// @dynamic
export class Keyboard {
  private static listeners = [];
  private static activeListener;
  private static keyMap = {};

  static observe(keyCombination: Array<number>, removeAfterCallback = true, callback: () => void): any {
    this.listeners.push({
      combination: keyCombination,
      callback: callback,
      removeAfterCallback: removeAfterCallback
    })
  }

  static onKeydown(event) {
    if (!this.listeners.length) return;
    this.keyMap[event.keyCode] = true;

    for (let i in this.listeners) {
      let check = true;
      this.activeListener = this.listeners[i];

      for (let key of this.activeListener.combination) {
        if (!this.keyMap[key]) {
          check = false;
          break;
        }
      }
      
      if (check) {
        if (this.activeListener.removeAfterCallback) {
          for (let key of this.activeListener.combination) this.keyMap[key] = false;
          this.listeners.splice(parseInt(i), 1);
        }

        this.activeListener.callback();
      }
    }
  }

  static onKeyUp(event) {
    this.keyMap[event.keyCode] = false;
  }

  // public static onRouteChange() {
  //   if (this.activeListener && this.activeListener.removeAfterCallback) {
  //     for (let i in this.listeners) {
  //       var item = this.listeners[i];
  //       if (item.combination == this.activeListener.combination) this.listeners.splice(parseInt(i), 1);
  //     }
  //   }
  // }
}