import { Injectable, NgZone, inject, signal } from '@angular/core';

@Injectable({ providedIn: 'root' })
export class OnlineStatusService {
  private readonly zone = inject(NgZone);
  readonly online = signal(this.readOnlineState());

  constructor() {
    if (typeof window === 'undefined') {
      return;
    }

    window.addEventListener('online', () => this.setOnline(true));
    window.addEventListener('offline', () => this.setOnline(false));
  }

  private setOnline(online: boolean): void {
    this.zone.run(() => this.online.set(online));
  }

  private readOnlineState(): boolean {
    return typeof navigator === 'undefined' ? true : navigator.onLine;
  }
}