next.config.ts

import type { NextConfig } from "next"

const isDev = process.env.NODE_ENV !== "production"

// Pages are statically rendered, so Next's inline bootstrap scripts need 'unsafe-inline'.
// Moving to nonce-based CSP would require rendering every page dynamically.
const contentSecurityPolicy = [
  "default-src 'self'",
  `script-src 'self' 'unsafe-inline'${isDev ? " 'unsafe-eval'" : ""}`,
  "style-src 'self' 'unsafe-inline'",
  "font-src 'self'",
  "img-src 'self' data: https://avatars.githubusercontent.com",
  // The landing-page check-up reads public repos straight from GitHub in the browser
  "connect-src 'self' https://api.github.com",
  "object-src 'none'",
  "base-uri 'self'",
  // Sign-in submits a form that redirects to GitHub's OAuth page
  "form-action 'self' https://github.com",
  "frame-ancestors 'none'",
  ...(isDev ? [] : ["upgrade-insecure-requests"]),
].join("; ")

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

const nextConfig: NextConfig = {
  poweredByHeader: false,
  async headers() {
    return [{ source: "/:path*", headers: securityHeaders }]
  },
}

export default nextConfig