// 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.Generic;
using System.Linq;
using Microsoft.CodeAnalysis.CSharp.Syntax;
using Microsoft.CodeAnalysis.CSharp.Utilities;
using Microsoft.CodeAnalysis.Shared.Extensions;
 
namespace Microsoft.CodeAnalysis.CSharp.Extensions;
 
internal static class NameSyntaxExtensions
{
    public static IList<NameSyntax> GetNameParts(this NameSyntax nameSyntax)
        => new NameSyntaxIterator(nameSyntax).ToList();
 
    public static NameSyntax GetLastDottedName(this NameSyntax nameSyntax)
    {
        var parts = nameSyntax.GetNameParts();
        return parts[parts.Count - 1];
    }
 
    public static SyntaxToken GetNameToken(this NameSyntax nameSyntax)
    {
        while (true)
        {
            if (nameSyntax.Kind() == SyntaxKind.IdentifierName)
            {
                return ((IdentifierNameSyntax)nameSyntax).Identifier;
            }
            else if (nameSyntax.Kind() == SyntaxKind.QualifiedName)
            {
                nameSyntax = ((QualifiedNameSyntax)nameSyntax).Right;
            }
            else if (nameSyntax.Kind() == SyntaxKind.GenericName)
            {
                return ((GenericNameSyntax)nameSyntax).Identifier;
            }
            else if (nameSyntax.Kind() == SyntaxKind.AliasQualifiedName)
            {
                nameSyntax = ((AliasQualifiedNameSyntax)nameSyntax).Name;
            }
            else
            {
                throw new NotSupportedException();
            }
        }
    }
 
    public static bool CanBeReplacedWithAnyName(this NameSyntax nameSyntax)
    {
        if (nameSyntax.Parent?.Kind()
                is SyntaxKind.AliasQualifiedName
                or SyntaxKind.NameColon
                or SyntaxKind.NameEquals
                or SyntaxKind.TypeParameterConstraintClause)
        {
            return false;
        }
 
        if (nameSyntax.CheckParent<QualifiedNameSyntax>(q => q.Right == nameSyntax) ||
            nameSyntax.CheckParent<MemberAccessExpressionSyntax>(m => m.Name == nameSyntax))
        {
            return false;
        }
 
        // TODO(cyrusn): Add more cases as the language changes.
        return true;
    }
}