#nullable enable
using System;
using System.Runtime.CompilerServices;
using System.Runtime.InteropServices;
using Xunit;

namespace Avalonia
{
    [Flags]
    internal enum TestPlatforms
    {
        Windows = 0x01,
        MacOS = 0x02,
        Linux = 0x04,
        All = Windows | MacOS | Linux,
    }

    internal class PlatformFactAttribute : FactAttribute
    {
        public PlatformFactAttribute(
            TestPlatforms platforms,
            string? reason = null,
            [CallerFilePath] string? sourceFilePath = null,
            [CallerLineNumber] int sourceLineNumber = -1)
            : base(sourceFilePath, sourceLineNumber)
        {
            Platforms = platforms;
            if (!IsSupported())
                Skip = $"Ignored on {RuntimeInformation.OSDescription}" +
                        (reason is not null ? $" reason: '{reason}'" : "");

        }

        public TestPlatforms Platforms { get; }

        private bool IsSupported()
        {
            if (RuntimeInformation.IsOSPlatform(OSPlatform.Windows))
                return Platforms.HasFlag(TestPlatforms.Windows);
            if (RuntimeInformation.IsOSPlatform(OSPlatform.OSX))
                return Platforms.HasFlag(TestPlatforms.MacOS);
            if (RuntimeInformation.IsOSPlatform(OSPlatform.Linux))
                return Platforms.HasFlag(TestPlatforms.Linux);
            return false;
        }
    }
}