// 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.Collections.Immutable;
using System.Threading;
using System.Threading.Tasks;
using Roslyn.Utilities;
 
namespace Microsoft.CodeAnalysis.FindSymbols
{
    internal sealed partial class TopLevelSyntaxTreeIndex : AbstractSyntaxIndex<TopLevelSyntaxTreeIndex>
    {
        private readonly DeclarationInfo _declarationInfo;
        private readonly ExtensionMethodInfo _extensionMethodInfo;
 
        private readonly Lazy<HashSet<DeclaredSymbolInfo>> _declaredSymbolInfoSet;
 
        private TopLevelSyntaxTreeIndex(
            Checksum? checksum,
            DeclarationInfo declarationInfo,
            ExtensionMethodInfo extensionMethodInfo)
            : base(checksum)
        {
            _declarationInfo = declarationInfo;
            _extensionMethodInfo = extensionMethodInfo;
 
            _declaredSymbolInfoSet = new(() => new(this.DeclaredSymbolInfos));
        }
 
        public ImmutableArray<DeclaredSymbolInfo> DeclaredSymbolInfos => _declarationInfo.DeclaredSymbolInfos;
 
        /// <summary>
        /// Same as <see cref="DeclaredSymbolInfos"/>, just stored as a set for easy containment checks.
        /// </summary>
        public HashSet<DeclaredSymbolInfo> DeclaredSymbolInfoSet => _declaredSymbolInfoSet.Value;
 
        public ImmutableDictionary<string, ImmutableArray<int>> ReceiverTypeNameToExtensionMethodMap
            => _extensionMethodInfo.ReceiverTypeNameToExtensionMethodMap;
 
        public bool ContainsExtensionMethod
            => _extensionMethodInfo.ContainsExtensionMethod;
 
        public static ValueTask<TopLevelSyntaxTreeIndex> GetRequiredIndexAsync(Document document, CancellationToken cancellationToken)
            => GetRequiredIndexAsync(document, ReadIndex, CreateIndex, cancellationToken);
 
        public static ValueTask<TopLevelSyntaxTreeIndex?> GetIndexAsync(Document document, CancellationToken cancellationToken)
            => GetIndexAsync(document, ReadIndex, CreateIndex, cancellationToken);
 
        [PerformanceSensitive("https://devdiv.visualstudio.com/DevDiv/_workitems/edit/1224834", OftenCompletesSynchronously = true)]
        public static ValueTask<TopLevelSyntaxTreeIndex?> GetIndexAsync(Document document, bool loadOnly, CancellationToken cancellationToken)
            => GetIndexAsync(document, loadOnly, ReadIndex, CreateIndex, cancellationToken);
    }
}