package httputil

import (
	"encoding/json"
	"net/http"
	"strings"
)

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

func WriteError(w http.ResponseWriter, status int, msg string) {
	WriteJSON(w, status, map[string]string{"error": msg})
}

// AuthMiddleware validates the Authorization: Bearer <key> header.
// If secretKey is empty, auth is disabled and all requests pass through.
// /health is always exempt.
func AuthMiddleware(secretKey string, next http.Handler) http.Handler {
	return http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) {
		if secretKey == "" || r.URL.Path == "/health" {
			next.ServeHTTP(w, r)
			return
		}
		token, ok := strings.CutPrefix(r.Header.Get("Authorization"), "Bearer ")
		if !ok || token != secretKey {
			WriteError(w, http.StatusUnauthorized, "unauthorized")
			return
		}
		next.ServeHTTP(w, r)
	})
}