import type { NextConfig } from 'next';

const configuredBasePath = process.env.OPENMAIC_BASE_PATH?.trim().replace(/\/+$/, '') || '';
const basePath = configuredBasePath && configuredBasePath.startsWith('/') ? configuredBasePath : '';

const nextConfig: NextConfig = {
  // Keep `next dev` in its own build directory so its startup reset never
  // wipes a production `next build` output shared through `.next`. Start the
  // dev server with NEXT_DIST_DIR=.next-dev; production build/start keep the
  // default `.next`.
  distDir: process.env.NEXT_DIST_DIR || '.next',
  output: process.env.VERCEL ? undefined : 'standalone',
  ...(basePath ? { basePath } : {}),
  env: {
    NEXT_PUBLIC_OPENMAIC_BASE_PATH: basePath,
  },
  transpilePackages: ['mathml2omml', 'pptxgenjs', '@openmaic/importer'],
  // These agent packages do a runtime `import(specifier)` with a computed
  // specifier (to lazily load node:fs/os/path without breaking browser/Vite
  // builds). webpack can't statically analyze that and bundling it throws
  // "Cannot find module as expression is too dynamic" at runtime on the server
  // (the "Edit with AI" Pro-mode path), which broke the #619 keep-alive e2e.
  // Mark them server-external so Next loads them natively and the dynamic
  // import resolves as a real Node call.
  serverExternalPackages: [
    '@earendil-works/pi-ai',
    '@earendil-works/pi-agent-core',
    '@openmaic/generation',
    // instrumentation.ts imports the PostgreSQL-backed persistence scheduler.
    // Keep pg in Node at runtime; bundling it for webpack's non-Node graphs
    // tries to resolve conditional fs/path/stream imports and breaks builds.
    'pg',
  ],
  experimental: {
    proxyClientMaxBodySize: '200mb',
  },
  webpack(config, { nextRuntime, webpack }) {
    if (nextRuntime === 'edge') {
      // instrumentation.ts is compiled for both runtimes. Its guarded Node
      // branch owns the PostgreSQL asset collector; omitting that module from
      // the Edge graph keeps pg's fs/path/stream imports out of middleware
      // without weakening the Node server schedule.
      config.plugins.push(
        new webpack.IgnorePlugin({ resourceRegExp: /asset-collector-schedule$/ }),
      );
    }
    return config;
  },
  async headers() {
    const extraAncestors = process.env.ALLOWED_FRAME_ANCESTORS?.trim();
    const frameAncestors = extraAncestors ? `'self' ${extraAncestors}` : "'self'";

    return [
      {
        source: '/(.*)',
        headers: [
          // X-Frame-Options only supports SAMEORIGIN (no allow-list),
          // so we omit it when custom ancestors are configured.
          ...(!extraAncestors ? [{ key: 'X-Frame-Options', value: 'SAMEORIGIN' }] : []),
          {
            key: 'Content-Security-Policy',
            value: `frame-ancestors ${frameAncestors}`,
          },
        ],
      },
    ];
  },
};

export default nextConfig;