// 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.Collections.Generic;
using System.Collections.Immutable;
using System.Linq;
using Roslyn.Utilities;

namespace Microsoft.CodeAnalysis.CodeGeneration
{
    internal class CodeGenerationNamespaceSymbol(string name, IList<INamespaceOrTypeSymbol> members) : CodeGenerationNamespaceOrTypeSymbol(null, null, default, Accessibility.NotApplicable, default, name), INamespaceSymbol
    {
        private readonly IList<INamespaceOrTypeSymbol> _members = members ?? SpecializedCollections.EmptyList<INamespaceOrTypeSymbol>();

        public override bool IsNamespace => true;

        public override bool IsType => false;

        protected override CodeGenerationSymbol Clone()
            => new CodeGenerationNamespaceSymbol(this.Name, _members);

        public override SymbolKind Kind => SymbolKind.Namespace;

        public override void Accept(SymbolVisitor visitor)
            => visitor.VisitNamespace(this);

        public override TResult Accept<TResult>(SymbolVisitor<TResult> visitor)
            => visitor.VisitNamespace(this);

        public override TResult Accept<TArgument, TResult>(SymbolVisitor<TArgument, TResult> visitor, TArgument argument)
            => visitor.VisitNamespace(this, argument);

        public new IEnumerable<INamespaceOrTypeSymbol> GetMembers()
            => _members;

        IEnumerable<INamespaceOrTypeSymbol> INamespaceSymbol.GetMembers(string name)
            => GetMembers().Where(m => m.Name == name);

        public IEnumerable<INamespaceSymbol> GetNamespaceMembers()
            => GetMembers().OfType<INamespaceSymbol>();

        public bool IsGlobalNamespace
        {
            get
            {
                return this.Name == string.Empty;
            }
        }

        public NamespaceKind NamespaceKind => NamespaceKind.Module;

        public Compilation ContainingCompilation => null;

        public static INamedTypeSymbol ImplicitType => null;

        public ImmutableArray<INamespaceSymbol> ConstituentNamespaces
        {
            get
            {
                return ImmutableArray.Create<INamespaceSymbol>(this);
            }
        }
    }
}
