Add the group story confirmation dialog to the V3 media send flow.

feature/media-send/src/main/java/org/signal/mediasend/MediaSendScreen.kt

@@ -10,12 +10,14 @@ import androidx.compose.material3.Surface
 import androidx.compose.runtime.Composable
 import androidx.compose.runtime.CompositionLocalProvider
 import androidx.compose.runtime.LaunchedEffect
+import androidx.compose.runtime.getValue
 import androidx.compose.ui.Modifier
 import androidx.compose.ui.res.stringResource
 import androidx.lifecycle.viewmodel.compose.viewModel
 import androidx.navigationevent.NavigationEventDispatcherOwner
 import androidx.navigationevent.compose.LocalNavigationEventDispatcherOwner
 import org.signal.core.ui.compose.Dialogs
+import org.signal.core.ui.compose.LocalDisplayNameProvider
 import org.signal.core.ui.compose.theme.SignalTheme
 import org.signal.mediasend.edit.MediaEditScreenDialogs
 
@@ -71,6 +73,17 @@ fun MediaSendScreen(
           )
         }
 
+        viewModel.addToGroupStoryDialog.Content { recipientId, onDismissRequest, onConfirm, _, onDeny ->
+          val groupName: String by LocalDisplayNameProvider.current(recipientId.id)
+
+          MediaEditScreenDialogs.AddToGroupStoryConfirmationDialog(
+            groupName = groupName,
+            onAddToStory = onConfirm,
+            onDeny = onDeny,
+            onDismissRequest = onDismissRequest
+          )
+        }
+
         viewModel.writeStoragePermission.Content()
 
         MediaSendNavDisplay(

feature/media-send/src/main/java/org/signal/mediasend/MediaSendViewModel.kt

@@ -124,6 +124,7 @@ class MediaSendViewModel(
   internal val usernameScannedDialog = DialogController<String>()
   internal val linkedDeviceScannedDialog = DialogController<Unit>()
   internal val saveToStorageDialog = DialogController<Unit>()
+  internal val addToGroupStoryDialog = DialogController<MediaRecipientId>()
 
   internal val writeStoragePermission = PermissionController(
     permission = Manifest.permission.WRITE_EXTERNAL_STORAGE,
@@ -1108,11 +1109,26 @@ class MediaSendViewModel(
   //region Send
 
   /**
-   * Leaves the editor, either on to destination selection or straight into the send.
+   * Advances out of the editor: either on to contact selection, or into the send itself.
+   *
+   * The add-to-group-story flow has no review step of its own, so the send is gated behind a confirmation naming the
+   * group. Denying it leaves the editor exactly as it was — nothing is marked as sending until the user confirms.
    */
   private fun onNextClick() {
-    if (state.value.isContactSelectionRequired) {
+    val snapshot = state.value
+
+    if (snapshot.isContactSelectionRequired) {
       backStack.goToSend()
+      return
+    }
+
+    val recipientId = snapshot.recipientId
+    if (snapshot.isAddToGroupStoryFlow && recipientId != null) {
+      viewModelScope.launch {
+        if (addToGroupStoryDialog.show(recipientId) == DialogResult.POSITIVE) {
+          performSend()
+        }
+      }
     } else {
       performSend()
     }

feature/media-send/src/main/java/org/signal/mediasend/edit/MediaEditScreenDialogs.kt

@@ -46,6 +46,27 @@ object MediaEditScreenDialogs {
     )
   }
 
+  /**
+   * Last chance to back out before the media is posted to [groupName]'s story.
+   */
+  @Composable
+  fun AddToGroupStoryConfirmationDialog(
+    groupName: String,
+    onAddToStory: () -> Unit,
+    onDeny: () -> Unit,
+    onDismissRequest: () -> Unit
+  ) {
+    Dialogs.SimpleAlertDialog(
+      title = "",
+      body = stringResource(R.string.MediaSendDialogs__add_to_the_group_story, groupName),
+      confirm = stringResource(R.string.MediaSendDialogs__add_to_story),
+      onConfirm = onAddToStory,
+      dismiss = stringResource(android.R.string.cancel),
+      onDeny = onDeny,
+      onDismissRequest = onDismissRequest
+    )
+  }
+
   @Composable
   fun SaveToStorageConfirmationDialog(
     onSave: (doNotShowAgain: Boolean) -> Unit,
@@ -113,6 +134,19 @@ private fun DiscardEditsConfirmationDialogPreview() {
   }
 }
 
+@Preview
+@Composable
+private fun AddToGroupStoryConfirmationDialogPreview() {
+  Previews.Preview {
+    MediaEditScreenDialogs.AddToGroupStoryConfirmationDialog(
+      groupName = "Signal Android",
+      onAddToStory = {},
+      onDeny = {},
+      onDismissRequest = {}
+    )
+  }
+}
+
 @Preview
 @Composable
 private fun SaveToStorageConfirmationDialogPreview() {

feature/media-send/src/main/res/values/strings.xml

@@ -16,6 +16,10 @@
   <string name="MediaSendDialogs__dont_show_again">Don\'t show again</string>
   <!-- Progress dialog message shown while the media being edited is written out to the phone\'s storage. -->
   <string name="MediaSendDialogs__saving_media">Saving attachment to storage…</string>
+  <!-- Dialog message asking the user to confirm that the media should be added to a group\'s story. The placeholder is the group\'s name. -->
+  <string name="MediaSendDialogs__add_to_the_group_story">Add to the group story \"%1$s\"</string>
+  <!-- Confirmation button that adds the media to the group\'s story. -->
+  <string name="MediaSendDialogs__add_to_story">Add to story</string>
   <!-- Accessibility label for the row that lets the user add a text message to accompany the media being sent. -->
   <string name="AddAMessageRow__add_a_message">Add a message</string>
   <!-- Accessibility description for the button that opens the emoji keyboard. -->