import { useEffect, useState } from "react";

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

export interface ToastItem {
  id: number;
  type: ToastType;
  message: string;
  onRetry?: () => void;
}

let toastId = 0;
const listeners = new Set<(items: ToastItem[]) => void>();
let queue: ToastItem[] = [];

function notify() {
  listeners.forEach((fn) => fn([...queue]));
}

function dismiss(id: number) {
  queue = queue.filter((t) => t.id !== id);
  notify();
}

export function toast(message: string, type: ToastType = "info", onRetry?: () => void) {
  const id = ++toastId;
  queue = [...queue.slice(-4), { id, type, message, onRetry }];
  notify();
  setTimeout(() => dismiss(id), type === "error" ? 5000 : 3000);
  return id;
}

toast.success = (msg: string) => toast(msg, "success");
toast.error = (msg: string, onRetry?: () => void) => toast(msg, "error", onRetry);
toast.info = (msg: string) => toast(msg, "info");

export function useToastState() {
  const [items, setItems] = useState<ToastItem[]>([]);
  useEffect(() => {
    listeners.add(setItems);
    return () => { listeners.delete(setItems); };
  }, []);
  return { items, dismiss };
}