package main

import (
	"fmt"
	"log"
	"math/rand"
	"net/http"
	"strconv"
	"strings"

	"github.com/miekg/dns"
)

type dnsHandler struct{}

func (h *dnsHandler) ServeDNS(w dns.ResponseWriter, r *dns.Msg) {
	msg := new(dns.Msg)
	msg.SetReply(r)
	msg.Authoritative = true

	for _, question := range r.Question {
		fmt.Printf("Received query: %s (%d)\n", question.Name, question.Qtype)

		if question.Qtype == dns.TypeCNAME || question.Qtype == dns.TypeA || question.Qtype == dns.TypeAAAA {
			if question.Name == "google.com." {
				msg.Answer = append(msg.Answer, &dns.CNAME{
					Hdr: dns.RR_Header{
						Name:   question.Name,
						Rrtype: dns.TypeCNAME,
						Class:  dns.ClassINET,
						Ttl:    30,
					},
					Target: "test0.imposter.cringe-studios.com.",
				})

				continue
			}
			if strings.HasPrefix(question.Name, "test") && strings.HasSuffix(question.Name, ".imposter.cringe-studios.com.") {
				num := question.Name[4:strings.Index(question.Name, ".imposter.cringe-studios.com.")]

				number, err := strconv.ParseUint(num, 10, 64)
				number++

				log.Println(num)

				if err != nil {
					log.Fatal("sus", err)
				}

				msg.Answer = append(msg.Answer, &dns.CNAME{
					Hdr: dns.RR_Header{
						Name:   question.Name,
						Rrtype: dns.TypeCNAME,
						Class:  dns.ClassINET,
						Ttl:    30,
					},
					Target: "test" + strconv.Itoa(int(number)) + ".imposter.cringe-studios.com.",
				})

				continue
			}

			if question.Name == "random-number.imposter.cringe-studios.com." {
				theNumber := rand.Intn(10000)

				msg.Answer = append(msg.Answer, &dns.CNAME{
					Hdr: dns.RR_Header{
						Name:   question.Name,
						Rrtype: dns.TypeCNAME,
						Class:  dns.ClassINET,
						Ttl:    30,
					},
					Target: "number-" + strconv.Itoa(theNumber) + ".imposter.cringe-studios.com.",
				})

				continue
			}

			if question.Name == "amogus.imposter.cringe-studios.com." {
				msg.Answer = append(msg.Answer, &dns.CNAME{
					Hdr: dns.RR_Header{
						Name:   question.Name,
						Rrtype: dns.TypeCNAME,
						Class:  dns.ClassINET,
						Ttl:    30,
					},
					Target: "test(test.imposter.cringe-studios.com.",
				})

				continue
			}

			//			msg.Answer = append(msg.Answer, &dns.NXNAME{
			//				Hdr: dns.RR_Header{
			//					Name:   question.Name,
			//					Rrtype: dns.TypeNXNAME,
			//					Class:  dns.ClassINET,
			//					Ttl:    30,
			//				},
			//			})
		}
	}

	w.WriteMsg(msg)
}

func getPage(w http.ResponseWriter, r *http.Request) {
	w.Write([]byte("Hello World!"))
}

func main() {
	handler := new(dnsHandler)

	server := &dns.Server{
		Addr:      ":53",
		Net:       "udp",
		Handler:   handler,
		UDPSize:   65535,
		ReusePort: true,
	}

	go func() {
		err := server.ListenAndServe()
		if err != nil {
			log.Fatalln("failed to listen", err)
		}
	}()

	http.HandleFunc("/", getPage)
	http.ListenAndServe(":6980", nil)
}