[WOOMOB-1347] - Booking details note - discard changes dialog

WooCommerce/src/main/kotlin/com/woocommerce/android/ui/bookings/note/BookingNoteFragment.kt

@@ -29,7 +29,6 @@ class BookingNoteFragment : BaseFragment() {
         return composeView {
             BookingNoteScreen(
                 viewModel = viewModel,
-                onBack = { findNavController().popBackStack() },
             )
         }
     }
@@ -45,6 +44,7 @@ class BookingNoteFragment : BaseFragment() {
                 is MultiLiveEvent.Event.ShowSnackbar -> {
                     uiMessageResolver.showSnack(event.message)
                 }
+
                 is MultiLiveEvent.Event.Exit -> {
                     findNavController().navigateUp()
                 }

WooCommerce/src/main/kotlin/com/woocommerce/android/ui/bookings/note/BookingNoteScreen.kt

@@ -29,27 +29,25 @@ import androidx.compose.ui.text.TextRange
 import androidx.compose.ui.text.input.TextFieldValue
 import androidx.compose.ui.unit.dp
 import com.woocommerce.android.R
+import com.woocommerce.android.ui.compose.Render
 import com.woocommerce.android.ui.compose.component.Toolbar
 import com.woocommerce.android.ui.compose.component.WCTextButton
 
 @Composable
 fun BookingNoteScreen(
     viewModel: BookingNoteViewModel,
-    onBack: () -> Unit,
 ) {
     val viewState by viewModel.state.observeAsState()
     viewState?.let {
         BookingNoteScreen(
             viewState = it,
-            onBack = onBack,
         )
     }
 }
 
 @Composable
 fun BookingNoteScreen(
     viewState: BookingNoteViewState,
-    onBack: () -> Unit,
 ) {
     val focusRequester = remember { FocusRequester() }
 
@@ -62,7 +60,7 @@ fun BookingNoteScreen(
         topBar = {
             Toolbar(
                 title = stringResource(R.string.booking_note_screen_title),
-                onNavigationButtonClick = onBack,
+                onNavigationButtonClick = viewState.onBackPressed,
                 actions = {
                     if (viewState.isSaveVisible) {
                         WCTextButton(
@@ -105,6 +103,8 @@ fun BookingNoteScreen(
             }
         }
     }
+
+    viewState.dialogState?.Render()
 }
 
 @Composable

WooCommerce/src/main/kotlin/com/woocommerce/android/ui/bookings/note/BookingNoteViewModel.kt

@@ -5,6 +5,7 @@ import androidx.lifecycle.SavedStateHandle
 import androidx.lifecycle.asLiveData
 import com.woocommerce.android.R
 import com.woocommerce.android.ui.bookings.BookingsRepository
+import com.woocommerce.android.ui.compose.DialogState
 import com.woocommerce.android.viewmodel.MultiLiveEvent
 import com.woocommerce.android.viewmodel.ScopedViewModel
 import com.woocommerce.android.viewmodel.navArgs
@@ -25,18 +26,22 @@ class BookingNoteViewModel @Inject constructor(
     private val initialNoteState = MutableStateFlow("")
     private val editedNoteState = MutableStateFlow<String?>(null)
     private val noteSaveStatusFlow = MutableStateFlow<NoteSaveStatus>(NoteSaveStatus.Idle)
+    private val dialogStateFlow = MutableStateFlow<DialogState?>(null)
 
     val state: LiveData<BookingNoteViewState> = combine(
         initialNoteState,
         editedNoteState,
-        noteSaveStatusFlow
-    ) { initialNote, editedNote, noteSaveStatus ->
+        noteSaveStatusFlow,
+        dialogStateFlow,
+    ) { initialNote, editedNote, noteSaveStatus, dialogState ->
         BookingNoteViewState(
             initialNote = initialNote,
             editedNote = editedNote,
             noteSaveStatus = noteSaveStatus,
             onNoteChange = ::onNoteChange,
             onSaveClicked = ::saveNote,
+            onBackPressed = ::onBackPressed,
+            dialogState = dialogState,
         )
     }.asLiveData()
 
@@ -57,6 +62,40 @@ class BookingNoteViewModel @Inject constructor(
         editedNoteState.value = value
     }
 
+    private fun onBackPressed() {
+        if (noteSaveStatusFlow.value == NoteSaveStatus.InProgress) {
+            return
+        }
+        val initial = initialNoteState.value.trim()
+        val current = editedNoteState.value.orEmpty().trim()
+        val noteHasChanged = initial != current
+        if (noteHasChanged) {
+            dialogStateFlow.value = DialogState(
+                message = R.string.booking_note_discard_changes_message,
+                positiveButton = DialogState.DialogButton(
+                    text = R.string.booking_note_discard_changes_discard,
+                    onClick = ::onDiscardChanges
+                ),
+                negativeButton = DialogState.DialogButton(
+                    text = R.string.cancel,
+                    onClick = ::onDismissDialog
+                ),
+                onDismiss = ::onDismissDialog,
+            )
+        } else {
+            triggerEvent(MultiLiveEvent.Event.Exit)
+        }
+    }
+
+    private fun onDiscardChanges() {
+        dialogStateFlow.value = null
+        triggerEvent(MultiLiveEvent.Event.Exit)
+    }
+
+    private fun onDismissDialog() {
+        dialogStateFlow.value = null
+    }
+
     private fun saveNote() {
         launch {
             noteSaveStatusFlow.value = NoteSaveStatus.InProgress

WooCommerce/src/main/kotlin/com/woocommerce/android/ui/bookings/note/BookingNoteViewState.kt

@@ -1,11 +1,15 @@
 package com.woocommerce.android.ui.bookings.note
 
+import com.woocommerce.android.ui.compose.DialogState
+
 data class BookingNoteViewState(
     val initialNote: String = "",
     val editedNote: String? = null,
     val noteSaveStatus: NoteSaveStatus = NoteSaveStatus.Idle,
     val onNoteChange: (String) -> Unit = {},
     val onSaveClicked: () -> Unit = {},
+    val onBackPressed: () -> Unit = {},
+    val dialogState: DialogState? = null,
 ) {
 
     val isSaveVisible: Boolean

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

@@ -61,6 +61,9 @@
     <string name="this_month">This Month</string>
     <string name="this_year">This Year</string>
     <string name="discard">Discard</string>
+    <!-- Booking note discard changes dialog -->
+    <string name="booking_note_discard_changes_message">Are you sure you want to discard these changes?</string>
+    <string name="booking_note_discard_changes_discard">Discard changes</string>
     <string name="products">Products</string>
     <string name="point_of_sale">Point of Sale</string>
     <string name="custom_amounts">Custom Amounts</string>

WooCommerce/src/test/kotlin/com/woocommerce/android/ui/bookings/note/BookingNoteViewModelTest.kt

@@ -2,6 +2,7 @@ package com.woocommerce.android.ui.bookings.note
 
 import androidx.lifecycle.SavedStateHandle
 import com.woocommerce.android.R
+import com.woocommerce.android.model.UiString
 import com.woocommerce.android.ui.bookings.BookingsRepository
 import com.woocommerce.android.util.getOrAwaitValue
 import com.woocommerce.android.viewmodel.BaseUnitTest
@@ -180,6 +181,103 @@ class BookingNoteViewModelTest : BaseUnitTest() {
         assertThat(finalState.noteSaveStatus).isEqualTo(NoteSaveStatus.Idle)
     }
 
+    @Test
+    fun `given no changes, when back pressed, then exit is triggered and no dialog`() = testBlocking {
+        // Given
+        val viewModel = createViewModel()
+        val state = viewModel.state.getOrAwaitValue()
+
+        // When
+        state.onBackPressed()
+
+        // Then
+        val event = viewModel.event.getOrAwaitValue()
+        assertThat(event).isEqualTo(MultiLiveEvent.Event.Exit)
+        val latestState = viewModel.state.getOrAwaitValue()
+        assertThat(latestState.dialogState).isNull()
+    }
+
+    @Test
+    fun `given changed note, when back pressed, then show discard dialog with correct copy and buttons`() = testBlocking {
+        // Given
+        val viewModel = createViewModel()
+        val state = viewModel.state.getOrAwaitValue()
+        state.onNoteChange("Changed note")
+        viewModel.state.getOrAwaitValue()
+
+        // When
+        state.onBackPressed()
+
+        // Then
+        val withDialog = viewModel.state.getOrAwaitValue()
+        val dialog = withDialog.dialogState
+        check(dialog != null)
+        // Verify message and buttons types/ids
+        assertThat(dialog.message).isInstanceOf(UiString.UiStringRes::class.java)
+        assertThat((dialog.message as UiString.UiStringRes).stringRes)
+            .isEqualTo(R.string.booking_note_discard_changes_message)
+        val positive = dialog.positiveButton
+        val negative = dialog.negativeButton
+        check(positive != null && negative != null)
+        assertThat((positive.text as UiString.UiStringRes).stringRes)
+            .isEqualTo(R.string.booking_note_discard_changes_discard)
+        assertThat((negative.text as UiString.UiStringRes).stringRes)
+            .isEqualTo(R.string.cancel)
+
+        // Clicking negative should dismiss dialog and not exit
+        negative.onClick()
+        val afterDismiss = viewModel.state.getOrAwaitValue()
+        assertThat(afterDismiss.dialogState).isNull()
+    }
+
+    @Test
+    fun `when confirm discard in dialog, then exit is triggered`() = testBlocking {
+        // Given
+        val viewModel = createViewModel()
+        val state = viewModel.state.getOrAwaitValue()
+        state.onNoteChange("Changed note")
+        viewModel.state.getOrAwaitValue()
+        state.onBackPressed()
+        val withDialog = viewModel.state.getOrAwaitValue()
+        val positive = withDialog.dialogState?.positiveButton
+        check(positive != null)
+
+        // When
+        positive.onClick()
+
+        // Then
+        val event = viewModel.event.getOrAwaitValue()
+        assertThat(event).isEqualTo(MultiLiveEvent.Event.Exit)
+    }
+
+    @Test
+    fun `when save in progress and back pressed, then do nothing (no dialog, no exit)`() = testBlocking {
+        // Given a slow repository update to keep InProgress state
+        whenever(bookingsRepository.updateNote(any(), any())).doSuspendableAnswer {
+            delay(200)
+            Result.success(Unit)
+        }
+        val viewModel = createViewModel()
+        val state = viewModel.state.getOrAwaitValue()
+        state.onNoteChange("Changed")
+        viewModel.state.getOrAwaitValue()
+
+        // Start save
+        state.onSaveClicked()
+        val inProgress = viewModel.state.getOrAwaitValue()
+        assertThat(inProgress.noteSaveStatus).isEqualTo(NoteSaveStatus.InProgress)
+
+        // When
+        inProgress.onBackPressed()
+
+        // Then: dialog remains null while in progress
+        val stillInProgress = viewModel.state.getOrAwaitValue()
+        assertThat(stillInProgress.dialogState).isNull()
+
+        // Clean up
+        advanceUntilIdle()
+    }
+
     private fun createViewModel(
         savedState: SavedStateHandle = savedStateHandle,
     ): BookingNoteViewModel {