Best posts made by oskaremilsson

What is it?
Hub TCP server for using the IR module via HTTP.
Both to record of new signals with a given name and to play them back.
Using net since SDK doesn't have the nodejs HTTP-module available.

Why?
I really wanted to be able to call my IR module from my phone homescreen or Google Home (via IFTTT). I got it working so I wanted to share it if anyone else find it helpful

The code is what could be called a POC, so code feedback and/or changes are totally welcome.

How does it work?

1. Record a signal GET {ip}:1338?record={name_of_signal}
2. Plays a signal GET {ip}:1338?cmd={name_of_signal}
3. Cancel recording GET {ip}:1338?cancelRecord=true

Example;

1. call GET 192.168.0.100:1338?record=volume_up
2. Press Volume Up on remote towards IR module
3. returns 200 OK Signal volume_up stored!
4. call GET 192.168.0.100:1338?cmd=volume_up
5. returns 200 OK Signal sent!
6. Volume goes up

The code

module.json

{
	"name": "IRTCP",
	"version": "1.0.0"
}

main.js

// main.js
const net = require("net");
const ir = require("ir");
const datastore = require("datastore");

const utils = require("./utils");

const respondToClient = function(c, statusCode, message) {
	c.write(
		"HTTP/1.1 " + statusCode + "\r\n" +
		"\r\n"
	);
	c.write(message);
	c.end();
}

const handleCmd = function(c, cmd) {
	datastore.get(cmd, function(err, strBuffer) {
		if (!err && strBuffer) {
			var signal = new Uint32Array(utils.str2ab(strBuffer));
			if (!ArrayBuffer.isView(signal)) {
				return respondToClient(c, "422 Unprocessable Entity", "Unknown signal");
			}

			ir.play(signal, function(err) {
				if (!err) {
					return respondToClient(c, "200 OK", "Signal sent");
				}
				return respondToClient(c, "500 Internal Server Error", "Couldn't send signal");
			});
		} else {
			return respondToClient(c, "422 Unprocessable Entity", "Unknown cmd");
		}
	});
}

const handleRecord = function(c, name) {
	/* TODO: add a timeout for listening for complete */
	ir.record();
	console.log("recording signal...");

	ir.on("recordComplete", function(signal) {	
		datastore.put(name, utils.ab2str(signal.buffer), function(err) {
			if (!err) {
				console.log("Signal " + name + " stored!");
				return respondToClient(c, "200 OK", "Signal " + name + " stored!");
			} else {
				return respondToClient(c, "500 Internal Server Error", "Couldn't store signal");
			}
		});
	});
}


var server = net.createServer(function(c) {
  console.log('server connected');
  c.on('end', function() {
    console.log('server disconnected');
  });

	c.on('data', function(data) {
		console.log(data);
		var match = data.toString().match(/GET \/\?.[^ ]*/);

		if (!match) {
			return respondToClient(c, "403 Forbidden", "Forbidden method");
		}

		var params = utils.parseParams(match[0].split("GET /?")[1]);
		
		if (params.cmd) {
			return handleCmd(c, params.cmd);
		} else if (params.record && params.record.length > 0) {
			return handleRecord(c, params.record);
		} else if (params.cancelRecord) {
			ir.cancelRecord();
			console.log("recording canceled!");
			return respondToClient(c, "200 OK", "Recording canceled!");
		} else {
			return respondToClient(c, "403 Forbidden", "Forbidden params");
		}
	});
});

server.listen(1338, function() {
  console.log('server bound', server.address().port);
});

utils.js

const ab2str = function(buf) {
  return String.fromCharCode.apply(null, new Uint16Array(buf));
}

const str2ab = function(str) {
  var buf = new ArrayBuffer(str.length*2);
  var bufView = new Uint16Array(buf);
  for (var i=0, strLen=str.length; i < strLen; i++) {
    bufView[i] = str.charCodeAt(i);
  }
  return buf;
}

const parseParams = function (s) {
	var obj = {};
	var arr = s.split("&");
	var temp;

	for (i = 0; i < arr.length; i++) {
		temp = arr[i].split("=");
		obj[temp[0]] = temp[1];
	}
	
	return obj;
};

exports.ab2str = ab2str;
exports.str2ab = str2ab;
exports.parseParams = parseParams;