function Circle(color) {
    this.color = color;

    this.toString = function () {
        return `${this.color.getColorName()} Circle`;
    };
}

function Rectangle(color) {
    this.color = color;

    this.toString = function () {
        return `${this.color.getColorName()} Rectangle`;
    };
}

function Triangle(color) {
    this.color = color;

    this.toString = function () {
        return `${this.color.getColorName()} Triangle`;
    };
}

function Red() {
    this.getColorName = function () {
        return 'Red';
    }
}

function Blue() {
    this.getColorName = function () {
        return 'Blue';
    }
}
function Green() {
    this.getColorName = function () {
        return 'Green';
    }
}

const redColor = new Red();
const blueColor = new Blue();
const greenColor = new Green();

const redCircle = new Circle(redColor);
const blueCircle = new Circle(blueColor);
const greenRectangle = new Rectangle(greenColor);

var RemoteControl = function(tv) {
    this.tv = tv;
    this.on = function() {
        this.tv.on();
    };
    this.off = function() {
        this.tv.off();
    };
    this.setChannel = function(ch) {
        this.tv.tuneChannel(ch);
    };
};
/* Newer, Better Remote Control */
var PowerRemote = function(tv) {
    this.tv = tv;
    this.currChannel = 0;
    this.setChannel = function(ch) {
        this.currChannel = ch;
        this.tv.tuneChannel(ch);
    };
    this.nextChannel = function() {
        this.setChannel(this.currChannel + 1);
    };
    this.prevChannel = function() {
        this.setChannel(this.currChannel - 1);
    };
};
PowerRemote.prototype = new RemoteControl();
/** TV Interface
    Since there are no Interfaces in JavaScript I am just
    going to use comments to define what the implementors
    should implement
    function on
    function off
    function tuneChannel(channel)
*/
/* Sony TV */
var SonyTV = function() {
    this.on = function() {
        console.log('Sony TV is on');
    };
    this.off = function() {
        console.log('Sony TV is off');
    };
    this.tuneChannel = function(ch) {
        console.log('Sony TV tuned to channel ' + ch);
    };
}
/* Toshiba TV */
var ToshibaTV = function() {
    this.on = function() {
        console.log('Welcome to Toshiba entertainment');
    };
    this.off = function() {
        console.log('Goodbye Toshiba user');
    };
    this.tuneChannel = function(ch) {
        console.log('Channel ' + ch + ' is set on your Toshiba television');
    };
}
/* Let's see it in action */
var sony = new SonyTV(),
    toshiba = new ToshibaTV(),
    std_remote = new RemoteControl(sony),
    pwr_remote = new PowerRemote(toshiba);