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

@Injectable({providedIn: 'root'})
export class NotificationService {

  private readonly notificationSound = new Audio('/public/sounds/notification.mp3');
  private readonly notificationStorageKey = 'chat-notifications-enabled';
  private readonly _notificationEnabled = signal<boolean>(
    localStorage.getItem(this.notificationStorageKey) === 'true'
  );
  public readonly notificationEnabled = this._notificationEnabled.asReadonly();

  async requestPermission(): Promise<boolean> {
    if (!('Notification' in window)) {
      console.log('This browser does not support notifications');
      return false;
    }

    if (Notification.permission === 'granted') {
      return true;
    }

    if (Notification.permission === 'denied') {
      console.log('Notification permission was denied');
      return false;
    }

    const permission = await Notification.requestPermission();
    if (permission === 'granted') {
      this.enableSound()
      return true
    }
    return false;
  }

  notify(title: string, body: string | null) {
    if (!this.notificationEnabled()) {
      return;
    }
    if (Notification.permission === 'granted') {
      if (body === null) {
        new Notification(title);
      } else {
        new Notification(title, {body});
      }
      this.playSound();
    }
  }

  private enableSound() {
    this.notificationSound.muted = true;
    this.notificationSound.play()
      .then(() => {
        this.notificationSound.pause();
        this.notificationSound.currentTime = 0;
        this.notificationSound.muted = false;
      })
      .catch((error) => {
        console.log('Could not unlock notification sound:', error);
        this.notificationSound.muted = false;
      });
  }

  private playSound() {
    this.notificationSound.currentTime = 0;
    this.notificationSound.play().catch((error) => {
      console.log('Could not play notification sound:', error);
    });
  }

  enableNotifications() {
    this._notificationEnabled.set(true);
    localStorage.setItem(this.notificationStorageKey, 'true');
  }

  disableNotifications() {
    this._notificationEnabled.set(false);
    localStorage.setItem(this.notificationStorageKey, 'false');
  }
}