class LibraryPresenter @AssistedInject constructor(
    @Assisted private val navigator: Navigator,
    private val authRepository: AuthRepository,
    private val userRepository: UserRepository,
) : Presenter<LibraryScreen.State> {

    @Composable
    override fun present(): LibraryScreen.State {
        val scope = rememberCoroutineScope()
        var sideEffect by rememberRetained { mutableStateOf<LibraryScreen.SideEffect?>(null) }
        
        val userProfileState by produceRetainedState<LibraryScreen.UserProfileState>(
            initialValue = LibraryScreen.UserProfileState.Loading
        ) {
            userRepository.getUserProfile()
                .onSuccess { user ->
                    value = LibraryScreen.UserProfileState.Success(
                        nickname = user.nickname,
                        email = user.email
                    )
                }
                .onFailure { exception ->
                    handleException(
                        exception = exception,
                        onServerError = { message ->
                            value = LibraryScreen.UserProfileState.Error(message)
                        },
                        onNetworkError = { message ->
                            value = LibraryScreen.UserProfileState.Error(message)
                        },
                        onLoginRequired = {
                            navigator.resetRoot(LoginScreen)
                        },
                    )
                }
        }

        fun handleEvent(event: LibraryScreen.Event) {
            when (event) {
                is LibraryScreen.Event.InitSideEffect -> {
                    sideEffect = null
                }

                is LibraryScreen.Event.OnLogoutButtonClick -> { 
                    // ...
                }
            }
        }

        return LibraryScreen.State(
            userProfile = userProfileState,
            sideEffect = sideEffect,
            eventSink = ::handleEvent,
        )
    }

    @CircuitInject(LibraryScreen::class, ActivityRetainedComponent::class)
    @AssistedFactory
    fun interface Factory {
        fun create(navigator: Navigator): LibraryPresenter
    }
}

@Parcelize
data object LibraryScreen : Screen {
    sealed interface UserProfileState {
        data object Loading : UserProfileState
        data class Success(val nickname: String, val email: String) : UserProfileState
        data class Error(val message: String) : UserProfileState
    }

    data class State(
        val userProfile: UserProfileState = UserProfileState.Loading,
        val sideEffect: SideEffect? = null,
        val eventSink: (Event) -> Unit,
    ) : CircuitUiState

    sealed interface SideEffect {
        data class ShowToast(val message: String) : SideEffect
    }

    sealed interface Event : CircuitUiEvent {
        data object InitSideEffect : Event
        data object OnLogoutButtonClick : Event
    }
}

@CircuitInject(LibraryScreen::class, ActivityRetainedComponent::class)
@Composable
internal fun Library(
    state: LibraryScreen.State,
    modifier: Modifier = Modifier,
) {
    HandleLibrarySideEffects(
        state = state,
        eventSink = state.eventSink,
    )

    Column(
        modifier = modifier.fillMaxSize(),
        horizontalAlignment = Alignment.CenterHorizontally,
        verticalArrangement = Arrangement.Center,
    ) {
        LibraryContent(
            state = state,
            modifier = modifier,
        )
    }
}

@Composable
internal fun LibraryContent(
    state: LibraryScreen.State,
    modifier: Modifier = Modifier,
) {
    Column(
        modifier = modifier.fillMaxSize(),
        horizontalAlignment = Alignment.CenterHorizontally,
        verticalArrangement = Arrangement.Center,
    ) {
        Box(modifier = modifier.fillMaxSize()) {
            Column(
                modifier = Modifier.fillMaxSize(),
                horizontalAlignment = Alignment.CenterHorizontally,
                verticalArrangement = Arrangement.Center,
            ) {
                Text(text = "내 서재")
                Spacer(modifier = Modifier.height(16.dp))
                // 변경 부분(예시)
                when (state.userProfile) {
                    is LibraryScreen.UserProfileState.Loading -> {
                        CircularProgressIndicator()
                    }
                    is LibraryScreen.UserProfileState.Success -> {
                        Text(text = state.userProfile.nickname)
                        Spacer(modifier = Modifier.height(16.dp))
                        Text(text = state.userProfile.email)
                    }
                    is LibraryScreen.UserProfileState.Error -> {
                        Text(text = "프로필 로딩 실패")
                        Spacer(modifier = Modifier.height(16.dp))
                        Text(text = state.userProfile.message)
                    }
                }
            }
            BooketButton(
                onClick = {
                    state.eventSink(LibraryScreen.Event.OnLogoutButtonClick)
                },
                modifier = Modifier
                    .fillMaxWidth()
                    .padding(start = 32.dp, end = 32.dp, bottom = 32.dp)
                    .height(56.dp)
                    .align(Alignment.BottomCenter),
                text = {
                    Text(
                        text = stringResource(id = R.string.logout),
                        fontSize = 18.sp,
                        style = TextStyle(
                            fontWeight = FontWeight.SemiBold,
                            fontSize = 18.sp,
                            lineHeight = 25.sp,
                        ),
                    )
                },
            )
        }
    }
}