// Licensed to the .NET Foundation under one or more agreements.
// The .NET Foundation licenses this file to you under the MIT license.
 
using Microsoft.Build.Framework;
using Microsoft.Build.Utilities;
using System;
using System.IO;
using System.IO.Compression;
using System.Linq;
using System.Reflection.PortableExecutable;
using System.Threading;
 
namespace Microsoft.DotNet.Arcade.Sdk
{
#if NET472
    [LoadInSeparateAppDomain]
    public sealed class Unsign : AppDomainIsolatedTask
    {
        static Unsign() => AssemblyResolution.Initialize();
#else
    public class Unsign : Microsoft.Build.Utilities.Task
    {
#endif
        [Required]
        public string FilePath { get; set; }
 
        public override bool Execute()
        {
#if NET472
            AssemblyResolution.Log = Log;
#endif
            try
            {
                ExecuteImpl();
                return !Log.HasLoggedErrors;
            }
            finally
            {
#if NET472
                AssemblyResolution.Log = null;
#endif
            }
        }
 
        private void ExecuteImpl()
        {
            using (var stream = File.Open(FilePath, FileMode.Open, FileAccess.ReadWrite, FileShare.Read))
            using (var peReader = new PEReader(stream))
            {
                var headers = peReader.PEHeaders;
                var entry = headers.PEHeader.CertificateTableDirectory;
                if (entry.Size == 0)
                {
                    return;
                }
 
                using (var writer = new BinaryWriter(stream))
                {
                    int certificateTableDirectoryOffset = (headers.PEHeader.Magic == PEMagic.PE32Plus) ? 144 : 128;
                    stream.Position = peReader.PEHeaders.PEHeaderStartOffset + certificateTableDirectoryOffset;
 
                    writer.Write((long)0);
                    writer.Flush();
                }
            }
        }
    }
}