Provide feedback in UI about network issues and allow for retrying

app/src/main/java/com/github/swent/echo/compose/association/AssociationScreen.kt

@@ -6,11 +6,17 @@ import androidx.compose.foundation.layout.fillMaxSize
 import androidx.compose.foundation.layout.height
 import androidx.compose.foundation.layout.padding
 import androidx.compose.material3.Scaffold
+import androidx.compose.material3.SnackbarHost
+import androidx.compose.material3.SnackbarHostState
 import androidx.compose.runtime.Composable
+import androidx.compose.runtime.LaunchedEffect
 import androidx.compose.runtime.collectAsState
 import androidx.compose.runtime.getValue
+import androidx.compose.runtime.mutableStateOf
+import androidx.compose.runtime.remember
 import androidx.compose.ui.Alignment
 import androidx.compose.ui.Modifier
+import androidx.compose.ui.platform.LocalContext
 import androidx.compose.ui.platform.testTag
 import androidx.compose.ui.res.stringResource
 import androidx.compose.ui.unit.dp
@@ -21,6 +27,7 @@ import com.github.swent.echo.compose.event.EventTitleAndBackButton
 import com.github.swent.echo.data.model.Association
 import com.github.swent.echo.ui.navigation.NavigationActions
 import com.github.swent.echo.ui.navigation.Routes
+import com.github.swent.echo.viewmodels.association.AssociationStatus
 import com.github.swent.echo.viewmodels.association.AssociationViewModel
 
 /**
@@ -33,10 +40,13 @@ fun AssociationScreen(
         AssociationViewModel, // The ViewModel that provides the data for the screen
     navActions: NavigationActions // The actions that can be performed for navigation
 ) {
-    // Collect the state of followed associations, committee associations, and all associations
+    // Collect the state of followed associations, committee associations all associations,
+    // snackbarHostState and status
     val followedAssociations by associationViewModel.followedAssociations.collectAsState()
     val committeeAssociations by associationViewModel.committeeAssociations.collectAsState()
     val showAllAssociations by associationViewModel.showAllAssociations.collectAsState()
+    val snackbarHostState by remember { mutableStateOf(SnackbarHostState()) }
+    val status by associationViewModel.status.collectAsState()
 
     // Create a list of pages for the Pager
     val pages =
@@ -59,6 +69,18 @@ fun AssociationScreen(
     // Define the space between the search bar and the pages
     val spaceBetweenSearchAndPages = 8.dp
 
+    // Display a Snackbar if we are in Error state
+    val errorMessage =
+        LocalContext.current.resources.getString(
+            R.string.association_subscription_error_network_failure
+        )
+    if (status is AssociationStatus.Error) {
+        LaunchedEffect(status) {
+            snackbarHostState.showSnackbar(errorMessage, withDismissAction = true)
+            associationViewModel.resetErrorState()
+        }
+    }
+
     // Scaffold provides a framework for material design surfaces
     Scaffold(
         topBar = {
@@ -73,7 +95,8 @@ fun AssociationScreen(
                 }
             }
         },
-        modifier = Modifier.fillMaxSize().testTag("association_screen")
+        modifier = Modifier.fillMaxSize().testTag("association_screen"),
+        snackbarHost = { SnackbarHost(hostState = snackbarHostState) }
     ) { paddingValues ->
         Column(
             modifier = Modifier.padding(paddingValues),

app/src/main/java/com/github/swent/echo/compose/authentication/CreateProfile.kt

@@ -40,6 +40,7 @@ import androidx.compose.material.icons.filled.KeyboardArrowDown
 import androidx.compose.material.icons.filled.KeyboardArrowUp
 import androidx.compose.material.icons.outlined.Delete
 import androidx.compose.material.icons.outlined.Edit
+import androidx.compose.material3.Button
 import androidx.compose.material3.Card
 import androidx.compose.material3.CircularProgressIndicator
 import androidx.compose.material3.DropdownMenu
@@ -51,7 +52,6 @@ import androidx.compose.material3.IconButton
 import androidx.compose.material3.InputChip
 import androidx.compose.material3.InputChipDefaults
 import androidx.compose.material3.MaterialTheme
-import androidx.compose.material3.OutlinedButton
 import androidx.compose.material3.OutlinedTextField
 import androidx.compose.material3.Scaffold
 import androidx.compose.material3.SmallFloatingActionButton
@@ -98,6 +98,7 @@ import com.github.swent.echo.data.model.SectionEPFL
 import com.github.swent.echo.data.model.Semester
 import com.github.swent.echo.data.model.SemesterEPFL
 import com.github.swent.echo.data.model.Tag
+import com.github.swent.echo.data.repository.RepositoryStoreWhileNoInternetException
 import com.github.swent.echo.ui.navigation.NavigationActions
 import com.github.swent.echo.ui.navigation.Routes
 import com.github.swent.echo.viewmodels.authentication.CreateProfileState
@@ -243,7 +244,12 @@ fun ProfileCreationUI(
                 modifier = Modifier.fillMaxWidth()
             )
         },
-        snackbarHost = { SnackbarHost(hostState = snackbarHostState) }
+        snackbarHost = {
+            SnackbarHost(
+                hostState = snackbarHostState,
+                modifier = Modifier.testTag("profile-creation-snackbar")
+            )
+        }
     ) { innerPadding ->
         Box(
             modifier = modifier.fillMaxSize().padding(innerPadding).testTag("profile-creation"),
@@ -341,9 +347,10 @@ fun ProfileCreationUI(
                 Spacer(modifier = modifier.weight(1f))
                 val errorLN = stringResource(R.string.profile_creation_empty_LN)
                 val errorFN = stringResource(R.string.profile_creation_empty_FN)
+                val errorNetwork = stringResource(R.string.profile_creation_error_network_failure)
 
                 // Save button
-                OutlinedButton(
+                Button(
                     onClick = {
                         if (firstName.isBlank() || lastName.isBlank()) {
                             scope.launch {
@@ -360,8 +367,17 @@ fun ProfileCreationUI(
                                 }
                             }
                         } else {
-                            onSave(firstName, lastName)
-                            navAction.navigateTo(Routes.MAP)
+                            try {
+                                onSave(firstName, lastName)
+                                navAction.navigateTo(Routes.MAP)
+                            } catch (e: RepositoryStoreWhileNoInternetException) {
+                                scope.launch {
+                                    snackbarHostState.showSnackbar(
+                                        errorNetwork,
+                                        withDismissAction = true
+                                    )
+                                }
+                            }
                         }
                     },
                     modifier = modifier.fillMaxWidth().testTag("Save"),

app/src/main/java/com/github/swent/echo/compose/components/JoinEventButton.kt

@@ -1,17 +1,27 @@
 package com.github.swent.echo.compose.components
 
+import androidx.compose.foundation.layout.Box
 import androidx.compose.foundation.layout.width
 import androidx.compose.material3.Button
+import androidx.compose.material3.SnackbarHost
+import androidx.compose.material3.SnackbarHostState
 import androidx.compose.material3.Text
 import androidx.compose.runtime.Composable
+import androidx.compose.runtime.LaunchedEffect
 import androidx.compose.runtime.collectAsState
 import androidx.compose.runtime.getValue
+import androidx.compose.runtime.mutableStateOf
+import androidx.compose.runtime.remember
+import androidx.compose.ui.Alignment
+import androidx.compose.ui.Modifier
+import androidx.compose.ui.platform.LocalContext
 import androidx.compose.ui.platform.testTag
 import androidx.compose.ui.res.stringResource
 import androidx.compose.ui.unit.Dp
 import androidx.hilt.navigation.compose.hiltViewModel
 import com.github.swent.echo.R
 import com.github.swent.echo.data.model.Event
+import com.github.swent.echo.viewmodels.myevents.MyEventStatus
 import com.github.swent.echo.viewmodels.myevents.MyEventsViewModel
 
 /**
@@ -30,25 +40,42 @@ fun JoinEventButton(event: Event, isOnline: Boolean, buttonWidth: Dp, refreshEve
     val myEventsViewModel: MyEventsViewModel = hiltViewModel()
     // Observe the list of events that the user has joined.
     val joinedEvents by myEventsViewModel.joinedEvents.collectAsState()
-    // Create a button for joining or leaving the event.
-    Button(
-        // The button is enabled if the user is online and the event is not full.
-        enabled = isOnline && (event.participantCount < event.maxParticipants),
-        // When the button is clicked, the user joins or leaves the event.
-        onClick = { myEventsViewModel.joinOrLeaveEvent(event, refreshEvents) },
-        // Set the width of the button and a test tag for testing purposes.
-        modifier =
-            androidx.compose.ui.Modifier.width(buttonWidth)
-                .testTag("list_join_event_${event.eventId}")
-    ) {
-        // The text of the button depends on whether the user has joined the event.
-        Text(
-            if (joinedEvents.map { it.eventId }.contains(event.eventId))
-            // If the user has joined the event, the button says "Leave".
-            stringResource(id = R.string.list_drawer_leave_event)
-            else
-            // If the user has not joined the event, the button says "Join".
-            stringResource(id = R.string.list_drawer_join_event)
-        )
+
+    // Snackbar for displaying errors
+    val snackbarHostState by remember { mutableStateOf(SnackbarHostState()) }
+    val status by myEventsViewModel.status.collectAsState()
+    val errorMessage =
+        LocalContext.current.resources.getString(R.string.event_join_error_network_failure)
+    if (status is MyEventStatus.Error) {
+        LaunchedEffect(status) {
+            snackbarHostState.showSnackbar(errorMessage, withDismissAction = true)
+            myEventsViewModel.resetErrorState()
+        }
+    }
+
+    Box {
+        // Create a button for joining or leaving the event.
+        Button(
+            // The button is enabled if the user is online and the event is not full.
+            enabled = isOnline && (event.participantCount < event.maxParticipants),
+            // When the button is clicked, the user joins or leaves the event.
+            onClick = { myEventsViewModel.joinOrLeaveEvent(event, refreshEvents) },
+            // Set the width of the button and a test tag for testing purposes.
+            modifier =
+                androidx.compose.ui.Modifier.width(buttonWidth)
+                    .align(Alignment.Center)
+                    .testTag("list_join_event_${event.eventId}")
+        ) {
+            // The text of the button depends on whether the user has joined the event.
+            Text(
+                if (joinedEvents.map { it.eventId }.contains(event.eventId))
+                // If the user has joined the event, the button says "Leave".
+                stringResource(id = R.string.list_drawer_leave_event)
+                else
+                // If the user has not joined the event, the button says "Join".
+                stringResource(id = R.string.list_drawer_join_event)
+            )
+        }
+        SnackbarHost(hostState = snackbarHostState, modifier = Modifier.align(Alignment.Center))
     }
 }

app/src/main/java/com/github/swent/echo/compose/event/EventScreen.kt

@@ -103,8 +103,7 @@ fun EventScreen(
             ) {
                 if (canDelete) {
                     DeleteEventButton(enabled = isOnline) {
-                        // TODO: delete the event in the repository
-                        onEventDeleted()
+                        eventViewModel.deleteEvent(onEventDeleted)
                     }
                 }
                 OutlinedButton(

app/src/main/java/com/github/swent/echo/viewmodels/association/AssociationViewModel.kt

@@ -8,6 +8,7 @@ import com.github.swent.echo.data.model.Association
 import com.github.swent.echo.data.model.Event
 import com.github.swent.echo.data.model.toAssociationHeader
 import com.github.swent.echo.data.repository.Repository
+import com.github.swent.echo.data.repository.RepositoryStoreWhileNoInternetException
 import dagger.hilt.android.lifecycle.HiltViewModel
 import javax.inject.Inject
 import kotlinx.coroutines.flow.MutableStateFlow
@@ -49,6 +50,8 @@ constructor(
     val searched = _searched.asStateFlow()
     // Online status
     val isOnline = networkService.isOnline
+    private val _status = MutableStateFlow<AssociationStatus>(AssociationStatus.Okay)
+    val status = _status.asStateFlow()
 
     // Initialize the ViewModel
     init {
@@ -70,10 +73,14 @@ constructor(
 
     // Handle follow/unfollow association
     fun onFollowAssociationChanged(association: Association) {
+        _status.value = AssociationStatus.Okay
+        val revertAction: () -> Unit
         if (_followedAssociations.value.contains(association)) {
             _followedAssociations.value -= association
+            revertAction = { _followedAssociations.value += association }
         } else {
             _followedAssociations.value += association
+            revertAction = { _followedAssociations.value -= association }
         }
         viewModelScope.launch {
             val userProfile = repository.getUserProfile(authenticationService.getCurrentUserID()!!)
@@ -82,10 +89,20 @@ constructor(
                     associationsSubscriptions =
                         _followedAssociations.value.toAssociationHeader().toSet()
                 )
-            repository.setUserProfile(updatedProfile!!)
+            try {
+                repository.setUserProfile(updatedProfile!!)
+            } catch (e: RepositoryStoreWhileNoInternetException) {
+                _status.value = AssociationStatus.Error
+                revertAction()
+            }
         }
     }
 
+    // Reset error state
+    fun resetErrorState() {
+        _status.value = AssociationStatus.Okay
+    }
+
     // Set searched term
     fun setSearched(searched: String) {
         _searched.value = searched
@@ -121,3 +138,10 @@ constructor(
         viewModelScope.launch { allEvents = repository.getAllEvents() }
     }
 }
+
+// Status of the Association screen/viewmodel
+sealed class AssociationStatus {
+    data object Okay : AssociationStatus()
+
+    data object Error : AssociationStatus()
+}

app/src/main/java/com/github/swent/echo/viewmodels/event/EventViewModel.kt

@@ -13,6 +13,7 @@ import com.github.swent.echo.data.model.EventCreator
 import com.github.swent.echo.data.model.Location
 import com.github.swent.echo.data.model.Tag
 import com.github.swent.echo.data.repository.Repository
+import com.github.swent.echo.data.repository.RepositoryStoreWhileNoInternetException
 import dagger.hilt.android.lifecycle.HiltViewModel
 import javax.inject.Inject
 import kotlinx.coroutines.flow.MutableStateFlow
@@ -141,22 +142,40 @@ constructor(
         } else if (_status.value == EventStatus.Saved) {
             Log.w("save event", "trying to save the event but it's already saved")
         } else {
+            val eventStatusBeforeSaving = _status.value
             if (eventIsValid()) {
                 _status.value = EventStatus.Saving
                 viewModelScope.launch {
-                    if (isEventNew.value) {
-                        val eventId = repository.createEvent(event.value)
-                        _event.value = event.value.copy(eventId = eventId)
-                    } else {
-                        repository.setEvent(event.value)
+                    try {
+                        if (isEventNew.value) {
+                            val eventId = repository.createEvent(event.value)
+                            _event.value = event.value.copy(eventId = eventId)
+                        } else {
+                            repository.setEvent(event.value)
+                        }
+                        _isEventNew.value = false
+                        _status.value = EventStatus.Saved
+                    } catch (e: RepositoryStoreWhileNoInternetException) {
+                        _status.value =
+                            EventStatus.Error(R.string.event_creation_error_network_failure)
                     }
-                    _isEventNew.value = false
-                    _status.value = EventStatus.Saved
                 }
             }
         }
     }
 
+    // delete the current event in the repository
+    fun deleteEvent(onEventDeleted: () -> Unit) {
+        viewModelScope.launch {
+            try {
+                repository.deleteEvent(event.value)
+                onEventDeleted()
+            } catch (e: RepositoryStoreWhileNoInternetException) {
+                _status.value = EventStatus.Error(R.string.event_creation_error_network_failure)
+            }
+        }
+    }
+
     /** Change event status from error to modified. */
     fun dismissError() {
         if (_status.value is EventStatus.Error) {