Fix selecting custom fetch interval not persisting sometimes

app/src/main/java/eu/kanade/domain/manga/interactor/UpdateManga.kt

@@ -81,9 +81,9 @@ class UpdateManga(
         dateTime: ZonedDateTime = ZonedDateTime.now(),
         window: Pair<Long, Long> = fetchInterval.getWindow(dateTime),
     ): Boolean {
-        return fetchInterval.toMangaUpdateOrNull(manga, dateTime, window)
-            ?.let { mangaRepository.update(it) }
-            ?: false
+        return mangaRepository.update(
+            fetchInterval.toMangaUpdate(manga, dateTime, window),
+        )
     }
 
     suspend fun awaitUpdateLastUpdate(mangaId: Long): Boolean {

app/src/main/java/eu/kanade/presentation/manga/components/MangaDialogs.kt

@@ -30,6 +30,7 @@ import tachiyomi.presentation.core.i18n.pluralStringResource
 import tachiyomi.presentation.core.i18n.stringResource
 import java.time.Instant
 import java.time.temporal.ChronoUnit
+import kotlin.math.absoluteValue
 
 @Composable
 fun DeleteChaptersDialog(
@@ -85,7 +86,7 @@ fun SetIntervalDialog(
         title = { Text(stringResource(MR.strings.pref_library_update_smart_update)) },
         text = {
             Column {
-                if (nextUpdateDays != null && nextUpdateDays >= 0) {
+                if (nextUpdateDays != null && nextUpdateDays >= 0 && interval >= 0) {
                     Text(
                         stringResource(
                             MR.strings.manga_interval_expected_update,
@@ -96,8 +97,8 @@ fun SetIntervalDialog(
                             ),
                             pluralStringResource(
                                 MR.plurals.day,
-                                count = interval,
-                                interval,
+                                count = interval.absoluteValue,
+                                interval.absoluteValue,
                             ),
                         ),
                     )
@@ -105,7 +106,6 @@ fun SetIntervalDialog(
                     Spacer(Modifier.height(MaterialTheme.padding.small))
                 }
 
-                // TODO: selecting "1" then doesn't allow for future changes unless defaulting first?
                 if (onValueChanged != null && (isDevFlavor || isPreviewBuildType)) {
                     Text(stringResource(MR.strings.manga_interval_custom_amount))
 

app/src/main/java/eu/kanade/presentation/manga/components/MangaInfoHeader.kt

@@ -201,14 +201,14 @@ fun MangaActionRow(
             onLongClick = onEditCategory,
         )
         MangaActionButton(
-            title = if (nextUpdateDays != null) {
-                pluralStringResource(
+            title = when (nextUpdateDays) {
+                null -> stringResource(MR.strings.not_applicable)
+                0 -> stringResource(MR.strings.manga_interval_expected_update_soon)
+                else -> pluralStringResource(
                     MR.plurals.day,
                     count = nextUpdateDays,
                     nextUpdateDays,
                 )
-            } else {
-                stringResource(MR.strings.not_applicable)
             },
             icon = Icons.Default.HourglassEmpty,
             color = if (isUserIntervalMode) MaterialTheme.colorScheme.primary else defaultActionButtonColor,

app/src/main/java/eu/kanade/tachiyomi/ui/manga/MangaScreenModel.kt

@@ -378,14 +378,17 @@ class MangaScreenModel(
 
     fun setFetchInterval(manga: Manga, interval: Int) {
         screenModelScope.launchIO {
+            if (
                 updateManga.awaitUpdateFetchInterval(
                     // Custom intervals are negative
                     manga.copy(fetchInterval = -interval),
                 )
+            ) {
                 val updatedManga = mangaRepository.getMangaById(manga.id)
                 updateSuccessState { it.copy(manga = updatedManga) }
             }
         }
+    }
 
     /**
      * Returns true if the manga has any downloads.

domain/src/main/java/tachiyomi/domain/manga/interactor/FetchInterval.kt

@@ -14,11 +14,11 @@ class FetchInterval(
     private val getChaptersByMangaId: GetChaptersByMangaId,
 ) {
 
-    suspend fun toMangaUpdateOrNull(
+    suspend fun toMangaUpdate(
         manga: Manga,
         dateTime: ZonedDateTime,
         window: Pair<Long, Long>,
-    ): MangaUpdate? {
+    ): MangaUpdate {
         val interval = manga.fetchInterval.takeIf { it < 0 } ?: calculateInterval(
             chapters = getChaptersByMangaId.await(manga.id, applyScanlatorFilter = true),
             zone = dateTime.zone,
@@ -30,11 +30,7 @@ class FetchInterval(
         }
         val nextUpdate = calculateNextUpdate(manga, interval, dateTime, currentWindow)
 
-        return if (manga.nextUpdate == nextUpdate && manga.fetchInterval == interval) {
-            null
-        } else {
-            MangaUpdate(id = manga.id, nextUpdate = nextUpdate, fetchInterval = interval)
-        }
+        return MangaUpdate(id = manga.id, nextUpdate = nextUpdate, fetchInterval = interval)
     }
 
     fun getWindow(dateTime: ZonedDateTime): Pair<Long, Long> {
@@ -96,10 +92,10 @@ class FetchInterval(
         dateTime: ZonedDateTime,
         window: Pair<Long, Long>,
     ): Long {
-        return if (
-            manga.nextUpdate !in window.first.rangeTo(window.second + 1) ||
-            manga.fetchInterval == 0
-        ) {
+        if (manga.nextUpdate in window.first.rangeTo(window.second + 1)) {
+            return manga.nextUpdate
+        }
+
         val latestDate = ZonedDateTime.ofInstant(
             if (manga.lastUpdate > 0) Instant.ofEpochMilli(manga.lastUpdate) else Instant.now(),
             dateTime.zone,
@@ -109,21 +105,18 @@ class FetchInterval(
         val timeSinceLatest = ChronoUnit.DAYS.between(latestDate, dateTime).toInt()
         val cycle = timeSinceLatest.floorDiv(
             interval.absoluteValue.takeIf { interval < 0 }
-                    ?: doubleInterval(interval, timeSinceLatest, doubleWhenOver = 10),
+                ?: increaseInterval(interval, timeSinceLatest, increaseWhenOver = 10),
         )
-            latestDate.plusDays((cycle + 1) * interval.toLong()).toEpochSecond(dateTime.offset) * 1000
-        } else {
-            manga.nextUpdate
-        }
+        return latestDate.plusDays((cycle + 1) * interval.toLong()).toEpochSecond(dateTime.offset) * 1000
     }
 
-    private fun doubleInterval(delta: Int, timeSinceLatest: Int, doubleWhenOver: Int): Int {
+    private fun increaseInterval(delta: Int, timeSinceLatest: Int, increaseWhenOver: Int): Int {
         if (delta >= MAX_INTERVAL) return MAX_INTERVAL
 
         // double delta again if missed more than 9 check in new delta
         val cycle = timeSinceLatest.floorDiv(delta) + 1
-        return if (cycle > doubleWhenOver) {
-            doubleInterval(delta * 2, timeSinceLatest, doubleWhenOver)
+        return if (cycle > increaseWhenOver) {
+            increaseInterval(delta * 2, timeSinceLatest, increaseWhenOver)
         } else {
             delta
         }

i18n/src/commonMain/resources/MR/base/strings.xml

@@ -683,9 +683,9 @@
     <string name="display_mode_chapter">Chapter %1$s</string>
     <string name="manga_display_interval_title">Estimate every</string>
     <string name="manga_display_modified_interval_title">Set to update every</string>
-    <string name="manga_interval_header">Next update</string>
     <!-- "... around 2 days" -->
-    <string name="manga_interval_expected_update">Next update expected in around %1$s, checking around every %2$s</string>
+    <string name="manga_interval_expected_update">New chapters predicted to be released in around %1$s, checking around every %2$s.</string>
+    <string name="manga_interval_expected_update_soon">Soon</string>
     <string name="manga_interval_custom_amount">Custom update frequency:</string>
     <string name="chapter_downloading_progress">Downloading (%1$d/%2$d)</string>
     <string name="chapter_error">Error</string>