// 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.Collections.Generic;
using System.Collections.Immutable;
using System.Threading;
using System.Threading.Tasks;
using Microsoft.CodeAnalysis.Completion;
using Microsoft.CodeAnalysis.Completion.Providers;
using Microsoft.CodeAnalysis.LanguageService;
using Roslyn.Utilities;
 
namespace Microsoft.CodeAnalysis.CSharp.Completion.Providers;
 
internal sealed partial class UnnamedSymbolCompletionProvider
{
    private readonly ImmutableArray<KeyValuePair<string, string>> IndexerProperties =
        [KeyValuePairUtil.Create(KindName, IndexerKindName)];
 
    private void AddIndexers(CompletionContext context, ImmutableArray<ISymbol> indexers)
    {
        if (indexers.Length == 0)
            return;
 
        context.AddItem(SymbolCompletionItem.CreateWithSymbolId(
            displayText: "this",
            displayTextSuffix: "[]",
            filterText: "this",
            sortText: "this",
            symbols: indexers,
            rules: CompletionItemRules.Default,
            contextPosition: context.Position,
            properties: IndexerProperties,
            isComplexTextEdit: true));
    }
 
    // Remove the dot, but leave the ? if one is there.  Place the caret one space back so it is between the braces.
    private static Task<CompletionChange> GetIndexerChangeAsync(Document document, CompletionItem item, CancellationToken cancellationToken)
        => ReplaceTextAfterOperatorAsync(document, item, text: "[]", keepQuestion: true, positionOffset: -1, cancellationToken);
 
    private static Task<CompletionDescription> GetIndexerDescriptionAsync(Document document, CompletionItem item, SymbolDescriptionOptions options, CancellationToken cancellationToken)
        => SymbolCompletionItem.GetDescriptionAsync(item, document, options, cancellationToken);
}