m-dns/host/host.go

package host

import (
	"fmt"
	"net"
	"os"
	"strconv"
	"strings"

	"git.giaever.org/joachimmg/go-log.git/log"
	"git.giaever.org/joachimmg/m-dns/errors"
)

type HostString string
type HostIP net.IP
type HostIPs []HostIP
type HostIPvType int
type HostPort int

const (
	IPv4 HostIPvType = iota << 1
	IPv6 HostIPvType = iota << 1
	NoIP HostIPvType = iota << 1
)

type Host struct {
	service  HostString
	domain   HostString
	hostname HostString
	ips      HostIPs
	port     HostPort
}

func New() *Host {
	return new(Host)
}

func (h *Host) SetService(s string) error {
	if err := HostString(s).validService(); err != nil {
		return err
	}
	h.service = HostString(s)
	return nil
}

func (h *Host) SetDomain(d string) error {
	if len(d) == 0 {
		d = "local."
	}

	if err := HostString(d).validDomain(); err != nil {
		return err
	}

	h.domain = HostString(d)
	return nil
}

func (h *Host) SetHostname(hn string) error {
	if len(hn) == 0 {
		var err error
		hn, err = os.Hostname()
		if err != nil {
			log.Warningln(h, hn, err)
			return errors.HostHostnameCouldNotDetermine
		}
		hn = fmt.Sprintf("%s.", hn)
	}

	if err := HostString(hn).validHostname(); err != nil {
		return err
	}

	h.hostname = HostString(hn)
	return nil
}

func (h *Host) SetIPs(i []net.IP) error {
	if len(i) == 0 {
		var err error
		i, err = net.LookupIP(fmt.Sprintf("%s%s", h.GetHostname(), h.GetDomain()))

		if err != nil {
			log.Warningln(h, err)
			return errors.HostIPCouldNotDetermine
		}

	}

	var ips HostIPs

	for _, ip := range i {
		ips = append(ips, HostIP(ip))
	}

	if err := ips.validIPs(); err != nil {
		log.Warningln(err)
		return err
	}

	h.ips = ips
	return nil
}

func (h *Host) SetPort(p int) error {
	if err := HostPort(p).validPort(); err != nil {
		return err
	}
	h.port = HostPort(p)
	return nil
}

func (h *Host) GetService() HostString {
	if err := h.service.validService(); err != nil {
		log.Panicln(err)
	}
	return h.service
}

func (h *Host) GetDomain() HostString {
	if err := h.domain.validDomain(); err != nil {
		log.Panicln(err)
	}
	return h.domain
}

func (h *Host) GetHostname() HostString {
	if err := h.hostname.validHostname(); err != nil {
		log.Panicln(err)
	}
	return h.hostname
}

func (h *Host) GetIPs() HostIPs {
	if err := h.ips.validIPs(); err != nil {
		log.Panicln(err)
	}
	return h.ips
}

func (h *Host) GetPort() HostPort {
	if err := h.port.validPort(); err != nil {
		log.Panicln(err)
	}
	return h.port
}

func (h *Host) String() string {
	return fmt.Sprintf("Service: %s\nDomain: %s\nHostname: %s\nIPs: %s\nPort: %s\n",
		h.GetService(),
		h.GetDomain(),
		h.GetHostname(),
		strings.Join(h.GetIPs().String(), ", "),
		h.GetPort(),
	)
}

func (h HostString) ValidFQDM() bool {
	if len(h) == 0 {
		log.Warningln("Cannot be blank", h)
		return false
	}

	if h[len(h)-1] != '.' {
		log.Warningf("Missing trailing '.' in <%s>", h)
		return false
	}

	return true
}

func (h HostString) validService() error {
	if len(h) == 0 {
		log.Warningln("Service is empty", h)
		return errors.HostServiceIsEmpty
	}
	return nil
}

func (h HostString) validHostname() error {
	if !h.ValidFQDM() {
		return errors.HostHostnameNotFQDM
	}
	return nil
}

func (h HostString) validDomain() error {
	if !h.ValidFQDM() {
		return errors.HostDomainNotFQDM
	}
	return nil
}

func (h HostString) TrimDot() string {
	return strings.Trim(h.String(), ".")
}

func (h HostString) String() string {
	return string(h)
}

func (h HostIPs) validIPs() error {
	for _, ip := range h {
		if t := ip.Type(); t == NoIP {
			return errors.HostIPAddressIsInvalid
		}
	}
	return nil
}

func (h HostIPs) String() []string {
	s := []string{}
	for _, ip := range h {
		s = append(s, ip.String())
	}
	return s
}

func (h HostIP) Type() HostIPvType {
	if h.AsIP().To4() != nil {
		return IPv4
	}

	if h.AsIP().To16() != nil {
		return IPv6
	}

	return NoIP
}

func (h HostIP) AsIP() net.IP {
	return net.IP(h)
}

func (h HostIP) String() string {
	return h.AsIP().String()
}

func (h HostPort) validPort() error {
	if h <= 0 {
		log.Warningf("Port <%d> is invalid.", h)
		return errors.HostPortInvalid
	}
	return nil
}

func (h HostPort) Uint16() uint16 {
	return uint16(h)
}

func (h HostPort) String() string {
	return strconv.Itoa(int(h))
}