// 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 Roslyn.Utilities;

namespace Microsoft.CodeAnalysis.CodeLens;

internal sealed class LocationComparer : IEqualityComparer<Location>
{
    public static LocationComparer Instance { get; } = new LocationComparer();

    public bool Equals(Location x, Location y)
    {
        if (x != null && x.IsInSource && y != null && y.IsInSource)
        {
            return x.SourceSpan.Equals(y.SourceSpan) &&
                   x.SourceTree.FilePath.Equals(y.SourceTree.FilePath, StringComparison.OrdinalIgnoreCase);
        }

        return object.Equals(x, y);
    }

    public int GetHashCode(Location obj)
    {
        if (obj != null && obj.IsInSource)
        {
            return Hash.Combine(obj.SourceSpan.GetHashCode(),
               StringComparer.OrdinalIgnoreCase.GetHashCode(obj.SourceTree.FilePath));
        }

        return obj?.GetHashCode() ?? 0;
    }
}