package middleware

import (
	"log"
	"net/http"
	"strings"

	"golang.org/x/time/rate"
)

func SecurityHeaders(next http.Handler) http.Handler {
	return http.HandlerFunc(func(w http.ResponseWriter, req *http.Request) {
		w.Header().Set("X-Content-Type-Options", "nosniff")
		w.Header().Set("X-Frame-Options", "DENY")
		w.Header().Set("Referrer-Policy", "strict-origin-when-cross-origin")
		next.ServeHTTP(w, req)
	})
}

func NoListing(next http.Handler) http.Handler {
	return http.HandlerFunc(func(w http.ResponseWriter, req *http.Request) {
		if strings.HasSuffix(req.URL.Path, "/") {
			http.NotFound(w, req)
			return
		}
		next.ServeHTTP(w, req)
	})
}

func WKDHeaders(next http.Handler) http.Handler {
	return http.HandlerFunc(func(w http.ResponseWriter, req *http.Request) {
		w.Header().Set("Content-Type", "application/octet-stream")
		w.Header().Set("Access-Control-Allow-Origin", "*")
		next.ServeHTTP(w, req)
	})
}

// RateLimit is parameterized by the limiter instance, so each module
// that needs rate limiting owns its own limiter rather than sharing
// a package-level global.
func RateLimit(limiter *rate.Limiter) func(http.Handler) http.Handler {
	return func(next http.Handler) http.Handler {
		return http.HandlerFunc(func(w http.ResponseWriter, req *http.Request) {
			if !limiter.Allow() {
				log.Println("rate limit exceeded")
				w.WriteHeader(http.StatusTooManyRequests)
				return
			}
			next.ServeHTTP(w, req)
		})
	}
}