package dns

import (
	"net"
	"reflect"
	"strconv"
)

// Field returns the rdata field i as a string. Fields are indexed starting from 1.
// Non existing fields will return the empty string. RR types that holds slice data,
// for instance the NSEC type bitmap will return a single string where the types
// are concatenated using a space.
func Field(r RR, i int) string {
	if i == 0 {
		return ""
	}
	d := reflect.ValueOf(r).Elem().Field(i)
	switch k := d.Kind(); k {
	case reflect.String:
		return d.String()
	case reflect.Int, reflect.Int8, reflect.Int16, reflect.Int32, reflect.Int64:
		return strconv.FormatInt(d.Int(), 10)
	case reflect.Uint, reflect.Uint8, reflect.Uint16, reflect.Uint32, reflect.Uint64:
		return strconv.FormatUint(d.Uint(), 10)
	case reflect.Slice:
		switch reflect.ValueOf(r).Elem().Type().Field(i).Tag {
		case `dns:"a"`:
			// TODO(miek): We hmm store this as 16 bytes
			if d.Len() < net.IPv6len {
				return net.IPv4(byte(d.Index(0).Uint()),
					byte(d.Index(1).Uint()),
					byte(d.Index(2).Uint()),
					byte(d.Index(3).Uint())).String()
			}
			return net.IPv4(byte(d.Index(12).Uint()),
				byte(d.Index(13).Uint()),
				byte(d.Index(14).Uint()),
				byte(d.Index(15).Uint())).String()
		case `dns:"aaaa"`:
			return net.IP{
				byte(d.Index(0).Uint()),
				byte(d.Index(1).Uint()),
				byte(d.Index(2).Uint()),
				byte(d.Index(3).Uint()),
				byte(d.Index(4).Uint()),
				byte(d.Index(5).Uint()),
				byte(d.Index(6).Uint()),
				byte(d.Index(7).Uint()),
				byte(d.Index(8).Uint()),
				byte(d.Index(9).Uint()),
				byte(d.Index(10).Uint()),
				byte(d.Index(11).Uint()),
				byte(d.Index(12).Uint()),
				byte(d.Index(13).Uint()),
				byte(d.Index(14).Uint()),
				byte(d.Index(15).Uint()),
			}.String()
		case `dns:"nsec"`:
			if d.Len() == 0 {
				return ""
			}
			s := Type(d.Index(0).Uint()).String()
			for i := 1; i < d.Len(); i++ {
				s += " " + Type(d.Index(i).Uint()).String()
			}
			return s
		case `dns:"wks"`:
			if d.Len() == 0 {
				return ""
			}
			s := strconv.Itoa(int(d.Index(0).Uint()))
			for i := 0; i < d.Len(); i++ {
				s += " " + strconv.Itoa(int(d.Index(i).Uint()))
			}
			return s
		default:
			// if it does not have a tag its a string slice
			fallthrough
		case `dns:"txt"`:
			if d.Len() == 0 {
				return ""
			}
			s := d.Index(0).String()
			for i := 1; i < d.Len(); i++ {
				s += " " + d.Index(i).String()
			}
			return s
		}
	}
	return ""
}

// NumField returns the number of rdata fields r has.
func NumField(r RR) int {
	return reflect.ValueOf(r).Elem().NumField() - 1 // Remove RR_Header
}

/*
func format(r RR, f fmt.State, c rune) {
	switch c {
	case 'N':
		f.Write([]byte(r.Header().Name))
	case 'C':
		f.Write([]byte(Class(r.Header().Class).String()))
	case 'D':
		f.Write([]byte(strconv.Itoa(int(r.Header().Ttl))))
	case 'Y':
		f.Write([]byte(Type(r.Header().Rrtype).String()))
	case 's':
		f.Write([]byte(r.String()))
	default:
		println(string(c))
		f.Write([]byte("TODO"))
	}
}

func format_Header(h *RR_Header, f fmt.State, c rune) {
	switch c {
	case 'N':
		f.Write([]byte(h.Name))
	case 'C':
		f.Write([]byte(Class(h.Class).String()))
	case 'D':
		f.Write([]byte(strconv.Itoa(int(h.Ttl))))
	case 'Y':
		f.Write([]byte(Type(h.Rrtype).String()))
	case 's':
		f.Write([]byte(h.String()))
	default:
		f.Write([]byte("TODO"))
	}
}

func (h *RR_Header) Format(f fmt.State, c rune)  { format_Header(h, f, c) }
func (rr *RFC3597) Format(f fmt.State, c rune)   { format(rr, f, c) }
func (rr *PrivateRR) Format(f fmt.State, c rune) { format(rr, f, c) }
func (rr *IPSECKEY) Format(f fmt.State, c rune)  { format(rr, f, c) }
func (rr *ANY) Format(f fmt.State, c rune)       { format(rr, f, c) }

// Quick 'n dirty:
// for i in $(egrep '\sType.*:.*new\(' types.go | awk '{ print $6 } ' | sed 's/new(//' | sed 's/)//'); do
// echo "func (rr *$i) Format(f fmt.State, c rune) { format(rr, f, c) }" ; done

func (rr *A) Format(f fmt.State, c rune)          { format(rr, f, c) }
func (rr *AAAA) Format(f fmt.State, c rune)       { format(rr, f, c) }
func (rr *AFSDB) Format(f fmt.State, c rune)      { format(rr, f, c) }
func (rr *CDS) Format(f fmt.State, c rune)        { format(rr, f, c) }
func (rr *CERT) Format(f fmt.State, c rune)       { format(rr, f, c) }
func (rr *CNAME) Format(f fmt.State, c rune)      { format(rr, f, c) }
func (rr *DHCID) Format(f fmt.State, c rune)      { format(rr, f, c) }
func (rr *DLV) Format(f fmt.State, c rune)        { format(rr, f, c) }
func (rr *DNAME) Format(f fmt.State, c rune)      { format(rr, f, c) }
func (rr *KEY) Format(f fmt.State, c rune)        { format(rr, f, c) }
func (rr *DNSKEY) Format(f fmt.State, c rune)     { format(rr, f, c) }
func (rr *DS) Format(f fmt.State, c rune)         { format(rr, f, c) }
func (rr *EUI48) Format(f fmt.State, c rune)      { format(rr, f, c) }
func (rr *EUI64) Format(f fmt.State, c rune)      { format(rr, f, c) }
func (rr *GID) Format(f fmt.State, c rune)        { format(rr, f, c) }
func (rr *GPOS) Format(f fmt.State, c rune)       { format(rr, f, c) }
func (rr *EID) Format(f fmt.State, c rune)        { format(rr, f, c) }
func (rr *HINFO) Format(f fmt.State, c rune)      { format(rr, f, c) }
func (rr *HIP) Format(f fmt.State, c rune)        { format(rr, f, c) }
func (rr *KX) Format(f fmt.State, c rune)         { format(rr, f, c) }
func (rr *L32) Format(f fmt.State, c rune)        { format(rr, f, c) }
func (rr *L64) Format(f fmt.State, c rune)        { format(rr, f, c) }
func (rr *LOC) Format(f fmt.State, c rune)        { format(rr, f, c) }
func (rr *LP) Format(f fmt.State, c rune)         { format(rr, f, c) }
func (rr *MB) Format(f fmt.State, c rune)         { format(rr, f, c) }
func (rr *MD) Format(f fmt.State, c rune)         { format(rr, f, c) }
func (rr *MF) Format(f fmt.State, c rune)         { format(rr, f, c) }
func (rr *MG) Format(f fmt.State, c rune)         { format(rr, f, c) }
func (rr *MINFO) Format(f fmt.State, c rune)      { format(rr, f, c) }
func (rr *MR) Format(f fmt.State, c rune)         { format(rr, f, c) }
func (rr *MX) Format(f fmt.State, c rune)         { format(rr, f, c) }
func (rr *NAPTR) Format(f fmt.State, c rune)      { format(rr, f, c) }
func (rr *NID) Format(f fmt.State, c rune)        { format(rr, f, c) }
func (rr *NINFO) Format(f fmt.State, c rune)      { format(rr, f, c) }
func (rr *NIMLOC) Format(f fmt.State, c rune)     { format(rr, f, c) }
func (rr *NS) Format(f fmt.State, c rune)         { format(rr, f, c) }
func (rr *NSAP) Format(f fmt.State, c rune)       { format(rr, f, c) }
func (rr *NSAPPTR) Format(f fmt.State, c rune)    { format(rr, f, c) }
func (rr *NSEC3) Format(f fmt.State, c rune)      { format(rr, f, c) }
func (rr *NSEC3PARAM) Format(f fmt.State, c rune) { format(rr, f, c) }
func (rr *NSEC) Format(f fmt.State, c rune)       { format(rr, f, c) }
func (rr *OPENPGPKEY) Format(f fmt.State, c rune) { format(rr, f, c) }
func (rr *OPT) Format(f fmt.State, c rune)        { format(rr, f, c) }
func (rr *PTR) Format(f fmt.State, c rune)        { format(rr, f, c) }
func (rr *RKEY) Format(f fmt.State, c rune)       { format(rr, f, c) }
func (rr *RP) Format(f fmt.State, c rune)         { format(rr, f, c) }
func (rr *PX) Format(f fmt.State, c rune)         { format(rr, f, c) }
func (rr *SIG) Format(f fmt.State, c rune)        { format(rr, f, c) }
func (rr *RRSIG) Format(f fmt.State, c rune)      { format(rr, f, c) }
func (rr *RT) Format(f fmt.State, c rune)         { format(rr, f, c) }
func (rr *SOA) Format(f fmt.State, c rune)        { format(rr, f, c) }
func (rr *SPF) Format(f fmt.State, c rune)        { format(rr, f, c) }
func (rr *SRV) Format(f fmt.State, c rune)        { format(rr, f, c) }
func (rr *SSHFP) Format(f fmt.State, c rune)      { format(rr, f, c) }
func (rr *TA) Format(f fmt.State, c rune)         { format(rr, f, c) }
func (rr *TALINK) Format(f fmt.State, c rune)     { format(rr, f, c) }
func (rr *TKEY) Format(f fmt.State, c rune)       { format(rr, f, c) }
func (rr *TLSA) Format(f fmt.State, c rune)       { format(rr, f, c) }
func (rr *TSIG) Format(f fmt.State, c rune)       { format(rr, f, c) }
func (rr *TXT) Format(f fmt.State, c rune)        { format(rr, f, c) }
func (rr *UID) Format(f fmt.State, c rune)        { format(rr, f, c) }
func (rr *UINFO) Format(f fmt.State, c rune)      { format(rr, f, c) }
func (rr *URI) Format(f fmt.State, c rune)        { format(rr, f, c) }
func (rr *WKS) Format(f fmt.State, c rune)        { format(rr, f, c) }
func (rr *X25) Format(f fmt.State, c rune)        { format(rr, f, c) }
*/