// 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.Diagnostics;

namespace Microsoft.CodeAnalysis.CSharp.Symbols.PublicModel
{
    internal sealed class NonErrorNamedTypeSymbol : NamedTypeSymbol
    {
        private readonly Symbols.NamedTypeSymbol _underlying;

        public NonErrorNamedTypeSymbol(Symbols.NamedTypeSymbol underlying, CodeAnalysis.NullableAnnotation nullableAnnotation)
            : base(nullableAnnotation)
        {
            Debug.Assert(underlying is object);
            Debug.Assert(!underlying.IsErrorType());
            _underlying = underlying;
        }

        protected override ITypeSymbol WithNullableAnnotation(CodeAnalysis.NullableAnnotation nullableAnnotation)
        {
            Debug.Assert(nullableAnnotation != _underlying.DefaultNullableAnnotation);
            Debug.Assert(nullableAnnotation != this.NullableAnnotation);
            return new NonErrorNamedTypeSymbol(_underlying, nullableAnnotation);
        }

        internal override CSharp.Symbol UnderlyingSymbol => _underlying;
        internal override Symbols.NamespaceOrTypeSymbol UnderlyingNamespaceOrTypeSymbol => _underlying;
        internal override Symbols.TypeSymbol UnderlyingTypeSymbol => _underlying;
        internal override Symbols.NamedTypeSymbol UnderlyingNamedTypeSymbol => _underlying;
    }
}