package middleware

import (
	"net/http"
)

// SecurityHeaders adds common security headers to responses.
func SecurityHeaders(next http.Handler) http.Handler {
	return http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) {
		// Prevent MIME type sniffing
		w.Header().Set("X-Content-Type-Options", "nosniff")

		// Prevent clickjacking
		w.Header().Set("X-Frame-Options", "DENY")

		// Enable XSS filter
		w.Header().Set("X-XSS-Protection", "1; mode=block")

		// Content Security Policy (strict for API)
		w.Header().Set("Content-Security-Policy", "default-src 'none'")

		// Referrer Policy
		w.Header().Set("Referrer-Policy", "strict-origin-when-cross-origin")

		// Cache control for API responses
		w.Header().Set("Cache-Control", "no-store, max-age=0")

		// HSTS (HTTP Strict Transport Security) - only in production
		// w.Header().Set("Strict-Transport-Security", "max-age=31536000; includeSubDomains")

		next.ServeHTTP(w, r)
	})
}