git.r.bdr.sh - rbdr/tomato-sauce/blob - lib/tomato_sauce.js

   1 'use strict';
   2
   3 const Net = require('net');
   4 const EventEmitter = require('events');
   5
   6 const Util = require('./util');
   7
   8 // Interpret as Command Sequences.
   9 const kEscape = new Buffer([0xFF, 0xF4, 0XFF, 0xFD, 0x06]); // IAC IP IAC DO TIMING_MARK
  10 const kNAWSRequest = new Buffer([0xFF, 0xFD, 0X1F]); // IAC DO NAWS
  11 const kNAWSResponse = new Buffer([0xFF, 0xFB, 0X1F, 0xFF, 0xFA, 0X1F]); // IAC WILL NAWS IAC SB NAWS
  12
  13 // Main tomato sauce class. Properties:
  14 // * screens <TomatoSauce.IScreen[]>
  15 // * renderers <TomatoSauce.IRenderer[]>
  16 // * port <int>
  17 // * frequency <int>
  18 // * modulation <int>
  19 //
  20 // The main entry point is the #run() function.
  21 //
  22 // It emits a listening event that contains the server information on
  23 // the `server` key inside the `data` property of the event.
  24 //
  25 // It also emits an error event that contains the error information on
  26 // the `error` key inside the `data` property of the event.
  27 const TomatoSauce = class TomatoSauce extends EventEmitter {
  28
  29   constructor (config) {
  30     super();
  31
  32     this.screens = [];
  33     this.renderers = [];
  34
  35     Object.assign(this, config || {});
  36   }
  37
  38   // Here's where things get started.
  39   run () {
  40     this._startServer();
  41     this._bindEvents();
  42   }
  43
  44   // Creates a socket, server based on the configuration. Emits the
  45   // listening event when ready.
  46   _startServer () {
  47     const server = Net.createServer();
  48     this.server = server;
  49     server.listen(this.port, function () {
  50       this.emit('listening', {
  51         data: {
  52           server: server
  53         }
  54       });
  55     }.bind(this));
  56   }
  57
  58   _bindEvents () {
  59     // Send the error event all the way up.
  60     this.server.on('error', function (err) {
  61       this.emit('error', {
  62         data: {
  63           error: err
  64         }
  65       });
  66     }.bind(this));
  67
  68     // Send the error event all the way up.
  69     this.server.on('connection', function (socket) {
  70       this._renderScreen(socket);
  71     }.bind(this));
  72   }
  73
  74   // Obtains viewport size, and initializes a random screen with a random
  75   // renderer, setting the required interval to draw.
  76   _renderScreen (socket) {
  77     let connectionData = {
  78       width: null,
  79       height: null,
  80       modulation: 0,
  81       screen: this._getScreen(),
  82       renderer: this._getRenderer(),
  83       socket: socket
  84     };
  85     let interval = null;
  86
  87     socket.write(kNAWSRequest);
  88
  89     socket.on('data', function (data) {
  90       if (data.slice(0, 6).compare(kNAWSResponse) === 0) {
  91         connectionData.width = Util.parse16BitBuffer(data.slice(6, 8));
  92         connectionData.height = Util.parse16BitBuffer(data.slice(8, 10));
  93
  94         socket.write('\x1B[2J'); // Clear the Screen (CSI 2 J)
  95         interval = setInterval(this._writeMessage.bind(this, connectionData), this.frequency);
  96       }
  97
  98       if (data.compare(kEscape) === 0) {
  99         socket.write('\n');
 100         clearInterval(interval);
 101         socket.end();
 102       }
 103     }.bind(this));
 104   }
 105
 106   // Resets the cursor, gets a frame and sends it to the socket.
 107   _writeMessage (connectionData) {
 108     let payload = connectionData.screen(connectionData.modulation, connectionData.width, connectionData.height, connectionData.renderer);
 109     let message = `\x1B[1;1H${payload}`; // reset cursor position before payload
 110
 111     connectionData.modulation = (connectionData.modulation + this.modulation) % 256;
 112     connectionData.socket.write(message);
 113   }
 114
 115   _getScreen () {
 116     return Util.pickRandom(this.screens);
 117   }
 118
 119   _getRenderer () {
 120     return Util.pickRandom(this.renderers);
 121   }
 122 };
 123
 124 // Defaults.
 125 TomatoSauce.prototype.port = 9999;
 126 TomatoSauce.prototype.frequency = 333;
 127 TomatoSauce.prototype.modulation = 5;
 128
 129 module.exports = TomatoSauce;