import { Injectable, inject, signal, computed } from '@angular/core';
import { NOTIFICATION_CONFIG } from '../providers/notification-config.provider';
import type { NtfNotification, NtfGroup } from '../types/notification.types';
import { groupByDate } from '../utils/time.utils';

@Injectable()
export class NotificationService {
  private config = inject(NOTIFICATION_CONFIG);

  readonly notifications = signal<NtfNotification[]>([]);

  readonly unreadCount = computed(() =>
    this.notifications().filter((n) => n.status === 'unread').length,
  );

  readonly grouped = computed<NtfGroup[]>(() => {
    const items = this.notifications().filter((n) => n.status !== 'archived');
    const dateGroups = groupByDate(items);

    return dateGroups.map((g) => ({
      id: g.label.toLowerCase().replace(/\s+/g, '-'),
      label: g.label,
      notifications: g.items,
    }));
  });

  add(notification: NtfNotification): void {
    this.notifications.update((list) => [notification, ...list]);
  }

  markRead(notificationId: string): void {
    this.notifications.update((list) =>
      list.map((n) => (n.id === notificationId ? { ...n, status: 'read' as const } : n)),
    );
  }

  markAllRead(): void {
    this.notifications.update((list) =>
      list.map((n) => (n.status === 'unread' ? { ...n, status: 'read' as const } : n)),
    );
  }

  archive(notificationId: string): void {
    this.notifications.update((list) =>
      list.map((n) => (n.id === notificationId ? { ...n, status: 'archived' as const } : n)),
    );
  }

  remove(notificationId: string): void {
    this.notifications.update((list) => list.filter((n) => n.id !== notificationId));
  }

  clear(): void {
    this.notifications.set([]);
  }
}