package runtime

import (
	"encoding/json"
	"errors"
	"strings"
	"sync"
	"testing"
	"time"

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

	"github.com/novox/mesh-tools/node-tools/internal/bus"
	mt "github.com/novox/mesh-tools/node-tools/internal/meshtest"
)

// A bundle's seat traffic through moduleBus.Seat (novox/hq ADR 0259 §3), against a real bus: publish under
// its own name with the id prefixed and a duplicate said; the record read without naming the bucket; a
// worker and a proof subject bound once however often a restarted child asks; and nothing beyond what the
// membership lists.
func TestABundlesSeatTrafficGoesThroughItsModulesBus(t *testing.T) {
	mesh := mt.New(t)
	nc, err := nats.Connect(mt.URL(t))
	if err != nil {
		t.Fatal(err)
	}
	t.Cleanup(nc.Close)
	js, _ := nc.JetStream()
	if _, err := js.AddStream(&nats.StreamConfig{Name: "SEAT_OPERATOR_CHANNEL", Retention: nats.WorkQueuePolicy,
		Subjects: []string{"mesh.seat.operator-channel.accept.>"}}); err != nil {
		t.Fatal(err)
	}
	if _, err := js.AddConsumer("SEAT_OPERATOR_CHANNEL", &nats.ConsumerConfig{Durable: "SEAT_OPERATOR_CHANNEL_worker",
		AckPolicy: nats.AckExplicitPolicy, FilterSubject: "mesh.seat.operator-channel.accept.>"}); err != nil {
		t.Fatal(err)
	}
	kv, err := js.CreateKeyValue(&nats.KeyValueConfig{Bucket: "messenger_asks"})
	if err != nil {
		t.Fatal(err)
	}
	_, _ = kv.Put("mesh-delivery.d-1", []byte(`{"state":"open"}`))
	asker := mt.MembershipOf("mesh-delivery", "anchor", false, nil)
	asker.SeatTraffic = &bus.SeatTraffic{Publish: []string{"mesh.seat.operator-channel.accept.ask.mesh-delivery"},
		Records: []string{"$JS.API.DIRECT.GET.KV_messenger_asks.$KV.messenger_asks.mesh-delivery.>"}}
	router := mt.MembershipOf("messenger", "anchor", false, nil)
	router.SeatTraffic = &bus.SeatTraffic{Answers: []string{"mesh.seat.intake.proof.code.*"},
		Workers: []bus.SeatWorker{{Stream: "SEAT_OPERATOR_CHANNEL", Consumer: "SEAT_OPERATOR_CHANNEL_worker",
			Filter: "mesh.seat.operator-channel.accept.>"}}}
	mesh.Issue(t, asker)
	mesh.Issue(t, router)
	conn := connect(t, "node-tools", "anchor")
	conn.Follow("mesh-delivery")
	conn.Follow("messenger")
	mt.Until(t, func() error {
		if conn.Membership("mesh-delivery") == nil || conn.Membership("messenger") == nil {
			return errors.New("not issued yet")
		}
		return nil
	})
	all := &consumers{conn: conn, logf: t.Logf, of: map[string]*moduleEvents{}}
	asking := all.forModule("mesh-delivery").(*moduleBus)
	routing := all.forModule("messenger").(*moduleBus)

	publish := json.RawMessage(`{"subject":"mesh.seat.operator-channel.accept.ask.mesh-delivery","body":{"id":"d-1"},"id":"d-1"}`)
	first, err := asking.Seat("publish", publish, nil)
	if err != nil {
		t.Fatal(err)
	}
	again, _ := asking.Seat("publish", publish, nil)
	if !strings.Contains(string(first), `"duplicate":false`) || !strings.Contains(string(again), `"duplicate":true`) {
		t.Errorf("the same id twice: %s, then %s", first, again)
	}
	if _, err := asking.Seat("publish", json.RawMessage(`{"subject":"mesh.seat.operator-channel.accept.ask.mesh-controller","body":{}}`), nil); err == nil {
		t.Error("a module submitted under another's name")
	}
	got, err := asking.Seat("record", json.RawMessage(`{"key":"d-1"}`), nil)
	if err != nil || !strings.Contains(string(got), `"state":"open"`) {
		t.Errorf("the record read without its bucket: %s %v", got, err)
	}

	var mu sync.Mutex
	var taken []string
	handOn := func(method string, params any) (json.RawMessage, error) {
		mu.Lock()
		defer mu.Unlock()
		raw, _ := json.Marshal(params)
		taken = append(taken, method+" "+string(raw))
		return json.RawMessage(`{}`), nil
	}
	for i := 0; i < 2; i++ { // a child that started again asks again
		if _, err := routing.Seat("take", json.RawMessage(`{"worker":"SEAT_OPERATOR_CHANNEL_worker"}`), handOn); err != nil {
			t.Fatal(err)
		}
	}
	deadline := time.Now().Add(10 * time.Second)
	for {
		mu.Lock()
		n := len(taken)
		mu.Unlock()
		if n >= 1 || time.Now().After(deadline) {
			break
		}
		time.Sleep(50 * time.Millisecond)
	}
	time.Sleep(300 * time.Millisecond)
	mu.Lock()
	if len(taken) != 1 || !strings.Contains(taken[0], "mesh/work") || !strings.Contains(taken[0], `"x-event-id":"mesh-delivery.d-1"`) {
		t.Errorf("taken %v", taken)
	}
	mu.Unlock()
	if _, err := asking.Seat("take", json.RawMessage(`{"worker":"SEAT_OPERATOR_CHANNEL_worker"}`), handOn); err == nil {
		t.Error("an asker took the router's work")
	}
	if _, err := asking.Seat("answer", json.RawMessage(`{"subject":"mesh.seat.intake.proof.code.*"}`), handOn); err == nil {
		t.Error("an asker answered proofs")
	}
	if _, err := asking.Seat("anything", json.RawMessage(`{}`), nil); err == nil {
		t.Error("an unknown verb was answered")
	}
}

// A lost compare-and-set is answered with its code, so the SDK knows it without reading words.
func TestALostCompareAndSetCarriesItsCode(t *testing.T) {
	mesh := mt.New(t)
	mesh.Bucket(t, "messenger_asks")
	m := mt.MembershipOf("messenger", "anchor", false, nil)
	m.State = []bus.StateIssued{{Name: "asks", Bucket: "messenger_asks", Writes: true}}
	mesh.Issue(t, m)
	conn := connect(t, "node-tools", "anchor")
	conn.Follow("messenger")
	mt.Until(t, func() error {
		if conn.Membership("messenger") == nil {
			return errors.New("not issued yet")
		}
		return nil
	})
	b := (&consumers{conn: conn, logf: t.Logf, of: map[string]*moduleEvents{}}).forModule("messenger")
	if _, err := b.State("create", json.RawMessage(`{"state":"asks","key":"a","value":{}}`)); err != nil {
		t.Fatal(err)
	}
	_, err := b.State("create", json.RawMessage(`{"state":"asks","key":"a","value":{}}`))
	var coded interface{ ErrorCode() int }
	if !errors.As(err, &coded) || coded.ErrorCode() != -32010 || !errors.Is(err, bus.ErrStateChanged) {
		t.Errorf("a second create: %v", err)
	}
	if _, err := b.State("update", json.RawMessage(`{"state":"asks","key":"a","value":{},"revision":0}`)); err == nil {
		t.Error("an update of revision zero was taken")
	}
}