package runtime

import (
	"encoding/json"
	"sort"
	"strings"
	"testing"
	"time"

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

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

// novox/hq ADR 0197: what a runtime serves, it announces — the NATS services protocol's discovery,
// read here with NATS's own types, each endpoint a subject actually served — and the announcement
// follows a re-issued membership.
func TestTheRuntimeAnnouncesWhatItServesInTheServicesProtocol(t *testing.T) {
	mesh := mt.New(t)
	mesh.Issue(t, mt.MembershipOf("alpha", "anchor", false, nil))
	mesh.Issue(t, mt.MembershipOf("beta", "anchor", false, map[string][]string{"node-shelf": {"list", "clear"}}))
	nodeTools := connect(t, "node-tools", "anchor")
	stop, err := Run(nodeTools, []Served{
		{"alpha", []string{mt.Fixture("many-alpha.serve.mjs")}},
		{"beta", []string{mt.Fixture("many-beta.serve.mjs")}},
	}, nil, (&mt.Logs{}).Logf)
	if err != nil {
		t.Fatal(err)
	}
	defer stop()

	nc, err := nats.Connect(mt.URL(t))
	if err != nil {
		t.Fatal(err)
	}
	defer nc.Close()
	info := func() micro.Info {
		t.Helper()
		msg, err := nc.Request("$SRV.INFO.node-tools.anchor", nil, 2*time.Second)
		if err != nil {
			t.Fatal(err)
		}
		var i micro.Info
		if err := json.Unmarshal(msg.Data, &i); err != nil {
			t.Fatal(err)
		}
		return i
	}
	subjects := func(i micro.Info) string {
		var out []string
		for _, e := range i.Endpoints {
			out = append(out, e.Subject+"|"+e.QueueGroup+"|"+e.Metadata["kind"]+"|"+e.Metadata["module"]+"|"+e.Metadata["seat"]+"|"+e.Metadata["scope"]+"|"+e.Metadata["interchangeable"])
		}
		sort.Strings(out)
		return strings.Join(out, "\n")
	}

	got := info()
	if got.Type != micro.InfoResponseType || got.Name != "node-tools" || got.ID != "anchor" || got.Version == "" {
		t.Errorf("identity: %+v", got.ServiceIdentity)
	}
	want := strings.Join([]string{
		"mesh.mod.alpha.tool.one.anchor||tool|alpha|||false",
		"mesh.mod.alpha.tool.two.anchor||tool|alpha|||false",
		"mesh.mod.beta.tool.five.anchor||tool|beta|||false",
		"mesh.mod.beta.tool.four.anchor||tool|beta|||false",
		"mesh.mod.beta.tool.three.anchor||tool|beta|||false",
		"mesh.seat.node-shelf.tool.clear.anchor||seat|beta|node-shelf|node|false",
		"mesh.seat.node-shelf.tool.list.anchor||seat|beta|node-shelf|node|false",
	}, "\n")
	if s := subjects(got); s != want {
		t.Errorf("announced:\n%s\nwant:\n%s", s, want)
	}
	for _, e := range got.Endpoints {
		if e.Metadata["node"] != "anchor" || e.Metadata["description"] == "" || !json.Valid([]byte(e.Metadata["schema"])) {
			t.Errorf("endpoint metadata: %+v", e)
		}
	}

	// Every subject announced is answered.
	asker := connect(t, "console", "workstation")
	for _, e := range got.Endpoints {
		if _, err := asker.Ask("", map[string]any{}, e.Subject); err != nil {
			t.Errorf("announced %s and does not answer it: %v", e.Subject, err)
		}
	}

	// PING answers with the same identity, and a request for another service is not answered.
	if msg, err := nc.Request("$SRV.PING", nil, 2*time.Second); err != nil || !strings.Contains(string(msg.Data), micro.PingResponseType) {
		t.Errorf("ping: %v %v", msg, err)
	}
	if _, err := nc.Request("$SRV.INFO.somebody-else", nil, 300*time.Millisecond); err == nil {
		t.Error("answered a request for another service")
	}

	// alpha is re-issued a plain subject: the announcement says so, and says it is interchangeable.
	mesh.Issue(t, mt.MembershipOf("alpha", "anchor", true, nil))
	var after string
	for i := 0; i < 40; i++ {
		after = subjects(info())
		if strings.Contains(after, "mesh.mod.alpha.tool.one|serve.alpha|tool|alpha|||true") {
			break
		}
		time.Sleep(100 * time.Millisecond)
	}
	if !strings.Contains(after, "mesh.mod.alpha.tool.one|serve.alpha|tool|alpha|||true") ||
		!strings.Contains(after, "mesh.mod.alpha.tool.one.anchor||tool|alpha|||true") {
		t.Errorf("after a re-issued membership:\n%s", after)
	}
	_ = bus.Served{}
}