package buscompose

import (
	"encoding/json"
	"os"
	"path/filepath"
	"reflect"
	"strings"
	"testing"
)

// Defends issue 1377 and novox/hq ADR 0547 §5: this is the controller's bus composer copied, and it composes byte for
// byte what the controller's composes. testdata/controller-user-lists.json was written by the controller's own
// internal/broker (mesh-controller branch fix/1945-mesh-grants-publishes-memberships, and fix/1790-grants-create-buckets for the grants part creating declared streams), lists and memberships, from fixtures_test.go compiled there unchanged; composed.conf is the
// controller's golden of the whole server configuration. A row that differs is the copy drifting from the controller,
// which is a fault while both compose (until the controller loses its lease, ADR 0547 §13).
func TestTheCopiedComposerComposesAsTheControllers(t *testing.T) {
	raw, err := os.ReadFile(filepath.Join("testdata", "controller-user-lists.json"))
	if err != nil {
		t.Fatal(err)
	}
	var want []struct {
		Name, List  string
		Missing     []string
		Err         string
		Memberships json.RawMessage
	}
	if err := json.Unmarshal(raw, &want); err != nil {
		t.Fatal(err)
	}
	fixtures := UserListFixtures()
	if len(want) != len(fixtures) {
		t.Fatalf("%d fixtures, %d lists the controller composed", len(fixtures), len(want))
	}
	for i, f := range fixtures {
		t.Run(f.Name, func(t *testing.T) {
			if want[i].Name != f.Name {
				t.Fatalf("fixture %q against the controller's %q", f.Name, want[i].Name)
			}
			list, missing, err := ComposedFor(f)
			got := ""
			if err != nil {
				got = err.Error()
			}
			if got != want[i].Err {
				t.Fatalf("error %q, the controller's %q", got, want[i].Err)
			}
			if strings.Join(missing, ",") != strings.Join(want[i].Missing, ",") {
				t.Errorf("left out %v, the controller %v", missing, want[i].Missing)
			}
			if list != want[i].List {
				t.Errorf("the list differs from the controller's:\n%s", list)
			}
			// And every membership the records issue, as the controller's MembershipFor makes it (ADR 0547 §5): the
			// grants part publishes them.
			raw, err := json.Marshal(MembershipsFor(f))
			if err != nil {
				t.Fatal(err)
			}
			var gotM, wasM any
			if err := json.Unmarshal(raw, &gotM); err != nil {
				t.Fatal(err)
			}
			if err := json.Unmarshal(want[i].Memberships, &wasM); err != nil {
				t.Fatal(err)
			}
			if !reflect.DeepEqual(gotM, wasM) {
				t.Errorf("the memberships differ from the controller's:\n%s", raw)
			}
		})
	}
	// An asker on a seat pulled by kind hears what that seat's workers gave up on, and no other stream's dead letters
	// (novox/hq issue 734: a check ask given up during a bus reload left its try running for ever).
	t.Run("an asker reads its seat's dead letters", func(t *testing.T) {
		build := Seat{Name: "node-build-go", Scope: "node", Accepts: []string{"delivery", "check", "recheck"}, PulledByKind: true}
		perms, err := PermissionsFor(Principal{Kind: KindModule, Node: "one", Module: "mesh-delivery-checker", Uses: []Seat{build}})
		if err != nil {
			t.Fatal(err)
		}
		for subject, want := range map[string]bool{
			"$JS.API.CONSUMER.CREATE.DEAD_LETTERS.x1.mesh.events.dead.SEAT_NODE_BUILD_GO.>":      true,
			"$JS.API.CONSUMER.CREATE.DEAD_LETTERS.x1.mesh.events.dead.SEAT_NODE_BUILD_GO.w.next": true,
			"$JS.API.CONSUMER.DELETE.DEAD_LETTERS.x1":                                            true,
			"$JS.API.CONSUMER.MSG.NEXT.DEAD_LETTERS.x1":                                          true,
			"$JS.API.CONSUMER.CREATE.DEAD_LETTERS.x1.mesh.events.dead.EVENTS.>":                  false,
			"$JS.API.CONSUMER.CREATE.DEAD_LETTERS.x1":                                            false,
			"$JS.API.STREAM.PURGE.DEAD_LETTERS":                                                  false,
			"$JS.FC.DEAD_LETTERS.x1":                                                             false,
		} {
			if got := MayPublish(perms, subject); got != want {
				t.Errorf("may publish %s: %v, want %v", subject, got, want)
			}
		}
		plain, err := PermissionsFor(Principal{Kind: KindModule, Node: "one", Module: "shop",
			Uses: []Seat{{Name: "telegram-sender", Accepts: []string{"send"}}}})
		if err != nil {
			t.Fatal(err)
		}
		if MayPublish(plain, "$JS.API.CONSUMER.DELETE.DEAD_LETTERS.x1") {
			t.Error("a user of a seat not pulled by kind reads DEAD_LETTERS")
		}
	})
	t.Run("the controller's golden server configuration", func(t *testing.T) {
		seat := Seat{Name: "telegram-sender", Accepts: []string{"send"}, Emits: []string{"delivered", "failed"}}
		got, err := Compose(
			Server{ClientPort: 4222, MonitoringPort: 8222, StoreDir: "/data",
				TLSCert: "/tls/tls.crt", TLSKey: "/tls/tls.key", TLSCA: "/tls/ca.crt"},
			[]Principal{
				{Kind: KindController, PasswordHash: "$2a$11$cccccccccccccccccccccc"},
				{Kind: KindEnrolment, Node: "one", PasswordHash: "$2a$11$eeeeeeeeeeeeeeeeeeeeee"},
				{Kind: KindNode, Node: "one", PasswordHash: "$2a$11$nnnnnnnnnnnnnnnnnnnnnn"},
				{Kind: KindModule, Node: "one", Module: "telegram", Holds: []Seat{seat},
					Serves: []string{"status"}, PasswordHash: "$2a$11$tttttttttttttttttttttt"},
				{Kind: KindModule, Node: "two", Module: "shop", Uses: []Seat{seat},
					Emits: []string{"order.placed"}, PasswordHash: "$2a$11$ssssssssssssssssssssss"},
				{Kind: KindModule, Node: "two", Module: "audit",
					Consumes: []string{"shop.order.placed"}, PasswordHash: "$2a$11$aaaaaaaaaaaaaaaaaaaaaa"},
				{Kind: KindModule, Node: "one", Module: WatchmanModule, PasswordHash: "$2a$11$wwwwwwwwwwwwwwwwwwwwww"},
				{Kind: KindModule, Node: "one", Module: "nats", SnapshotsTheBus: true,
					Serves: []string{"nats_streams"}, PasswordHash: "$2a$11$bbbbbbbbbbbbbbbbbbbbbb"},
			})
		if err != nil {
			t.Fatal(err)
		}
		want, err := os.ReadFile(filepath.Join("testdata", "composed.conf"))
		if err != nil {
			t.Fatal(err)
		}
		if got != string(want) {
			t.Errorf("the configuration differs from the controller's golden:\n%s", got)
		}
	})
}