package broker

import (
	"context"
	"slices"
	"strings"
	"testing"
	"time"

	"github.com/nats-io/nats.go/jetstream"

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

// **The controller may write every bucket it writes** (novox/hq to-be 45 §1, issue 269). Writing a
// key is a publish to the bucket's own subject, which the management interface's grant does not
// cover: the cancelled sets' writes timed out for want of this, and the controller's own buckets
// would have.
func TestTheControllerMayWriteEveryBucketItWrites(t *testing.T) {
	p, err := PermissionsFor(Principal{Kind: KindController, PasswordHash: "x"})
	if err != nil {
		t.Fatal(err)
	}
	want := []string{"$KV." + CallsBucket + ".>", "$KV." + HandActsBucket + ".>",
		"$KV." + AssignmentsBucket + ".>", "$KV." + DeclaredConfigBucket + ".>"}
	for _, seat := range seatsTheControllerAsks {
		if hasCancelledSet(seat) {
			want = append(want, "$KV."+CancelledSetName(seat)+".>")
		}
	}
	for _, subject := range want {
		if !slices.Contains(p.Publish, subject) {
			t.Errorf("the controller may not publish %s, so it cannot write that bucket", subject)
		}
	}
	if slices.Contains(p.Publish, "$KV.>") {
		t.Error("the controller may write any bucket, a module's state included")
	}
}

// **A module reads a record mirror through `reads`, and never writes it** (ADR 0201 §1, design 54 §5,
// design 57 F3): granted the direct reads and watches of the bucket, and refused at composition a grant to
// write it, whose writer is the controller.
func TestAModuleReadsTheControllersMirrorsAndWritesNone(t *testing.T) {
	reader := Principal{Kind: KindModule, Node: "one", Module: "mesh-config", PasswordHash: "x",
		Reads: []string{"mesh-controller." + MirrorAssignments, "mesh-controller." + MirrorDeclaredConfig}}
	p, err := PermissionsFor(reader)
	if err != nil {
		t.Fatal(err)
	}
	for _, bucket := range []string{AssignmentsBucket, DeclaredConfigBucket} {
		for _, subject := range []string{"$JS.API.STREAM.INFO.KV_" + bucket, "$JS.API.DIRECT.GET.KV_" + bucket + ".>",
			"$JS.API.CONSUMER.CREATE.KV_" + bucket + ".>"} {
			if !slices.Contains(p.Publish, subject) {
				t.Errorf("a module reading %s may not publish %s", bucket, subject)
			}
		}
		for _, subject := range p.Publish {
			if SubjectsOverlap(subject, "$KV."+bucket+".>") {
				t.Errorf("a module reading %s may write it through %s", bucket, subject)
			}
		}
		if err := CheckWriters(reader, []string{"$KV." + bucket + ".>"}); err == nil {
			t.Errorf("a module granted a write of %s would compose", bucket)
		}
	}
}

// **A machine's node tools may say they are there, as that machine and no other** (novox/hq to-be 45
// S11), and the controller may hear the bus's advisories and ask who answers — read-only, named.
func TestTheWatchedSignalsMayBeSaidAndHeard(t *testing.T) {
	tools, err := PermissionsFor(Principal{Kind: KindNodeTools, Node: "anchor", Module: RuntimeModule, PasswordHash: "x"})
	if err != nil {
		t.Fatal(err)
	}
	if !slices.Contains(tools.Publish, "mesh.control.anchor.tools-alive") {
		t.Error("the node tools may not say they are there")
	}
	for _, s := range tools.Publish {
		if strings.Contains(s, "tools-alive") && s != "mesh.control.anchor.tools-alive" {
			t.Errorf("the node tools may say %s", s)
		}
	}
	controller, err := PermissionsFor(Principal{Kind: KindController, PasswordHash: "x"})
	if err != nil {
		t.Fatal(err)
	}
	for _, s := range BusAdvisories {
		if !slices.Contains(controller.Subscribe, s) {
			t.Errorf("the controller may not hear %s", s)
		}
	}
	if !slices.Contains(controller.Publish, "$SRV.INFO") || slices.Contains(controller.Subscribe, "$JS.EVENT.>") {
		t.Error("the controller may not ask who answers, or hears every API call")
	}
}

// The controller's record of what it asked the operator is bounded (correctness review of 2026-10-08): one
// value a key, a month's age, and a size it cannot outgrow.
func TestWhatTheControllerAskedIsBounded(t *testing.T) {
	js, err := Dial(testbus.URL(t))
	if err != nil {
		t.Fatal(err)
	}
	defer js.Close()
	if err := js.EnsureControllerBuckets(); err != nil {
		t.Fatal(err)
	}
	ctx, cancel := context.WithTimeout(context.Background(), 10*time.Second)
	defer cancel()
	kv, err := jetstream.New(js.Conn())
	if err != nil {
		t.Fatal(err)
	}
	bucket, err := kv.KeyValue(ctx, AskedBucket)
	if err != nil {
		t.Fatal(err)
	}
	status, err := bucket.Status(ctx)
	if err != nil {
		t.Fatal(err)
	}
	info := status.(*jetstream.KeyValueBucketStatus).StreamInfo()
	if status.History() != 1 || status.TTL() != AskedKeptFor || info.Config.MaxBytes <= 0 || info.Config.MaxBytes > 64<<20 {
		t.Errorf("history %d, age %s, bytes %d", status.History(), status.TTL(), info.Config.MaxBytes)
	}
}