// 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.Threading;
 
namespace Microsoft.CodeAnalysis.SignatureHelp
{
    internal abstract partial class AbstractSignatureHelpProvider
    {
        internal class SymbolKeySignatureHelpItem : SignatureHelpItem, IEquatable<SymbolKeySignatureHelpItem>
        {
            public SymbolKey? SymbolKey { get; }
 
            public SymbolKeySignatureHelpItem(
                ISymbol symbol,
                bool isVariadic,
                Func<CancellationToken, IEnumerable<TaggedText>>? documentationFactory,
                IEnumerable<TaggedText> prefixParts,
                IEnumerable<TaggedText> separatorParts,
                IEnumerable<TaggedText> suffixParts,
                IEnumerable<SignatureHelpParameter> parameters,
                IEnumerable<TaggedText>? descriptionParts)
                : base(isVariadic, documentationFactory, prefixParts, separatorParts, suffixParts, parameters, descriptionParts)
            {
                SymbolKey = symbol?.GetSymbolKey();
            }
 
            public override bool Equals(object? obj)
                => Equals(obj as SymbolKeySignatureHelpItem);
 
            public bool Equals(SymbolKeySignatureHelpItem? obj)
            {
                return ReferenceEquals(this, obj) ||
                    (obj?.SymbolKey != null &&
                     SymbolKey != null &&
                     CodeAnalysis.SymbolKey.GetComparer(ignoreCase: false, ignoreAssemblyKeys: false).Equals(SymbolKey.Value, obj.SymbolKey.Value));
            }
 
            public override int GetHashCode()
            {
                if (SymbolKey == null)
                {
                    return 0;
                }
 
                var comparer = CodeAnalysis.SymbolKey.GetComparer(ignoreCase: false, ignoreAssemblyKeys: false);
                return comparer.GetHashCode(SymbolKey.Value);
            }
        }
    }
}