// Learning JavaScript
// chapter 14 : Asynchronous Programming

// Promise & Events

const EventEmitter = require('events').EventEmitter;

class Countdown extends EventEmitter {
    constructor(seconds, superstitious) {
        super();
        this.seconds = seconds;
        this.superstitious = superstitious;
    }
    go() {
        const countdown = this;
        return new Promise(function(resolve, reject) {
            for (let i = countdown.seconds; i >= 0; i--) {
                setTimeout(function() {
                    if (countdown.superstitious && i === 13)
                        return reject(new Error('Oh my god'));
                    countdown.emit('tick', i);
                    if (i === 0) resolve();
                }, (countdown.seconds - i) * 1000);
            }
        });
    }
}

const c = new Countdown(5);

c.on('tick', function(i) {
    if (i > 0) console.log(i + '...');
});

c
    .go()
    .then(function() {
        console.log('Go!');
    })
    .catch(function(err) {
        console.error(err.message);
    });