// Licensed to the .NET Foundation under one or more agreements.
// The .NET Foundation licenses this file to you under the MIT license.
// See the LICENSE file in the project root for more information.
 
using System;
using System.Collections.Immutable;
using System.Threading;
using System.Threading.Tasks;
using Microsoft.CodeAnalysis.CodeActions;
using Microsoft.CodeAnalysis.Editor.Host;
 
namespace Microsoft.CodeAnalysis.Editor.Implementation.Suggestions;
 
internal partial class SuggestedActionWithNestedFlavors
{
    private partial class PreviewChangesSuggestedAction
    {
        private sealed class PreviewChangesCodeAction : CodeAction
        {
            private readonly Workspace _workspace;
            private readonly CodeAction _originalCodeAction;
            private readonly Func<CancellationToken, Task<SolutionPreviewResult?>> _getPreviewResultAsync;
 
            public PreviewChangesCodeAction(Workspace workspace, CodeAction originalCodeAction, Func<CancellationToken, Task<SolutionPreviewResult?>> getPreviewResultAsync)
            {
                _workspace = workspace;
                _originalCodeAction = originalCodeAction;
                _getPreviewResultAsync = getPreviewResultAsync;
            }
 
            public override string Title => EditorFeaturesResources.Preview_changes2;
 
            private protected override async Task<ImmutableArray<CodeActionOperation>> GetOperationsCoreAsync(
                Solution originalSolution, IProgress<CodeAnalysisProgress> progressTracker, CancellationToken cancellationToken)
            {
                cancellationToken.ThrowIfCancellationRequested();
                var previewDialogService = _workspace.Services.GetService<IPreviewDialogService>();
                if (previewDialogService == null)
                {
                    return [];
                }
 
                var previewResult = await _getPreviewResultAsync(cancellationToken).ConfigureAwait(true);
                if (previewResult?.ChangeSummary is not { } changeSummary)
                {
                    return [];
                }
 
                var changedSolution = previewDialogService.PreviewChanges(
                    EditorFeaturesResources.Preview_Changes,
                    "vs.codefix.previewchanges",
                    _originalCodeAction.Title,
                    EditorFeaturesResources.Changes,
                    CodeAnalysis.Glyph.OpenFolder,
                    changeSummary.NewSolution,
                    changeSummary.OldSolution,
                    showCheckBoxes: false);
 
                if (changedSolution == null)
                {
                    // User pressed the cancel button.
                    return [];
                }
 
                cancellationToken.ThrowIfCancellationRequested();
                return await _originalCodeAction.GetOperationsAsync(originalSolution, progressTracker, cancellationToken).ConfigureAwait(false);
            }
        }
    }
}