import { NextResponse } from "next/server";
import { applyPromoCode, removePromoCode } from "@/lib/medusa";
import { parseBody, isNonEmptyString, isValidMedusaId, badRequest, checkCsrf } from "@/lib/apiUtils";

// POST /api/cart/[cartId]/promotions — apply a promo code
export async function POST(
  request: Request,
  { params }: { params: Promise<{ cartId: string }> },
) {
  const csrfError = await checkCsrf();
  if (csrfError) return csrfError;

  const { cartId } = await params;
  if (!isValidMedusaId(cartId)) {
    return badRequest("Invalid cart ID format");
  }

  const body = await parseBody<{ code?: unknown }>(request);
  if (!body) return badRequest("Invalid request body");

  const { code } = body;
  if (!isNonEmptyString(code)) {
    return badRequest("Missing or invalid promo code");
  }

  try {
    const cart = await applyPromoCode(cartId, code.trim());
    return NextResponse.json(cart);
  } catch (e) {
    const msg = (e as Error).message ?? "";
    console.error("[cart:promo:apply]", msg);
    return NextResponse.json(
      { error: "Invalid or expired promo code" },
      { status: 400 },
    );
  }
}

// DELETE /api/cart/[cartId]/promotions — remove a promo code
export async function DELETE(
  request: Request,
  { params }: { params: Promise<{ cartId: string }> },
) {
  const csrfError = await checkCsrf();
  if (csrfError) return csrfError;

  const { cartId } = await params;
  if (!isValidMedusaId(cartId)) {
    return badRequest("Invalid cart ID format");
  }

  const body = await parseBody<{ code?: unknown }>(request);
  if (!body) return badRequest("Invalid request body");

  const { code } = body;
  if (!isNonEmptyString(code)) {
    return badRequest("Missing or invalid promo code");
  }

  try {
    const cart = await removePromoCode(cartId, code.trim());
    return NextResponse.json(cart);
  } catch (e) {
    console.error("[cart:promo:remove]", (e as Error).message);
    return NextResponse.json(
      { error: "Failed to remove promo code" },
      { status: 500 },
    );
  }
}