BookmarksViewModel - Before adding domain layer

BookmarksViewModel.kt

/* Copyright 2022 Google LLC.	
   SPDX-License-Identifier: Apache-2.0 */

class BookmarksViewModel @Inject constructor(
    newsRepository: NewsRepository,
    private val userDataRepository: UserDataRepository
) : ViewModel() {
    
    // #1. Obtain a list of bookmarks.
    private val bookmarks: StateFlow<Set<String>> =
        userDataRepository.userDataStream
            .map { userData ->
                userData.bookmarkedNewsResources
            }
            .stateIn(...)

    val feedState: StateFlow<NewsFeedUiState> =
        newsRepository
            .getNewsResourcesStream() // #2 Obtain news resources
            .combine(bookmarks) { newsResources, bookmarks -> // #3 Combine data
                newsResources
                    // #4 Only show bookmarked news resources 
                    .filter { newsResource -> bookmarks.contains(newsResource.id) }
                    .map { SaveableNewsResource(it, true) }
            }
            .map<List<SaveableNewsResource>, <NewsFeedUiState>(NewsFeedUiState::Success)
            .onStart { emit(Loading) }
            .stateIn(...)
    ...
}