// 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 Microsoft.CodeAnalysis.Shared.Extensions;

namespace Microsoft.CodeAnalysis
{
    internal partial struct SymbolKey
    {
        private static class TypeParameterSymbolKey
        {
            public static void Create(ITypeParameterSymbol symbol, SymbolKeyWriter visitor)
            {
                if (symbol.TypeParameterKind == TypeParameterKind.Cref)
                {
                    visitor.WriteBoolean(true);
                    visitor.WriteLocation(symbol.Locations[0]);
                }
                else
                {
                    visitor.WriteBoolean(false);
                    visitor.WriteString(symbol.MetadataName);
                    visitor.WriteSymbolKey(symbol.ContainingSymbol);
                }
            }

            public static SymbolKeyResolution Resolve(SymbolKeyReader reader)
            {
                var isCref = reader.ReadBoolean();

                if (isCref)
                {
                    var location = reader.ReadLocation();
                    var resolution = reader.ResolveLocation(location);
                    return resolution.GetValueOrDefault();
                }
                else
                {
                    var metadataName = reader.ReadString();
                    var containingSymbolResolution = reader.ReadSymbolKey();

                    using var result = PooledArrayBuilder<ITypeParameterSymbol>.GetInstance();
                    foreach (var containingSymbol in containingSymbolResolution)
                    {
                        foreach (var typeParam in containingSymbol.GetTypeParameters())
                        {
                            if (typeParam.MetadataName == metadataName)
                            {
                                result.AddIfNotNull(typeParam);
                            }
                        }
                    }

                    return CreateResolution(result);
                }
            }
        }
    }
}