feat (gitlab): disable comments on unsupported file changes in editor and show a warning

#IJPL-204613 Fixed

IJ-CR-181587

(cherry picked from commit 1a431191ab6f71f6db520a4b0f589836609b9299)

# Conflicts:
#	community/plugins/gitlab/gitlab-core/src/org/jetbrains/plugins/gitlab/mergerequest/ui/editor/GitLabMergeRequestEditorReviewController.kt
#	community/plugins/gitlab/gitlab-core/src/org/jetbrains/plugins/gitlab/mergerequest/ui/editor/GitLabMergeRequestEditorReviewViewModel.kt


(cherry picked from commit 6cf315fce34fd715e81364571228cc80c5cdb7a2)

IJ-MR-183241

GitOrigin-RevId: a81cae6dda265885f62f5a4b0c4754850341c747

platform/collaboration-tools/src/com/intellij/collaboration/ui/codereview/editor/ReviewInEditorUtil.kt

@@ -9,6 +9,7 @@ import com.intellij.openapi.actionSystem.DefaultActionGroup
 import com.intellij.openapi.actionSystem.Separator
 import com.intellij.openapi.application.EDT
 import com.intellij.openapi.application.EdtImmediate
+import com.intellij.openapi.application.UI
 import com.intellij.openapi.diff.LineStatusMarkerColorScheme
 import com.intellij.openapi.editor.Document
 import com.intellij.openapi.editor.Editor
@@ -21,6 +22,8 @@ import com.intellij.ui.JBColor
 import kotlinx.coroutines.Dispatchers
 import kotlinx.coroutines.awaitCancellation
 import kotlinx.coroutines.withContext
+import org.jetbrains.annotations.ApiStatus
+import org.jetbrains.annotations.Nls
 import java.awt.Color
 
 object ReviewInEditorUtil {
@@ -105,23 +108,50 @@ object ReviewInEditorUtil {
   }
 
   suspend fun showReviewToolbarWithActions(vm: CodeReviewInEditorViewModel, editor: Editor, vararg additionalActions: AnAction): Nothing {
-    withContext(Dispatchers.EDT) {
-      val toolbarActionGroup = DefaultActionGroup(
+    val toolbarActionGroup = withContext(Dispatchers.UI) {
+      DefaultActionGroup(
         *additionalActions,
         CodeReviewInEditorToolbarActionGroup(vm),
         Separator.getInstance()
       )
+    }
 
+    showInspectionWidgetAction(editor, toolbarActionGroup)
+  }
+
+  /**
+   * This is a very special case for GitLab plugin to show on a file with an empty diff
+   */
+  @ApiStatus.Internal
+  suspend fun showReviewToolbarWithWarning(
+    vm: CodeReviewInEditorViewModel, editor: Editor,
+    vararg additionalActions: AnAction,
+    warningSupplier: () -> @Nls String,
+  ): Nothing {
+    val toolbarActionGroup = withContext(Dispatchers.UI) {
+      DefaultActionGroup(
+        *additionalActions,
+        CodeReviewInEditorToolbarActionGroup(vm, warningSupplier),
+        Separator.getInstance()
+      )
+    }
+
+    showInspectionWidgetAction(editor, toolbarActionGroup)
+  }
+
+  // Awaits cancellation indefinitely until scope is cancelled
+  private suspend fun showInspectionWidgetAction(editor: Editor, action: AnAction): Nothing {
+    withContext(Dispatchers.EDT) {
       val editorMarkupModel = editor.markupModel as? EditorMarkupModel
       if (editorMarkupModel == null) {
         error("Editor markup model is not available")
       }
-      editorMarkupModel.addInspectionWidgetAction(toolbarActionGroup, Constraints.FIRST)
+      editorMarkupModel.addInspectionWidgetAction(action, Constraints.FIRST)
       try {
         awaitCancellation()
       }
       finally {
-        editorMarkupModel.removeInspectionWidgetAction(toolbarActionGroup)
+        editorMarkupModel.removeInspectionWidgetAction(action)
       }
     }
   }

platform/collaboration-tools/src/com/intellij/collaboration/ui/codereview/editor/action/CodeReviewInEditorToolbarActionGroup.kt

@@ -15,10 +15,14 @@ import com.intellij.openapi.project.DumbAware
 import com.intellij.openapi.project.DumbAwareAction
 import com.intellij.openapi.util.NlsActions
 import org.jetbrains.annotations.ApiStatus
+import org.jetbrains.annotations.Nls
 import javax.swing.Icon
 
 @ApiStatus.Internal
-class CodeReviewInEditorToolbarActionGroup(private val vm: CodeReviewInEditorViewModel) : ActionGroup(), DumbAware {
+class CodeReviewInEditorToolbarActionGroup(
+  private val vm: CodeReviewInEditorViewModel,
+  private val customWarningSupplier: (() -> @Nls String)? = null,
+) : ActionGroup(), DumbAware {
   private val updateAction = UpdateAction()
 
   private val disableReviewAction =
@@ -49,15 +53,17 @@ class CodeReviewInEditorToolbarActionGroup(private val vm: CodeReviewInEditorVie
     val synced = !vm.updateRequired.value
     with(e.presentation) {
       description = CollaborationToolsBundle.message("review.editor.mode.description.title")
+      val customWarning = customWarningSupplier?.invoke()
+      val detailedDescription = customWarning ?: CollaborationToolsBundle.message("review.editor.mode.description")
       val tooltip = HelpTooltip()
         .setTitle(CollaborationToolsBundle.message("review.editor.mode.description.title"))
-        .setDescription(CollaborationToolsBundle.message("review.editor.mode.description"))
+        .setDescription(detailedDescription)
       putClientProperty(ActionButton.CUSTOM_HELP_TOOLTIP, tooltip)
 
       if (shown) {
         text = CollaborationToolsBundle.message("review.editor.mode.title")
         putClientProperty(ActionUtil.SHOW_TEXT_IN_TOOLBAR, true)
-        icon = if (synced) null else getWarningIcon()
+        icon = if (customWarning != null || !synced) getWarningIcon() else null
       }
       else {
         text = null

plugins/gitlab/gitlab-core/resources/messages/GitLabBundle.properties

@@ -154,7 +154,9 @@ merge.request.review.submit.action.tooltip=Submit merge request review
 merge.request.details.changes.empty=No changes
 merge.request.diff.file.name=Diff for Merge Request !{0}
 merge.request.diff.empty.patch.warning=Comments are disabled for this change because the GitLab server returned an empty diff.\
-  \ Typically, this means that the file is too big. If this is not the case, please report the issue via the Help menu.
+  \ This means that either this file is too big or it was renamed or moved without any changes.
+merge.request.editor.empty.patch.warning=Review Mode is disabled for this file because the GitLab server returned an empty diff.\
+  \ This means that either this file is too big or it was renamed or moved without any changes.
 
 # Merge request timeline
 merge.request.timeline.error=Failed to load timeline

plugins/gitlab/gitlab-core/src/org/jetbrains/plugins/gitlab/mergerequest/ui/editor/GitLabMergeRequestEditorReviewController.kt

@@ -25,6 +25,8 @@ import kotlinx.coroutines.flow.*
 import org.jetbrains.plugins.gitlab.api.dto.GitLabUserDTO
 import org.jetbrains.plugins.gitlab.mergerequest.GitLabMergeRequestsPreferences
 import org.jetbrains.plugins.gitlab.mergerequest.ui.GitLabProjectViewModel
+import org.jetbrains.plugins.gitlab.mergerequest.ui.editor.GitLabMergeRequestEditorReviewViewModel.FileReviewState
+import org.jetbrains.plugins.gitlab.util.GitLabBundle
 import org.jetbrains.plugins.gitlab.util.GitLabStatistics
 
 @OptIn(ExperimentalCoroutinesApi::class)
@@ -52,23 +54,42 @@ internal class GitLabMergeRequestEditorReviewController(private val project: Pro
         .flatMapLatest {
           it?.currentMergeRequestReviewVm ?: flowOf(null)
         }.collectLatest { reviewVm ->
-          reviewVm?.getFileVm(file)?.collectScoped { fileVm ->
-            if (fileVm != null) supervisorScope {
-              launchNow {
-                ReviewInEditorUtil.showReviewToolbar(reviewVm, editor)
-              }
-
-              val enabledFlow = reviewVm.discussionsViewOption.map { it != DiscussionsViewOption.DONT_SHOW }
-              val syncedFlow = reviewVm.localRepositorySyncStatus.map { it?.getOrNull()?.incoming != true }
-              combine(enabledFlow, syncedFlow) { enabled, synced -> enabled && synced }.distinctUntilChanged().collectLatest { enabled ->
-                if (enabled) showReview(fileVm, editor)
-              }
+          reviewVm?.getFileStateFlow(file)?.collectScoped { fileState ->
+            when (fileState) {
+              is FileReviewState.ReviewEnabled -> showReview(reviewVm, fileState.vm, editor)
+              FileReviewState.ReviewDisabledEmptyDiff -> showEmptyDiffNotification(reviewVm, editor)
+              FileReviewState.NotInReview -> return@collectScoped
             }
           }
         }
     }.cancelOnDispose(editorDisposable)
   }
 
+  private suspend fun showReview(
+    reviewVm: GitLabMergeRequestEditorReviewViewModel,
+    fileVm: GitLabMergeRequestEditorReviewFileViewModel,
+    editor: EditorEx,
+  ): Nothing {
+    supervisorScope {
+      launchNow {
+        ReviewInEditorUtil.showReviewToolbar(reviewVm, editor)
+      }
+
+      val enabledFlow = reviewVm.discussionsViewOption.map { it != DiscussionsViewOption.DONT_SHOW }
+      val syncedFlow = reviewVm.localRepositorySyncStatus.map { it?.getOrNull()?.incoming != true }
+      combine(enabledFlow, syncedFlow) { enabled, synced -> enabled && synced }.distinctUntilChanged().collectLatest { enabled ->
+        if (enabled) showReview(fileVm, editor)
+      }
+      awaitCancellation()
+    }
+  }
+
+  private suspend fun showEmptyDiffNotification(reviewVm: GitLabMergeRequestEditorReviewViewModel, editor: Editor): Nothing {
+    ReviewInEditorUtil.showReviewToolbarWithWarning(reviewVm, editor) {
+      GitLabBundle.message("merge.request.editor.empty.patch.warning")
+    }
+  }
+
   private suspend fun showReview(fileVm: GitLabMergeRequestEditorReviewFileViewModel, editor: EditorEx): Nothing {
     withContext(Dispatchers.Main) {
       val preferences = project.serviceAsync<GitLabMergeRequestsPreferences>()

plugins/gitlab/gitlab-core/src/org/jetbrains/plugins/gitlab/mergerequest/ui/editor/GitLabMergeRequestEditorReviewViewModel.kt

@@ -3,7 +3,9 @@ package org.jetbrains.plugins.gitlab.mergerequest.ui.editor
 
 import com.intellij.collaboration.async.launchNow
 import com.intellij.collaboration.async.mapNullableScoped
+import com.intellij.collaboration.async.mapScoped
 import com.intellij.collaboration.async.mapState
+import com.intellij.collaboration.async.stateInNow
 import com.intellij.collaboration.ui.codereview.diff.DiffLineLocation
 import com.intellij.collaboration.ui.codereview.diff.DiscussionsViewOption
 import com.intellij.collaboration.ui.codereview.editor.CodeReviewInEditorViewModel
@@ -67,8 +69,13 @@ class GitLabMergeRequestEditorReviewViewModel internal constructor(
   private val changesRequest = MutableSharedFlow<Unit>(replay = 1)
 
   val actualChangesState: StateFlow<ChangesState> = _actualChangesState.asStateFlow()
+  private val actualChanges: StateFlow<GitBranchComparisonResult?> = actualChangesState.mapNotNull {
+    (it as? ChangesState.Loaded)?.changes
+  }.distinctUntilChangedBy {
+    it.baseSha + it.headSha + it.mergeBaseSha
+  }.stateInNow(cs, null)
 
-  private val filesVms: MutableMap<FilePath, Flow<GitLabMergeRequestEditorReviewFileViewModel?>> = mutableMapOf()
+  private val filesVms: MutableMap<FilePath, Flow<FileReviewState>> = mutableMapOf()
   private val diffRequestsMulticaster = EventDispatcher.create(DiffRequestListener::class.java)
 
   @OptIn(ExperimentalCoroutinesApi::class)
@@ -140,34 +147,29 @@ class GitLabMergeRequestEditorReviewViewModel internal constructor(
   /**
    * A view model for [virtualFile] review
    */
-  fun getFileVm(virtualFile: VirtualFile): Flow<GitLabMergeRequestEditorReviewFileViewModel?> {
+  fun getFileStateFlow(virtualFile: VirtualFile): Flow<FileReviewState> {
     if (!virtualFile.isValid || virtualFile.isDirectory ||
         !VfsUtilCore.isAncestor(projectMapping.remote.repository.root, virtualFile, true)) {
-      return flowOf(null)
+      return flowOf(FileReviewState.NotInReview)
     }
     val filePath = VcsContextFactory.getInstance().createFilePathOn(virtualFile)
     changesRequest.tryEmit(Unit)
     //TODO: do not recreate VMs on changes change
     return filesVms.getOrPut(filePath) {
-      actualChangesState.mapNotNull {
-        (it as? ChangesState.Loaded)?.changes
-      }.distinctUntilChangedBy {
-        it.baseSha + it.headSha + it.mergeBaseSha
-      }.transform { parsedChanges ->
-        val change = parsedChanges.changes.find { it.filePathAfter == filePath }
+      actualChanges.mapScoped { parsedChanges ->
+        val change = parsedChanges?.changes?.find { it.filePathAfter == filePath }
         if (change == null) {
-          emit(null)
-          return@transform
+          return@mapScoped FileReviewState.NotInReview
         }
         val diffData = parsedChanges.patchesByChange[change] ?: run {
           LOG.info("Diff data not found for change $change")
-          emit(null)
-          return@transform
+          return@mapScoped FileReviewState.NotInReview
+        }
+        if (diffData.patch.hunks.isEmpty()) {
+          return@mapScoped FileReviewState.ReviewDisabledEmptyDiff
         }
         val changeSelection = ListSelection.create(parsedChanges.changes, change)
-        emit(changeSelection to diffData)
-      }.mapNullableScoped { (change, diffData) ->
-        createChangeVm(change, diffData)
+        FileReviewState.ReviewEnabled(createChangeVm(changeSelection, diffData))
       }
     }
   }
@@ -203,6 +205,12 @@ class GitLabMergeRequestEditorReviewViewModel internal constructor(
     data object Error : ChangesState
     class Loaded(val changes: GitBranchComparisonResult) : ChangesState
   }
+
+  sealed interface FileReviewState {
+    data object NotInReview : FileReviewState
+    data object ReviewDisabledEmptyDiff : FileReviewState
+    data class ReviewEnabled(val vm: GitLabMergeRequestEditorReviewFileViewModel) : FileReviewState
+  }
 }
 
 private fun interface DiffRequestListener : EventListener {