package link

import (
	"context"
	"errors"
	"strings"
	"testing"
	"time"

	"git.novox.be/novox/mesh-sdk/go/busretry"
	"github.com/nats-io/nats.go"
)

// A declared tool check asked over a real bus, through the queue, on the link the node-engine holds:
// the tool's answer is read, and a tool nothing serves is said as such (novox/hq ADR 0240, to-be 48 §3).
func TestNatsAToolCheckIsAskedOnTheLink(t *testing.T) {
	conn, js := aBus(t)
	const node = "toolcheck"
	served, err := conn.Subscribe(ToolSubject("sensors", "sensors_health", node), func(m *nats.Msg) {
		_ = m.Respond([]byte(`{"result":{"healthy":true}}`))
	})
	if err != nil {
		t.Fatal(err)
	}
	t.Cleanup(func() { _ = served.Unsubscribe() })
	if err := conn.Flush(); err != nil {
		t.Fatal(err)
	}

	q := &Session{Membership: Membership{Node: node}}
	q.Attach(t.Context(), &natsLink{conn: conn, js: js, node: node})
	ctx, cancel := context.WithTimeout(t.Context(), 2*time.Second)
	defer cancel()
	a, err := q.AskTool(ctx, "sensors", "sensors_health")
	if err != nil || !a.Healthy {
		t.Fatalf("a served healthy tool read as %+v (%v)", a, err)
	}
	_, err = q.AskTool(ctx, "sensors", "nothing_serves_this")
	if err == nil || !strings.Contains(err.Error(), "nothing on this machine answers") {
		t.Fatalf("a tool nothing serves read as %v", err)
	}
	// The bus's "no responders" is kept beside ErrNotAsked, so a reader that asks again while its request reached no one
	// (busretry.Undelivered) sees it (issue 1966: the seat list's first read fell into its holder's re-serve and was never
	// asked again).
	_, err = (&natsLink{conn: conn, js: js, node: node}).Ask(ctx, ToolSubject("sensors", "nothing_serves_this", node), nil)
	if !errors.Is(err, ErrNotAsked) || !errors.Is(err, nats.ErrNoResponders) || !busretry.Undelivered(err) {
		t.Fatalf("an ask nothing serves read as %v: want ErrNotAsked and the bus's no responders, undelivered", err)
	}
}