package api

import (
	"net/http"
)

// secureHeaders adds strict, privacy-preserving headers to static responses.
func (s *Server) secureHeaders(next http.Handler) http.Handler {
	return http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) {
		w.Header().Set("Referrer-Policy", "no-referrer")
		w.Header().Set("Cross-Origin-Opener-Policy", "same-origin")
		w.Header().Set("Cross-Origin-Resource-Policy", "same-site")
		w.Header().Set("Permissions-Policy", "camera=(), microphone=(), geolocation=(), interest-cohort=(), browsing-topics=()")
		w.Header().Set("X-Frame-Options", "DENY")
		w.Header().Set("X-Content-Type-Options", "nosniff")
		w.Header().Set("Strict-Transport-Security", "max-age=15552000; includeSubDomains; preload")
		next.ServeHTTP(w, r)
	})
}

// MountStatic mounts a static file server under a prefix onto the provided mux.
// Usage (from main): s.MountStatic(mux, "/", http.Dir(staticDir))
func (s *Server) MountStatic(mux *http.ServeMux, prefix string, fs http.FileSystem) {
	if prefix == "" {
		prefix = "/"
	}
	h := http.StripPrefix(prefix, http.FileServer(fs))
	mux.Handle(prefix, s.secureHeaders(h))
}