package link

import (
	"context"
	"crypto/ed25519"
	"encoding/json"
	"strings"
	"testing"
	"time"

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

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

// A fresh setuid search is asked of the machine on its own subject, signed under its own context — never a
// hand-over's — naming no path, and the engine's answer comes back (novox/hq issue 361). The engine holds the
// same subject and context (mesh-host internal/link, TestTheSetuidSearchAskKeepsItsSubjectAndContext).
func TestASetuidSearchIsAskedOfTheMachineSignedUnderItsOwnContext(t *testing.T) {
	if broker.AskSetuidSearchSubject("laptop") != "mesh.node.laptop.ask.setuid-search" ||
		SetuidSearchContext != "novox-mesh setuid-search v1\n" {
		t.Fatalf("the subject %q, the context %q", broker.AskSetuidSearchSubject("laptop"), SetuidSearchContext)
	}
	conn, err := nats.Connect(testbus.URL(t))
	if err != nil {
		t.Fatal(err)
	}
	t.Cleanup(conn.Close)
	signer, public := testSigner(t)
	var heard HandOverAsk
	engine, err := conn.Subscribe(broker.AskSetuidSearchSubject("laptop"), func(msg *nats.Msg) {
		var signed SignedHandOver
		_ = json.Unmarshal(msg.Data, &signed)
		if ed25519.Verify(public, append([]byte(HandOverContext), signed.Ask...), signed.Signature) ||
			!ed25519.Verify(public, append([]byte(SetuidSearchContext), signed.Ask...), signed.Signature) {
			_ = msg.Respond([]byte(`{"refused":"not signed as a setuid search"}`))
			return
		}
		_ = json.Unmarshal(signed.Ask, &heard)
		body, _ := json.Marshal(HandOverAnswer{Said: "a new search starts, asked by " + heard.By})
		_ = msg.Respond(body)
	})
	if err != nil {
		t.Fatal(err)
	}
	t.Cleanup(func() { _ = engine.Unsubscribe() })
	a, err := AskSetuidSearch(context.Background(), conn, signer, "laptop", "jo", 5*time.Second)
	if err != nil || a.Said != "a new search starts, asked by jo" {
		t.Fatalf("answered %+v, %v", a, err)
	}
	if heard.Node != "laptop" || heard.Path != "" || heard.Nonce == "" || heard.Expires.IsZero() {
		t.Fatalf("the engine heard %+v", heard)
	}
	if _, err := AskSetuidSearch(context.Background(), conn, signer, "anchor", "jo", 5*time.Second); err == nil ||
		!strings.Contains(err.Error(), "no search was started") {
		t.Fatalf("a machine with no engine listening: %v", err)
	}
}