// 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.Collections.Generic;
using System.Collections.Immutable;
using Microsoft.CodeAnalysis.Text;

namespace Microsoft.CodeAnalysis
{
    /// <summary>
    /// Represents either a namespace or a type.
    /// </summary>
    /// <remarks>
    /// This interface is reserved for implementation by its associated APIs. We reserve the right to
    /// change it in the future.
    /// </remarks>
    public interface INamespaceOrTypeSymbol : ISymbol
    {
        /// <summary>
        /// Get all the members of this symbol.
        /// </summary>
        /// <returns>An ImmutableArray containing all the members of this symbol. If this symbol has no members,
        /// returns an empty ImmutableArray. Never returns Null.</returns>
        ImmutableArray<ISymbol> GetMembers();

        /// <summary>
        /// Get all the members of this symbol that have a particular name.
        /// </summary>
        /// <returns>An ImmutableArray containing all the members of this symbol with the given name. If there are
        /// no members with this name, returns an empty ImmutableArray. Never returns Null.</returns>
        ImmutableArray<ISymbol> GetMembers(string name);

        /// <summary>
        /// Get all the members of this symbol that are types.
        /// </summary>
        /// <returns>An ImmutableArray containing all the types that are members of this symbol. If this symbol has no type members,
        /// returns an empty ImmutableArray. Never returns null.</returns>
        ImmutableArray<INamedTypeSymbol> GetTypeMembers();

        /// <summary>
        /// Get all the members of this symbol that are types that have a particular name, of any arity.
        /// </summary>
        /// <returns>An ImmutableArray containing all the types that are members of this symbol with the given name.
        /// If this symbol has no type members with this name,
        /// returns an empty ImmutableArray. Never returns null.</returns>
        ImmutableArray<INamedTypeSymbol> GetTypeMembers(string name);

        /// <summary>
        /// Get all the members of this symbol that are types that have a particular name and arity
        /// </summary>
        /// <returns>An ImmutableArray containing all the types that are members of this symbol with the given name and arity.
        /// If this symbol has no type members with this name and arity,
        /// returns an empty ImmutableArray. Never returns null.</returns>
        ImmutableArray<INamedTypeSymbol> GetTypeMembers(string name, int arity);

        /// <summary>
        /// Returns true if this symbol is a namespace. If it is not a namespace, it must be a type.
        /// </summary>
        bool IsNamespace { get; }

        /// <summary>
        /// Returns true if this symbols is a type. If it is not a type, it must be a namespace.
        /// </summary>
        bool IsType { get; }
    }
}