package broker

import (
	"strings"
	"testing"
)

// Which bus the mesh is on is one fact, and being told about both is refused.
//
// **Not a warning.** A mesh half on each bus is one where a declaration goes out on one and the
// report comes back on the other, and every component reports success while it happens — which is
// the exact failure ADR 0074 exists to catch, arriving through configuration instead of through code.
func TestBeingToldAboutBothBusesIsRefused(t *testing.T) {
	err := MustBeOneBus("amqps://broker:5671/", "nats://bus:4222")
	if err == nil {
		t.Fatal("a control plane told about both buses was allowed to start")
	}
	// The remedy is in the words, because whoever reads this has to choose one and the wrong choice
	// is a rollout half done.
	for _, want := range []string{AMQPVarName, NATSVar, "unset"} {
		if !strings.Contains(err.Error(), want) {
			t.Errorf("the refusal does not mention %s: %v", want, err)
		}
	}
}

// One bus, or none, is ordinary. None is a control plane that publishes nothing and holds records,
// which several of its own commands are.
func TestOneBusOrNeitherIsAllowed(t *testing.T) {
	for _, c := range []struct{ what, amqp, nats string }{
		{"the bus the mesh runs on today", "amqps://broker:5671/", ""},
		{"the bus being built", "", "nats://bus:4222"},
		{"neither", "", ""},
		{"neither, with whitespace for an address", "  ", "\t"},
	} {
		if err := MustBeOneBus(c.amqp, c.nats); err != nil {
			t.Errorf("%s was refused: %v", c.what, err)
		}
	}
}