// 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.Immutable;
using System.Diagnostics;
using Roslyn.Utilities;
 
namespace Microsoft.CodeAnalysis.Host
{
    internal sealed class WorkspaceMetadataFileReferenceResolver : MetadataReferenceResolver, IEquatable<WorkspaceMetadataFileReferenceResolver>
    {
        private readonly IMetadataService _metadataService;
        internal readonly RelativePathResolver PathResolver;
 
        public WorkspaceMetadataFileReferenceResolver(IMetadataService metadataService, RelativePathResolver pathResolver)
        {
            Debug.Assert(metadataService != null);
            Debug.Assert(pathResolver != null);
 
            _metadataService = metadataService;
            PathResolver = pathResolver;
        }
 
        public override ImmutableArray<PortableExecutableReference> ResolveReference(string reference, string baseFilePath, MetadataReferenceProperties properties)
        {
            var path = PathResolver.ResolvePath(reference, baseFilePath);
            if (path == null)
            {
                return ImmutableArray<PortableExecutableReference>.Empty;
            }
 
            return ImmutableArray.Create(_metadataService.GetReference(path, properties));
        }
 
        public bool Equals(WorkspaceMetadataFileReferenceResolver other)
        {
            return other != null
                && _metadataService == other._metadataService
                && PathResolver.Equals(other.PathResolver);
        }
 
        public override int GetHashCode()
            => Hash.Combine(_metadataService, Hash.Combine(PathResolver, 0));
 
        public override bool Equals(object other) => Equals(other as WorkspaceMetadataFileReferenceResolver);
    }
}