package server

import (
	curl "cfTest/curl"
	"context"
	"io"
	"log"
	"net"
	"net/http"
	"runtime"
	"time"
)

type CurlServer struct {
	curl.UnimplementedCurlWithResolveServer
}

func (s *CurlServer) CurlWithResolveParam(ctx context.Context, requestCurlObject *curl.CurlRequest) (*curl.CurlReply, error) {
	log.Printf("url Received: %v", requestCurlObject.GetUrl())
	log.Printf("ip Received: %v", requestCurlObject.GetIp())
	log.Printf("UA Received: %v", requestCurlObject.GetUA())
	log.Printf("UseHeadMethod Received: %v", requestCurlObject.GetUseHeadMethod())

	// UA
	var UA = ""
	if len(requestCurlObject.GetUA()) == 0 {
		UA = generateDefaultUserAgent()
	} else {
		UA = requestCurlObject.GetUA()
	}

	// Server
	// 创建一个自定义的 Transport
	transport := &CustomTransport{
		Transport: &http.Transport{
			DialContext: func(ctx context.Context, network, addr string) (net.Conn, error) {
				dialer := &net.Dialer{
					Timeout:   30 * time.Second,
					KeepAlive: 30 * time.Second,
					DualStack: true,
				}

				// 修改addr -> 指向IP地址
				addr = requestCurlObject.GetIp() + ":443"
				log.Println("addr = ", addr)
				conn, err := dialer.DialContext(ctx, network, addr)
				if err != nil {
					return nil, err
				}
				return conn, nil
			},
		},
		// 指定UA
		UserAgent:     UA,
		UseHeadMethod: requestCurlObject.GetUseHeadMethod(),
	}

	// 创建一个使用自定义 Transport 的 HTTP 客户端
	client := &http.Client{
		Transport: transport,
	}

	// 发起 HTTP 请求
	resp, err := client.Get(requestCurlObject.GetUrl())
	if err != nil {
		return nil, err
	}
	defer resp.Body.Close()

	// 解析响应结果
	log.Println("Code = ", resp.StatusCode)

	body, err := io.ReadAll(resp.Body)
	if err != nil {
		return nil, err
	}
	log.Println("Body = ", string(body))
	log.Println("header = ", resp.Header)

	return &curl.CurlReply{
		Code: int32(resp.StatusCode),
		Body: string(body),
	}, nil
}

type CustomTransport struct {
	Transport     http.RoundTripper
	UserAgent     string
	UseHeadMethod bool
}

func (t *CustomTransport) RoundTrip(req *http.Request) (*http.Response, error) {
	req.Header.Set("User-Agent", t.UserAgent)
	if t.UseHeadMethod {
		req.Method = http.MethodHead
	}
	return t.Transport.RoundTrip(req)
}

func generateDefaultUserAgent() string {
	// 获取操作系统名称和版本号
	osInfo := runtime.GOOS
	// 获取编程语言和版本号
	langInfo := "Go/" + runtime.Version()
	// 获取应用程序运行时的信息
	appInfo := "Executor/1.0"

	return appInfo + " (" + osInfo + "; " + langInfo + ")"
}