package dns

import (
	"log/slog"
	"os"
	"time"
)

type LogConfig struct {
	Logger *slog.Logger
	Level  slog.Level
}

func NewDefaultLogConfig() *LogConfig {
	return &LogConfig{
		Logger: slog.New(slog.NewJSONHandler(os.Stderr, &slog.HandlerOptions{
			Level: slog.LevelInfo,
		})),
		Level: slog.LevelInfo,
	}
}

func LoggingMiddleware(config *LogConfig) func(Handler) Handler {
	if config == nil {
		config = NewDefaultLogConfig()
	}

	return func(next Handler) Handler {
		return HandlerFunc(func(w ResponseWriter, r *Request) {
			start := time.Now()

			next.ServeDNS(w, r)

			duration := time.Since(start)
			question := r.Message.Question[0]
			config.Logger.Info("query",
				"class", question.QClass.String(),
				"type", question.QType.String(),
				"name", question.QName,
				"rcode", r.Message.Header.RCode.String(),
				"remote_addr", r.RemoteAddr,
				"time_taken", duration.Nanoseconds(),
			)
		})
	}
}