StoreBackEnd/pkg/network/ClientMulticast.go

package network

import (
	"StoreBackEnd/pkg/protocol/repository"
	"StoreBackEnd/pkg/protocol/rules/writers"
	"fmt"
	"net"
	"time"
)

// CreateClientMulticast Méthode de construction d'un instance de la stuct ClientMulticast
func CreateClientMulticast(address string, domain string, port int, second time.Duration, repository *repository.ProtocolRepository) ClientMulticast {
	return ClientMulticast{
		address:    address,
		domain:     domain,
		port:       port,
		second:     second,
		repository: repository,
	}
}

// ClientMulticast Cette structure représente une communication en multicast.
// TODO : Prévoir une fermeture de la connection (con.Close())
type ClientMulticast struct {
	// address Adresse de multicast
	address string

	// address Domain de du StoreBackEnd
	domain string

	// port Port de connexion en unicast
	port int

	// second Temps en seconde entre chaque ping
	second time.Duration

	// Repository de protocol permettant de
	repository *repository.ProtocolRepository
}

// Run Cette méthode démarre une commmunication multicast
func (client ClientMulticast) Run() {
	addr, failedRA := client.ResolveAddr()
	if failedRA {
		return
	}

	con, failedDU := client.DialUdp(addr)
	if failedDU {
		return
	}

	cmd, correct := client.repository.ExecuteWriter(writers.HelloRulePrefix, client.domain, fmt.Sprintf("%d", client.port))
	if !correct {
		println("[ClientMulticast] Hello rule isn't correct (" + cmd + ")")
		return
	}

	for {
		_, _ = con.Write([]byte(cmd))
		time.Sleep(time.Second * client.second)
	}

}

// ResolveAddr Permet de résoude l'addresse
func (client ClientMulticast) ResolveAddr() (*net.UDPAddr, bool) {
	addr, errResUdp := net.ResolveUDPAddr("udp", client.address)

	if errResUdp != nil {
		println(errResUdp.Error())
		return nil, true
	}
	return addr, false
}

// DialUdp Ouvre une connection UDP
func (client ClientMulticast) DialUdp(addr *net.UDPAddr) (*net.UDPConn, bool) {
	con, errDial := net.DialUDP("udp", nil, addr)
	if errDial != nil {
		println(errDial.Error())
		return nil, true
	}
	return con, false
}