feat(internal/handler): enhance proxy handler to preserve compression and content type

internal/handler/proxy.go

@@ -97,8 +97,16 @@ func (h *ProxyHandler) ServeHTTP(w http.ResponseWriter, r *http.Request) {
 		}
 	}
 
+	// 设置接受压缩内容的header
+	proxyReq.Header.Set("Accept-Encoding", r.Header.Get("Accept-Encoding"))
+
 	// 发送代理请求
-	client := &http.Client{}
+	client := &http.Client{
+		Transport: &http.Transport{
+			// 禁用自动处理压缩，让我们能完整传递压缩内容
+			DisableCompression: true,
+		},
+	}
 	resp, err := client.Do(proxyReq)
 	if err != nil {
 		http.Error(w, "Error forwarding request", http.StatusBadGateway)
@@ -108,8 +116,23 @@ func (h *ProxyHandler) ServeHTTP(w http.ResponseWriter, r *http.Request) {
 	}
 	defer resp.Body.Close()
 
-	// 复制响应 header
+	// 复制所有响应头
-	copyHeader(w.Header(), resp.Header)
+	for k, vv := range resp.Header {
+		for _, v := range vv {
+			w.Header().Add(k, v)
+		}
+	}
+
+	// 确保Content-Type正确设置
+	contentType := resp.Header.Get("Content-Type")
+	if contentType != "" {
+		w.Header().Set("Content-Type", contentType)
+	}
+
+	// 保持原始的Content-Encoding
+	if encoding := resp.Header.Get("Content-Encoding"); encoding != "" {
+		w.Header().Set("Content-Encoding", encoding)
+	}
 
 	// 设置响应状态码
 	w.WriteHeader(resp.StatusCode)
@@ -138,17 +161,18 @@ func (h *ProxyHandler) ServeHTTP(w http.ResponseWriter, r *http.Request) {
 			}
 		}
 	} else {
-		// 如果不支持 Flusher，使用普通的 io.Copy
 		bytesCopied, err = io.Copy(w, resp.Body)
 		if err != nil {
 			log.Printf("Error copying response: %v", err)
 		}
 	}
 
-	// 记录访问日志
+	// 记录访问日志，添加内容类型信息
-	log.Printf("[%s] %s %s -> %s -> %d (%d bytes) [%v]",
+	log.Printf("[%s] %s %s -> %s -> %d (%d bytes) [%v] Content-Type: %s, Encoding: %s",
 		getClientIP(r), r.Method, r.URL.Path, targetURL,
-		resp.StatusCode, bytesCopied, time.Since(startTime))
+		resp.StatusCode, bytesCopied, time.Since(startTime),
+		resp.Header.Get("Content-Type"),
+		resp.Header.Get("Content-Encoding"))
 }
 
 func copyHeader(dst, src http.Header) {