package link

import (
	"fmt"
	"os"
	"strings"
	"testing"
	"time"

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

// **A reader's own consumer gone is not a consumer lost**: every bucket watch and stream read-back
// makes and deletes one, many a minute, and the bus says so each time (found running the controller
// against a real bus: five a tick).
func TestOnlyTheMeshsOwnConsumersAreSaidLost(t *testing.T) {
	deleted := func(stream, consumer string) bool {
		_, ok := ReadAdvisory("$JS.EVENT.ADVISORY.CONSUMER.DELETED."+stream+"."+consumer,
			[]byte(`{"type":"io.nats.jetstream.advisory.v1.consumer_action","stream":"`+stream+`","consumer":"`+consumer+`","action":"delete"}`))
		return ok
	}
	for _, c := range [][2]string{{"EVENTS", "controller"}, {"CONTROL", "controller"}, {"NODES", "anchor"},
		{"EVENTS", "anchor_shop"}, {"SEAT_NODE_BUILD_AGENT", "SEAT_NODE_BUILD_AGENT_worker"}} {
		if !deleted(c[0], c[1]) {
			t.Errorf("%s on %s deleted is not said", c[1], c[0])
		}
	}
	for _, c := range [][2]string{{"KV_mesh-controller_conditions", "381UWW5Y"}, {"EVENTS", "E7vVYoe6"},
		{"SEAT_NODE_BUILD_AGENT", "Rcnt6jla"}, {"ASSIGNMENTS", "x"}} {
		if deleted(c[0], c[1]) {
			t.Errorf("a reader's own consumer %s on %s is said lost", c[1], c[0])
		}
	}
	a, ok := ReadAdvisory("$JS.EVENT.ADVISORY.CONSUMER.MAX_DELIVERIES.EVENTS.anchor_shop",
		[]byte(`{"stream":"EVENTS","consumer":"anchor_shop","stream_seq":7,"deliveries":5}`))
	if !ok || a.Kind != AdvisoryMaxDeliveries || a.ID != "EVENTS.anchor_shop" ||
		a.Said != "how shop on anchor hears what it consumes handed message 7 over 5 times and gave up on it: "+
			"it will not be delivered again, and what it asked for was not done" {
		t.Fatalf("%+v", a)
	}
}

// **A question the bus refuses is answered as refused at once**, not after its timeout: against a
// server whose only user may not publish where it asks.
func TestNatsARefusedQuestionIsSaidAtOnce(t *testing.T) {
	url := os.Getenv("MESH_TEST_NATS_REFUSING")
	if url == "" {
		t.Skip("MESH_TEST_NATS_REFUSING unset: a server whose user may not publish mesh.seat.>")
	}
	conn, err := nats.Connect(url)
	if err != nil {
		t.Fatal(err)
	}
	defer conn.Close()
	started := time.Now()
	_, err = AskSeatTool(t.Context(), conn, "node-intrusion-prevention", "banned", "anchor", map[string]any{}, 10*time.Second)
	if err == nil || !strings.Contains(err.Error(), "the bus refused") {
		t.Fatalf("answered %v", err)
	}
	if took := time.Since(started); took > 3*time.Second {
		t.Fatalf("a refusal took %s to be known", took)
	}
}

// The refusal reaches whoever waits on that subject, and only them.
func TestNatsARefusalReachesItsWaiter(t *testing.T) {
	url := os.Getenv("MESH_TEST_NATS")
	if url == "" {
		t.Skip("MESH_TEST_NATS unset")
	}
	conn, err := nats.Connect(url)
	if err != nil {
		t.Fatal(err)
	}
	defer conn.Close()
	mine, stop := refusalsOf(conn, "mesh.seat.s.tool.v.anchor")
	defer stop()
	other, stopOther := refusalsOf(conn, "mesh.seat.s.tool.v.laptop")
	defer stopOther()
	conn.ErrorHandler()(conn, nil, fmt.Errorf("%w: Permissions Violation for Publish to %q",
		nats.ErrPermissionViolation, "mesh.seat.s.tool.v.anchor"))
	select {
	case <-mine:
	case <-time.After(time.Second):
		t.Fatal("the waiter was not told")
	}
	select {
	case <-other:
		t.Fatal("another subject's waiter was told")
	default:
	}
}