Check notification permission on new pair alert (#118)

* Check notification permission on new pair alert

* fix frequent sorting

* Ask notification permission immediately if pair alerts already exist

app/src/main/java/dev/arkbuilders/rate/data/permission/NotificationPermissionHelper.kt

@@ -0,0 +1,23 @@
+package dev.arkbuilders.rate.data.permission
+
+import android.Manifest
+import android.content.Context
+import android.content.pm.PackageManager
+import android.os.Build
+import androidx.core.content.ContextCompat
+import javax.inject.Inject
+import javax.inject.Singleton
+
+@Singleton
+class NotificationPermissionHelper @Inject constructor(
+    private val ctx: Context,
+) {
+    fun isGranted(): Boolean {
+        return if (Build.VERSION.SDK_INT >= Build.VERSION_CODES.TIRAMISU) {
+            ContextCompat.checkSelfPermission(ctx, Manifest.permission.POST_NOTIFICATIONS) ==
+                PackageManager.PERMISSION_GRANTED
+        } else {
+            true
+        }
+    }
+}

app/src/main/java/dev/arkbuilders/rate/domain/usecase/CalcFrequentCurrUseCase.kt

@@ -32,7 +32,7 @@ class CalcFrequentCurrUseCase @Inject constructor(
     private fun mapToSortRating(list: List<CodeUseStat>): List<Pair<CurrencyCode, Double>> {
         val now = OffsetDateTime.now()
         return list.map { stat ->
-            val daysPassed = Duration.between(now, stat.lastUsedDate).toDays()
+            val daysPassed = Duration.between(stat.lastUsedDate, now).toDays()
             val timeFactor = daysPassed * 0.5
             stat.code to stat.count.toDouble() - timeFactor
         }.toList()

app/src/main/java/dev/arkbuilders/rate/presentation/pairalert/PairAlertConditionScreen.kt

@@ -2,6 +2,10 @@
 
 package dev.arkbuilders.rate.presentation.pairalert
 
+import android.Manifest
+import android.widget.Toast
+import androidx.activity.compose.rememberLauncherForActivityResult
+import androidx.activity.result.contract.ActivityResultContracts
 import androidx.compose.foundation.background
 import androidx.compose.foundation.clickable
 import androidx.compose.foundation.layout.Arrangement
@@ -69,17 +73,41 @@ import timber.log.Timber
 @Destination
 @Composable
 fun PairAlertConditionScreen(navigator: DestinationsNavigator) {
+    val ctx = LocalContext.current
+    val notificationPermissionLauncher =
+        rememberLauncherForActivityResult(
+            ActivityResultContracts.RequestPermission(),
+        ) { isGranted ->
+            if (isGranted.not()) {
+                Toast.makeText(
+                    ctx,
+                    ctx.getString(R.string.alert_post_notification_permission_explanation),
+                    Toast.LENGTH_SHORT,
+                ).show()
+            }
+        }
+
     val viewModel: PairAlertViewModel =
         viewModel(factory = DIManager.component.pairAlertVMFactory())
 
     val state by viewModel.collectAsState()
     val snackState = remember { SnackbarHostState() }
-    val ctx = LocalContext.current
 
     val isEmpty = state.pages.isEmpty()
 
     viewModel.collectSideEffect { effect ->
         when (effect) {
+            is PairAlertEffect.NavigateToAdd ->
+                navigator.navigate(
+                    AddPairAlertScreenDestination(
+                        pairAlertId = effect.pairId,
+                    ),
+                )
+
+            PairAlertEffect.AskNotificationPermission -> {
+                notificationPermissionLauncher.launch(Manifest.permission.POST_NOTIFICATIONS)
+            }
+
             is PairAlertEffect.ShowSnackbarAdded ->
                 snackState.showSnackbar(effect.visuals)
 
@@ -118,9 +146,7 @@ fun PairAlertConditionScreen(navigator: DestinationsNavigator) {
                 contentColor = Color.White,
                 containerColor = ArkColor.Secondary,
                 shape = CircleShape,
-                onClick = {
-                    navigator.navigate(AddPairAlertScreenDestination())
-                },
+                onClick = viewModel::onNewPair,
             ) {
                 Icon(Icons.Default.Add, contentDescription = "")
             }
@@ -137,13 +163,13 @@ fun PairAlertConditionScreen(navigator: DestinationsNavigator) {
             when {
                 state.noInternet -> NoInternetScreen(viewModel::onRefreshClick)
                 state.initialized.not() -> LoadingScreen()
-                isEmpty -> Empty(navigator)
+                isEmpty -> Empty(navigator, onNewPair = viewModel::onNewPair)
                 else ->
                     Content(
                         state,
                         onDelete = viewModel::onDelete,
                         onClick = { pair ->
-                            navigator.navigate(AddPairAlertScreenDestination(pair.id))
+                            viewModel.onNewPair(pair.id)
                         },
                         onEnableToggle = viewModel::onEnableToggle,
                     )
@@ -337,7 +363,10 @@ private fun PairAlertItem(
 }
 
 @Composable
-private fun Empty(navigator: DestinationsNavigator) {
+private fun Empty(
+    navigator: DestinationsNavigator,
+    onNewPair: () -> Unit,
+) {
     Box(modifier = Modifier.fillMaxSize()) {
         Column(
             modifier = Modifier.align(Alignment.Center),
@@ -365,9 +394,7 @@ private fun Empty(navigator: DestinationsNavigator) {
             )
             AppButton(
                 modifier = Modifier.padding(top = 24.dp),
-                onClick = {
-                    navigator.navigate(AddPairAlertScreenDestination())
-                },
+                onClick = { onNewPair() },
             ) {
                 Icon(
                     painter = painterResource(id = R.drawable.ic_add),

app/src/main/java/dev/arkbuilders/rate/presentation/pairalert/PairAlertViewModel.kt

@@ -3,6 +3,7 @@ package dev.arkbuilders.rate.presentation.pairalert
 import androidx.lifecycle.ViewModel
 import androidx.lifecycle.ViewModelProvider
 import androidx.lifecycle.viewModelScope
+import dev.arkbuilders.rate.data.permission.NotificationPermissionHelper
 import dev.arkbuilders.rate.domain.model.PairAlert
 import dev.arkbuilders.rate.domain.repo.AnalyticsManager
 import dev.arkbuilders.rate.domain.repo.CurrencyRepo
@@ -33,6 +34,10 @@ data class PairAlertScreenState(
 )
 
 sealed class PairAlertEffect {
+    data class NavigateToAdd(val pairId: Long? = null) : PairAlertEffect()
+
+    data object AskNotificationPermission : PairAlertEffect()
+
     data class ShowSnackbarAdded(
         val visuals: NotifyAddedSnackbarVisuals,
     ) : PairAlertEffect()
@@ -44,6 +49,7 @@ class PairAlertViewModel(
     private val pairAlertRepo: PairAlertRepo,
     private val currencyRepo: CurrencyRepo,
     private val analyticsManager: AnalyticsManager,
+    private val notificationPermissionHelper: NotificationPermissionHelper,
 ) : ViewModel(), ContainerHost<PairAlertScreenState, PairAlertEffect> {
     override val container: Container<PairAlertScreenState, PairAlertEffect> =
         container(
@@ -53,6 +59,14 @@ class PairAlertViewModel(
     init {
         analyticsManager.trackScreen("PairAlertScreen")
 
+        intent {
+            if (pairAlertRepo.getAll().isNotEmpty() &&
+                notificationPermissionHelper.isGranted().not()
+            ) {
+                postSideEffect(PairAlertEffect.AskNotificationPermission)
+            }
+        }
+
         intent {
             if (currencyRepo.isRatesAvailable().not()) {
                 reduce {
@@ -91,6 +105,15 @@ class PairAlertViewModel(
             }.launchIn(viewModelScope)
         }
 
+    fun onNewPair(pairId: Long? = null) =
+        intent {
+            if (notificationPermissionHelper.isGranted()) {
+                postSideEffect(PairAlertEffect.NavigateToAdd(pairId))
+            } else {
+                postSideEffect(PairAlertEffect.AskNotificationPermission)
+            }
+        }
+
     fun onRefreshClick() =
         intent {
             reduce { state.copy(noInternet = false) }
@@ -127,12 +150,14 @@ class PairAlertViewModelFactory @Inject constructor(
     private val pairAlertRepo: PairAlertRepo,
     private val currencyRepo: CurrencyRepo,
     private val analyticsManager: AnalyticsManager,
+    private val notificationPermissionHelper: NotificationPermissionHelper,
 ) : ViewModelProvider.Factory {
     override fun <T : ViewModel> create(modelClass: Class<T>): T {
         return PairAlertViewModel(
             pairAlertRepo,
             currencyRepo,
             analyticsManager,
+            notificationPermissionHelper,
         ) as T
     }
 }

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

@@ -41,6 +41,7 @@
     <string name="alert_empty_title">No Alerts at the Moment</string>
     <string name="alert_empty_desc">Stay updated! We\'ll post any important notifications or changes in exchange rates here.</string>
     <string name="new_alert">New Alert</string>
+    <string name="alert_post_notification_permission_explanation">Application requires permission to post pair alert notifications.</string>
     <string name="alert_snackbar_new_title">Alert for %1$s has been created</string>
     <string name="alert_snackbar_new_desc">You’ll get notified when %1$s price is %2$s %3$s %4$s</string>
     <string name="alert_snackbar_removed_title">Alert for %1$s has been deleted</string>