import { realpathSync } from "node:fs";
import path from "node:path";
import type { NextConfig } from "next";

/**
 * While onvif is linked to a local checkout outside this project (e.g. the fork, installed
 * with `npm install ../onvif --no-save`), Turbopack only resolves files inside its root, so
 * the root must contain both (Next docs, 03-api-reference/08-turbopack.md "Root directory").
 * Returns undefined for a normal install, leaving the auto-detected root alone.
 */
function linkedPackagesRoot(project: string, packages: string[]): string | undefined {
  let root = project;
  for (const name of packages) {
    let target: string;
    try {
      target = realpathSync(path.join(project, "node_modules", name));
    } catch {
      continue;
    }
    while (path.relative(root, target).startsWith("..")) root = path.dirname(root);
  }
  return root === project ? undefined : root;
}

const project = process.cwd();
const turbopackRoot = linkedPackagesRoot(project, ["onvif"]);

const nextConfig: NextConfig = {
  // A build and a dev server sharing .next fight over it; NEXT_DIST_DIR lets a build run
  // to one side while someone is working.
  ...(process.env.NEXT_DIST_DIR && { distDir: process.env.NEXT_DIST_DIR }),
  // What gets published: a minimal server plus only the files it needs, so installing the
  // package doesn't drag in Next and React (vrek iss-ej4ahga).
  output: "standalone",
  // Runtime data and the downloaded MediaMTX binary are not part of the app.
  outputFileTracingExcludes: { "/*": ["bin/**/*", ".data/**/*", "node_modules/@img/**/*", "node_modules/sharp/**/*"] },
  // next/image is unused, and leaving it on pulls sharp's platform binaries (tens of MB).
  images: { unoptimized: true },
  // onvif uses Node's dgram/os modules; load it with native require instead of bundling.
  // onvif is bundled rather than listed in serverExternalPackages. Externalizing it made
  // Turbopack emit require("onvif-<hash>") — a name that exists nowhere — because the
  // dependency comes from a git URL, which broke the published package (vrek iss-9zcawn7).
  // Bundled, discovery (dgram) and camera reads work from an installed copy.
  ...(turbopackRoot && { turbopack: { root: turbopackRoot } }),
};

export default nextConfig;