import type { NextConfig } from "next";

const isProd = process.env.NODE_ENV === "production";
const staging = process.env.STAGING_MODE === "1";

const securityHeaders = [
  { key: "X-Content-Type-Options", value: "nosniff" },
  { key: "X-Frame-Options", value: "SAMEORIGIN" },
  { key: "Referrer-Policy", value: "strict-origin-when-cross-origin" },
  { key: "Permissions-Policy", value: "camera=(), microphone=(), geolocation=(), browsing-topics=()" },
  {
    key: "Content-Security-Policy",
    value: [
      "default-src 'self'",
      `script-src 'self'${isProd ? "" : " 'unsafe-eval'"} 'unsafe-inline'`,
      "style-src 'self' 'unsafe-inline'",
      "img-src 'self' data: blob:",
      "font-src 'self' data:",
      "connect-src 'self'",
      "frame-src 'self' blob:",
      "object-src 'self'",
      "base-uri 'self'",
      "form-action 'self'",
      "frame-ancestors 'self'",
      ...(isProd ? ["upgrade-insecure-requests"] : []),
    ].join("; "),
  },
  ...(isProd ? [{ key: "Strict-Transport-Security", value: "max-age=31536000; includeSubDomains" }] : []),
  ...(staging ? [{ key: "X-Robots-Tag", value: "noindex, nofollow" }] : []),
];

const nextConfig: NextConfig = {
  distDir: process.env.NEXT_DIST_DIR || ".next",
  reactStrictMode: true,
  poweredByHeader: false,
  serverExternalPackages: ["pg", "pino", "@node-rs/argon2", "pdfjs-dist", "pdf-lib", "drizzle-orm"],
  experimental: { serverActions: { bodySizeLimit: "2mb" } },
  async headers() {
    return [
      { source: "/(.*)", headers: securityHeaders },
      {
        source: "/papers/:path*",
        headers: [{ key: "Cache-Control", value: "public, max-age=31536000, immutable" }],
      },
    ];
  },
};

export default nextConfig;