// 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 : ISmartIndent
    {
        private readonly ITextView _textView;
        private readonly EditorOptionsService _editorOptionsService;
 
        public SmartIndent(ITextView textView, EditorOptionsService editorOptionsService)
        {
            _textView = textView;
            _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.Services, explicitFormat: false);
                var parsedDocument = ParsedDocument.CreateSynchronously(document, cancellationToken);
                var result = newService.GetIndentation(parsedDocument, line.LineNumber, indentationOptions, cancellationToken);
                return result.GetIndentation(_textView, line);
            }
        }
    }
}