// 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.Threading;
using Microsoft.CodeAnalysis.Editor.Shared.Extensions;
using Microsoft.CodeAnalysis.Indentation;
using Microsoft.CodeAnalysis.Internal.Log;
using Microsoft.CodeAnalysis.Options;
using Microsoft.CodeAnalysis.Shared.Extensions;
using Microsoft.CodeAnalysis.Text;
using Microsoft.VisualStudio.Text;
using Microsoft.VisualStudio.Text.Editor;
 
namespace Microsoft.CodeAnalysis.Editor.Implementation.SmartIndent;
 
internal partial class SmartIndent(ITextView textView, EditorOptionsService editorOptionsService) : ISmartIndent
{
    private readonly ITextView _textView = textView;
    private readonly EditorOptionsService _editorOptionsService = editorOptionsService;
 
    public int? GetDesiredIndentation(ITextSnapshotLine line)
        => GetDesiredIndentation(line, CancellationToken.None);
 
    public void Dispose()
    {
    }
 
    private int? GetDesiredIndentation(ITextSnapshotLine line, CancellationToken cancellationToken)
    {
        if (line == null)
            throw new ArgumentNullException(nameof(line));
 
        using (Logger.LogBlock(FunctionId.SmartIndentation_Start, cancellationToken))
        {
            var document = line.Snapshot.GetOpenDocumentInCurrentContextWithChanges();
            if (document == null)
                return null;
 
            var newService = document.GetLanguageService<IIndentationService>();
            if (newService == null)
                return null;
 
            var indentationOptions = line.Snapshot.TextBuffer.GetIndentationOptions(_editorOptionsService, document.Project.GetFallbackAnalyzerOptions(), document.Project.Services, explicitFormat: false);
            var parsedDocument = ParsedDocument.CreateSynchronously(document, cancellationToken);
            var result = newService.GetIndentation(parsedDocument, line.LineNumber, indentationOptions, cancellationToken);
            return result.GetIndentation(_textView, line);
        }
    }
}