// 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.Composition;
 
namespace Microsoft.CodeAnalysis.Host.Mef;
 
/// <summary>
/// Use this attribute to declare a <see cref="IDynamicFileInfoProvider"/> implementation for MEF
/// </summary>
[MetadataAttribute]
[AttributeUsage(AttributeTargets.Class)]
internal sealed class ExportDynamicFileInfoProviderAttribute : ExportAttribute
{
    /// <summary>
    /// file extensions this <see cref="IDynamicFileInfoProvider"/> can handle such as cshtml
    /// 
    /// match will be done by <see cref="StringComparer.OrdinalIgnoreCase"/>
    /// </summary>
    public IEnumerable<string> Extensions { get; }
 
    public ExportDynamicFileInfoProviderAttribute(params string[] extensions)
        : base(typeof(IDynamicFileInfoProvider))
    {
        if (extensions?.Length == 0)
        {
            throw new ArgumentException(nameof(extensions));
        }
 
        Extensions = extensions;
    }
}