// 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 [];
        }

        return [_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);
}