// 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.
 
#nullable disable
 
using System;
using System.Collections.Generic;
using System.Collections.Immutable;
using System.Composition;
using System.Linq;
using System.Threading;
using System.Threading.Tasks;
using Microsoft.CodeAnalysis.Host.Mef;
 
namespace Microsoft.CodeAnalysis.BraceMatching;
 
[Export(typeof(IBraceMatchingService)), Shared]
[method: ImportingConstructor]
[method: Obsolete(MefConstruction.ImportingConstructorMessage, error: true)]
internal sealed class BraceMatchingService(
    [ImportMany] IEnumerable<Lazy<IBraceMatcher, LanguageMetadata>> braceMatchers) : IBraceMatchingService
{
    private readonly ImmutableArray<Lazy<IBraceMatcher, LanguageMetadata>> _braceMatchers = braceMatchers.ToImmutableArray();
 
    public async Task<BraceMatchingResult?> GetMatchingBracesAsync(Document document, int position, BraceMatchingOptions options, CancellationToken cancellationToken)
    {
        var text = await document.GetValueTextAsync(cancellationToken).ConfigureAwait(false);
        if (position < 0 || position > text.Length)
        {
            throw new ArgumentException(nameof(position));
        }
 
        var matchers = _braceMatchers.Where(b => b.Metadata.Language == document.Project.Language);
        foreach (var matcher in matchers)
        {
            cancellationToken.ThrowIfCancellationRequested();
            var braces = await matcher.Value.FindBracesAsync(document, position, options, cancellationToken).ConfigureAwait(false);
            if (braces.HasValue)
            {
                return braces;
            }
        }
 
        return null;
    }
}