// 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 Microsoft.CodeAnalysis.CSharp.Syntax;
 
namespace Microsoft.CodeAnalysis.CSharp.Utilities;
 
internal class NameSyntaxIterator : IEnumerable<NameSyntax>
{
    private readonly NameSyntax _name;
 
    public NameSyntaxIterator(NameSyntax name)
        => _name = name ?? throw new ArgumentNullException(nameof(name));
 
    public IEnumerator<NameSyntax> GetEnumerator()
    {
        var nodes = new LinkedList<NameSyntax>();
 
        var currentNode = _name;
        while (true)
        {
            if (currentNode.Kind() == SyntaxKind.QualifiedName)
            {
                var qualifiedName = currentNode as QualifiedNameSyntax;
                nodes.AddFirst(qualifiedName.Right);
                currentNode = qualifiedName.Left;
            }
            else
            {
                nodes.AddFirst(currentNode);
                break;
            }
        }
 
        return nodes.GetEnumerator();
    }
 
    System.Collections.IEnumerator System.Collections.IEnumerable.GetEnumerator()
        => GetEnumerator();
}