import { auth } from "@/app/(auth)/auth";
import {
  createCheckoutSession,
  isBillingConfigured,
} from "@/lib/billing/gateway";
import { ChatbotError } from "@/lib/errors";

export async function POST(request: Request) {
  const session = await auth();
  if (!session?.user) {
    return new ChatbotError("unauthorized:chat").toResponse();
  }

  if (!isBillingConfigured()) {
    return Response.json(
      {
        error: "billing_not_configured",
        message:
          "Set EGBE_PAYMENT_GATEWAY_URL, EGBE_GATEWAYS_TOKEN, and PRO_STRIPE_PRICE_ID to enable upgrades.",
      },
      { status: 501 }
    );
  }

  const appSlug = process.env.APP_SLUG ?? "chatbot";
  const baseUrl =
    process.env.NEXT_PUBLIC_BASE_URL ?? new URL(request.url).origin;

  try {
    const result = await createCheckoutSession({
      userId: session.user.id,
      customerEmail: session.user.email ?? undefined,
      appSlug,
      baseUrl,
    });
    return Response.json({ url: result.url, id: result.id });
  } catch (error) {
    const message = error instanceof Error ? error.message : "checkout failed";
    return Response.json({ error: "checkout_failed", message }, { status: 502 });
  }
}