From 66718d447a3cbd72f00296da4a32d366ef75426c Mon Sep 17 00:00:00 2001
From: Harsh Shandilya <me@msfjarvis.dev>
Date: Thu, 14 Apr 2022 18:30:15 +0530
Subject: [PATCH] android: sort saved posts by creation time

---
 .../kotlin/dev/msfjarvis/claw/android/ui/ext.kt    | 14 ++++++++++++++
 .../claw/android/ui/lists/DatabasePosts.kt         |  3 ++-
 2 files changed, 16 insertions(+), 1 deletion(-)

diff --git a/android/src/main/kotlin/dev/msfjarvis/claw/android/ui/ext.kt b/android/src/main/kotlin/dev/msfjarvis/claw/android/ui/ext.kt
index 54727ad4..09e5bb97 100644
--- a/android/src/main/kotlin/dev/msfjarvis/claw/android/ui/ext.kt
+++ b/android/src/main/kotlin/dev/msfjarvis/claw/android/ui/ext.kt
@@ -29,6 +29,10 @@ import dev.msfjarvis.claw.common.theme.DarkThemeColors
 import dev.msfjarvis.claw.common.theme.LightThemeColors
 import dev.msfjarvis.claw.common.urllauncher.UrlLauncher
 import dev.msfjarvis.claw.database.local.SavedPost
+import java.text.SimpleDateFormat
+import java.time.ZoneId
+import java.time.ZonedDateTime
+import java.util.Locale
 import kotlin.math.ln
 
 private const val AnimationDuration = 100
@@ -49,6 +53,16 @@ fun slideOutAnimation(): ExitTransition {
   )
 }
 
+/**
+ * Parses a given [String] into a [ZonedDateTime]. This method only works on dates in the format
+ * returned by the Lobsters API, and is not a general purpose parsing solution.
+ */
+fun String.asZonedDateTime(): ZonedDateTime {
+  val sdf = SimpleDateFormat("yyyy-MM-dd'T'HH:mm:ss.SSS", Locale.US)
+  val date = checkNotNull(sdf.parse(this))
+  return date.toInstant().atZone(ZoneId.systemDefault())
+}
+
 // The destination needs to be tracked like this rather than used directly since
 // `NavController#currentDestination` is not a Composable state.
 @Composable
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 1a921819..61f00616 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
@@ -5,6 +5,7 @@ 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.common.posts.PostActions
 import dev.msfjarvis.claw.common.ui.Divider
 import dev.msfjarvis.claw.database.local.SavedPost
@@ -21,7 +22,7 @@ fun DatabasePosts(
     state = listState,
     modifier = modifier,
   ) {
-    items(items) { item ->
+    items(items.sortedBy { post -> post.createdAt.asZonedDateTime() }) { item ->
       ListItem(
         item = item,
         isSaved = isSaved,