add domain whois/dns support, refactor codebase

internal/server/middleware.go

@@ -0,0 +1,57 @@
+package server
+
+import (
+	"compress/gzip"
+	"fmt"
+	"log/slog"
+	"net/http"
+	"strings"
+	"time"
+)
+
+// gzipResponseWriter is a wrapper for gzip compression.
+type gzipResponseWriter struct {
+	http.ResponseWriter
+	Writer *gzip.Writer
+}
+
+func (w gzipResponseWriter) Write(b []byte) (int, error) {
+	return w.Writer.Write(b)
+}
+
+func (w gzipResponseWriter) Close() {
+	if err := w.Writer.Close(); err != nil {
+		slog.Error("failed to close gzip writer", "error", err)
+	}
+}
+
+// newGzipResponseWriter wraps the ResponseWriter if the client accepts gzip.
+func newGzipResponseWriter(w http.ResponseWriter, r *http.Request) http.ResponseWriter {
+	if strings.Contains(r.Header.Get("Accept-Encoding"), "gzip") {
+		w.Header().Set("Content-Encoding", "gzip")
+		gz := gzip.NewWriter(w)
+		return gzipResponseWriter{ResponseWriter: w, Writer: gz}
+	}
+	return w
+}
+
+// loggingMiddleware logs the incoming HTTP request and its duration.
+func loggingMiddleware(next http.Handler) http.Handler {
+	return http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) {
+		if r.URL.Path == "/favicon.ico" {
+			next.ServeHTTP(w, r)
+			return
+		}
+
+		start := time.Now()
+		next.ServeHTTP(w, r)
+		duration := time.Since(start)
+
+		slog.Info(fmt.Sprintf("%s %s from %s in %s",
+			r.Method,
+			r.URL.Path,
+			GetRealIP(r),
+			duration,
+		))
+	})
+}