import { NextResponse } from "next/server";

/**
 * JSON response helper for the public REST API. Serialises BigInt (Prisma ids)
 * to strings — JSON.stringify throws on BigInt otherwise — and sets permissive
 * CORS so the game client / external integrations can read it (mirrors the
 * AtomCMS API CORS config).
 */
export function apiJson(data: unknown, init?: ResponseInit): NextResponse {
  const body = JSON.stringify(data, (_k, v) => (typeof v === "bigint" ? v.toString() : v));
  return new NextResponse(body, {
    status: init?.status ?? 200,
    headers: {
      "content-type": "application/json; charset=utf-8",
      "access-control-allow-origin": "*",
      "cache-control": "no-store",
      ...(init?.headers ?? {}),
    },
  });
}

/** Standard error envelope. */
export function apiError(message: string, status = 400): NextResponse {
  return apiJson({ error: message }, { status });
}

/** Clamp a ?page / ?perPage pair from search params. */
export function pagination(searchParams: URLSearchParams, defaultPer = 20, maxPer = 100) {
  const page = Math.max(1, Number(searchParams.get("page") ?? "1") || 1);
  const perPage = Math.min(maxPer, Math.max(1, Number(searchParams.get("perPage") ?? defaultPer) || defaultPer));
  return { page, perPage, skip: (page - 1) * perPage, take: perPage };
}