86 lines
3.0 KiB
Kotlin
86 lines
3.0 KiB
Kotlin
/*
|
|
* Copyright © 2021-2024 Harsh Shandilya.
|
|
* Use of this source code is governed by an MIT-style
|
|
* license that can be found in the LICENSE file or at
|
|
* https://opensource.org/licenses/MIT.
|
|
*/
|
|
package dev.msfjarvis.claw.android.paging
|
|
|
|
import androidx.paging.PagingSource
|
|
import androidx.paging.PagingState
|
|
import com.slack.eithernet.ApiResult.Failure
|
|
import com.slack.eithernet.ApiResult.Success
|
|
import dagger.assisted.Assisted
|
|
import dagger.assisted.AssistedFactory
|
|
import dagger.assisted.AssistedInject
|
|
import dev.msfjarvis.claw.android.viewmodel.ReadPostsRepository
|
|
import dev.msfjarvis.claw.android.viewmodel.SavedPostsRepository
|
|
import dev.msfjarvis.claw.core.injection.IODispatcher
|
|
import dev.msfjarvis.claw.database.local.SavedPost
|
|
import dev.msfjarvis.claw.model.LobstersPost
|
|
import dev.msfjarvis.claw.model.UIPost
|
|
import dev.msfjarvis.claw.model.toUIPost
|
|
import java.io.IOException
|
|
import kotlinx.coroutines.CoroutineDispatcher
|
|
import kotlinx.coroutines.flow.first
|
|
import kotlinx.coroutines.withContext
|
|
|
|
class LobstersPagingSource
|
|
@AssistedInject
|
|
constructor(
|
|
@Assisted private val remoteFetcher: RemoteFetcher<LobstersPost>,
|
|
@IODispatcher private val ioDispatcher: CoroutineDispatcher,
|
|
private val savedPostsRepository: SavedPostsRepository,
|
|
private val readPostsRepository: ReadPostsRepository,
|
|
) : PagingSource<Int, UIPost>() {
|
|
private lateinit var savedPosts: List<String>
|
|
private lateinit var readPosts: List<String>
|
|
|
|
override suspend fun load(params: LoadParams<Int>): LoadResult<Int, UIPost> {
|
|
if (!::savedPosts.isInitialized) {
|
|
savedPosts = savedPostsRepository.savedPosts.first().map(SavedPost::shortId)
|
|
}
|
|
if (!::readPosts.isInitialized) {
|
|
readPosts = readPostsRepository.readPosts.first()
|
|
}
|
|
val page = params.key ?: STARTING_PAGE_INDEX
|
|
return when (val result = withContext(ioDispatcher) { remoteFetcher.getItemsAtPage(page) }) {
|
|
is Success ->
|
|
LoadResult.Page(
|
|
itemsBefore = (page - 1) * PAGE_SIZE,
|
|
data =
|
|
result.value.map {
|
|
it
|
|
.toUIPost()
|
|
.copy(
|
|
isSaved = savedPosts.contains(it.shortId),
|
|
isRead = readPosts.contains(it.shortId),
|
|
)
|
|
},
|
|
prevKey = if (page == STARTING_PAGE_INDEX) null else page - 1,
|
|
nextKey = page + 1,
|
|
)
|
|
is Failure.NetworkFailure -> LoadResult.Error(result.error)
|
|
is Failure.UnknownFailure -> LoadResult.Error(result.error)
|
|
is Failure.HttpFailure,
|
|
is Failure.ApiFailure -> LoadResult.Error(IOException("API returned an invalid response"))
|
|
}
|
|
}
|
|
|
|
override fun getRefreshKey(state: PagingState<Int, UIPost>): Int? {
|
|
return state.anchorPosition?.let { anchorPosition ->
|
|
(anchorPosition / PAGE_SIZE).coerceAtLeast(STARTING_PAGE_INDEX)
|
|
}
|
|
}
|
|
|
|
@AssistedFactory
|
|
interface Factory {
|
|
fun create(remoteFetcher: RemoteFetcher<LobstersPost>): LobstersPagingSource
|
|
}
|
|
|
|
companion object {
|
|
const val PAGE_SIZE = 25
|
|
const val STARTING_PAGE_INDEX = 1
|
|
}
|
|
}
|