// 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.

namespace Microsoft.CodeAnalysis;

internal partial struct SymbolKey
{
    private sealed class ArrayTypeSymbolKey : AbstractSymbolKey<IArrayTypeSymbol>
    {
        public static readonly ArrayTypeSymbolKey Instance = new();

        public sealed override void Create(IArrayTypeSymbol symbol, SymbolKeyWriter visitor)
        {
            visitor.WriteSymbolKey(symbol.ElementType);
            visitor.WriteInteger(symbol.Rank);
        }

        protected sealed override SymbolKeyResolution Resolve(
            SymbolKeyReader reader, IArrayTypeSymbol? contextualSymbol, out string? failureReason)
        {
            var elementTypeResolution = reader.ReadSymbolKey(contextualSymbol?.ElementType, out var elementTypeFailureReason);
            var rank = reader.ReadInteger();

            if (elementTypeFailureReason != null)
            {
                failureReason = $"({nameof(ArrayTypeSymbolKey)} {nameof(elementTypeResolution)} failed -> {elementTypeFailureReason})";
                return default;
            }

            using var result = PooledArrayBuilder<IArrayTypeSymbol>.GetInstance(elementTypeResolution.SymbolCount);
            foreach (var typeSymbol in elementTypeResolution.OfType<ITypeSymbol>())
                result.AddIfNotNull(reader.Compilation.CreateArrayTypeSymbol(typeSymbol, rank));

            return CreateResolution(result, $"({nameof(ArrayTypeSymbolKey)})", out failureReason);
        }
    }
}