import { createContext, useCallback, useContext, useEffect, useRef, useState, type ReactNode } from 'react';
import { registerPartnerToastListener, type PartnerToastVariant } from '../lib/toast';

type PartnerToastContextValue = {
  showToast: (message: string, variant?: PartnerToastVariant) => void;
};

const PartnerToastContext = createContext<PartnerToastContextValue | null>(null);

export function PartnerToastProvider({ children }: { children: ReactNode }) {
  const [toast, setToast] = useState('');
  const [variant, setVariant] = useState<PartnerToastVariant>('success');
  const timerRef = useRef<number | null>(null);

  const showToast = useCallback((message: string, nextVariant: PartnerToastVariant = 'success') => {
    if (timerRef.current) window.clearTimeout(timerRef.current);
    setVariant(nextVariant);
    setToast(message);
    timerRef.current = window.setTimeout(() => {
      setToast('');
      timerRef.current = null;
    }, nextVariant === 'error' ? 3000 : 2000);
  }, []);

  useEffect(() => {
    registerPartnerToastListener(showToast);
    return () => {
      registerPartnerToastListener(null);
      if (timerRef.current) window.clearTimeout(timerRef.current);
    };
  }, [showToast]);

  return (
    <PartnerToastContext.Provider value={{ showToast }}>
      {children}
      {toast ? (
        <div
          className={`partner-toast${variant === 'error' ? ' partner-toast--error' : ''}`}
          role="alert"
          aria-live="assertive"
        >
          {toast}
        </div>
      ) : null}
    </PartnerToastContext.Provider>
  );
}

export function usePartnerToast(): PartnerToastContextValue {
  const ctx = useContext(PartnerToastContext);
  if (!ctx) throw new Error('usePartnerToast 必须在 PartnerToastProvider 内使用');
  return ctx;
}