package streamoffsets_test

import (
	"context"
	"testing"

	"galaxy/rtmanager/internal/adapters/redisstate"
	"galaxy/rtmanager/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(), "start_jobs")
	require.NoError(t, err)
	assert.False(t, found)
	assert.Empty(t, id)
}

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

	require.NoError(t, store.Save(context.Background(), "start_jobs", "1700000000000-0"))

	id, found, err := store.Load(context.Background(), "start_jobs")
	require.NoError(t, err)
	assert.True(t, found)
	assert.Equal(t, "1700000000000-0", id)

	// The persisted key must follow the rtmanager keyspace prefix.
	expectedKey := redisstate.Keyspace{}.StreamOffset("start_jobs")
	assert.True(t, server.Exists(expectedKey),
		"key %q must exist after Save", expectedKey)
}

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

	require.NoError(t, store.Save(context.Background(), "start_jobs", "100-0"))
	require.NoError(t, store.Save(context.Background(), "start_jobs", "200-0"))

	id, found, err := store.Load(context.Background(), "start_jobs")
	require.NoError(t, err)
	assert.True(t, found)
	assert.Equal(t, "200-0", id)
}

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

	require.Error(t, store.Save(context.Background(), "", "100-0"))
	require.Error(t, store.Save(context.Background(), "start_jobs", ""))

	_, _, err := store.Load(context.Background(), "")
	require.Error(t, err)
}

func TestKeyspaceStreamOffsetIsPrefixed(t *testing.T) {
	key := redisstate.Keyspace{}.StreamOffset("start_jobs")
	assert.NotEmpty(t, key)
	assert.Contains(t, key, "rtmanager:stream_offsets:")
	// base64url-encoded label must not contain raw colons or spaces.
	suffix := key[len("rtmanager:stream_offsets:"):]
	assert.NotContains(t, suffix, ":")
}