/* global console, require */
var opcua = require("node-opcua");

var server = new opcua.OPCUAServer({
    port: 4334 // the port of the listening socket of the server
});

function post_initialize() {

    var addressSpace = server.engine.addressSpace;
    
    var myDevice = addressSpace.addObject({
        organizedBy: addressSpace.rootFolder.objects,
        browseName: "MyDevice"
    });

    _"adding a method on the device object"

    _"binding the method with your own function"

}

server.initialize(post_initialize);

server.start(function() {
    console.log("Server is now listening ... ( press CTRL+C to stop)");
});

var method = addressSpace.addMethod(myDevice,{

    browseName: "Bark",

    inputArguments:  [
        {
            name:"nbBarks",
            description: { text: "specifies the number of time I should bark" },
            dataType: opcua.DataType.UInt32        
        },{
            name:"volume",
            description: { text: "specifies the sound volume [0 = quiet ,100 = loud]" },
            dataType: opcua.DataType.UInt32
        }
     ],

    outputArguments: [{
         name:"Barks",
         description:{ text: "the generated barks" },
         dataType: opcua.DataType.String ,
         valueRank: 1
    }]
});

// optionally, we can adjust userAccessLevel attribute 
method.outputArguments.userAccessLevel = opcua.makeAccessLevel("CurrentRead");
method.inputArguments.userAccessLevel = opcua.makeAccessLevel("CurrentRead");

method.bindMethod(function(inputArguments,context,callback) {

    var nbBarks = inputArguments[0].value;
    var volume =  inputArguments[1].value;

    console.log("Hello World ! I will bark ",nbBarks," times");
    console.log("the requested volume is ",volume,"");
    var sound_volume = Array(volume).join("!");

    var barks = []; for(var i=0;i<nbBarks;i++){ barks.push("Whaff" + sound_volume);}

    var callMethodResult = {
        statusCode: opcua.StatusCodes.Good,
        outputArguments: [{
                dataType: opcua.DataType.String,
                arrayType: opcua.VariantArrayType.Array,
                value :barks
        }]
    };
    callback(null,callMethodResult);
});