package streamoffsets_test

import (
	"context"
	"testing"

	"galaxy/gamemaster/internal/adapters/redisstate"
	"galaxy/gamemaster/internal/adapters/redisstate/streamoffsets"

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

func newOffsetStore(t *testing.T) (*streamoffsets.Store, *miniredis.Miniredis) {
	t.Helper()
	server := miniredis.RunT(t)
	client := redis.NewClient(&redis.Options{Addr: server.Addr()})
	t.Cleanup(func() { _ = client.Close() })

	store, err := streamoffsets.New(streamoffsets.Config{Client: client})
	require.NoError(t, err)
	return store, server
}

func TestNewRejectsNilClient(t *testing.T) {
	_, err := streamoffsets.New(streamoffsets.Config{})
	require.Error(t, err)
}

func TestLoadMissingReturnsNotFound(t *testing.T) {
	store, _ := newOffsetStore(t)
	id, found, err := store.Load(context.Background(), "health_events")
	require.NoError(t, err)
	assert.False(t, found)
	assert.Empty(t, id)
}

func TestSaveLoadRoundTrip(t *testing.T) {
	store, server := newOffsetStore(t)

	const entryID = "1700000000000-0"
	require.NoError(t, store.Save(context.Background(), "health_events", entryID))

	id, found, err := store.Load(context.Background(), "health_events")
	require.NoError(t, err)
	assert.True(t, found)
	assert.Equal(t, entryID, id)

	// Verify the namespace prefix lands as expected.
	expectedKey := redisstate.Keyspace{}.StreamOffset("health_events")
	assert.True(t, server.Exists(expectedKey),
		"key %q must exist after Save", expectedKey)
}

func TestSaveOverwritesPreviousValue(t *testing.T) {
	store, _ := newOffsetStore(t)

	require.NoError(t, store.Save(context.Background(), "health_events", "1-0"))
	require.NoError(t, store.Save(context.Background(), "health_events", "2-0"))

	id, found, err := store.Load(context.Background(), "health_events")
	require.NoError(t, err)
	assert.True(t, found)
	assert.Equal(t, "2-0", id)
}

func TestSaveRejectsBadInputs(t *testing.T) {
	store, _ := newOffsetStore(t)

	require.Error(t, store.Save(context.Background(), "", "1-0"))
	require.Error(t, store.Save(context.Background(), "health_events", ""))
	//nolint:staticcheck // intentional nil ctx test
	require.Error(t, store.Save(nil, "health_events", "1-0"))
}

func TestLoadRejectsBadInputs(t *testing.T) {
	store, _ := newOffsetStore(t)

	_, _, err := store.Load(context.Background(), "")
	require.Error(t, err)
	//nolint:staticcheck // intentional nil ctx test
	_, _, err = store.Load(nil, "health_events")
	require.Error(t, err)
}

func TestNilStoreOperationsRejected(t *testing.T) {
	var store *streamoffsets.Store
	_, _, err := store.Load(context.Background(), "health_events")
	require.Error(t, err)
	require.Error(t, store.Save(context.Background(), "health_events", "1-0"))
}