package middleware

import (
	"log/slog"
	"net/http"
	"time"
)

// responseWriter 捕获状态码，实现 http.ResponseWriter。
type responseWriter struct {
	http.ResponseWriter
	status int
}

func (rw *responseWriter) WriteHeader(code int) {
	rw.status = code
	rw.ResponseWriter.WriteHeader(code)
}

// Audit 记录每个 HTTP 请求的结构化审计日志。
func Audit(next http.Handler) http.Handler {
	return http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) {
		start := time.Now()
		rw := &responseWriter{ResponseWriter: w, status: 200}

		next.ServeHTTP(rw, r)

		subject := "anonymous"
		if sub, ok := r.Context().Value(KeySubject).(string); ok {
			subject = sub
		}

		slog.Info("request",
			"method", r.Method,
			"path", r.URL.Path,
			"status", rw.status,
			"duration_ms", time.Since(start).Milliseconds(),
			"subject", subject,
			"remote_addr", r.RemoteAddr,
		)
	})
}