﻿// 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(
            ISymbol symbol,
            bool isVariadic,
            Func<CancellationToken, IEnumerable<TaggedText>>? documentationFactory,
            IEnumerable<TaggedText> prefixParts,
            IEnumerable<TaggedText> separatorParts,
            IEnumerable<TaggedText> suffixParts,
            IEnumerable<SignatureHelpParameter> parameters,
            IEnumerable<TaggedText>? descriptionParts) : SignatureHelpItem(isVariadic, documentationFactory, prefixParts, separatorParts, suffixParts, parameters, descriptionParts), IEquatable<SymbolKeySignatureHelpItem>
        {
            public SymbolKey? SymbolKey { get; } = 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);
            }
        }
    }
}
