feat(service): add snackbar to undo a timer reset

Closes #109

app/src/main/java/org/nsh07/pomodoro/data/StateRepository.kt

@@ -20,6 +20,7 @@ package org.nsh07.pomodoro.data
 import androidx.compose.material3.ColorScheme
 import androidx.compose.material3.lightColorScheme
 import kotlinx.coroutines.flow.MutableStateFlow
+import org.nsh07.pomodoro.service.TimerStateSnapshot
 import org.nsh07.pomodoro.ui.settingsScreen.viewModel.SettingsState
 import org.nsh07.pomodoro.ui.timerScreen.viewModel.TimerState
 
@@ -28,4 +29,6 @@ class StateRepository {
     val settingsState = MutableStateFlow(SettingsState())
     var timerFrequency: Float = 60f
     var colorScheme: ColorScheme = lightColorScheme()
+    var timerStateSnapshot: TimerStateSnapshot =
+        TimerStateSnapshot(time = 0, timerState = TimerState())
 }

app/src/main/java/org/nsh07/pomodoro/service/ServiceHelper.kt

@@ -35,6 +35,12 @@ class ServiceHelper(private val context: Context) {
                     context.startService(it)
                 }
 
+            TimerAction.UndoReset ->
+                Intent(context, TimerService::class.java).also {
+                    it.action = TimerService.Actions.UNDO_RESET.toString()
+                    context.startService(it)
+                }
+
             is TimerAction.SkipTimer ->
                 Intent(context, TimerService::class.java).also {
                     it.action = TimerService.Actions.SKIP.toString()

app/src/main/java/org/nsh07/pomodoro/service/TimerService.kt

@@ -75,6 +75,8 @@ class TimerService : Service() {
 
     private var lastSavedDuration = 0L
 
+    private val timerStateSnapshot by lazy { stateRepository.timerStateSnapshot }
+
     private val saveLock = Mutex()
     private var job = SupervisorJob()
     private val timerScope = CoroutineScope(Dispatchers.IO + job)
@@ -134,6 +136,8 @@ class TimerService : Service() {
                 }
             }
 
+            Actions.UNDO_RESET.toString() -> undoReset()
+
             Actions.SKIP.toString() -> skipScope.launch { skipTimer(true) }
 
             Actions.STOP_ALARM.toString() -> stopAlarm()
@@ -326,6 +330,16 @@ class TimerService : Service() {
     private suspend fun resetTimer() {
         val settingsState = _settingsState.value
 
+        timerStateSnapshot.save(
+            lastSavedDuration,
+            time,
+            cycles,
+            startTime,
+            pauseTime,
+            pauseDuration,
+            _timerState.value
+        )
+
         saveTimeToDb()
         lastSavedDuration = 0
         time = settingsState.focusTime
@@ -349,6 +363,16 @@ class TimerService : Service() {
         updateProgressSegments()
     }
 
+    private fun undoReset() {
+        lastSavedDuration = timerStateSnapshot.lastSavedDuration
+        time = timerStateSnapshot.time
+        cycles = timerStateSnapshot.cycles
+        startTime = timerStateSnapshot.startTime
+        pauseTime = timerStateSnapshot.pauseTime
+        pauseDuration = timerStateSnapshot.pauseDuration
+        _timerState.update { timerStateSnapshot.timerState }
+    }
+
     private suspend fun skipTimer(fromButton: Boolean = false) {
         val settingsState = _settingsState.value
         saveTimeToDb()
@@ -517,6 +541,6 @@ class TimerService : Service() {
     }
 
     enum class Actions {
-        TOGGLE, SKIP, RESET, STOP_ALARM, UPDATE_ALARM_TONE
+        TOGGLE, SKIP, RESET, UNDO_RESET, STOP_ALARM, UPDATE_ALARM_TONE
     }
 }

app/src/main/java/org/nsh07/pomodoro/service/TimerStateSnapshot.kt

@@ -0,0 +1,48 @@
+/*
+ * Copyright (c) 2025 Nishant Mishra
+ *
+ * This file is part of Tomato - a minimalist pomodoro timer for Android.
+ *
+ * Tomato is free software: you can redistribute it and/or modify it under the terms of the GNU
+ * General Public License as published by the Free Software Foundation, either version 3 of the
+ * License, or (at your option) any later version.
+ *
+ * Tomato is distributed in the hope that it will be useful, but WITHOUT ANY WARRANTY; without even
+ * the implied warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU General
+ * Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License along with Tomato.
+ * If not, see <https://www.gnu.org/licenses/>.
+ */
+
+package org.nsh07.pomodoro.service
+
+import org.nsh07.pomodoro.ui.timerScreen.viewModel.TimerState
+
+data class TimerStateSnapshot(
+    var lastSavedDuration: Long = 0L,
+    var time: Long,
+    var cycles: Int = 0,
+    var startTime: Long = 0L,
+    var pauseTime: Long = 0L,
+    var pauseDuration: Long = 0L,
+    var timerState: TimerState
+) {
+    fun save(
+        lastSavedDuration: Long,
+        time: Long,
+        cycles: Int,
+        startTime: Long,
+        pauseTime: Long,
+        pauseDuration: Long,
+        timerState: TimerState
+    ) {
+        this.lastSavedDuration = lastSavedDuration
+        this.time = time
+        this.cycles = cycles
+        this.startTime = startTime
+        this.pauseTime = pauseTime
+        this.pauseDuration = pauseDuration
+        this.timerState = timerState
+    }
+}

app/src/main/java/org/nsh07/pomodoro/ui/timerScreen/TimerScreen.kt

@@ -18,6 +18,7 @@
 package org.nsh07.pomodoro.ui.timerScreen
 
 import android.Manifest
+import android.annotation.SuppressLint
 import android.os.Build
 import androidx.activity.compose.rememberLauncherForActivityResult
 import androidx.activity.result.contract.ActivityResultContracts
@@ -65,6 +66,10 @@ import androidx.compose.material3.MaterialTheme.motionScheme
 import androidx.compose.material3.MaterialTheme.shapes
 import androidx.compose.material3.MaterialTheme.typography
 import androidx.compose.material3.Scaffold
+import androidx.compose.material3.SnackbarDuration
+import androidx.compose.material3.SnackbarHost
+import androidx.compose.material3.SnackbarHostState
+import androidx.compose.material3.SnackbarResult
 import androidx.compose.material3.Surface
 import androidx.compose.material3.Text
 import androidx.compose.material3.TopAppBar
@@ -74,6 +79,7 @@ import androidx.compose.runtime.LaunchedEffect
 import androidx.compose.runtime.getValue
 import androidx.compose.runtime.mutableStateOf
 import androidx.compose.runtime.remember
+import androidx.compose.runtime.rememberCoroutineScope
 import androidx.compose.runtime.setValue
 import androidx.compose.ui.Alignment
 import androidx.compose.ui.Alignment.Companion.CenterHorizontally
@@ -83,6 +89,7 @@ import androidx.compose.ui.graphics.StrokeCap
 import androidx.compose.ui.graphics.drawscope.Stroke
 import androidx.compose.ui.hapticfeedback.HapticFeedbackType
 import androidx.compose.ui.input.nestedscroll.nestedScroll
+import androidx.compose.ui.platform.LocalContext
 import androidx.compose.ui.platform.LocalDensity
 import androidx.compose.ui.platform.LocalHapticFeedback
 import androidx.compose.ui.res.painterResource
@@ -94,8 +101,8 @@ import androidx.compose.ui.tooling.preview.Preview
 import androidx.compose.ui.unit.dp
 import androidx.compose.ui.unit.sp
 import androidx.navigation3.ui.LocalNavAnimatedContentScope
+import kotlinx.coroutines.launch
 import org.nsh07.pomodoro.R
-import org.nsh07.pomodoro.ui.mergePaddingValues
 import org.nsh07.pomodoro.ui.theme.AppFonts.googleFlex600
 import org.nsh07.pomodoro.ui.theme.AppFonts.robotoFlexTopBar
 import org.nsh07.pomodoro.ui.theme.TomatoTheme
@@ -103,7 +110,6 @@ import org.nsh07.pomodoro.ui.timerScreen.viewModel.TimerAction
 import org.nsh07.pomodoro.ui.timerScreen.viewModel.TimerMode
 import org.nsh07.pomodoro.ui.timerScreen.viewModel.TimerState
 
-
 @OptIn(ExperimentalMaterial3Api::class, ExperimentalMaterial3ExpressiveApi::class)
 @Composable
 fun SharedTransitionScope.TimerScreen(
@@ -115,7 +121,9 @@ fun SharedTransitionScope.TimerScreen(
     modifier: Modifier = Modifier
 ) {
     val motionScheme = motionScheme
+    val scope = rememberCoroutineScope()
     val haptic = LocalHapticFeedback.current
+    val context = LocalContext.current
 
     val color by animateColorAsState(
         if (timerState.timerMode == TimerMode.FOCUS) colorScheme.primary
@@ -139,6 +147,7 @@ fun SharedTransitionScope.TimerScreen(
     )
 
     val scrollBehavior = TopAppBarDefaults.exitUntilCollapsedScrollBehavior()
+    val snackbarHostState = remember { SnackbarHostState() }
 
     Scaffold(
         topBar = {
@@ -215,16 +224,16 @@ fun SharedTransitionScope.TimerScreen(
                 scrollBehavior = scrollBehavior
             )
         },
+        bottomBar = { Spacer(Modifier.height(contentPadding.calculateBottomPadding())) },
+        snackbarHost = { SnackbarHost(snackbarHostState) },
         modifier = modifier
             .nestedScroll(scrollBehavior.nestedScrollConnection)
     ) { innerPadding ->
-        val insets = mergePaddingValues(innerPadding, contentPadding)
         LazyColumn(
             verticalArrangement = Arrangement.Center,
             horizontalAlignment = CenterHorizontally,
-            contentPadding = insets,
-            modifier = Modifier
-                .fillMaxSize()
+            contentPadding = innerPadding,
+            modifier = Modifier.fillMaxSize()
         ) {
             item {
                 Column(horizontalAlignment = CenterHorizontally) {
@@ -411,6 +420,19 @@ fun SharedTransitionScope.TimerScreen(
                                     onClick = {
                                         onAction(TimerAction.ResetTimer)
                                         haptic.performHapticFeedback(HapticFeedbackType.VirtualKey)
+
+                                        @SuppressLint("LocalContextGetResourceValueCall")
+                                        scope.launch {
+                                            val result = snackbarHostState.showSnackbar(
+                                                context.getString(R.string.timer_reset_message),
+                                                actionLabel = context.getString(R.string.undo),
+                                                withDismissAction = true,
+                                                duration = SnackbarDuration.Long
+                                            )
+                                            if (result == SnackbarResult.ActionPerformed) {
+                                                onAction(TimerAction.UndoReset)
+                                            }
+                                        }
                                     },
                                     colors = IconButtonDefaults.filledTonalIconButtonColors(
                                         containerColor = colorContainer

app/src/main/java/org/nsh07/pomodoro/ui/timerScreen/viewModel/TimerAction.kt

@@ -1,8 +1,18 @@
 /*
  * Copyright (c) 2025 Nishant Mishra
  *
- * You should have received a copy of the GNU General Public License
- * along with this program.  If not, see <https://www.gnu.org/licenses/>.
+ * This file is part of Tomato - a minimalist pomodoro timer for Android.
+ *
+ * Tomato is free software: you can redistribute it and/or modify it under the terms of the GNU
+ * General Public License as published by the Free Software Foundation, either version 3 of the
+ * License, or (at your option) any later version.
+ *
+ * Tomato is distributed in the hope that it will be useful, but WITHOUT ANY WARRANTY; without even
+ * the implied warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU General
+ * Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License along with Tomato.
+ * If not, see <https://www.gnu.org/licenses/>.
  */
 
 package org.nsh07.pomodoro.ui.timerScreen.viewModel
@@ -11,6 +21,7 @@ sealed interface TimerAction {
     data class SkipTimer(val fromButton: Boolean) : TimerAction
 
     data object ResetTimer : TimerAction
+    data object UndoReset : TimerAction
     data object StopAlarm : TimerAction
     data object ToggleTimer : TimerAction
 }

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

@@ -111,4 +111,6 @@
     <string name="auto_start_next_timer">Auto start next timer</string>
     <string name="secure_aod">Secure AOD</string>
     <string name="secure_aod_desc">Automatically lock your device after a timeout, while keeping the AOD visible</string>
+    <string name="timer_reset_message">Timer reset</string>
+    <string name="undo">Undo</string>
 </resources>