import type { NextConfig } from "next";

const s3Host = process.env.S3_ENDPOINT
  ? new URL(process.env.S3_ENDPOINT).hostname
  : "";

// Derive the Clerk frontend API host from the publishable key so the
// CSP allowlist always matches the active environment.
// Clerk key format is:
//   pk_test_<slug>-<randomSuffix>  -> <slug>.clerk.accounts.dev
//   pk_live_<slug>-<randomSuffix>  -> <slug>.clerk.services
// The slug itself may contain hyphens and digits, so the suffix is
// only the final dash-group. The regex greedily captures the slug.
function clerkFrontendApiHost(): string | null {
  const key = process.env.NEXT_PUBLIC_CLERK_PUBLISHABLE_KEY;
  if (!key) return null;
  const m = key.match(/^pk_(test|live)_(.+?)-([a-z0-9]+)$/i);
  if (!m) return null;
  const slug = m[2].toLowerCase();
  return m[1].toLowerCase() === "test"
    ? `${slug}.clerk.accounts.dev`
    : `${slug}.clerk.services`;
}

const clerkFapiHost = clerkFrontendApiHost();

const csp = [
  "default-src 'self'",
  // Clerk user avatars are served from img.clerk.com; S3 hosts are
  // also allowed for memorial uploads. data:/blob: for in-app previews.
  "img-src 'self' data: blob: https://img.clerk.com https:",
  "font-src 'self' data:",
  "style-src 'self' 'unsafe-inline'",
  // script-src: must include the Clerk FAPI host because Clerk JS is
  // loaded from <fapiHost>/npm/@clerk/clerk-js@<v>/dist/clerk.browser.js
  "script-src 'self' 'unsafe-inline' 'unsafe-eval'" +
    (clerkFapiHost ? ` https://${clerkFapiHost}` : ""),
  // connect-src: Clerk JS talks to <fapiHost> for all session calls.
  "connect-src 'self' https://api.clerk.com" +
    (clerkFapiHost ? ` https://${clerkFapiHost} wss://${clerkFapiHost}` : ""),
  "frame-ancestors 'self'",
].join("; ");

const securityHeaders = [
  { key: "Strict-Transport-Security", value: "max-age=63072000; includeSubDomains; preload" },
  { key: "X-Frame-Options", value: "SAMEORIGIN" },
  { key: "X-Content-Type-Options", value: "nosniff" },
  { key: "Referrer-Policy", value: "strict-origin-when-cross-origin" },
  { key: "Permissions-Policy", value: "camera=(), microphone=(), geolocation=()" },
  { key: "Content-Security-Policy", value: csp },
];

const nextConfig: NextConfig = {
  output: "standalone",
  poweredByHeader: false,
  compress: true,
  images: {
    remotePatterns: [
      { protocol: "https", hostname: "img.clerk.com" },
      ...(s3Host ? [{ protocol: "https", hostname: s3Host }] : []),
    ] as NonNullable<NonNullable<NextConfig["images"]>["remotePatterns"]>,
  },
  async headers() {
    return [
      {
        source: "/:path*",
        headers: securityHeaders,
      },
    ];
  },
};

export default nextConfig;