package server

import (
	"crypto/subtle"
	"encoding/json"
	"log"
	"net/http"
	"time"
)

func writeJSON(w http.ResponseWriter, v any) {
	w.Header().Set("Content-Type", "application/json")
	_ = json.NewEncoder(w).Encode(v)
}

func requestLog(next http.Handler) http.Handler {
	return http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) {
		start := time.Now()
		next.ServeHTTP(w, r)
		log.Printf("%s %s %s", r.Method, r.URL.Path, time.Since(start).Round(time.Millisecond))
	})
}

func securityHeaders(next http.Handler) http.Handler {
	return http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) {
		w.Header().Set("X-Content-Type-Options", "nosniff")
		w.Header().Set("Referrer-Policy", "no-referrer")
		w.Header().Set("Content-Security-Policy", "default-src 'self'; style-src 'self' 'unsafe-inline'; form-action 'self'")
		next.ServeHTTP(w, r)
	})
}

func basicAuth(next http.Handler, username, password string) http.Handler {
	return http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) {
		if r.URL.Path == "/healthz" {
			next.ServeHTTP(w, r)
			return
		}
		if username == "" || password == "" {
			http.Error(w, "basic auth is not configured", http.StatusServiceUnavailable)
			return
		}
		gotUser, gotPass, ok := r.BasicAuth()
		if !ok || subtle.ConstantTimeCompare([]byte(gotUser), []byte(username)) != 1 || subtle.ConstantTimeCompare([]byte(gotPass), []byte(password)) != 1 {
			w.Header().Set("WWW-Authenticate", `Basic realm="log-guardian"`)
			http.Error(w, "unauthorized", http.StatusUnauthorized)
			return
		}
		next.ServeHTTP(w, r)
	})
}