export {};

interface ToastOptions {
  message: string;
  duration?: number;
}

/** Lazily create and return the toast container element. */
const toastContainer = (): HTMLElement => {
  let container = document.getElementById('toast-container');
  if (!container) {
    container = document.createElement('div');
    container.id = 'toast-container';
    container.className = 'fixed bottom-4 right-4 z-[100] flex flex-col gap-2';
    container.setAttribute('role', 'status');
    container.setAttribute('aria-live', 'polite');
    container.setAttribute('aria-relevant', 'additions');
    document.body.appendChild(container);
  }
  return container;
};

/**
 * Show a toast notification with optional auto-dismiss.
 * Exposed globally via window.showToast.
 */
const showToast = ({ message, duration = 3000 }: ToastOptions): void => {
  const container = toastContainer();
  const template = document.getElementById('toast-template') as HTMLTemplateElement | null;

  if (!template) {
    return;
  }

  const toast = (template.content.cloneNode(true) as DocumentFragment)
    .firstElementChild as HTMLElement;
  if (!toast) return;
  toast.setAttribute('role', 'status');
  toast.setAttribute('aria-live', 'polite');
  const messageEl = toast.querySelector('.toast-message');
  const closeBtn = toast.querySelector('.toast-close');

  if (messageEl) {
    messageEl.textContent = message;
  }

  let removed = false;
  let dismissTimeout: number | undefined;
  let removeTimeout: number | undefined;

  const remove = (): void => {
    if (removed) return;
    removed = true;
    if (typeof dismissTimeout === 'number') window.clearTimeout(dismissTimeout);
    if (typeof removeTimeout === 'number') window.clearTimeout(removeTimeout);
    toast.remove();
  };

  closeBtn?.addEventListener('click', remove);

  container.appendChild(toast);

  // trigger entrance animation
  requestAnimationFrame(() => {
    toast.classList.remove('translate-y-2', 'opacity-0');
  });

  // auto-dismiss with exit animation
  dismissTimeout = window.setTimeout(() => {
    toast.classList.add('translate-y-2', 'opacity-0');
    removeTimeout = window.setTimeout(remove, 300);
  }, duration);
};

declare global {
  interface Window {
    showToast: typeof showToast;
  }
}

window.showToast = showToast;