import { Injectable } from '@angular/core';

const ID = 'helgoland-notifier';
const TIME_IN_MS = 3000;

@Injectable()
export class NotifierService {

  private notifierTimeout: any;

  constructor() {
    const notifierElement = document.getElementById(ID);
    if (!notifierElement) {
      const node = document.createElement('div');
      node.id = ID;
      node.className = 'hide';
      const textNode = document.createTextNode('');
      node.appendChild(textNode);
      document.body.appendChild(node);
    }
  }

  public notify(text: string) {
    clearTimeout(this.notifierTimeout);
    const notifierElement = document.getElementById(ID);
    notifierElement.innerHTML = text;
    notifierElement.className = notifierElement.className.replace('hide', 'show');
    this.notifierTimeout = setTimeout(() => {
      notifierElement.className = notifierElement.className.replace('show', 'hide');
    }, TIME_IN_MS);
  }
}