'll will reduce delay setTimeout(() => { this.sendPing() }, 200) } }