Keep reminders off dateless tasks on every edit path (#159)

CHANGELOG.md

@@ -7,10 +7,10 @@ All notable changes to this project are documented here. The format follows
 
 ## [Unreleased]
 
-### Added
-- A "Description in reminders" setting under Notifications sets how much of a
-  task's description a reminder shows: none, a short preview of up to three
-  lines (the new default), or all of it as before (#156).
+### Fixed
+- Removing a task's last date also removes its reminders, so the task can be
+  saved again. Reminders you picked yourself come back when you set a new date
+  (#159).
 
 ## [1.3.1] - 2026-11-09
 

app/src/main/java/de/jeanlucmakiola/agendula/data/prefs/SettingsPrefs.kt

@@ -54,9 +54,6 @@ fun TimeFormatPref.is24Hour(systemIs24Hour: Boolean): Boolean = when (this) {
     TimeFormatPref.TWENTY_FOUR_HOUR -> true
 }
 
-/** How much of a task's description a due reminder shows when expanded. */
-enum class ReminderDescription { HIDDEN, SHORT, FULL }
-
 const val DEFAULT_SNOOZE_MINUTES = 10
 /** Done starts folded away, to keep the open tasks in focus. */ val DEFAULT_COLLAPSED_SECTIONS: Set<TaskSection> = setOf(TaskSection.COMPLETED)
 
@@ -106,7 +103,6 @@ data class Settings(
     val sortOrder: TaskSortOrder = TaskSortOrder.DUE,
     /** How long a reminder's "Snooze" action puts it off. */
     val snoozeMinutes: Int = DEFAULT_SNOOZE_MINUTES,
-    val reminderDescription: ReminderDescription = ReminderDescription.SHORT,
     val timeFormat: TimeFormatPref = TimeFormatPref.AUTO,
     /** The first day of the week; `null` follows the locale. */
     val weekStart: DayOfWeek? = null,
@@ -175,9 +171,6 @@ class SettingsPrefs @Inject constructor(
             sortOrder = p[SORT_ORDER]?.let { runCatching { TaskSortOrder.valueOf(it) }.getOrNull() }
                 ?: TaskSortOrder.DUE,
             snoozeMinutes = p[SNOOZE_MINUTES]?.takeIf { it > 0 } ?: DEFAULT_SNOOZE_MINUTES,
-            reminderDescription = p[REMINDER_DESCRIPTION]
-                ?.let { runCatching { ReminderDescription.valueOf(it) }.getOrNull() }
-                ?: ReminderDescription.SHORT,
             timeFormat = p[TIME_FORMAT]?.let { runCatching { TimeFormatPref.valueOf(it) }.getOrNull() }
                 ?: TimeFormatPref.AUTO,
             autofocusTitle = p[AUTOFOCUS_TITLE] ?: true,
@@ -206,9 +199,6 @@ class SettingsPrefs @Inject constructor(
 
     suspend fun setSnoozeMinutes(minutes: Int) = dataStore.edit { it[SNOOZE_MINUTES] = minutes.coerceAtLeast(1) }
 
-    suspend fun setReminderDescription(pref: ReminderDescription) =
-        dataStore.edit { it[REMINDER_DESCRIPTION] = pref.name }
-
     suspend fun setSyncIntervalMinutes(minutes: Int) = dataStore.edit { it[SYNC_INTERVAL] = minutes }
 
     suspend fun setPushEnabled(enabled: Boolean) = dataStore.edit { it[PUSH_ENABLED] = enabled }
@@ -355,7 +345,6 @@ class SettingsPrefs @Inject constructor(
         val DEFAULT_EDIT_FIELDS = stringSetPreferencesKey("default_edit_fields")
         val SORT_ORDER = stringPreferencesKey("sort_order")
         val SNOOZE_MINUTES = intPreferencesKey("snooze_minutes")
-        val REMINDER_DESCRIPTION = stringPreferencesKey("reminder_description")
         val TIME_FORMAT = stringPreferencesKey("time_format")
         val WEEK_START = stringPreferencesKey("week_start")
         val AUTOFOCUS_TITLE = booleanPreferencesKey("autofocus_title")

app/src/main/java/de/jeanlucmakiola/agendula/data/reminders/TaskNotifier.kt

@@ -18,7 +18,6 @@ import androidx.core.content.ContextCompat
 import androidx.core.content.edit
 import de.jeanlucmakiola.agendula.MainActivity
 import de.jeanlucmakiola.agendula.R
-import de.jeanlucmakiola.agendula.data.prefs.ReminderDescription
 import de.jeanlucmakiola.agendula.data.prefs.Settings
 import de.jeanlucmakiola.agendula.domain.readableDescription
 import de.jeanlucmakiola.agendula.data.prefs.is24Hour
@@ -87,11 +86,7 @@ class TaskNotifier @Inject constructor(
                 ),
             )
         }
-        val description = reminderBody(
-            task.description?.readableDescription(),
-            settings.reminderDescription,
-            lineChars = (NOTIFICATION_LINE_CHARS / context.resources.configuration.fontScale).toInt(),
-        )
+        val description = task.description?.readableDescription()?.trim()?.takeIf { it.isNotBlank() }
         val tapIntent = PendingIntent.getActivity(
             context,
             task.taskId.toInt(),
@@ -282,96 +277,3 @@ internal fun expandedText(dueLine: String?, description: String?): String? = whe
     dueLine == null -> description
     else -> "$dueLine\n\n$description"
 }
-
-/** Rough characters per line of an expanded notification on a phone, at the default font size. */
-private const val NOTIFICATION_LINE_CHARS = 40
-
-/** The description a reminder shows, as [mode] asks; null when there is none to show. */
-internal fun reminderBody(
-    description: String?,
-    mode: ReminderDescription,
-    lineChars: Int = NOTIFICATION_LINE_CHARS,
-): String? {
-    val text = description?.trim()?.takeIf { it.isNotBlank() } ?: return null
-    return when (mode) {
-        ReminderDescription.HIDDEN -> null
-        ReminderDescription.SHORT -> shortDescription(text, lineChars = lineChars)
-        ReminderDescription.FULL -> text
-    }
-}
-
-/**
- * [description] cut to about [maxLines] lines of an expanded notification,
- * ending in an ellipsis when anything was left out. Blank lines are dropped,
- * and a long line counts as the lines it wraps to.
- */
-internal fun shortDescription(
-    description: String,
-    maxLines: Int = 3,
-    lineChars: Int = NOTIFICATION_LINE_CHARS,
-): String {
-    val perLine = lineChars.coerceAtLeast(2)
-    val lines = description.lines().map { it.trimEnd() }.filter { it.isNotBlank() }
-    val kept = mutableListOf<String>()
-    var rowsLeft = maxLines
-    for ((index, line) in lines.withIndex()) {
-        val width = displayWidth(line)
-        val rows = (width + perLine - 1) / perLine
-        val last = index == lines.lastIndex
-        // The ellipsis after a line that ends the budget needs a cell of its own.
-        val fits = rows < rowsLeft || (rows == rowsLeft && (last || width < rows * perLine))
-        if (fits) {
-            kept += line
-            rowsLeft -= rows
-            if (rowsLeft == 0 && !last) return ellipsize(kept)
-            continue
-        }
-        if (rowsLeft > 0) kept += cutAtWord(line, rowsLeft * perLine - 1)
-        return ellipsize(kept)
-    }
-    return kept.joinToString("\n")
-}
-
-private fun ellipsize(lines: List<String>): String =
-    lines.joinToString("\n").trimEnd { it.isWhitespace() || it in ".,;:" } + "\u2026"
-
-/** [line] cut to at most [max] cells, at a word break when there is one, never inside a character. */
-private fun cutAtWord(line: String, max: Int): String {
-    var end = 0
-    var width = 0
-    while (end < line.length) {
-        val codePoint = line.codePointAt(end)
-        width += cellsOf(codePoint)
-        if (width > max) break
-        end += Character.charCount(codePoint)
-    }
-    if (end >= line.length || line[end].isWhitespace()) return line.substring(0, end)
-    val cut = line.substring(0, end)
-    val space = cut.indexOfLast { it.isWhitespace() }
-    return if (space > end / 2) cut.substring(0, space) else cut
-}
-
-/** How many cells [text] takes, wide characters (CJK, emoji) counting two. */
-private fun displayWidth(text: String): Int {
-    var width = 0
-    var i = 0
-    while (i < text.length) {
-        val codePoint = text.codePointAt(i)
-        width += cellsOf(codePoint)
-        i += Character.charCount(codePoint)
-    }
-    return width
-}
-
-private fun cellsOf(codePoint: Int): Int = when {
-    Character.isSupplementaryCodePoint(codePoint) -> 2
-    Character.UnicodeScript.of(codePoint) in WIDE_SCRIPTS -> 2
-    else -> 1
-}
-
-private val WIDE_SCRIPTS = setOf(
-    Character.UnicodeScript.HAN,
-    Character.UnicodeScript.HIRAGANA,
-    Character.UnicodeScript.KATAKANA,
-    Character.UnicodeScript.HANGUL,
-)

app/src/main/java/de/jeanlucmakiola/agendula/ui/edit/TaskEditViewModel.kt

@@ -149,6 +149,9 @@ class TaskEditViewModel @Inject constructor(
     private var loadedDue: Instant? = null
     private var loadedAllDay = false
 
+    /** The reminders the user picked before clearing the task's last date, and whether they were all-day ones. */
+    private var setAside: Pair<List<TaskReminder>, Boolean>? = null
+
     /** Start a fresh task, optionally pre-selecting a list / parent. */
     fun bindNew(
         presetListId: Long? = null,
@@ -255,7 +258,7 @@ class TaskEditViewModel @Inject constructor(
                     isOccurrence = task.isOccurrence,
                     lists = lists,
                     parentCandidates = loadParents(task.listId, selfId = taskId),
-                ),
+                ).let { if (it.start == null && it.due == null) it.withoutReminders() else it },
             ).also { baseline = it.toForm() }
             editingOccurrence = task.occurrenceStart
         }
@@ -309,15 +312,15 @@ class TaskEditViewModel @Inject constructor(
     /** Switching list invalidates the parent (it lived in the old list); reload candidates. */
     fun onListChange(listId: Long) {
         if (_state.value.listId == listId) return // re-picking the same list keeps the parent
-        update { it.copy(listId = listId, parentId = null, errors = emptySet()).withDefaultReminders() }
+        update { it.copy(listId = listId, parentId = null, errors = emptySet()).withDatedReminders() }
         viewModelScope.launch {
             val candidates = loadParents(listId, selfId = editingTaskId)
             update { it.copy(parentCandidates = candidates) }
         }
     }
 
-    fun onStartChange(value: Instant?) = update { it.copy(start = value).withDefaultReminders() }
-    fun onDueChange(value: Instant?) = update { it.copy(due = value).withDefaultReminders() }
+    fun onStartChange(value: Instant?) = update { it.copy(start = value).withDatedReminders() }
+    fun onDueChange(value: Instant?) = update { it.copy(due = value).withDatedReminders() }
     /**
      * All-day and timed values use different conventions (UTC midnight vs. a real
      * instant in the device zone), so the switch has to move the timestamps too —
@@ -335,7 +338,7 @@ class TaskEditViewModel @Inject constructor(
         )
         if (!it.remindersTouched) {
             loadedReminders = carried(loadedReminders, switched)
-            return@update switched.withDefaultReminders()
+            return@update switched.withDatedReminders()
         }
         switched.copy(reminders = carried(it.reminders, switched).sortedForDisplay(switched))
     }
@@ -352,6 +355,28 @@ class TaskEditViewModel @Inject constructor(
         return carried
     }
 
+    /**
+     * [withDefaultReminders] for a task that may have lost its dates: with none
+     * left its reminders have nothing to count from and go (#159). Those the user
+     * picked are set aside and come back with the next date; untouched ones come
+     * back from [loadedReminders] anyway.
+     */
+    private fun TaskEditUiState.withDatedReminders(): TaskEditUiState {
+        if (start == null && due == null) {
+            if (reminders.isEmpty()) return this
+            if (remindersTouched) setAside = reminders to isAllDay
+            return withoutReminders()
+        }
+        val aside = setAside ?: return withDefaultReminders()
+        setAside = null
+        val restored = if (aside.second == isAllDay) {
+            aside.first
+        } else {
+            StoredReminders.switched(aside.first, toForm(), settings, nowMillis(), ZoneId.systemDefault())
+        }
+        return copy(reminders = (reminders + restored).distinct().sortedForDisplay(this), remindersChosen = true)
+    }
+
     /**
      * The reminders the task will be saved with while the user has not
      * touched them: those it was loaded with, plus the defaults of the dates
@@ -474,6 +499,9 @@ private fun List<TaskReminder>.sortedForDisplay(state: TaskEditUiState): List<Ta
     sortedWith(taskReminderDisplayOrder(state.isAllDay, state.allDayMinuteOfDay))
 
 /** Snapshot the editable state as a validated [TaskForm]. */
+/** No reminders at all, stored as such. */
+private fun TaskEditUiState.withoutReminders(): TaskEditUiState = copy(reminders = emptyList(), remindersChosen = true)
+
 private fun TaskEditUiState.toForm(): TaskForm = TaskForm(
     title = title,
     listId = listId ?: 0L,

app/src/main/java/de/jeanlucmakiola/agendula/ui/settings/NotificationsScreen.kt

@@ -39,7 +39,6 @@ import androidx.core.app.NotificationManagerCompat
 import androidx.core.content.ContextCompat
 import androidx.core.net.toUri
 import de.jeanlucmakiola.agendula.R
-import de.jeanlucmakiola.agendula.data.prefs.ReminderDescription
 import de.jeanlucmakiola.agendula.data.prefs.SNOOZE_PRESETS
 import de.jeanlucmakiola.agendula.data.reminders.TaskNotifier
 import de.jeanlucmakiola.agendula.domain.TaskReminderOrder
@@ -114,7 +113,6 @@ internal fun NotificationsScreen(
     var showOffset by remember { mutableStateOf(false) }
     var showAllDay by remember { mutableStateOf(false) }
     var showSnooze by remember { mutableStateOf(false) }
-    var showDescription by remember { mutableStateOf(false) }
     var showAllDayTime by remember { mutableStateOf(false) }
     var perListExpanded by remember { mutableStateOf(false) }
     var expandedLists by remember { mutableStateOf(emptySet<Long>()) }
@@ -180,14 +178,8 @@ internal fun NotificationsScreen(
                 R.string.settings_allday_reminder_time_summary,
                 formatMinuteOfDay(state.settings.allDayReminderMinuteOfDay, LocalUse24HourFormat.current),
             ),
-            position = Position.Middle,
-            onClick = { showAllDayTime = true },
-        )
-        GroupedRow(
-            title = stringResource(R.string.settings_reminder_description),
-            summary = reminderDescriptionLabel(state.settings.reminderDescription),
             position = Position.Bottom,
-            onClick = { showDescription = true },
+            onClick = { showAllDayTime = true },
         )
 
         Spacer(Modifier.height(24.dp))
@@ -326,17 +318,6 @@ internal fun NotificationsScreen(
             onDismiss = { showSnooze = false },
         )
     }
-    if (showDescription) {
-        OptionPicker(
-            title = stringResource(R.string.settings_reminder_description),
-            options = ReminderDescription.entries,
-            selected = state.settings.reminderDescription,
-            label = { reminderDescriptionLabel(it) },
-            summary = { reminderDescriptionSummary(it) },
-            onSelect = viewModel::setReminderDescription,
-            onDismiss = { showDescription = false },
-        )
-    }
     if (showAllDayTime) {
         val minute = state.settings.allDayReminderMinuteOfDay
         TimePickerAlert(
@@ -373,24 +354,6 @@ private fun snoozeLabel(minutes: Int): String =
     if (minutes % 60 == 0) pluralStringResource(R.plurals.duration_hours, minutes / 60, minutes / 60)
     else pluralStringResource(R.plurals.duration_minutes, minutes, minutes)
 
-@Composable
-private fun reminderDescriptionLabel(pref: ReminderDescription): String = stringResource(
-    when (pref) {
-        ReminderDescription.HIDDEN -> R.string.settings_reminder_description_hidden
-        ReminderDescription.SHORT -> R.string.settings_reminder_description_short
-        ReminderDescription.FULL -> R.string.settings_reminder_description_full
-    },
-)
-
-@Composable
-private fun reminderDescriptionSummary(pref: ReminderDescription): String = stringResource(
-    when (pref) {
-        ReminderDescription.HIDDEN -> R.string.settings_reminder_description_hidden_summary
-        ReminderDescription.SHORT -> R.string.settings_reminder_description_short_summary
-        ReminderDescription.FULL -> R.string.settings_reminder_description_full_summary
-    },
-)
-
 /** Which list's override picker is open, and for which kind of task. */
 private data class OverrideTarget(val listId: Long, val allDay: Boolean)
 

app/src/main/java/de/jeanlucmakiola/agendula/ui/settings/SettingsViewModel.kt

@@ -6,7 +6,6 @@ import dagger.hilt.android.lifecycle.HiltViewModel
 import de.jeanlucmakiola.agendula.data.appname.LauncherName
 import de.jeanlucmakiola.agendula.data.appname.LauncherNameManager
 import de.jeanlucmakiola.agendula.data.di.IoDispatcher
-import de.jeanlucmakiola.agendula.data.prefs.ReminderDescription
 import de.jeanlucmakiola.agendula.data.prefs.Settings
 import de.jeanlucmakiola.agendula.data.prefs.SettingsPrefs
 import de.jeanlucmakiola.agendula.data.prefs.ThemeMode
@@ -260,7 +259,6 @@ class SettingsViewModel @Inject constructor(
     fun setTimeFormat(pref: TimeFormatPref) = viewModelScope.launch { prefs.setTimeFormat(pref) }
     fun setWeekStart(day: DayOfWeek?) = viewModelScope.launch { prefs.setWeekStart(day) }
     fun setSnoozeMinutes(minutes: Int) = viewModelScope.launch { prefs.setSnoozeMinutes(minutes) }
-    fun setReminderDescription(pref: ReminderDescription) = viewModelScope.launch { prefs.setReminderDescription(pref) }
     fun setShowAddSubtaskRow(show: Boolean) = viewModelScope.launch { prefs.setShowAddSubtaskRow(show) }
     fun setBottomAddBar(enabled: Boolean) = viewModelScope.launch { prefs.setBottomAddBar(enabled) }
     fun setDefaultStartToday(enabled: Boolean) = viewModelScope.launch { prefs.setDefaultStartToday(enabled) }

app/src/main/res/values/strings.xml

@@ -470,13 +470,6 @@
     <string name="settings_exact_alarms_blocked">Blocked — tap to allow exact reminders</string>
     <string name="settings_reliable_delivery">Reliable delivery</string>
     <string name="settings_snooze_duration">Snooze duration</string>
-    <string name="settings_reminder_description">Description in reminders</string>
-    <string name="settings_reminder_description_hidden">Hidden</string>
-    <string name="settings_reminder_description_short">Short</string>
-    <string name="settings_reminder_description_full">Full</string>
-    <string name="settings_reminder_description_hidden_summary">Only the title and due time</string>
-    <string name="settings_reminder_description_short_summary">A short preview of the description</string>
-    <string name="settings_reminder_description_full_summary">The whole description</string>
     <string name="settings_reliable_delivery_hint">Android may delay reminders to save battery. Exempt Agendula so they arrive on time.</string>
     <string name="settings_reliable_delivery_exempt">Exempt from battery optimisation — reminders arrive on time.</string>
     <string name="settings_default_list">Default list</string>

app/src/test/java/de/jeanlucmakiola/agendula/data/reminders/ShortDescriptionTest.kt

@@ -1,99 +0,0 @@
-package de.jeanlucmakiola.agendula.data.reminders
-
-import com.google.common.truth.Truth.assertThat
-import de.jeanlucmakiola.agendula.data.prefs.ReminderDescription
-import org.junit.jupiter.api.Test
-
-class ShortDescriptionTest {
-
-    @Test
-    fun `short text is left alone`() {
-        assertThat(shortDescription("Buy oat milk")).isEqualTo("Buy oat milk")
-    }
-
-    @Test
-    fun `three short lines fit`() {
-        assertThat(shortDescription("one\ntwo\nthree")).isEqualTo("one\ntwo\nthree")
-    }
-
-    @Test
-    fun `lines past the third are cut with an ellipsis`() {
-        assertThat(shortDescription("one\ntwo\nthree\nfour\nfive")).isEqualTo("one\ntwo\nthree…")
-    }
-
-    @Test
-    fun `blank lines take no room`() {
-        assertThat(shortDescription("one\n\n\ntwo\n  \nthree")).isEqualTo("one\ntwo\nthree")
-    }
-
-    @Test
-    fun `a long paragraph is cut at a word within the line budget`() {
-        val text = List(40) { "word" }.joinToString(" ")
-        val short = shortDescription(text, maxLines = 3, lineChars = 40)
-        assertThat(short).endsWith("word…")
-        assertThat(short.length).isAtMost(3 * 40)
-    }
-
-    @Test
-    fun `a wrapping line counts as the lines it takes`() {
-        val long = "a".repeat(70)
-        val short = shortDescription("$long\nsecond\nthird", maxLines = 3, lineChars = 40)
-        assertThat(short).isEqualTo("$long\nsecond…")
-    }
-
-    @Test
-    fun `a word with no break is cut hard`() {
-        val short = shortDescription("x".repeat(200), maxLines = 3, lineChars = 40)
-        assertThat(short).isEqualTo("x".repeat(119) + "…")
-    }
-
-    @Test
-    fun `trailing punctuation gives way to the ellipsis`() {
-        assertThat(shortDescription("one.\ntwo,\nthree.\nfour")).isEqualTo("one.\ntwo,\nthree…")
-    }
-
-    @Test
-    fun `a line that fills the budget exactly leaves room for the ellipsis`() {
-        val full = "a".repeat(120)
-        val short = shortDescription("$full\nmore", maxLines = 3, lineChars = 40)
-        assertThat(short).isEqualTo("a".repeat(119) + "…")
-    }
-
-    @Test
-    fun `a cut never splits an emoji`() {
-        val short = shortDescription("x".repeat(118) + "😀" + "y".repeat(10), maxLines = 3, lineChars = 40)
-        assertThat(short).isEqualTo("x".repeat(118) + "…")
-    }
-
-    @Test
-    fun `a word that ends right at the cut is kept`() {
-        val short = shortDescription("aaaa bbbb cccc", maxLines = 1, lineChars = 10)
-        assertThat(short).isEqualTo("aaaa bbbb…")
-    }
-
-    @Test
-    fun `tabs count as word breaks`() {
-        val short = shortDescription("Meeting\tagenda\tnotes", maxLines = 1, lineChars = 12)
-        assertThat(short).isEqualTo("Meeting…")
-    }
-
-    @Test
-    fun `no space is left before the ellipsis`() {
-        assertThat(shortDescription("see list :\nmore", maxLines = 1, lineChars = 40)).isEqualTo("see list…")
-    }
-
-    @Test
-    fun `wide characters take two cells`() {
-        val short = shortDescription("中".repeat(30), maxLines = 1, lineChars = 20)
-        assertThat(short).isEqualTo("中".repeat(9) + "…")
-    }
-
-    @Test
-    fun `the setting picks what the reminder shows`() {
-        val long = List(60) { "word" }.joinToString(" ")
-        assertThat(reminderBody(long, ReminderDescription.HIDDEN)).isNull()
-        assertThat(reminderBody(long, ReminderDescription.FULL)).isEqualTo(long)
-        assertThat(reminderBody(long, ReminderDescription.SHORT)).isEqualTo(shortDescription(long))
-        assertThat(reminderBody("  ", ReminderDescription.FULL)).isNull()
-    }
-}

app/src/test/java/de/jeanlucmakiola/agendula/ui/edit/TaskEditViewModelTest.kt

@@ -0,0 +1,176 @@
+package de.jeanlucmakiola.agendula.ui.edit
+
+import androidx.datastore.core.DataStore
+import androidx.datastore.preferences.core.Preferences
+import androidx.datastore.preferences.core.emptyPreferences
+import com.google.common.truth.Truth.assertThat
+import de.jeanlucmakiola.agendula.data.prefs.SettingsPrefs
+import de.jeanlucmakiola.agendula.data.tasks.ProviderEnvironment
+import de.jeanlucmakiola.agendula.data.tasks.ProviderResolver
+import de.jeanlucmakiola.agendula.data.tasks.TasksRepository
+import de.jeanlucmakiola.agendula.domain.Priority
+import de.jeanlucmakiola.agendula.domain.Task
+import de.jeanlucmakiola.agendula.domain.TaskDetail
+import de.jeanlucmakiola.agendula.domain.TaskFilter
+import de.jeanlucmakiola.agendula.domain.TaskForm
+import de.jeanlucmakiola.agendula.domain.TaskList
+import de.jeanlucmakiola.agendula.domain.TaskReminder
+import de.jeanlucmakiola.agendula.domain.TaskStatus
+import de.jeanlucmakiola.agendula.domain.recurrence.RecurringScope
+import kotlinx.coroutines.Dispatchers
+import kotlinx.coroutines.ExperimentalCoroutinesApi
+import kotlinx.coroutines.flow.Flow
+import kotlinx.coroutines.flow.MutableStateFlow
+import kotlinx.coroutines.flow.flowOf
+import kotlinx.coroutines.test.UnconfinedTestDispatcher
+import kotlinx.coroutines.test.resetMain
+import kotlinx.coroutines.test.setMain
+import org.junit.jupiter.api.AfterEach
+import org.junit.jupiter.api.BeforeEach
+import org.junit.jupiter.api.Test
+import java.lang.reflect.Proxy
+import kotlin.time.Clock
+import kotlin.time.Duration.Companion.days
+import kotlin.time.Instant
+
+/** Reminders on a task that loses or regains its dates in the editor (#159). */
+@OptIn(ExperimentalCoroutinesApi::class)
+class TaskEditViewModelTest {
+
+    private val due = Clock.System.now() + 3.days
+    private val reminder = TaskReminder(30)
+    private val repository = FakeRepository()
+
+    @BeforeEach fun setUp() = Dispatchers.setMain(UnconfinedTestDispatcher())
+
+    @AfterEach fun tearDown() = Dispatchers.resetMain()
+
+    private fun editing(start: Instant? = null, due: Instant? = this.due): TaskEditViewModel {
+        repository.task = task(start, due)
+        repository.reminders = listOf(reminder)
+        return TaskEditViewModel(repository, settingsPrefs()).apply { bindEdit(TASK_ID) }
+    }
+
+    @Test
+    fun `clearing the last date drops the reminders and the task saves`() {
+        val vm = editing()
+        vm.onDueChange(null)
+        vm.save()
+
+        assertThat(vm.state.value.errors).isEmpty()
+        assertThat(repository.saved?.reminders).isEmpty()
+        assertThat(repository.saved?.remindersChosen).isTrue()
+    }
+
+    @Test
+    fun `an all-day switch or another list does not bring them back`() {
+        val vm = editing()
+        vm.onDueChange(null)
+        vm.onAllDayChange(true)
+        vm.onListChange(LIST_ID + 1)
+
+        assertThat(vm.state.value.reminders).isEmpty()
+    }
+
+    @Test
+    fun `untouched reminders come back with a new date`() {
+        val vm = editing()
+        vm.onDueChange(null)
+        vm.onDueChange(due + 1.days)
+
+        assertThat(vm.state.value.reminders).contains(reminder)
+    }
+
+    @Test
+    fun `picked reminders come back with a new date`() {
+        val vm = editing()
+        val picked = TaskReminder(120)
+        vm.addReminder(picked)
+        vm.onDueChange(null)
+        vm.onDueChange(due + 1.days)
+
+        assertThat(vm.state.value.reminders).containsExactly(reminder, picked)
+    }
+
+    @Test
+    fun `clearing one of two dates keeps the reminders`() {
+        val vm = editing(start = due - 1.days)
+        vm.onDueChange(null)
+
+        assertThat(vm.state.value.reminders).containsExactly(reminder)
+    }
+
+    @Test
+    fun `a task stored without dates opens without its reminders`() {
+        val vm = editing(due = null)
+
+        assertThat(vm.state.value.reminders).isEmpty()
+        assertThat(vm.state.value.isDirty).isFalse()
+    }
+
+    private fun task(start: Instant?, due: Instant?) = Task(
+        taskId = TASK_ID,
+        listId = LIST_ID,
+        title = "Task",
+        description = null,
+        location = null,
+        url = null,
+        priority = Priority.NONE,
+        status = TaskStatus.NEEDS_ACTION,
+        percentComplete = null,
+        start = start,
+        due = due,
+        isAllDay = false,
+        timeZone = null,
+        completedAt = null,
+        listColor = 0,
+        taskColor = null,
+        listName = null,
+        accountName = null,
+        parentId = null,
+        isRecurring = false,
+        distanceFromCurrent = null,
+        created = null,
+        lastModified = null,
+    )
+
+    private class FakeRepository : TasksRepository by unsupported() {
+        var task: Task? = null
+        var reminders: List<TaskReminder> = emptyList()
+        var saved: TaskForm? = null
+
+        override fun taskLists() = flowOf(emptyList<TaskList>())
+        override fun tasks(filter: TaskFilter): Flow<List<Task>> = flowOf(emptyList())
+        override fun taskDetail(taskId: Long, occurrenceStart: Instant?) =
+            flowOf(task?.let { TaskDetail(it, emptyList()) })
+        override suspend fun remindersFor(taskId: Long) = reminders
+        override suspend fun updateTask(
+            taskId: Long,
+            form: TaskForm,
+            expectedLastModified: Instant?,
+            occurrenceStart: Instant?,
+            scope: RecurringScope,
+        ) {
+            saved = form
+        }
+    }
+
+    private class MemoryDataStore : DataStore<Preferences> {
+        override val data = MutableStateFlow(emptyPreferences())
+        override suspend fun updateData(transform: suspend (t: Preferences) -> Preferences) =
+            transform(data.value).also { data.value = it }
+    }
+
+    private fun settingsPrefs() = SettingsPrefs(MemoryDataStore(), ProviderResolver(unsupported<ProviderEnvironment>()))
+
+    private companion object {
+        const val TASK_ID = 1L
+        const val LIST_ID = 7L
+
+        /** Calls the test does not expect answer false or null. */
+        inline fun <reified T> unsupported(): T =
+            Proxy.newProxyInstance(T::class.java.classLoader, arrayOf(T::class.java)) { _, method, _ ->
+                if (method.returnType == Boolean::class.javaPrimitiveType) false else null
+            } as T
+    }
+}