// 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.IO;
using System.Reflection;
using System.Runtime.InteropServices;
using Roslyn.Utilities;
 
namespace BuildValidator
{
    internal static class IldasmUtilities
    {
        private static string GetArchitecture()
        {
#if NET8_0_OR_GREATER
            return RuntimeInformation.ProcessArchitecture.ToString().ToLowerInvariant();
#else
            return "x64";
#endif
        }
 
        private static string GetIldasmPath()
        {
            var ildasmExeName = PlatformInformation.IsWindows ? "ildasm.exe" : "ildasm";
            var directory = Path.GetDirectoryName(typeof(IldasmUtilities).GetTypeInfo().Assembly.Location) ?? throw new DirectoryNotFoundException();
            string ridName;
            if (RuntimeInformation.IsOSPlatform(OSPlatform.Windows))
            {
                ridName = "win-x64";
            }
            else if (RuntimeInformation.IsOSPlatform(OSPlatform.OSX))
            {
                ridName = "osx-x64";
            }
            else if (RuntimeInformation.IsOSPlatform(OSPlatform.Linux))
            {
                ridName = $"linux-{GetArchitecture()}";
            }
            else
            {
                throw new PlatformNotSupportedException();
            }
 
            return Path.Combine(directory, "runtimes", ridName, "native", ildasmExeName);
        }
 
        internal static readonly string IldasmPath = GetIldasmPath();
    }
}