using System;
using System.Xml.Linq;
using System.Linq;
using System.IO;
using System.IO.Compression;
using System.Reflection;

class Driver {
	static ZipArchiveEntry FindSpecFile (ZipArchive zip) {
		foreach (var entry in zip.Entries) {
			if (entry.Name.EndsWith (".nuspec"))
				return entry;
		}
		throw new Exception ("Could not find nuspec file");
	}

	static void DumpNuget (string nupkg) {
		var zip = new ZipArchive(new FileStream (nupkg, FileMode.Open));

		var nuspec = FindSpecFile (zip);
		var l = XElement.Load (new StreamReader (nuspec.Open ()));
		var version = (from el in l.Descendants() where el.Name.LocalName == "version" select el.Value).FirstOrDefault ();

		//
		// Logic copied from https://github.com/NuGet/NuGet.Client/blob/4cccb13833ad29d6a0bcff055460d964f1b49cfe/src/NuGet.Core/NuGet.Frameworks/DefaultFrameworkMappings.cs#L385
		//
		var entries = from e in zip.Entries where e.FullName.StartsWith ("lib/net4") && e.Name.EndsWith (".dll") select e;
		if (!entries.Any ()) {
			entries = from e in zip.Entries where e.FullName.StartsWith ("lib/netstandard1") && e.Name.EndsWith (".dll") select e;
		}

		foreach (var et in entries) {
			LoadAndDump (et, version);
		}
	}

	static bool dump_asm, dump_ver, dump_guids_for_msbuild;
	static void Main (string[] args) {

		if (args.Length > 1) {
			dump_asm = args [1].Equals ("asm");
			dump_ver = args [1].Equals ("ver");
			dump_guids_for_msbuild = args [1].Equals ("guids_for_msbuild");
		} else {
			dump_asm = true;
		}
		foreach (var f in Directory.GetFiles (args [0], "*.nupkg")) {
			DumpNuget (f);
		}
	}

	static byte[] StreamToArray (Stream s) {
		using(var ms = new MemoryStream ()) {
			s.CopyTo (ms);
			return ms.ToArray ();
		}
	}

	static int domain_id = 1;
	static void LoadAndDump (ZipArchiveEntry entry, string version) {
		// Console.WriteLine ("Dumping {0}", entry);
		var data = StreamToArray (entry.Open ());
		AppDomain ad = AppDomain.CreateDomain ("parse_" + ++domain_id);
		DoParse p = (DoParse)ad.CreateInstanceAndUnwrap (typeof (DoParse).Assembly.FullName, typeof (DoParse).FullName);
		p.ParseAssembly (data, version, entry.Name, entry.FullName, dump_asm, dump_ver, dump_guids_for_msbuild);
		AppDomain.Unload (ad);
	}
}

class DoParse : MarshalByRefObject {

	static int Hash (string str) {
		int h = 5381;
        for (int i = 0;  i < str.Length; ++i)
            h = ((h << 5) + h) ^ str[i];
		return h;
	}
	static string FileToEnum (string name) {
		switch (name) {
		case "System.Runtime.InteropServices.RuntimeInformation.dll": return "SYS_RT_INTEROP_RUNTIME_INFO";
		case "System.Globalization.Extensions.dll": return "SYS_GLOBALIZATION_EXT";
		case "System.IO.Compression.dll": return "SYS_IO_COMPRESSION";
		case "System.Net.Http.dll": return "SYS_NET_HTTP";
		case "System.Text.Encoding.CodePages.dll": return "SYS_TEXT_ENC_CODEPAGES";
		case "System.Reflection.DispatchProxy.dll": return "SYS_REF_DISP_PROXY";
		case "System.Threading.Overlapped.dll": return "SYS_THREADING_OVERLAPPED";
		default: throw new Exception ($"No idea what to do with {name}");
		}
	}

	static string FileToMoniker (string p) {
		var parts = p.Split (Path.DirectorySeparatorChar);
		return parts[parts.Length - 2];
	}

	public void ParseAssembly (byte[] data, string version, string name, string fullname, bool dump_asm, bool dump_ver, bool dump_guids_for_msbuild) {
		var a = Assembly.ReflectionOnlyLoad (data);
		var m = a.GetModules ()[0];
		var id = m.ModuleVersionId.ToString ().ToUpper ();
		var hash_code = Hash (id).ToString ("X");
		var str = FileToEnum (name);

		string ver_str = version + " " + FileToMoniker (fullname);	

		if (dump_asm)
			Console.WriteLine ($"IGNORED_ASSEMBLY (0x{hash_code}, {str}, \"{id}\", \"{ver_str}\"),");

		//IGNORED_ASM_VER (SYS_IO_COMPRESSION, 4, 1, 2, 0),
		var ver = a.GetName ().Version;
		if (dump_ver) {
			Console.WriteLine ($"IGNORED_ASM_VER ({str}, {ver.Major}, {ver.Minor}, {ver.Build}, {ver.Revision}),");
		} else if (dump_guids_for_msbuild) {
			// This needs to be kept in sync with FilterDeniedAssemblies msbuild task in msbuild
			Console.WriteLine ($"{name},{id},{ver.Major},{ver.Minor},{ver.Build},{ver.Revision}");
		}
		
	}
}