'use client';

import { useEffect, useRef } from 'react';

import { useCart } from '@/core/providers/store-provider';

/**
 * Mounts the Brainerce AI chat widget (the store's shopping assistant).
 *
 * Everything about the bot — name, avatar, colors, greeting, starter
 * questions, capabilities, guardrails — is configured by the merchant in the
 * Brainerce dashboard (Customers → Storefront Bot). This component renders
 * nothing until the bot is switched Live there, so it is always safe to keep
 * mounted.
 *
 * The widget's product cards call `onAddToCart`, which goes through the same
 * smartAddToCart + refreshCart path as the storefront's own product cards, so
 * the header cart count stays in sync.
 */
export function BrainerceBotWidget() {
  const { refreshCart } = useCart();
  const refreshCartRef = useRef(refreshCart);
  refreshCartRef.current = refreshCart;

  useEffect(() => {
    const connectionId =
      process.env.NEXT_PUBLIC_BRAINERCE_SALES_CHANNEL_ID ||
      process.env.NEXT_PUBLIC_BRAINERCE_CONNECTION_ID;
    if (!connectionId) return;

    let bot: { destroy(): void } | null = null;
    let cancelled = false;
    void import('brainerce/bot').then(({ BrainerceBot }) =>
      BrainerceBot.mount({
        connectionId,
        baseUrl: process.env.NEXT_PUBLIC_BRAINERCE_API_URL || undefined,
        // Order-lookup login gating: this template's own same-origin BFF proxy
        // (see src/app/api/store/[...path]/route.ts) already forwards the
        // shopper's httpOnly session cookie as a Bearer header — the same
        // mechanism @/core/lib/brainerce's own client uses. Opting the bot in
        // here lets it detect login state without the widget ever touching the
        // cookie itself.
        customerSessionProxyPath: '/api/store',
        onAddToCart: async ({ productId, variantId, quantity }) => {
          try {
            const { getClient } = await import('@/core/lib/brainerce');
            await getClient().smartAddToCart({
              productId,
              variantId: variantId ?? undefined,
              quantity,
            });
            await refreshCartRef.current();
            return true;
          } catch {
            return false; // widget falls back to the product page
          }
        },
      }).then((mounted) => {
        if (cancelled) mounted?.destroy();
        else bot = mounted;
      }),
    );
    return () => {
      cancelled = true;
      bot?.destroy();
    };
  }, []);

  return null;
}