package main

import (
	"log"
	"net/http"

	"github.com/darkit/goproxy"
	"github.com/darkit/goproxy/pkg/dns"
)

// WildcardDNSDelegate 通配符 DNS 代理委托
type WildcardDNSDelegate struct {
	goproxy.DefaultDelegate
	dnsResolver *dns.WildcardResolver
}

// ResolveBackend 解析后端服务器
func (d *WildcardDNSDelegate) ResolveBackend(req *http.Request) (string, error) {
	return d.dnsResolver.Resolve(req.URL.Host)
}

func main() {
	// 创建 DNS 解析器
	resolver := dns.NewWildcardResolver(map[string]string{
		"*.example.com": "http://backend.example.com",
		"*.test.com":    "http://backend.test.com",
	})

	// 创建通配符 DNS 代理委托
	delegate := &WildcardDNSDelegate{
		dnsResolver: resolver,
	}

	// 创建代理实例
	proxy := goproxy.NewProxy(
		goproxy.WithDelegate(delegate),
	)

	// 启动代理服务器
	log.Println("通配符 DNS 代理服务器启动在 :8080")
	log.Println("DNS 配置:")
	log.Printf("- *.example.com -> backend.example.com\n")
	log.Printf("- *.test.com -> backend.test.com\n")
	if err := http.ListenAndServe(":8080", proxy); err != nil {
		log.Fatalf("代理服务器启动失败: %v", err)
	}
}