package redisstate_test

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

	"galaxy/lobby/internal/adapters/redisstate"
	"galaxy/lobby/internal/domain/common"
	"galaxy/lobby/internal/domain/invite"
	"galaxy/lobby/internal/ports"

	"github.com/alicebob/miniredis/v2"
	"github.com/redis/go-redis/v9"
	"github.com/stretchr/testify/assert"
	"github.com/stretchr/testify/require"
)

func newInviteTestStore(t *testing.T) (*redisstate.InviteStore, *miniredis.Miniredis, *redis.Client) {
	t.Helper()

	server := miniredis.RunT(t)
	client := redis.NewClient(&redis.Options{Addr: server.Addr()})
	t.Cleanup(func() {
		_ = client.Close()
	})

	store, err := redisstate.NewInviteStore(client)
	require.NoError(t, err)

	return store, server, client
}

func fixtureInvite(t *testing.T, id common.InviteID, inviter, invitee string, gameID common.GameID) invite.Invite {
	t.Helper()

	now := time.Date(2026, 4, 23, 12, 0, 0, 0, time.UTC)
	record, err := invite.New(invite.NewInviteInput{
		InviteID:      id,
		GameID:        gameID,
		InviterUserID: inviter,
		InviteeUserID: invitee,
		Now:           now,
		ExpiresAt:     now.Add(7 * 24 * time.Hour),
	})
	require.NoError(t, err)
	return record
}

func TestNewInviteStoreRejectsNilClient(t *testing.T) {
	_, err := redisstate.NewInviteStore(nil)
	require.Error(t, err)
}

func TestInviteStoreSaveAndGet(t *testing.T) {
	ctx := context.Background()
	store, _, client := newInviteTestStore(t)

	record := fixtureInvite(t, "invite-a", "user-owner", "user-guest", "game-1")
	require.NoError(t, store.Save(ctx, record))

	got, err := store.Get(ctx, record.InviteID)
	require.NoError(t, err)
	assert.Equal(t, record.InviteID, got.InviteID)
	assert.Equal(t, record.InviteeUserID, got.InviteeUserID)
	assert.Equal(t, invite.StatusCreated, got.Status)
	assert.Equal(t, "", got.RaceName)
	assert.Nil(t, got.DecidedAt)
	assert.True(t, got.ExpiresAt.Equal(record.ExpiresAt))

	byGame, err := client.SMembers(ctx, "lobby:game_invites:"+base64URL(record.GameID.String())).Result()
	require.NoError(t, err)
	assert.ElementsMatch(t, []string{record.InviteID.String()}, byGame)

	byUser, err := client.SMembers(ctx, "lobby:user_invites:"+base64URL(record.InviteeUserID)).Result()
	require.NoError(t, err)
	assert.ElementsMatch(t, []string{record.InviteID.String()}, byUser)
}

func TestInviteStoreGetReturnsNotFound(t *testing.T) {
	ctx := context.Background()
	store, _, _ := newInviteTestStore(t)

	_, err := store.Get(ctx, common.InviteID("invite-missing"))
	require.ErrorIs(t, err, invite.ErrNotFound)
}

func TestInviteStoreSaveRejectsDuplicate(t *testing.T) {
	ctx := context.Background()
	store, _, _ := newInviteTestStore(t)

	record := fixtureInvite(t, "invite-a", "user-owner", "user-guest", "game-1")
	require.NoError(t, store.Save(ctx, record))

	err := store.Save(ctx, record)
	require.Error(t, err)
	assert.True(t, errors.Is(err, invite.ErrConflict))
}

func TestInviteStoreSaveRejectsNonCreated(t *testing.T) {
	ctx := context.Background()
	store, _, _ := newInviteTestStore(t)

	record := fixtureInvite(t, "invite-a", "user-owner", "user-guest", "game-1")
	record.Status = invite.StatusRevoked
	decidedAt := record.CreatedAt.Add(time.Minute)
	record.DecidedAt = &decidedAt

	err := store.Save(ctx, record)
	require.Error(t, err)
	assert.False(t, errors.Is(err, invite.ErrConflict))
}

func TestInviteStoreUpdateStatusRedeemSetsRaceName(t *testing.T) {
	ctx := context.Background()
	store, _, _ := newInviteTestStore(t)

	record := fixtureInvite(t, "invite-a", "user-owner", "user-guest", "game-1")
	require.NoError(t, store.Save(ctx, record))

	at := record.CreatedAt.Add(time.Hour)
	require.NoError(t, store.UpdateStatus(ctx, ports.UpdateInviteStatusInput{
		InviteID:     record.InviteID,
		ExpectedFrom: invite.StatusCreated,
		To:           invite.StatusRedeemed,
		At:           at,
		RaceName:     "Lunar Raider",
	}))

	got, err := store.Get(ctx, record.InviteID)
	require.NoError(t, err)
	assert.Equal(t, invite.StatusRedeemed, got.Status)
	assert.Equal(t, "Lunar Raider", got.RaceName)
	require.NotNil(t, got.DecidedAt)
	assert.True(t, got.DecidedAt.Equal(at.UTC()))
}

func TestInviteStoreUpdateStatusTerminalTransitions(t *testing.T) {
	cases := []struct {
		name   string
		target invite.Status
	}{
		{"declined", invite.StatusDeclined},
		{"revoked", invite.StatusRevoked},
		{"expired", invite.StatusExpired},
	}

	for _, tc := range cases {
		t.Run(tc.name, func(t *testing.T) {
			ctx := context.Background()
			store, _, _ := newInviteTestStore(t)

			record := fixtureInvite(t, common.InviteID("invite-"+tc.name), "user-owner", "user-guest", "game-1")
			require.NoError(t, store.Save(ctx, record))

			at := record.CreatedAt.Add(30 * time.Minute)
			require.NoError(t, store.UpdateStatus(ctx, ports.UpdateInviteStatusInput{
				InviteID:     record.InviteID,
				ExpectedFrom: invite.StatusCreated,
				To:           tc.target,
				At:           at,
			}))

			got, err := store.Get(ctx, record.InviteID)
			require.NoError(t, err)
			assert.Equal(t, tc.target, got.Status)
			assert.Equal(t, "", got.RaceName)
			require.NotNil(t, got.DecidedAt)
			assert.True(t, got.DecidedAt.Equal(at.UTC()))
		})
	}
}

func TestInviteStoreUpdateStatusRejectsRedeemWithoutRaceName(t *testing.T) {
	ctx := context.Background()
	store, _, _ := newInviteTestStore(t)

	record := fixtureInvite(t, "invite-a", "user-owner", "user-guest", "game-1")
	require.NoError(t, store.Save(ctx, record))

	err := store.UpdateStatus(ctx, ports.UpdateInviteStatusInput{
		InviteID:     record.InviteID,
		ExpectedFrom: invite.StatusCreated,
		To:           invite.StatusRedeemed,
		At:           record.CreatedAt.Add(time.Minute),
	})
	require.Error(t, err)
	assert.False(t, errors.Is(err, invite.ErrInvalidTransition))
}

func TestInviteStoreUpdateStatusRejectsRaceNameOnNonRedeem(t *testing.T) {
	ctx := context.Background()
	store, _, _ := newInviteTestStore(t)

	record := fixtureInvite(t, "invite-a", "user-owner", "user-guest", "game-1")
	require.NoError(t, store.Save(ctx, record))

	err := store.UpdateStatus(ctx, ports.UpdateInviteStatusInput{
		InviteID:     record.InviteID,
		ExpectedFrom: invite.StatusCreated,
		To:           invite.StatusDeclined,
		At:           record.CreatedAt.Add(time.Minute),
		RaceName:     "Nope",
	})
	require.Error(t, err)
	assert.False(t, errors.Is(err, invite.ErrInvalidTransition))
}

func TestInviteStoreUpdateStatusRejectsInvalidTransitionWithoutMutation(t *testing.T) {
	ctx := context.Background()
	store, _, _ := newInviteTestStore(t)

	record := fixtureInvite(t, "invite-a", "user-owner", "user-guest", "game-1")
	require.NoError(t, store.Save(ctx, record))

	err := store.UpdateStatus(ctx, ports.UpdateInviteStatusInput{
		InviteID:     record.InviteID,
		ExpectedFrom: invite.StatusRedeemed,
		To:           invite.StatusExpired,
		At:           record.CreatedAt.Add(time.Minute),
	})
	require.Error(t, err)
	assert.True(t, errors.Is(err, invite.ErrInvalidTransition))
}

func TestInviteStoreUpdateStatusReturnsConflictOnExpectedFromMismatch(t *testing.T) {
	ctx := context.Background()
	store, _, _ := newInviteTestStore(t)

	record := fixtureInvite(t, "invite-a", "user-owner", "user-guest", "game-1")
	require.NoError(t, store.Save(ctx, record))

	require.NoError(t, store.UpdateStatus(ctx, ports.UpdateInviteStatusInput{
		InviteID:     record.InviteID,
		ExpectedFrom: invite.StatusCreated,
		To:           invite.StatusRevoked,
		At:           record.CreatedAt.Add(time.Minute),
	}))

	err := store.UpdateStatus(ctx, ports.UpdateInviteStatusInput{
		InviteID:     record.InviteID,
		ExpectedFrom: invite.StatusCreated,
		To:           invite.StatusDeclined,
		At:           record.CreatedAt.Add(2 * time.Minute),
	})
	require.Error(t, err)
	assert.True(t, errors.Is(err, invite.ErrConflict))
}

func TestInviteStoreUpdateStatusReturnsNotFoundForMissingRecord(t *testing.T) {
	ctx := context.Background()
	store, _, _ := newInviteTestStore(t)

	err := store.UpdateStatus(ctx, ports.UpdateInviteStatusInput{
		InviteID:     common.InviteID("invite-missing"),
		ExpectedFrom: invite.StatusCreated,
		To:           invite.StatusDeclined,
		At:           time.Now().UTC(),
	})
	require.ErrorIs(t, err, invite.ErrNotFound)
}

func TestInviteStoreGetByGameAndByUser(t *testing.T) {
	ctx := context.Background()
	store, _, _ := newInviteTestStore(t)

	i1 := fixtureInvite(t, "invite-a1", "user-owner", "user-1", "game-1")
	i2 := fixtureInvite(t, "invite-a2", "user-owner", "user-2", "game-1")
	i3 := fixtureInvite(t, "invite-a3", "user-owner", "user-1", "game-2")

	for _, record := range []invite.Invite{i1, i2, i3} {
		require.NoError(t, store.Save(ctx, record))
	}

	byGame1, err := store.GetByGame(ctx, "game-1")
	require.NoError(t, err)
	require.Len(t, byGame1, 2)

	byUser1, err := store.GetByUser(ctx, "user-1")
	require.NoError(t, err)
	require.Len(t, byUser1, 2)

	ids := collectInviteIDs(byUser1)
	sort.Strings(ids)
	assert.Equal(t, []string{"invite-a1", "invite-a3"}, ids)

	byGameMissing, err := store.GetByGame(ctx, "game-missing")
	require.NoError(t, err)
	assert.Empty(t, byGameMissing)
}

func TestInviteStoreGetByInviter(t *testing.T) {
	ctx := context.Background()
	store, _, _ := newInviteTestStore(t)

	i1 := fixtureInvite(t, "invite-i1", "user-owner-a", "user-guest-1", "game-1")
	i2 := fixtureInvite(t, "invite-i2", "user-owner-a", "user-guest-2", "game-2")
	i3 := fixtureInvite(t, "invite-i3", "user-owner-b", "user-guest-1", "game-3")

	for _, record := range []invite.Invite{i1, i2, i3} {
		require.NoError(t, store.Save(ctx, record))
	}

	byInviterA, err := store.GetByInviter(ctx, "user-owner-a")
	require.NoError(t, err)
	require.Len(t, byInviterA, 2)
	idsA := collectInviteIDs(byInviterA)
	sort.Strings(idsA)
	assert.Equal(t, []string{"invite-i1", "invite-i2"}, idsA)

	byInviterB, err := store.GetByInviter(ctx, "user-owner-b")
	require.NoError(t, err)
	require.Len(t, byInviterB, 1)
	assert.Equal(t, "invite-i3", byInviterB[0].InviteID.String())

	byInviterMissing, err := store.GetByInviter(ctx, "user-owner-none")
	require.NoError(t, err)
	assert.Empty(t, byInviterMissing)
}

func TestInviteStoreGetByInviterRetainsAfterStatusChange(t *testing.T) {
	ctx := context.Background()
	store, _, _ := newInviteTestStore(t)

	record := fixtureInvite(t, "invite-i", "user-owner-a", "user-guest", "game-1")
	require.NoError(t, store.Save(ctx, record))

	require.NoError(t, store.UpdateStatus(ctx, ports.UpdateInviteStatusInput{
		InviteID:     record.InviteID,
		ExpectedFrom: invite.StatusCreated,
		To:           invite.StatusRevoked,
		At:           record.CreatedAt.Add(time.Minute),
	}))

	matches, err := store.GetByInviter(ctx, "user-owner-a")
	require.NoError(t, err)
	require.Len(t, matches, 1)
	assert.Equal(t, invite.StatusRevoked, matches[0].Status)
}

func TestInviteStoreGetByGameDropsStaleIndexEntries(t *testing.T) {
	ctx := context.Background()
	store, server, _ := newInviteTestStore(t)

	record := fixtureInvite(t, "invite-a", "user-owner", "user-guest", "game-1")
	require.NoError(t, store.Save(ctx, record))

	server.Del("lobby:invites:" + base64URL(record.InviteID.String()))

	records, err := store.GetByGame(ctx, record.GameID)
	require.NoError(t, err)
	assert.Empty(t, records)
}

func collectInviteIDs(records []invite.Invite) []string {
	ids := make([]string, len(records))
	for index, record := range records {
		ids[index] = record.InviteID.String()
	}
	return ids
}