import type { NextConfig } from "next";

// Backend URL used for the SERVER-SIDE /api rewrite. Must resolve on the
// Docker network, so it must NOT be a public origin (that would create a loop).
// Use BACKEND_INTERNAL_URL (set at container runtime) so client components can
// independently use NEXT_PUBLIC_API_URL (public origin, baked at build time).
const API_BASE =
  process.env.BACKEND_INTERNAL_URL ||
  process.env.NEXT_PUBLIC_API_URL ||
  "http://backend:8000";

const nextConfig: NextConfig = {
  output: "standalone",

  // ── Performance: strip X-Powered-By header ──────────────────────────────
  poweredByHeader: false,

  // ── Performance: gzip compression handled by Next.js standalone server ──
  compress: true,

  // ── Compiler optimisations ───────────────────────────────────────────────
  compiler: {
    // Remove console.log statements from production builds
    removeConsole: process.env.NODE_ENV === "production"
      ? { exclude: ["error", "warn"] }
      : false,
  },

  // ── Tree-shake large packages (only import what is used) ─────────────────
  // This tells Next.js to side-effect-free import specific packages,
  // significantly reducing the bundle size for heavy libraries.
  experimental: {
    optimizePackageImports: [
      "lucide-react",
      "recharts",
      "framer-motion",
      "date-fns",
    ],
  },

  // ── API proxy rewrites ───────────────────────────────────────────────────
  async rewrites() {
    return [
      {
        source: "/api/:path*",
        destination: `${API_BASE}/api/:path*`,
      },
    ];
  },
};

export default nextConfig;