// Toast notifications ported from mnw.js:44-68.

/** Maximum simultaneously-visible toasts. Beyond this the oldest drops first so
 *  a burst of HTMX errors can't bury the viewport. */
const TOAST_MAX_VISIBLE = 5;

interface ToastDetail {
  message?: string;
  type?: string;
}

/** How long the fade-out animation runs before the node is removed. Matches the
 *  `.fade-out` transition in the stylesheet, so shortening it here drops the
 *  toast mid-animation. */
const TOAST_FADE_MS = 300;

/** Fade `toast` out after `lifetimeMs`, then remove it.
 *
 *  Extracted because `initHtmxGlue`'s error toast had its own verbatim copy of
 *  the same two nested timers. The lifetime stays the caller's business: this
 *  renderer's toasts live 3000ms and an error toast lives 6000ms, and which of
 *  those is right is a question for the semantic-timing work rather than for a
 *  helper that only exists to stop the dismissal being written twice. */
export function autoDismiss(toast: HTMLElement, lifetimeMs: number): void {
  setTimeout(() => {
    toast.classList.add('fade-out');
    setTimeout(() => toast.remove(), TOAST_FADE_MS);
  }, lifetimeMs);
}

/** Fire a toast. Rendered by the delegated listener installed by `initToasts`. */
export function showToast(message: string, type = 'error'): void {
  document.body.dispatchEvent(new CustomEvent<ToastDetail>('showToast', { detail: { message, type } }));
}

/** Install the toast renderer (caps the stack, auto-dismisses). Call once at
 *  startup. Ported from mnw.js:47. */
export function initToasts(): void {
  document.body.addEventListener('showToast', (evt) => {
    const detail = (evt as CustomEvent<ToastDetail>).detail;
    const container = document.getElementById('notifications');
    if (!container) return;
    while (container.childElementCount >= TOAST_MAX_VISIBLE) {
      container.firstElementChild?.remove();
    }
    const toast = document.createElement('div');
    toast.className = 'toast toast-' + (detail.type || 'info');
    toast.textContent = detail.message || 'Action completed';
    container.appendChild(toast);
    autoDismiss(toast, 3000);
  });
}