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

export type ToastType = 'error' | 'success' | 'info';

export interface Toast {
  id: number;
  type: ToastType;
  message: string;
}

/**
 * Lightweight, dependency-free toast/notification store. A single
 * ToastContainerComponent (mounted in the app root) renders whatever this holds.
 */
@Injectable({ providedIn: 'root' })
export class ToastService {
  private counter = 0;
  readonly toasts = signal<Toast[]>([]);

  error(message: string): void {
    this.show('error', message);
  }

  success(message: string): void {
    this.show('success', message);
  }

  info(message: string): void {
    this.show('info', message);
  }

  dismiss(id: number): void {
    this.toasts.update(list => list.filter(toast => toast.id !== id));
  }

  private show(type: ToastType, message: string): void {
    const id = ++this.counter;
    this.toasts.update(list => [...list, { id, type, message }]);
    const autoDismissMs = type === 'error' ? 8000 : 4000;
    setTimeout(() => this.dismiss(id), autoDismissMs);
  }
}