// 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.Linq;
using Microsoft.VisualStudio.Utilities;
 
namespace Microsoft.CodeAnalysis.Editor.Shared.Extensions;
 
/// <summary>
/// Helper class to perform ContentType best-match against a set of extensions. This could
/// become a public service.
/// </summary>
internal static class MefExtensions
{
    /// <summary>
    /// Given a list of extensions that provide content types, filter the list and return that
    /// subset which matches the given content type
    /// </summary>
    public static IList<Lazy<TExtension, TMetadata>> SelectMatchingExtensions<TExtension, TMetadata>(
        this IEnumerable<Lazy<TExtension, TMetadata>> extensions,
        params IContentType[] contentTypes)
        where TMetadata : IContentTypeMetadata
    {
        return extensions.SelectMatchingExtensions((IEnumerable<IContentType>)contentTypes);
    }
 
    /// <summary>
    /// Given a list of extensions that provide content types, filter the list and return that
    /// subset which matches any of the given content types.
    /// </summary>
    public static IList<Lazy<TExtension, TMetadata>> SelectMatchingExtensions<TExtension, TMetadata>(
        this IEnumerable<Lazy<TExtension, TMetadata>> extensions,
        IEnumerable<IContentType> contentTypes)
        where TMetadata : IContentTypeMetadata
    {
        return extensions.Where(h => contentTypes.Any(d => d.MatchesAny(h.Metadata.ContentTypes))).ToList();
    }
 
    public static IList<TExtension> SelectMatchingExtensionValues<TExtension, TMetadata>(
        this IEnumerable<Lazy<TExtension, TMetadata>> extensions,
        params IContentType[] contentTypes)
        where TMetadata : IContentTypeMetadata
    {
        return extensions.SelectMatchingExtensions(contentTypes).Select(p => p.Value).ToList();
    }
 
    public static Lazy<TExtension, TMetadata> SelectMatchingExtension<TExtension, TMetadata>(
        this IEnumerable<Lazy<TExtension, TMetadata>> extensions,
        params IContentType[] contentTypes)
        where TMetadata : IContentTypeMetadata
    {
        return extensions.SelectMatchingExtensions(contentTypes).Single();
    }
 
    public static TExtension SelectMatchingExtensionValue<TExtension, TMetadata>(
        this IEnumerable<Lazy<TExtension, TMetadata>> extensions,
        params IContentType[] contentTypes)
        where TMetadata : IContentTypeMetadata
    {
        return extensions.SelectMatchingExtension(contentTypes).Value;
    }
}