package query

import (
	"encoding/hex"
	"fmt"
	"strconv"
	"strings"
	"time"

	"git.froth.zone/sam/awl/pkg/util"
	"github.com/miekg/dns"
	"golang.org/x/net/idna"
)

const aaaa = "AAAA"

func (message *Message) displayQuestion(msg *dns.Msg, opts *util.Options, opt *dns.OPT) error {
	var (
		name string
		err  error
	)

	for _, question := range msg.Question {
		if opts.Display.UcodeTranslate {
			name, err = idna.ToUnicode(question.Name)
			if err != nil {
				return fmt.Errorf("punycode to unicode: %w", err)
			}
		} else {
			name = question.Name
		}

		message.Name = name
		message.Type = question.Qtype
		message.TypeName = dns.TypeToString[question.Qtype]
		message.Class = question.Qclass
		message.ClassName = dns.ClassToString[question.Qclass]
	}

	return nil
}

func (message *Message) displayAnswers(msg *dns.Msg, opts *util.Options, opt *dns.OPT) error {
	var (
		ttl  string
		name string
		err  error
	)

	for _, answer := range msg.Answer {
		temp := strings.Split(answer.String(), "\t")

		if opts.Display.TTL {
			if opts.Display.HumanTTL {
				ttl = (time.Duration(answer.Header().Ttl) * time.Second).String()
			} else {
				ttl = strconv.Itoa(int(answer.Header().Ttl))
			}
		}

		if opts.Display.UcodeTranslate {
			name, err = idna.ToUnicode(answer.Header().Name)
			if err != nil {
				return fmt.Errorf("punycode to unicode: %w", err)
			}
		} else {
			name = answer.Header().Name
		}

		switch dns.TypeToString[answer.Header().Rrtype] {
		case "A":
			message.AdditionalRRs = append(message.AdditionalRRs, Answer{
				Name:      name,
				ClassName: dns.ClassToString[answer.Header().Class],
				Class:     answer.Header().Class,
				TypeName:  dns.TypeToString[answer.Header().Rrtype],
				Type:      answer.Header().Rrtype,
				Rdlength:  answer.Header().Rdlength,
				TTL:       ttl,
				ValueA:    temp[len(temp)-1],
			})

		case aaaa:
			message.AdditionalRRs = append(message.AdditionalRRs, Answer{
				Name:      name,
				ClassName: dns.ClassToString[answer.Header().Class],
				Class:     answer.Header().Class,
				TypeName:  dns.TypeToString[answer.Header().Rrtype],
				Type:      answer.Header().Rrtype,
				Rdlength:  answer.Header().Rdlength,
				TTL:       ttl,
				ValueAAAA: temp[len(temp)-1],
			})
		}
	}

	return nil
}

func (message *Message) displayAuthority(msg *dns.Msg, opts *util.Options, opt *dns.OPT) error {
	var (
		ttl  string
		name string
		err  error
	)

	for _, ns := range msg.Ns {
		temp := strings.Split(ns.String(), "\t")

		if opts.Display.TTL {
			if opts.Display.HumanTTL {
				ttl = (time.Duration(ns.Header().Ttl) * time.Second).String()
			} else {
				ttl = strconv.Itoa(int(ns.Header().Ttl))
			}
		}

		if opts.Display.UcodeTranslate {
			name, err = idna.ToUnicode(ns.Header().Name)
			if err != nil {
				return fmt.Errorf("punycode to unicode: %w", err)
			}
		} else {
			name = ns.Header().Name
		}

		switch dns.TypeToString[ns.Header().Rrtype] {
		case "A":
			message.AdditionalRRs = append(message.AdditionalRRs, Answer{
				Name:      name,
				TypeName:  dns.TypeToString[ns.Header().Rrtype],
				Type:      ns.Header().Rrtype,
				Class:     ns.Header().Class,
				ClassName: dns.ClassToString[ns.Header().Class],
				Rdlength:  ns.Header().Rdlength,
				TTL:       ttl,
				ValueA:    temp[len(temp)-1],
			})

		case aaaa:
			message.AdditionalRRs = append(message.AdditionalRRs, Answer{
				Name:      name,
				TypeName:  dns.TypeToString[ns.Header().Rrtype],
				Type:      ns.Header().Rrtype,
				Class:     ns.Header().Class,
				ClassName: dns.ClassToString[ns.Header().Class],
				Rdlength:  ns.Header().Rdlength,
				TTL:       ttl,
				ValueAAAA: temp[len(temp)-1],
			})
		}
	}

	return nil
}

func (message *Message) displayAdditional(msg *dns.Msg, opts *util.Options, opt *dns.OPT) error {
	var (
		ttl  string
		name string
		err  error
	)

	for _, additional := range msg.Extra {
		if additional.Header().Rrtype == dns.StringToType["OPT"] {
			continue
		} else {
			temp := strings.Split(additional.String(), "\t")

			if opts.Display.TTL {
				if opts.Display.HumanTTL {
					ttl = (time.Duration(additional.Header().Ttl) * time.Second).String()
				} else {
					ttl = strconv.Itoa(int(additional.Header().Ttl))
				}
			}

			if opts.Display.UcodeTranslate {
				name, err = idna.ToUnicode(additional.Header().Name)
				if err != nil {
					return fmt.Errorf("punycode to unicode: %w", err)
				}
			} else {
				name = additional.Header().Name
			}
			switch dns.TypeToString[additional.Header().Rrtype] {
			case "A":
				message.AdditionalRRs = append(message.AdditionalRRs, Answer{
					Name:      name,
					TypeName:  dns.TypeToString[additional.Header().Rrtype],
					Type:      additional.Header().Rrtype,
					Class:     additional.Header().Rrtype,
					ClassName: dns.ClassToString[additional.Header().Class],
					Rdlength:  additional.Header().Rdlength,
					TTL:       ttl,
					ValueA:    temp[len(temp)-1],
				})

			case aaaa:
				message.AdditionalRRs = append(message.AdditionalRRs, Answer{
					Name:      name,
					TypeName:  dns.TypeToString[additional.Header().Rrtype],
					Type:      additional.Header().Rrtype,
					Class:     additional.Header().Rrtype,
					ClassName: dns.ClassToString[additional.Header().Class],
					Rdlength:  additional.Header().Rdlength,
					TTL:       ttl,
					ValueAAAA: temp[len(temp)-1],
				})
			}
		}
	}

	return nil
}

// ParseOpt parses opts.
func (message *Message) ParseOpt(rr dns.OPT) ([]Opts, error) {
	ret := []Opts{}
	// Most of this is taken from https://github.com/miekg/dns/blob/master/edns.go#L76

	ret = append(ret, Opts{
		Name:  "Version",
		Value: strconv.Itoa(int(rr.Version())),
	})

	if rr.Do() {
		ret = append(ret, Opts{
			Name:  "Flags",
			Value: "do",
		})
	} else {
		ret = append(ret, Opts{
			Name:  "Flags",
			Value: "",
		})
	}

	if rr.Hdr.Ttl&0x7FFF != 0 {
		ret = append(ret, Opts{
			Name:  "MBZ",
			Value: fmt.Sprintf("0x%04x", rr.Hdr.Ttl&0x7FFF),
		})
	}

	ret = append(ret, Opts{
		Name:  "UDP Buffer Size",
		Value: strconv.Itoa(int(rr.UDPSize())),
	})

	for _, opt := range rr.Option {
		switch opt.(type) {
		case *dns.EDNS0_NSID:
			str := opt.String()

			hex, err := hex.DecodeString(str)
			if err != nil {
				return nil, fmt.Errorf("%w", err)
			}

			ret = append(ret, Opts{
				Name:  "NSID",
				Value: fmt.Sprintf("%s (%s)", str, string(hex)),
			})
		case *dns.EDNS0_SUBNET:
			ret = append(ret, Opts{
				Name:  "Subnet",
				Value: opt.String(),
			})
		case *dns.EDNS0_COOKIE:
			ret = append(ret, Opts{
				Name:  "Cookie",
				Value: opt.String(),
			})
		case *dns.EDNS0_EXPIRE:
			ret = append(ret, Opts{
				Name:  "Expire",
				Value: opt.String(),
			})
		case *dns.EDNS0_TCP_KEEPALIVE:
			ret = append(ret, Opts{
				Name:  "TCP Keepalive",
				Value: opt.String(),
			})
		case *dns.EDNS0_UL:
			ret = append(ret, Opts{
				Name:  "Update Lease",
				Value: opt.String(),
			})
		case *dns.EDNS0_LLQ:
			ret = append(ret, Opts{
				Name:  "Long Lived Queries",
				Value: opt.String(),
			})
		case *dns.EDNS0_DAU:
			ret = append(ret, Opts{
				Name:  "DNSSEC Algorithm Understood",
				Value: opt.String(),
			})
		case *dns.EDNS0_DHU:
			ret = append(ret, Opts{
				Name:  "DS Hash Understood",
				Value: opt.String(),
			})
		case *dns.EDNS0_N3U:
			ret = append(ret, Opts{
				Name:  "NSEC3 Hash Understood",
				Value: opt.String(),
			})
		case *dns.EDNS0_LOCAL:
			ret = append(ret, Opts{
				Name:  "Local OPT",
				Value: opt.String(),
			})
		case *dns.EDNS0_PADDING:
			ret = append(ret, Opts{
				Name:  "Padding",
				Value: opt.String(),
			})
		case *dns.EDNS0_EDE:
			ret = append(ret, Opts{
				Name:  "EDE",
				Value: opt.String(),
			})
		case *dns.EDNS0_ESU:
			ret = append(ret, Opts{
				Name:  "ESU",
				Value: opt.String(),
			})
		}
	}

	return ret, nil
}