package broker

import (
	"slices"
	"testing"
	"time"

	"github.com/novox/mesh-controller/internal/testbus"
)

// On a real bus: a module's stream is made beside EVENTS without a clash, keeps what the module publishes on
// its own subjects, a granted consumer hears only its part, a narrowed grant narrows it, and a withdrawn one
// is removed (novox/hq ADR 0363).
//
//	go test ./internal/broker/ -run TestAModuleStreamOnARealBus
func TestAModuleStreamOnARealBus(t *testing.T) {
	js, err := Dial(testbus.URL(t))
	if err != nil {
		t.Fatal(err)
	}
	defer js.Close()
	for _, s := range []Stream{MeshStreams()[3], mailStream.Stream()} {
		_ = js.js.DeleteStream(s.Name)
		if err := js.EnsureStream(s); err != nil {
			t.Fatalf("%s: %v", s.Name, err)
		}
		defer func(name string) { _ = js.js.DeleteStream(name) }(s.Name)
	}
	for _, account := range []string{"mesh", "work"} {
		if _, err := js.js.Publish(ModuleStreamSubject("mesh-mail", "mail."+account+".message.added"), []byte("{}")); err != nil {
			t.Fatalf("publishing %s's mail: %v", account, err)
		}
	}
	if info, _ := js.js.StreamInfo(EventsStream); info.State.Msgs != 0 {
		t.Fatalf("EVENTS kept %d of the module stream's events", info.State.Msgs)
	}

	reader := Principal{Kind: KindModule, Node: "ace", Module: "reader", Hears: []Heard{mailHeard}}
	c := heardConsumer(reader, mailHeard)
	if err := js.EnsureConsumer(c); err != nil {
		t.Fatal(err)
	}
	time.Sleep(50 * time.Millisecond)
	if info, _ := js.js.ConsumerInfo("MAIL", c.Name); info.NumPending != 1 {
		t.Fatalf("the reader granted `mesh` has %d pending, want 1", info.NumPending)
	}
	narrowed := c
	narrowed.Filters = []string{"mesh.stream.mesh-mail.event.mail.mesh.message.changed"}
	if err := js.EnsureConsumer(narrowed); err != nil {
		t.Fatalf("narrowing the grant: %v", err)
	}
	removed, err := PruneHeard(js, []ModuleStream{mailStream}, nil)
	if err != nil {
		t.Fatal(err)
	}
	if !slices.Equal(removed, []string{"MAIL/ace_reader"}) {
		t.Fatalf("removed %v", removed)
	}
	if names, _ := js.ConsumerNames("MAIL"); len(names) != 0 {
		t.Fatalf("still on MAIL: %v", names)
	}
}