// Copyright 2021 Liuxiangchao iwind.liu@gmail.com. All rights reserved.

package models

import (
	"github.com/TeaOSLab/EdgeCommon/pkg/dnsconfigs"
	"github.com/iwind/TeaGo/types"
	"github.com/miekg/dns"
	"net"
	"strings"
)

type NSRecord struct {
	Id    int64
	Name  string
	Type  dnsconfigs.RecordType
	Value string

	MXPriority int32

	SRVPriority int32
	SRVWeight   int32
	SRVPort     int32

	CAAFlag int32
	CAATag  string

	Ttl      int32
	Weight   int32
	Version  int64
	RouteIds []string
	DomainId int64
}

func (this *NSRecord) ToRRAnswer(questionName string, rrClass uint16) dns.RR {
	if this.Ttl <= 0 {
		this.Ttl = 60
	}

	switch this.Type {
	case dnsconfigs.RecordTypeA:
		return &dns.A{
			Hdr: this.ToRRHeader(questionName, dns.TypeA, rrClass),
			A:   net.ParseIP(this.Value),
		}
	case dnsconfigs.RecordTypeCNAME:
		var value = this.Value
		if !strings.HasSuffix(value, ".") {
			value += "."
		}
		return &dns.CNAME{
			Hdr:    this.ToRRHeader(questionName, dns.TypeCNAME, rrClass),
			Target: value,
		}
	case dnsconfigs.RecordTypeAAAA:
		return &dns.AAAA{
			Hdr:  this.ToRRHeader(questionName, dns.TypeAAAA, rrClass),
			AAAA: net.ParseIP(this.Value),
		}
	case dnsconfigs.RecordTypeNS:
		var value = this.Value
		if !strings.HasSuffix(value, ".") {
			value += "."
		}
		return &dns.NS{
			Hdr: this.ToRRHeader(questionName, dns.TypeNS, rrClass),
			Ns:  value,
		}
	case dnsconfigs.RecordTypeMX:
		var value = this.Value
		if !strings.HasSuffix(value, ".") {
			value += "."
		}

		var preference uint16 = 0
		var priority = this.MXPriority
		if priority >= 0 {
			if priority > 65535 {
				priority = 65535
			}
			preference = types.Uint16(priority)
		}

		return &dns.MX{
			Hdr:        this.ToRRHeader(questionName, dns.TypeMX, rrClass),
			Preference: preference,
			Mx:         value,
		}
	case dnsconfigs.RecordTypeSRV:
		var priority uint16 = 10
		if this.SRVPriority > 0 {
			priority = uint16(this.SRVPriority)
		}

		var weight uint16 = 10
		if this.SRVWeight > 0 {
			weight = uint16(this.SRVWeight)
		}

		var port uint16 = 0
		if this.SRVPort > 0 {
			port = uint16(this.SRVPort)
		}

		var value = this.Value
		if !strings.HasSuffix(value, ".") {
			value += "."
		}

		return &dns.SRV{
			Hdr:      this.ToRRHeader(questionName, dns.TypeSRV, rrClass),
			Priority: priority,
			Weight:   weight,
			Port:     port,
			Target:   value,
		}
	case dnsconfigs.RecordTypeTXT:
		var values []string
		var runes = []rune(this.Value)
		const maxChars = 255
		for {
			if len(runes) <= maxChars {
				values = append(values, string(runes))
				break
			}
			values = append(values, string(runes[:maxChars]))
			runes = runes[maxChars:]
			if len(runes) == 0 {
				break
			}
		}

		return &dns.TXT{
			Hdr: this.ToRRHeader(questionName, dns.TypeTXT, rrClass),
			Txt: values, // TODO 可以添加多个
		}
	case dnsconfigs.RecordTypeCAA:
		var flag uint8 = 0
		if this.CAAFlag >= 0 && this.CAAFlag <= 128 {
			flag = uint8(this.CAAFlag)
		}

		var tag = this.CAATag
		if tag != "issue" && tag != "issuewild" && tag != "iodef" {
			tag = "issue"
		}

		return &dns.CAA{
			Hdr:   this.ToRRHeader(questionName, dns.TypeCAA, rrClass),
			Flag:  flag, // 0-128
			Tag:   tag,  // issue|issuewild|iodef
			Value: this.Value,
		}
	}

	return nil
}

func (this *NSRecord) ToRRHeader(questionName string, rrType uint16, rrClass uint16) dns.RR_Header {
	return dns.RR_Header{
		Name:   questionName,
		Rrtype: rrType,
		Class:  rrClass,
		Ttl:    uint32(this.Ttl),
	}
}