#!/usr/bin/env /Library/Frameworks/Mono.framework/Commands/csharp

// arguments are: <platform> <outputPath> <inputDirectory> <version>

using System.IO;
using System.Security.Cryptography;
using System.Text;
using System.Xml;

var args = Environment.GetCommandLineArgs ();
var expectedArgumentCount = 4;
if (args.Length != expectedArgumentCount + 2 /* 2 default arguments (executable + script) + 'expectedArgumentCount' arguments we're interested in */) {
	// first arg is "/Library/Frameworks/Mono.framework/Versions/4.8.0/lib/mono/4.5/csharp.exe"
	// second arg the script itself
	// then comes the ones we care about
	Console.WriteLine ($"Need {expectedArgumentCount} arguments, got {args.Length - 2}");
	Environment.Exit (1);
	return;
}

var platform = args [2];
var outputPath = args [3];
var inputDirectory = args [4];
var version = args [5];

string upgradeGuid;

switch (platform) {
	case "iOS":
		upgradeGuid = "e17c20f4-e9a6-445a-915a-dac336097012";
		break;
	case "tvOS":
		upgradeGuid = "951a188f-e59a-4db1-bc42-b3ca47edb4c6";
		break;
	case "watchOS":
		upgradeGuid = "b365f5c9-6bbf-4c66-957a-8868576b4ddc";
		break;
	case "macOS":
		upgradeGuid = "b64a436b-db46-4467-953c-bdcfc592d4da";
		break;
	default:
		Console.Error.WriteLine ($"Need to generate an upgradeGuid for {platform}");
		break;
}

List<string> components = new List<string> ();

Func<string, byte[]> GetHash = (string inputString) =>
{
	using (var algorithm = SHA256.Create ())
		return algorithm.ComputeHash (Encoding.UTF8.GetBytes (inputString));
};

Func<string, string> GetHashString = (string inputString) =>
{
	var sb = new StringBuilder ("S", 65);
	foreach (byte b in GetHash (inputString))
		sb.Append (b.ToString ("X2"));
		Console.WriteLine ($"{inputString} => {sb.ToString ()}");
	return sb.ToString ();
};

Func<string, string> GetId = (string path) =>
{
	var top_dir = inputDirectory;
	if (string.IsNullOrEmpty (path))
		return path;
	if (path.Length > top_dir.Length + 1) {
		path = path.Substring (top_dir.Length + 1);
	}
	return GetHashString (path);
};

Action<TextWriter, string, string> process = new Action<TextWriter, string, string> ((TextWriter writer, string indent, string directory) =>
{
	var entries = Directory.GetFileSystemEntries (directory);
	foreach (var entry in entries) {
		var name = Path.GetFileName (entry);
		var id = GetId (entry);
		if (Directory.Exists (entry)) {
			writer.WriteLine ($"{indent}  <Directory Id=\"{id}\" Name=\"{name}\">");
			process (writer, indent + "  ", entry);
			writer.WriteLine ($"{indent}  </Directory>");
		} else {
			components.Add (id);
			writer.WriteLine ($"{indent}  <Component Id=\"{id}\" Guid=\"*\">");
			writer.WriteLine ($"{indent}    <File Id=\"file_{id}\" Name=\"{name}\" KeyPath=\"yes\" Source=\"{entry}\" />");
			writer.WriteLine ($"{indent}  </Component>");
		}
	}
});

using (TextWriter writer = new StreamWriter (outputPath)) {

	writer.WriteLine ($"<?xml version=\"1.0\" encoding=\"UTF-8\"?>");
	writer.WriteLine ($"<Wix xmlns=\"http://schemas.microsoft.com/wix/2006/wi\">");
	writer.WriteLine ($"  <Product Name=\"Microsoft.NET.Workload.{platform}\" Id=\"*\" Language=\"1033\" Version=\"{version}\" Manufacturer=\"Microsoft\" UpgradeCode=\"{upgradeGuid}\">");
	writer.WriteLine ($"    <Package Id=\"*\" InstallerVersion=\"200\" Compressed=\"yes\" InstallScope=\"perMachine\" />");
	writer.WriteLine ($"    <MajorUpgrade DowngradeErrorMessage=\"A newer version of [ProductName] is already installed.\"/>");
	writer.WriteLine ($"    <MediaTemplate EmbedCab=\"yes\"/>");
	writer.WriteLine ($"    <Feature Id=\"ProductFeature\" Title=\"Microsoft.NET.Workload.{platform}\">");
	writer.WriteLine ($"      <ComponentGroupRef Id=\"ProductComponents\"/>");
	writer.WriteLine ($"    </Feature>");
	writer.WriteLine ($"  </Product>");
	writer.WriteLine ($"  <Fragment>");
	writer.WriteLine ($"    <Directory Id=\"TARGETDIR\" Name=\"SourceDir\">");
	writer.WriteLine ($"      <Directory Id=\"ProgramFiles64Folder\">");
	writer.WriteLine ($"        <Directory Id=\"dotnet\" Name=\"dotnet\">");
	process (writer, "        ", inputDirectory);
	writer.WriteLine ($"        </Directory>");
	writer.WriteLine ($"      </Directory>");
	writer.WriteLine ($"    </Directory>");
	writer.WriteLine ($"  </Fragment>");
	writer.WriteLine ($"  <Fragment>");
	writer.WriteLine ($"    <ComponentGroup Id=\"ProductComponents\">");
	foreach (var component in components)
		writer.WriteLine ($"      <ComponentRef Id=\"{component}\"/>");
	writer.WriteLine ($"    </ComponentGroup>");
	writer.WriteLine ($"  </Fragment>");
	writer.WriteLine ($"</Wix>");

}

Environment.Exit (0);