package registerracename_test

import (
	"context"
	"encoding/json"
	"errors"
	"io"
	"log/slog"
	"sync"
	"testing"
	"time"

	"galaxy/lobby/internal/adapters/mocks"
	"galaxy/lobby/internal/adapters/racenameinmem"
	"galaxy/lobby/internal/ports"
	"galaxy/lobby/internal/service/registerracename"
	"galaxy/lobby/internal/service/shared"
	"galaxy/notificationintent"

	"github.com/stretchr/testify/assert"
	"github.com/stretchr/testify/require"
	"go.uber.org/mock/gomock"
)

type intentRec struct {
	mu        sync.Mutex
	published []notificationintent.Intent
	err       error
}

func (r *intentRec) record(_ context.Context, intent notificationintent.Intent) (string, error) {
	r.mu.Lock()
	defer r.mu.Unlock()
	if r.err != nil {
		return "", r.err
	}
	r.published = append(r.published, intent)
	return "1", nil
}

func (r *intentRec) snapshot() []notificationintent.Intent {
	r.mu.Lock()
	defer r.mu.Unlock()
	return append([]notificationintent.Intent(nil), r.published...)
}

func (r *intentRec) setErr(err error) {
	r.mu.Lock()
	defer r.mu.Unlock()
	r.err = err
}

type userRec struct {
	mu       sync.Mutex
	elig     map[string]ports.Eligibility
	failures map[string]error
}

func (r *userRec) record(_ context.Context, userID string) (ports.Eligibility, error) {
	r.mu.Lock()
	defer r.mu.Unlock()
	if err, ok := r.failures[userID]; ok {
		return ports.Eligibility{}, err
	}
	if e, ok := r.elig[userID]; ok {
		return e, nil
	}
	return ports.Eligibility{Exists: false}, nil
}

func (r *userRec) setEligibility(userID string, e ports.Eligibility) {
	r.mu.Lock()
	defer r.mu.Unlock()
	if r.elig == nil {
		r.elig = make(map[string]ports.Eligibility)
	}
	r.elig[userID] = e
}

func (r *userRec) setFailure(userID string, err error) {
	r.mu.Lock()
	defer r.mu.Unlock()
	if r.failures == nil {
		r.failures = make(map[string]error)
	}
	r.failures[userID] = err
}

func newIntentMock(t *testing.T, rec *intentRec) *mocks.MockIntentPublisher {
	t.Helper()
	m := mocks.NewMockIntentPublisher(gomock.NewController(t))
	m.EXPECT().Publish(gomock.Any(), gomock.Any()).DoAndReturn(rec.record).AnyTimes()
	return m
}

func newUserMock(t *testing.T, rec *userRec) *mocks.MockUserService {
	t.Helper()
	m := mocks.NewMockUserService(gomock.NewController(t))
	m.EXPECT().GetEligibility(gomock.Any(), gomock.Any()).DoAndReturn(rec.record).AnyTimes()
	return m
}

func silentLogger() *slog.Logger { return slog.New(slog.NewTextHandler(io.Discard, nil)) }

func fixedClock(at time.Time) func() time.Time { return func() time.Time { return at } }

type fixture struct {
	now       time.Time
	directory *racenameinmem.Directory
	users     *userRec
	usersMock *mocks.MockUserService
	intents   *intentRec
	pubMock   *mocks.MockIntentPublisher
}

func newFixture(t *testing.T, now time.Time) *fixture {
	t.Helper()
	directory, err := racenameinmem.NewDirectory(racenameinmem.WithClock(fixedClock(now)))
	require.NoError(t, err)
	users := &userRec{}
	intents := &intentRec{}
	return &fixture{
		now:       now,
		directory: directory,
		users:     users,
		usersMock: newUserMock(t, users),
		intents:   intents,
		pubMock:   newIntentMock(t, intents),
	}
}

func (f *fixture) newService(t *testing.T) *registerracename.Service {
	t.Helper()
	svc, err := registerracename.NewService(registerracename.Dependencies{
		Directory: f.directory,
		Users:     f.usersMock,
		Intents:   f.pubMock,
		Clock:     fixedClock(f.now),
		Logger:    silentLogger(),
	})
	require.NoError(t, err)
	return svc
}

// seedPending creates a pending_registration for (gameID, userID,
// raceName) with eligibleUntil. It mirrors the production sequence
// (Reserve at approve-time, MarkPendingRegistration at game finish).
func (f *fixture) seedPending(
	t *testing.T,
	gameID, userID, raceName string,
	eligibleUntil time.Time,
) {
	t.Helper()
	require.NoError(t, f.directory.Reserve(context.Background(), gameID, userID, raceName))
	require.NoError(t, f.directory.MarkPendingRegistration(context.Background(), gameID, userID, raceName, eligibleUntil))
}

// seedRegistered creates an existing registered entry by walking through
// the full Reserve → MarkPending → Register flow. It is used to grow the
// `len(registered)` for quota tests.
func (f *fixture) seedRegistered(t *testing.T, gameID, userID, raceName string) {
	t.Helper()
	eligibleUntil := f.now.Add(24 * time.Hour)
	f.seedPending(t, gameID, userID, raceName, eligibleUntil)
	require.NoError(t, f.directory.Register(context.Background(), gameID, userID, raceName))
}

func defaultEligibility(maxRegistered int) ports.Eligibility {
	return ports.Eligibility{
		Exists:                 true,
		CanLogin:               true,
		CanJoinGame:            true,
		CanUpdateProfile:       true,
		MaxRegisteredRaceNames: maxRegistered,
	}
}

func TestNewServiceRejectsMissingDeps(t *testing.T) {
	t.Parallel()

	_, err := registerracename.NewService(registerracename.Dependencies{})
	require.Error(t, err)
}

func TestRegisterRaceNameHappyPath(t *testing.T) {
	t.Parallel()

	now := time.Date(2026, 4, 25, 12, 0, 0, 0, time.UTC)
	f := newFixture(t, now)
	f.users.setEligibility("user-1", defaultEligibility(2))
	f.seedPending(t, "game-1", "user-1", "Stellaris", now.Add(7*24*time.Hour))

	svc := f.newService(t)
	out, err := svc.Handle(context.Background(), registerracename.Input{
		Actor:        shared.NewUserActor("user-1"),
		SourceGameID: "game-1",
		RaceName:     "Stellaris",
	})
	require.NoError(t, err)
	assert.Equal(t, "game-1", out.SourceGameID)
	assert.Equal(t, "Stellaris", out.RaceName)
	expectedCanonical, err := f.directory.Canonicalize("Stellaris")
	require.NoError(t, err)
	assert.Equal(t, expectedCanonical, out.CanonicalKey)
	assert.Equal(t, now.UnixMilli(), out.RegisteredAtMs)

	registered, err := f.directory.ListRegistered(context.Background(), "user-1")
	require.NoError(t, err)
	require.Len(t, registered, 1)
	assert.Equal(t, "game-1", registered[0].SourceGameID)

	pending, err := f.directory.ListPendingRegistrations(context.Background(), "user-1")
	require.NoError(t, err)
	assert.Empty(t, pending)

	intents := f.intents.snapshot()
	require.Len(t, intents, 1)
	intent := intents[0]
	assert.Equal(t, notificationintent.NotificationTypeLobbyRaceNameRegistered, intent.NotificationType)
	require.Equal(t, []string{"user-1"}, intent.RecipientUserIDs)
	assert.Equal(t, "lobby.race_name.registered:game-1:user-1", intent.IdempotencyKey)
	var payload notificationintent.LobbyRaceNameRegisteredPayload
	require.NoError(t, json.Unmarshal([]byte(intent.PayloadJSON), &payload))
	assert.Equal(t, "Stellaris", payload.RaceName)
}

func TestRegisterRaceNameIdempotentRetry(t *testing.T) {
	t.Parallel()

	now := time.Date(2026, 4, 25, 12, 0, 0, 0, time.UTC)
	f := newFixture(t, now)
	f.users.setEligibility("user-1", defaultEligibility(1))
	f.seedPending(t, "game-1", "user-1", "Stellaris", now.Add(7*24*time.Hour))

	svc := f.newService(t)
	first, err := svc.Handle(context.Background(), registerracename.Input{
		Actor:        shared.NewUserActor("user-1"),
		SourceGameID: "game-1",
		RaceName:     "Stellaris",
	})
	require.NoError(t, err)

	second, err := svc.Handle(context.Background(), registerracename.Input{
		Actor:        shared.NewUserActor("user-1"),
		SourceGameID: "game-1",
		RaceName:     "Stellaris",
	})
	require.NoError(t, err)
	assert.Equal(t, first, second)

	registered, err := f.directory.ListRegistered(context.Background(), "user-1")
	require.NoError(t, err)
	assert.Len(t, registered, 1, "registration must remain idempotent")

	intents := f.intents.snapshot()
	require.Len(t, intents, 2, "idempotent retry republishes the intent")
	for _, intent := range intents {
		assert.Equal(t, "lobby.race_name.registered:game-1:user-1", intent.IdempotencyKey)
	}
}

func TestRegisterRaceNameRejectsAdminActor(t *testing.T) {
	t.Parallel()

	now := time.Date(2026, 4, 25, 12, 0, 0, 0, time.UTC)
	f := newFixture(t, now)

	svc := f.newService(t)
	_, err := svc.Handle(context.Background(), registerracename.Input{
		Actor:        shared.NewAdminActor(),
		SourceGameID: "game-1",
		RaceName:     "Stellaris",
	})
	require.ErrorIs(t, err, shared.ErrForbidden)
}

func TestRegisterRaceNameRejectsInvalidActor(t *testing.T) {
	t.Parallel()

	now := time.Date(2026, 4, 25, 12, 0, 0, 0, time.UTC)
	f := newFixture(t, now)

	svc := f.newService(t)
	_, err := svc.Handle(context.Background(), registerracename.Input{
		Actor:        shared.Actor{Kind: shared.ActorKindUser},
		SourceGameID: "game-1",
		RaceName:     "Stellaris",
	})
	require.Error(t, err)
	require.Contains(t, err.Error(), "actor")
}

func TestRegisterRaceNameRejectsEmptyRaceName(t *testing.T) {
	t.Parallel()

	now := time.Date(2026, 4, 25, 12, 0, 0, 0, time.UTC)
	f := newFixture(t, now)

	svc := f.newService(t)
	_, err := svc.Handle(context.Background(), registerracename.Input{
		Actor:        shared.NewUserActor("user-1"),
		SourceGameID: "game-1",
		RaceName:     "   ",
	})
	require.Error(t, err)
	require.Contains(t, err.Error(), "must not be empty")
}

func TestRegisterRaceNameRejectsInvalidName(t *testing.T) {
	t.Parallel()

	now := time.Date(2026, 4, 25, 12, 0, 0, 0, time.UTC)
	f := newFixture(t, now)

	svc := f.newService(t)
	_, err := svc.Handle(context.Background(), registerracename.Input{
		Actor:        shared.NewUserActor("user-1"),
		SourceGameID: "game-1",
		// "<>" fails ValidateTypeName.
		RaceName: "<>",
	})
	require.ErrorIs(t, err, ports.ErrInvalidName)
}

func TestRegisterRaceNameRejectsUnknownUser(t *testing.T) {
	t.Parallel()

	now := time.Date(2026, 4, 25, 12, 0, 0, 0, time.UTC)
	f := newFixture(t, now)

	svc := f.newService(t)
	_, err := svc.Handle(context.Background(), registerracename.Input{
		Actor:        shared.NewUserActor("user-ghost"),
		SourceGameID: "game-1",
		RaceName:     "Stellaris",
	})
	require.ErrorIs(t, err, shared.ErrSubjectNotFound)
}

func TestRegisterRaceNameRejectsPermanentBlock(t *testing.T) {
	t.Parallel()

	now := time.Date(2026, 4, 25, 12, 0, 0, 0, time.UTC)
	f := newFixture(t, now)
	f.users.setEligibility("user-1", ports.Eligibility{
		Exists:                 true,
		PermanentBlocked:       true,
		MaxRegisteredRaceNames: 2,
	})
	f.seedPending(t, "game-1", "user-1", "Stellaris", now.Add(7*24*time.Hour))

	svc := f.newService(t)
	_, err := svc.Handle(context.Background(), registerracename.Input{
		Actor:        shared.NewUserActor("user-1"),
		SourceGameID: "game-1",
		RaceName:     "Stellaris",
	})
	require.ErrorIs(t, err, shared.ErrForbidden)
}

func TestRegisterRaceNamePendingMissing(t *testing.T) {
	t.Parallel()

	now := time.Date(2026, 4, 25, 12, 0, 0, 0, time.UTC)
	f := newFixture(t, now)
	f.users.setEligibility("user-1", defaultEligibility(2))

	svc := f.newService(t)
	_, err := svc.Handle(context.Background(), registerracename.Input{
		Actor:        shared.NewUserActor("user-1"),
		SourceGameID: "game-1",
		RaceName:     "Stellaris",
	})
	require.ErrorIs(t, err, ports.ErrPendingMissing)
}

func TestRegisterRaceNamePendingForOtherUserSurfacesAsMissing(t *testing.T) {
	t.Parallel()

	now := time.Date(2026, 4, 25, 12, 0, 0, 0, time.UTC)
	f := newFixture(t, now)
	f.users.setEligibility("user-1", defaultEligibility(2))
	// Pending exists for a different user; the actor has none.
	f.seedPending(t, "game-1", "user-other", "Stellaris", now.Add(24*time.Hour))

	svc := f.newService(t)
	_, err := svc.Handle(context.Background(), registerracename.Input{
		Actor:        shared.NewUserActor("user-1"),
		SourceGameID: "game-1",
		RaceName:     "Stellaris",
	})
	// A pending entry held by a different user is reported as missing
	// for the actor: only registered names by another user surface as
	// ErrNameTaken on Register (see racenamedir.go port comment and
	// the Redis adapter behaviour).
	require.ErrorIs(t, err, ports.ErrPendingMissing)
}

func TestRegisterRaceNamePendingExpired(t *testing.T) {
	t.Parallel()

	now := time.Date(2026, 4, 25, 12, 0, 0, 0, time.UTC)
	f := newFixture(t, now)
	f.users.setEligibility("user-1", defaultEligibility(2))
	// Pending elig until is in the past relative to now.
	f.seedPending(t, "game-1", "user-1", "Stellaris", now.Add(-time.Minute))

	svc := f.newService(t)
	_, err := svc.Handle(context.Background(), registerracename.Input{
		Actor:        shared.NewUserActor("user-1"),
		SourceGameID: "game-1",
		RaceName:     "Stellaris",
	})
	require.ErrorIs(t, err, ports.ErrPendingExpired)
}

func TestRegisterRaceNameQuotaExceeded(t *testing.T) {
	t.Parallel()

	now := time.Date(2026, 4, 25, 12, 0, 0, 0, time.UTC)
	f := newFixture(t, now)
	// Free-tier quota = 1; user already has one registered name.
	f.users.setEligibility("user-1", defaultEligibility(1))
	f.seedRegistered(t, "game-existing", "user-1", "OldName")
	f.seedPending(t, "game-new", "user-1", "Stellaris", now.Add(24*time.Hour))

	svc := f.newService(t)
	_, err := svc.Handle(context.Background(), registerracename.Input{
		Actor:        shared.NewUserActor("user-1"),
		SourceGameID: "game-new",
		RaceName:     "Stellaris",
	})
	require.ErrorIs(t, err, ports.ErrQuotaExceeded)
}

func TestRegisterRaceNameUnlimitedQuotaAllowsManyRegistrations(t *testing.T) {
	t.Parallel()

	now := time.Date(2026, 4, 25, 12, 0, 0, 0, time.UTC)
	f := newFixture(t, now)
	// MaxRegisteredRaceNames=0 marker → unlimited.
	f.users.setEligibility("user-1", defaultEligibility(0))
	f.seedRegistered(t, "game-a", "user-1", "First")
	f.seedRegistered(t, "game-b", "user-1", "Second")
	f.seedPending(t, "game-c", "user-1", "Third", now.Add(24*time.Hour))

	svc := f.newService(t)
	_, err := svc.Handle(context.Background(), registerracename.Input{
		Actor:        shared.NewUserActor("user-1"),
		SourceGameID: "game-c",
		RaceName:     "Third",
	})
	require.NoError(t, err)
}

func TestRegisterRaceNameUserServiceUnavailable(t *testing.T) {
	t.Parallel()

	now := time.Date(2026, 4, 25, 12, 0, 0, 0, time.UTC)
	f := newFixture(t, now)
	f.users.setFailure("user-1", ports.ErrUserServiceUnavailable)
	f.seedPending(t, "game-1", "user-1", "Stellaris", now.Add(24*time.Hour))

	svc := f.newService(t)
	_, err := svc.Handle(context.Background(), registerracename.Input{
		Actor:        shared.NewUserActor("user-1"),
		SourceGameID: "game-1",
		RaceName:     "Stellaris",
	})
	require.ErrorIs(t, err, ports.ErrUserServiceUnavailable)
}

func TestRegisterRaceNameCommitsEvenIfPublishFails(t *testing.T) {
	t.Parallel()

	now := time.Date(2026, 4, 25, 12, 0, 0, 0, time.UTC)
	f := newFixture(t, now)
	f.users.setEligibility("user-1", defaultEligibility(2))
	f.seedPending(t, "game-1", "user-1", "Stellaris", now.Add(7*24*time.Hour))
	f.intents.setErr(errors.New("notification stream unavailable"))

	svc := f.newService(t)
	out, err := svc.Handle(context.Background(), registerracename.Input{
		Actor:        shared.NewUserActor("user-1"),
		SourceGameID: "game-1",
		RaceName:     "Stellaris",
	})
	require.NoError(t, err)
	assert.Equal(t, "Stellaris", out.RaceName)

	registered, err := f.directory.ListRegistered(context.Background(), "user-1")
	require.NoError(t, err)
	require.Len(t, registered, 1)
}