package middleware

import (
	"net/http"
)

// SecurityHeaders middleware lägger till säkerhetsheaders
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")
		
		// XSS Protection (legacy browsers)
		w.Header().Set("X-XSS-Protection", "1; mode=block")
		
		// Referrer policy
		w.Header().Set("Referrer-Policy", "strict-origin-when-cross-origin")
		
		// HSTS (endast i produktion med HTTPS)
		if r.TLS != nil || r.Header.Get("X-Forwarded-Proto") == "https" {
			w.Header().Set("Strict-Transport-Security", "max-age=31536000; includeSubDomains")
		}
		
		// Permissions Policy
		w.Header().Set("Permissions-Policy", "geolocation=(), microphone=(), camera=(), payment=()")
		
		// Content Security Policy
		w.Header().Set("Content-Security-Policy", "default-src 'self'; script-src 'self'; style-src 'self' 'unsafe-inline'; img-src 'self' data: https:; font-src 'self'; connect-src 'self';")
		
		next.ServeHTTP(w, r)
	})
}