// 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.

#nullable disable

using System;
using System.Collections.Generic;
using System.Linq;
using System.Threading;
using Microsoft.CodeAnalysis.Organizing.Organizers;

namespace Microsoft.CodeAnalysis.CSharp.Organizing;

internal sealed partial class CSharpOrganizingService
{
    private sealed class Rewriter(CSharpOrganizingService treeOrganizer, IEnumerable<ISyntaxOrganizer> organizers, SemanticModel semanticModel, CancellationToken cancellationToken) : CSharpSyntaxRewriter
    {
        private readonly Func<SyntaxNode, IEnumerable<ISyntaxOrganizer>> _nodeToOrganizersGetter = treeOrganizer.GetNodeToOrganizers(organizers.ToList());
        private readonly SemanticModel _semanticModel = semanticModel;
        private readonly CancellationToken _cancellationToken = cancellationToken;

        public override SyntaxNode DefaultVisit(SyntaxNode node)
        {
            _cancellationToken.ThrowIfCancellationRequested();
            return node;
        }

        public override SyntaxNode Visit(SyntaxNode node)
        {
            _cancellationToken.ThrowIfCancellationRequested();

            if (node == null)
            {
                return null;
            }

            // First, recurse into our children, updating them.
            node = base.Visit(node);

            // Now, try to update this new node itself.
            var organizers = _nodeToOrganizersGetter(node);
            foreach (var organizer in organizers)
            {
                node = organizer.OrganizeNode(_semanticModel, node, _cancellationToken);
            }

            return node;
        }
    }
}