node-red-nodes/social/music/69-mpd.js

/**
 * Copyright 2013 IBM Corp.
 *
 * Licensed under the Apache License, Version 2.0 (the "License");
 * you may not use this file except in compliance with the License.
 * You may obtain a copy of the License at
 *
 * http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 **/

var RED = require(process.env.NODE_RED_HOME+"/red/red");
var util = require("util");
var exec = require('child_process').exec;
var komponist = require('komponist');
var mpc = null;
exec("which mpd",function(err,stdout,stderr) {
    if (stdout.indexOf('mpd') == -1) {
        throw 'Error: Cannot find "mpd" command. Please install MPD.';
    }
});

exec("netstat -an | grep LISTEN | grep 6600",function(err,stdout,stderr) {
    if (stdout.indexOf('6600') == -1) {
        throw '[69-mpd.js] Error: MPD daemon not listening on port 6600. Please start MPD.';
    }
    komponist.createConnection(6600, 'localhost', function(err, client) {
        if (err) node.error("MPD: Failed to connect to MPD server");
        mpc = client;
    });
});


function MPDOut(n) {
    RED.nodes.createNode(this,n);
    var node = this;
    node.mpc = mpc;

    if (mpc != null) {
        this.on("input", function(msg) {
            if (msg != null) {
                try {
                    //node.mpc.command(msg.payload);
                    node.mpc.command(msg.payload, msg.param, function(err, results) {
                        if (err) { node.log("error: "+err); }
                        //else { console.log(results); }
                    });
                } catch (err) { node.log("error: "+err); }
            }
        });

        node.mpc.on('error', function(err) {
            node.log("error: "+err);
        });
    }
    else { node.warn("MPD not running"); }
}
RED.nodes.registerType("mpd out",MPDOut);

function MPDIn(n) {
    RED.nodes.createNode(this,n);
    var node = this;
    node.mpc = mpc;
    var oldMsg = "";

    if (mpc != null) {
        getSong();

        function getSong() {
            node.mpc.currentsong(function(err, info) {
                if (err) node.log(err);
                else {
                    var msg = {payload:{},topic:"music"};
                    msg.payload.Artist = info.Artist;
                    msg.payload.Album = info.Album;
                    msg.payload.Title = info.Title;
                    msg.payload.Genre = info.Genre;
                    msg.payload.Date = info.Date;
                    if (JSON.stringify(msg) != oldMsg) {
                        node.send(msg);
                        oldMsg = JSON.stringify(msg);
                    }
                }
            });
        }

        node.mpc.on('changed', function(system) {
            getSong();
        });

        this.on("close", function() {
           // node.mpc.command("stop");
        });
    }
    else { node.warn("MPD not running"); }
}
RED.nodes.registerType("mpd in",MPDIn);