From 692e294528cc93e4aa6300506b3fc757849a5e00 Mon Sep 17 00:00:00 2001
From: Harsh Shandilya <me@msfjarvis.dev>
Date: Mon, 9 May 2022 17:07:20 +0530
Subject: [PATCH] android: move sorting and grouping of saved posts to
 ViewModel

---
 .../dev/msfjarvis/claw/android/ui/LobstersApp.kt  |  2 +-
 .../claw/android/ui/lists/DatabasePosts.kt        |  8 +++-----
 .../claw/android/viewmodel/ClawViewModel.kt       | 15 +++++++++++++--
 3 files changed, 17 insertions(+), 8 deletions(-)

diff --git a/android/src/main/kotlin/dev/msfjarvis/claw/android/ui/LobstersApp.kt b/android/src/main/kotlin/dev/msfjarvis/claw/android/ui/LobstersApp.kt
index 3709497c..d5c83a43 100644
--- a/android/src/main/kotlin/dev/msfjarvis/claw/android/ui/LobstersApp.kt
+++ b/android/src/main/kotlin/dev/msfjarvis/claw/android/ui/LobstersApp.kt
@@ -73,7 +73,7 @@ fun LobstersApp(
 
   val hottestPosts = viewModel.hottestPosts.collectAsLazyPagingItems()
   val newestPosts = viewModel.newestPosts.collectAsLazyPagingItems()
-  val savedPosts by viewModel.savedPosts.collectAsState(emptyList())
+  val savedPosts by viewModel.savedPosts.collectAsState(emptyMap())
 
   LobstersTheme(
     providedValues =
diff --git a/android/src/main/kotlin/dev/msfjarvis/claw/android/ui/lists/DatabasePosts.kt b/android/src/main/kotlin/dev/msfjarvis/claw/android/ui/lists/DatabasePosts.kt
index d8438dab..2ba39770 100644
--- a/android/src/main/kotlin/dev/msfjarvis/claw/android/ui/lists/DatabasePosts.kt
+++ b/android/src/main/kotlin/dev/msfjarvis/claw/android/ui/lists/DatabasePosts.kt
@@ -6,28 +6,26 @@ import androidx.compose.foundation.lazy.LazyListState
 import androidx.compose.foundation.lazy.items
 import androidx.compose.runtime.Composable
 import androidx.compose.ui.Modifier
-import dev.msfjarvis.claw.android.ui.asZonedDateTime
 import dev.msfjarvis.claw.android.ui.decorations.MonthHeader
 import dev.msfjarvis.claw.common.posts.PostActions
 import dev.msfjarvis.claw.common.ui.Divider
 import dev.msfjarvis.claw.database.local.SavedPost
+import java.time.Month
 
 @OptIn(ExperimentalFoundationApi::class)
 @Composable
 fun DatabasePosts(
-  items: List<SavedPost>,
+  items: Map<Month, List<SavedPost>>,
   listState: LazyListState,
   isSaved: suspend (SavedPost) -> Boolean,
   postActions: PostActions,
   modifier: Modifier = Modifier,
 ) {
-  val sorted = items.sortedByDescending { post -> post.createdAt.asZonedDateTime() }
-  val grouped = sorted.groupBy { post -> post.createdAt.asZonedDateTime().month }
   LazyColumn(
     state = listState,
     modifier = modifier,
   ) {
-    grouped.forEach { (month, posts) ->
+    items.forEach { (month, posts) ->
       stickyHeader { MonthHeader(month = month) }
       items(posts) { item ->
         ListItem(
diff --git a/android/src/main/kotlin/dev/msfjarvis/claw/android/viewmodel/ClawViewModel.kt b/android/src/main/kotlin/dev/msfjarvis/claw/android/viewmodel/ClawViewModel.kt
index d2e1ad48..49efe1d9 100644
--- a/android/src/main/kotlin/dev/msfjarvis/claw/android/viewmodel/ClawViewModel.kt
+++ b/android/src/main/kotlin/dev/msfjarvis/claw/android/viewmodel/ClawViewModel.kt
@@ -6,12 +6,15 @@ import androidx.paging.Pager
 import androidx.paging.PagingConfig
 import dagger.hilt.android.lifecycle.HiltViewModel
 import dev.msfjarvis.claw.android.paging.LobstersPagingSource
+import dev.msfjarvis.claw.android.ui.asZonedDateTime
 import dev.msfjarvis.claw.api.LobstersApi
 import dev.msfjarvis.claw.database.local.SavedPost
+import java.time.Month
 import javax.inject.Inject
 import kotlinx.coroutines.Dispatchers
 import kotlinx.coroutines.ExperimentalCoroutinesApi
 import kotlinx.coroutines.flow.first
+import kotlinx.coroutines.flow.map
 import kotlinx.coroutines.flow.mapLatest
 import kotlinx.coroutines.launch
 import kotlinx.coroutines.withContext
@@ -41,11 +44,19 @@ constructor(
   val newestPosts
     get() = newestPostsPager.flow
 
-  val savedPosts
+  private val savedPostsFlow
     get() = repository.savedPosts
 
+  val savedPosts
+    get() = savedPostsFlow.map(::mapSavedPosts)
+
+  private fun mapSavedPosts(items: List<SavedPost>): Map<Month, List<SavedPost>> {
+    val sorted = items.sortedByDescending { post -> post.createdAt.asZonedDateTime() }
+    return sorted.groupBy { post -> post.createdAt.asZonedDateTime().month }
+  }
+
   suspend fun isPostSaved(post: SavedPost): Boolean {
-    return savedPosts
+    return savedPostsFlow
       .mapLatest { posts -> posts.map { it.shortId } }
       .mapLatest { shortIds -> post.shortId in shortIds }
       .first()