// create eureka service registries in each zone
func CreateEureka() {
	// setup name service and cross zone replication links
	znames := archaius.Conf.ZoneNames
	Create("eureka", EurekaPkg, archaius.Conf.Regions, 3)
	for n, ch := range eurekachan {
		var n1, n2 string
		switch names.Zone(n) {
		case znames[0]:
			n1 = znames[1]
			n2 = znames[2]
		case znames[1]:
			n1 = znames[0]
			n2 = znames[2]
		case znames[2]:
			n1 = znames[0]
			n2 = znames[1]
		}
		for nn, cch := range eurekachan {
			if names.Region(nn) == names.Region(n) && (names.Zone(nn) == n1 || names.Zone(nn) == n2) {
				//log.Println("Eureka cross connect from: " + n + " to " + nn)
				gotocol.Send(ch, gotocol.Message{gotocol.NameDrop, cch, time.Now(), gotocol.NilContext, nn})
			}
		}
	}
}

// send a message directly to a name via asgard, only used during setup
func SendToName(name string, msg gotocol.Message) {
	if noodles[name] != nil {
		gotocol.Send(noodles[name], msg)
	} else {
		log.Fatal("Asgard can't send to " + name)
	}
}

// Tell a source node how to connect to a target node directly by name, only used when Eureka can't be used
func Connect(source, target string) {
	if noodles[source] != nil && noodles[target] != nil {
		gotocol.Send(noodles[source], gotocol.Message{gotocol.NameDrop, noodles[target], time.Now(), gotocol.NilContext, target})
		//log.Println("Link " + source + " > " + target)
	} else {
		log.Fatal("Asgard can't link " + source + " > " + target)
	}
}

// NameDrop updates local buddy list
func NameDrop(dependencies *map[string]time.Time, microservices *map[string]chan gotocol.Message, msg gotocol.Message, name string, listener chan gotocol.Message, eureka map[string]chan gotocol.Message, crosszone ...bool) {
	if msg.ResponseChan == nil { // dependency by service name, needs to be looked up in eureka
		(*dependencies)[msg.Intention] = msg.Sent // remember it for later
		for _, ch := range eureka {
			//log.Println(name + " looking up " + msg.Intention)
			gotocol.Send(ch, gotocol.Message{gotocol.GetRequest, listener, time.Now(), gotocol.NilContext, msg.Intention})
		}
	} else { // update dependency with full name and listener channel
		microservice := msg.Intention // message body is buddy name
		if len(crosszone) > 0 || names.Zone(name) == names.Zone(microservice) {
			if microservice != name && (*microservices)[microservice] == nil { // don't talk to myself or record duplicates
				// remember how to talk to this buddy
				(*microservices)[microservice] = msg.ResponseChan // message channel is buddy's listener
				(*dependencies)[names.Service(microservice)] = msg.Sent
				for _, ch := range eureka {
					// tell one of the service registries I have a new buddy to talk to so it doesn't get logged more than once
					gotocol.Send(ch, gotocol.Message{gotocol.Inform, listener, time.Now(), gotocol.NilContext, name + " " + microservice})
					return
				}
			}
		}
	}
}

// distribute tokens to one zone of a cassandra cluster, this doesn't yet allow for clusters to grow or replace nodes
func Distribute(cass map[string]chan gotocol.Message) string {
	size := len(cass)
	// each node owns a share of the full range
	hashrange := uint32(0xFFFFFFFF) / uint32(size)
	// make a config string of the form cass1:0,cass4:1000,cass2:2000
	i := 0
	s := ""
	for n, _ := range cass {
		s += fmt.Sprintf("%s:%v,", n, hashrange*uint32(i))
		i++
	}
	s = strings.TrimSuffix(s, ",")
	// send the config to each node, repurposing the Chat message type as a kind of Gossip setup
	for _, c := range cass {
		gotocol.Send(c, gotocol.Message{gotocol.Chat, nil, time.Now(), gotocol.NilContext, s})
	}
	return s // for logging and test
}

// connect to eureka services in every region
func ConnectEveryEureka(name string) {
	for n, ch := range eurekachan {
		gotocol.Send(noodles[name], gotocol.Message{gotocol.Inform, ch, time.Now(), gotocol.NilContext, n})
	}
}

// Start a node using the named package, and connect it to any dependencies
func StartNode(name string, dependencies ...string) {
	if names.Package(name) == "eureka" {
		eurekachan[name] = make(chan gotocol.Message, archaius.Conf.Population)
		go eureka.Start(eurekachan[name], name)
		return
	} else {
		noodles[name] = make(chan gotocol.Message)
	}
	// start the service and tell it it's name
	switch names.Package(name) {
	case "pirate":
		go pirate.Start(noodles[name])
	case "elb":
		go elb.Start(noodles[name])
	case "denominator":
		go denominator.Start(noodles[name])
	case "zuul":
		go zuul.Start(noodles[name])
	case "karyon":
		go karyon.Start(noodles[name])
	case "monolith":
		go monolith.Start(noodles[name])
	case "staash":
		go staash.Start(noodles[name])
	case "priamCassandra":
		go priamCassandra.Start(noodles[name])
	case "store":
		go store.Start(noodles[name])
	default:
		log.Fatal("asgard: unknown package: " + names.Package(name))
	}
	noodles[name] <- gotocol.Message{gotocol.Hello, listener, time.Now(), gotocol.NilContext, name}
	// there is a eureka service registry in each zone, so in-zone services just get to talk to their local registry
	// elb are cross zone, so need to see all registries in a region
	// denominator are cross region so need to see all registries globally
	// priamCassandra depends explicitly on eureka for cross region clusters
	crossregion := false
	for _, d := range dependencies {
		if d == "eureka" {
			crossregion = true
		}
	}
	for n, ch := range eurekachan {
		if names.Region(name) == "*" || crossregion {
			// need to know every eureka in all zones and regions
			gotocol.Send(noodles[name], gotocol.Message{gotocol.Inform, ch, time.Now(), gotocol.NilContext, n})
		} else {
			if names.Zone(name) == "*" && names.Region(name) == names.Region(n) {
				// need every eureka in my region
				gotocol.Send(noodles[name], gotocol.Message{gotocol.Inform, ch, time.Now(), gotocol.NilContext, n})
			} else {
				if names.RegionZone(name) == names.RegionZone(n) {
					// just the eureka in this specific zone
					gotocol.Send(noodles[name], gotocol.Message{gotocol.Inform, ch, time.Now(), gotocol.NilContext, n})
				}
			}
		}
	}
	//log.Println(dependencies)
	// pass on symbolic dependencies without channels that will be looked up in Eureka later
	for _, dep := range dependencies {
		if dep != "" && dep != "eureka" { // ignore special case of eureka in dependency list
			//log.Println(name + " depends on " + dep)
			gotocol.Send(noodles[name], gotocol.Message{gotocol.NameDrop, nil, time.Now(), gotocol.NilContext, dep})
		}
	}
}