import { ReactNode } from 'react';

export interface NoticeItem {
  id: number;
  type: 'success' | 'error' | 'info';
  message: ReactNode;
  duration: number;
  timerId?: ReturnType<typeof setTimeout>;
}

type Listener = (notices: NoticeItem[]) => void;

let nextId = 0;
let notices: NoticeItem[] = [];
const listeners: Set<Listener> = new Set();

function notifyListeners() {
  listeners.forEach((listener) => listener([...notices])); // Pass a copy
}

// Shows a notification.

export function showNotice(
  type: 'success' | 'error' | 'info',
  message: ReactNode,
  duration?: number,
): number {
  const id = nextId++;
  const effectiveDuration =
    duration ?? (type === 'error' ? 8000 : type === 'info' ? 5000 : 3000); // Longer defaults

  const newNotice: NoticeItem = {
    id,
    type,
    message,
    duration: effectiveDuration,
  };

  // Auto-hide timer (only if duration is not null/0)
  if (effectiveDuration > 0) {
      newNotice.timerId = setTimeout(() => {
          hideNotice(id);
      }, effectiveDuration);
  }


  notices = [...notices, newNotice];
  notifyListeners();
  return id;
}

// Hides a specific notification by its ID.

export function hideNotice(id: number) {
  const notice = notices.find((n) => n.id === id);
  if (notice?.timerId) {
      clearTimeout(notice.timerId); // Clear timeout if manually closed
  }
  notices = notices.filter((n) => n.id !== id);
  notifyListeners();
}

// Subscribes a listener function to notice state changes.

export function subscribeNotices(listener: Listener): () => void {
  listeners.add(listener);
  listener([...notices]);
  return () => {
    listeners.delete(listener);
  };
}

// Function to clear all notices at once
export function clearAllNotices() {
    notices.forEach(n => {
        if (n.timerId) clearTimeout(n.timerId);
    });
    notices = [];
    notifyListeners();
}