package geosync

import (
	"context"
	"errors"
	"testing"
	"time"

	"galaxy/user/internal/domain/account"
	"galaxy/user/internal/domain/common"
	"galaxy/user/internal/ports"
	"galaxy/user/internal/service/shared"

	"github.com/stretchr/testify/require"
)

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

	createdAt := time.Unix(1_775_240_000, 0).UTC()
	updatedAt := createdAt.Add(5 * time.Minute)
	record := validAccountRecord(createdAt, createdAt)
	store := newFakeAccountStore(record)
	publisher := &recordingDeclaredCountryChangedPublisher{
		publishHook: func(event ports.DeclaredCountryChangedEvent) error {
			stored, err := store.GetByUserID(context.Background(), record.UserID)
			require.NoError(t, err)
			require.Equal(t, common.CountryCode("FR"), stored.DeclaredCountry)
			require.Equal(t, updatedAt, stored.UpdatedAt)
			require.Equal(t, common.Source("geo_profile_service"), event.Source)
			return nil
		},
	}

	service, err := NewSyncService(store, fixedClock{now: updatedAt}, publisher)
	require.NoError(t, err)

	result, err := service.Execute(context.Background(), SyncDeclaredCountryInput{
		UserID:          record.UserID.String(),
		DeclaredCountry: "FR",
	})
	require.NoError(t, err)
	require.Equal(t, record.UserID.String(), result.UserID)
	require.Equal(t, "FR", result.DeclaredCountry)
	require.Equal(t, updatedAt, result.UpdatedAt)
	require.Equal(t, 1, store.updateCalls)

	stored, err := store.GetByUserID(context.Background(), record.UserID)
	require.NoError(t, err)
	require.Equal(t, record.Email, stored.Email)
	require.Equal(t, record.UserName, stored.UserName)
	require.Equal(t, record.PreferredLanguage, stored.PreferredLanguage)
	require.Equal(t, record.TimeZone, stored.TimeZone)
	require.Equal(t, common.CountryCode("FR"), stored.DeclaredCountry)
	require.Equal(t, record.CreatedAt, stored.CreatedAt)
	require.Equal(t, updatedAt, stored.UpdatedAt)

	published := publisher.PublishedEvents()
	require.Len(t, published, 1)
	require.Equal(t, record.UserID, published[0].UserID)
	require.Equal(t, common.CountryCode("FR"), published[0].DeclaredCountry)
	require.Equal(t, updatedAt, published[0].UpdatedAt)
	require.Equal(t, common.Source("geo_profile_service"), published[0].Source)
}

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

	createdAt := time.Unix(1_775_240_000, 0).UTC()
	record := validAccountRecord(createdAt, createdAt.Add(5*time.Minute))
	store := newFakeAccountStore(record)
	publisher := &recordingDeclaredCountryChangedPublisher{}

	service, err := NewSyncService(store, fixedClock{now: createdAt.Add(time.Hour)}, publisher)
	require.NoError(t, err)

	result, err := service.Execute(context.Background(), SyncDeclaredCountryInput{
		UserID:          record.UserID.String(),
		DeclaredCountry: record.DeclaredCountry.String(),
	})
	require.NoError(t, err)
	require.Equal(t, record.UserID.String(), result.UserID)
	require.Equal(t, record.DeclaredCountry.String(), result.DeclaredCountry)
	require.Equal(t, record.UpdatedAt, result.UpdatedAt)
	require.Zero(t, store.updateCalls)
	require.Empty(t, publisher.PublishedEvents())
}

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

	service, err := NewSyncService(
		newFakeAccountStore(validAccountRecord(time.Unix(1_775_240_000, 0).UTC(), time.Unix(1_775_240_000, 0).UTC())),
		fixedClock{now: time.Unix(1_775_240_000, 0).UTC()},
		&recordingDeclaredCountryChangedPublisher{},
	)
	require.NoError(t, err)

	tests := []struct {
		name  string
		value string
	}{
		{name: "alias country code", value: "UK"},
		{name: "lowercase", value: "de"},
		{name: "non-country region", value: "EU"},
		{name: "wrong length", value: "DEU"},
	}

	for _, tt := range tests {
		tt := tt
		t.Run(tt.name, func(t *testing.T) {
			t.Parallel()

			_, err := service.Execute(context.Background(), SyncDeclaredCountryInput{
				UserID:          "user-123",
				DeclaredCountry: tt.value,
			})
			require.Error(t, err)
			require.Equal(t, shared.ErrorCodeInvalidRequest, shared.CodeOf(err))
			require.EqualError(t, err, "declared_country must be a valid ISO 3166-1 alpha-2 country code")
		})
	}
}

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

	service, err := NewSyncService(
		newFakeAccountStore(),
		fixedClock{now: time.Unix(1_775_240_000, 0).UTC()},
		&recordingDeclaredCountryChangedPublisher{},
	)
	require.NoError(t, err)

	_, err = service.Execute(context.Background(), SyncDeclaredCountryInput{
		UserID:          "user-missing",
		DeclaredCountry: "DE",
	})
	require.Error(t, err)
	require.Equal(t, shared.ErrorCodeSubjectNotFound, shared.CodeOf(err))
}

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

	createdAt := time.Unix(1_775_240_000, 0).UTC()
	updatedAt := createdAt.Add(time.Minute)
	record := validAccountRecord(createdAt, createdAt)
	store := newFakeAccountStore(record)
	publisher := &recordingDeclaredCountryChangedPublisher{
		err: errors.New("publisher unavailable"),
	}

	service, err := NewSyncService(store, fixedClock{now: updatedAt}, publisher)
	require.NoError(t, err)

	result, err := service.Execute(context.Background(), SyncDeclaredCountryInput{
		UserID:          record.UserID.String(),
		DeclaredCountry: "FR",
	})
	require.NoError(t, err)
	require.Equal(t, "FR", result.DeclaredCountry)
	require.Equal(t, updatedAt, result.UpdatedAt)

	stored, err := store.GetByUserID(context.Background(), record.UserID)
	require.NoError(t, err)
	require.Equal(t, common.CountryCode("FR"), stored.DeclaredCountry)
	require.Equal(t, updatedAt, stored.UpdatedAt)

	published := publisher.PublishedEvents()
	require.Len(t, published, 1)
	require.Equal(t, common.CountryCode("FR"), published[0].DeclaredCountry)
}

type fakeAccountStore struct {
	records     map[common.UserID]account.UserAccount
	updateCalls int
	updateErr   error
}

func newFakeAccountStore(records ...account.UserAccount) *fakeAccountStore {
	byUserID := make(map[common.UserID]account.UserAccount, len(records))
	for _, record := range records {
		byUserID[record.UserID] = record
	}

	return &fakeAccountStore{records: byUserID}
}

func (store *fakeAccountStore) Create(context.Context, ports.CreateAccountInput) error {
	return nil
}

func (store *fakeAccountStore) GetByUserID(_ context.Context, userID common.UserID) (account.UserAccount, error) {
	record, ok := store.records[userID]
	if !ok {
		return account.UserAccount{}, ports.ErrNotFound
	}

	return record, nil
}

func (store *fakeAccountStore) GetByEmail(_ context.Context, email common.Email) (account.UserAccount, error) {
	for _, record := range store.records {
		if record.Email == email {
			return record, nil
		}
	}

	return account.UserAccount{}, ports.ErrNotFound
}

func (store *fakeAccountStore) GetByUserName(_ context.Context, userName common.UserName) (account.UserAccount, error) {
	for _, record := range store.records {
		if record.UserName == userName {
			return record, nil
		}
	}

	return account.UserAccount{}, ports.ErrNotFound
}

func (store *fakeAccountStore) ExistsByUserID(_ context.Context, userID common.UserID) (bool, error) {
	_, ok := store.records[userID]
	return ok, nil
}

func (store *fakeAccountStore) Update(_ context.Context, record account.UserAccount) error {
	store.updateCalls++
	if store.updateErr != nil {
		return store.updateErr
	}
	if _, ok := store.records[record.UserID]; !ok {
		return ports.ErrNotFound
	}
	store.records[record.UserID] = record
	return nil
}

type recordingDeclaredCountryChangedPublisher struct {
	err         error
	publishHook func(event ports.DeclaredCountryChangedEvent) error
	published   []ports.DeclaredCountryChangedEvent
}

func (publisher *recordingDeclaredCountryChangedPublisher) PublishDeclaredCountryChanged(
	_ context.Context,
	event ports.DeclaredCountryChangedEvent,
) error {
	if err := event.Validate(); err != nil {
		return err
	}

	publisher.published = append(publisher.published, event)
	if publisher.publishHook != nil {
		if err := publisher.publishHook(event); err != nil {
			return err
		}
	}

	return publisher.err
}

func (publisher *recordingDeclaredCountryChangedPublisher) PublishedEvents() []ports.DeclaredCountryChangedEvent {
	events := make([]ports.DeclaredCountryChangedEvent, len(publisher.published))
	copy(events, publisher.published)
	return events
}

type fixedClock struct {
	now time.Time
}

func (clock fixedClock) Now() time.Time {
	return clock.now
}

func validAccountRecord(createdAt time.Time, updatedAt time.Time) account.UserAccount {
	return account.UserAccount{
		UserID:            common.UserID("user-123"),
		Email:             common.Email("pilot@example.com"),
		UserName:          common.UserName("player-abcdefgh"),
		PreferredLanguage: common.LanguageTag("en"),
		TimeZone:          common.TimeZoneName("Europe/Kaliningrad"),
		DeclaredCountry:   common.CountryCode("DE"),
		CreatedAt:         createdAt,
		UpdatedAt:         updatedAt,
	}
}

var (
	_ ports.UserAccountStore                = (*fakeAccountStore)(nil)
	_ ports.DeclaredCountryChangedPublisher = (*recordingDeclaredCountryChangedPublisher)(nil)
	_ ports.Clock                           = fixedClock{}
)