import type { NextConfig } from "next";

const nextConfig: NextConfig = {
  // Enable standalone output for Docker deployment
  output: 'standalone',

  // NOTE (Next.js 16): `eslint.ignoreDuringBuilds` was removed — `next build`
  // no longer runs ESLint itself (lint is now only `next lint` / `npm run lint`),
  // so there is nothing left to ignore here.

  // Skip TypeScript checking during build (for faster Docker builds)
  typescript: {
    ignoreBuildErrors: true,
  },
  
  // Optimize for production builds — Turbopack rules moved from the deprecated
  // experimental.turbo to the top-level turbopack key (Next 15.5).
  turbopack: {
    rules: {
      '*.svg': {
        loaders: ['@svgr/webpack'],
        as: '*.js',
      },
    },
  },
  
  // Image optimization
  images: {
    formats: ['image/webp', 'image/avif'],
    minimumCacheTTL: 60 * 60 * 24 * 30, // 30 days
  },
  
  // Security headers
  async headers() {
    return [
      {
        // Security headers apply to every route, including static assets.
        source: '/:path*',
        headers: [
          {
            key: 'X-Frame-Options',
            value: 'DENY',
          },
          {
            key: 'X-Content-Type-Options',
            value: 'nosniff',
          },
          {
            key: 'Referrer-Policy',
            value: 'origin-when-cross-origin',
          },
        ],
      },
      {
        // WHY: no-cache must not hit hashed build assets (_next/static) or
        // optimized images (_next/image); they are content-addressed and rely on
        // long-lived caching. Overriding them would re-download the bundle on
        // every page load.
        source: '/((?!_next/static|_next/image).*)',
        headers: [
          {
            key: 'Cache-Control',
            value: 'private, no-cache, must-revalidate, max-age=0',
          },
          { key: 'Pragma', value: 'no-cache' },
          { key: 'Expires', value: '0' },
        ],
      },
    ];
  },
};

export default nextConfig;