SOURCE

class Queue {
  constructor(name) {
    this.tasks = []
    const task = () => {
      console.log(`Hi! This is ${name}`)
      this.next()
    }
    this.tasks.push(task)
    setTimeout(() => {
      this.next()
    }, 0)
  }
  next() {
    const task = this.tasks.shift()
    task && task()
  }
  sleep(time) {
    this.sleepWrapper(time, false)
    return this
  }
  sleepFirst(time) {
    this.sleepWrapper(time, true)
    return this
  }
  sleepWrapper(time, first) {
    const task = () => {
      setTimeout(() => {
        console.log(`Wake up after ${time}`)
        this.next()
      }, time * 1000)
    }
    if (first) {
      this.tasks.unshift(task)
    } else {
      this.tasks.push(task)
    }
  }
  eat(food) {
    const task = () => {
      console.log(`Eat ${food}`);
      this.next();
    };
    this.tasks.push(task);
    return this;
  }
  static create(name){
      return new Queue(name);
  }
}

// Queue.create("“Hank”").sleep(3).eat("“dinner”")
// Queue.create("“Hank”").eat("“dinner”").eat("“supper”")
Queue.create("“Hank”").eat("“supper”").sleepFirst(5)