gitignore moment

.gitignore

@@ -159,10 +159,6 @@ publish/
 
 # NuGet Packages
 *.nupkg
-# The packages folder can be ignored because of Package Restore
-**/packages/*
-# except build/, which is used as an MSBuild target.
-!**/packages/build/
 # Uncomment if necessary however generally it will be regenerated when needed
 #!**/packages/repositories.config
 # NuGet v3's project.json files produces more ignoreable files

Torch/Packages/PackageManager.cs

@@ -0,0 +1,162 @@
+#nullable enable
+using System;
+using System.Collections.Generic;
+using System.Collections.Immutable;
+using System.IO;
+using System.Linq;
+using System.Reflection;
+using System.Runtime.Loader;
+using System.Security.Cryptography;
+using System.Text;
+using System.Threading;
+using System.Threading.Tasks;
+using NLog;
+using Torch.API;
+using Torch.API.Managers;
+using Torch.API.WebAPI.Plugins;
+using Torch.Managers;
+using Torch.Utils;
+
+namespace Torch.Packages;
+
+public class PackageManager : Manager, IPackageManager
+{
+    private readonly PluginManager _pluginManager;
+    private static readonly ILogger Log = LogManager.GetCurrentClassLogger();
+
+    private IPackageResolver? _packageResolver;
+
+    public PackageManager(ITorchBase torchInstance, PluginManager pluginManager) : base(torchInstance)
+    {
+        _pluginManager = pluginManager;
+    }
+
+    private AssemblyLoadContext? _loadContext;
+
+    private ImmutableHashSet<Package> _packages = ImmutableHashSet<Package>.Empty;
+    private ImmutableDictionary<Package,Assembly[]> _packageAssemblies = ImmutableDictionary<Package, Assembly[]>.Empty;
+    private DirectoryInfo? _packagesDirectory;
+    public IReadOnlySet<Package> Packages => _packages;
+    
+    public bool TryGetPackageAssemblies(Package package, out Assembly[]? assemblies)
+    {
+        if (!Packages.Contains(package))
+            throw new InvalidOperationException($"Package {package.Name} does not exist");
+        
+        return _packageAssemblies.TryGetValue(package, out assemblies);
+    }
+
+    internal async void LoadAsync(SemaphoreSlim semaphore)
+    {
+        _packagesDirectory = Directory.CreateDirectory(Path.Combine(Torch.InstancePath, "Packages"));
+        _packageResolver = new PackageResolver(new[]
+        { // TODO make this configurable
+            new PackageSource("nuget", "https://api.nuget.org/v3/index.json", new[] { "*" }, PackageSourceType.NuGet)
+        }, _packagesDirectory);
+        
+        try
+        {
+            var packages =
+                Torch.Config.Packages.ToImmutableDictionary(b => b[..b.IndexOf(':')], b => b[(b.IndexOf(':') + 1)..]);
+            await ResolvePackagesAsync(packages);
+
+            var resolvedPackages = await _packages.ToAsyncEnumerable()
+                                                  .SelectAwait(async b =>
+                                                  {
+                                                      var reader = await _packageResolver!.GetPackageAsync(b);
+                                                      var items = await reader.GetItemsAsync();
+
+                                                      return (b, items);
+                                                  }).ToDictionaryAsync(b => b.b.Name, b => b,
+                                                                       StringComparer.OrdinalIgnoreCase);
+
+            var dependencies = new Dictionary<PackageDependency, IEnumerable<IPackageItem>>(
+                resolvedPackages.Values.SelectMany(b => b.items.Dependencies)
+                                .Where(b => !resolvedPackages.ContainsKey(b.Key.Name))
+                                .GroupBy(b => b.Key.Name)
+                                .Select(b => b.MaxBy(c => c.Key.Version)));
+
+            _loadContext = new("PackageManager Context");
+
+            var dependencyAssemblies = await dependencies.ToAsyncEnumerable().SelectAwait(async pair =>
+            {
+                var (dep, items) = pair;
+                var assemblies = await LoadAssembliesFromItems(items);
+
+                return (dep, assemblies);
+            }).ToDictionaryAsync(b => b.dep, b => b.assemblies);
+
+            var packageAssemblies = await resolvedPackages.Values.ToAsyncEnumerable().SelectAwait(async b =>
+            {
+                var assemblies = await LoadAssembliesFromItems(b.items.Root);
+
+                return (b.b, assemblies);
+            }).ToDictionaryAsync(b => b.b, b => b.assemblies);
+
+            foreach (var assembly in dependencyAssemblies.Values.Concat(packageAssemblies.Values).SelectMany(b => b))
+            {
+                TorchLauncher.RegisterAssembly(assembly);
+            }
+
+            foreach (var (package, assemblies) in packageAssemblies)
+            {
+                using var hash = MD5.Create();
+                hash.Initialize();
+                var guid = new Guid(hash.ComputeHash(Encoding.UTF8.GetBytes(package.Name)));
+                
+                _pluginManager.InstantiatePlugin(new()
+                {
+                    Name = package.Name,
+                    Version = package.Version.ToString(),
+                    Guid = guid
+                }, assemblies);
+            }
+
+            _packageAssemblies = packageAssemblies.ToImmutableDictionary();
+        }
+        finally
+        {
+            semaphore.Release();
+        }
+    }
+
+    private async Task<Assembly[]> LoadAssembliesFromItems(IEnumerable<IPackageItem> items)
+    {
+        var dictionary = items.ToImmutableDictionary(b => b.FileName, StringComparer.OrdinalIgnoreCase);
+
+        var assemblies = await dictionary
+                               .Where(b => Path.GetExtension(b.Key)
+                                               .Equals("dll", StringComparison.OrdinalIgnoreCase))
+                               .ToAsyncEnumerable()
+                               .SelectAwait(async b =>
+                               {
+                                   dictionary.TryGetValue(
+                                       Path.ChangeExtension(b.Key, "pdb"), out var pdbItem);
+                                   return await LoadFromStream(b.Key, b.Value, pdbItem);
+                               }).ToArrayAsync();
+        return assemblies;
+    }
+
+    private async ValueTask<Assembly> LoadFromStream(string key, IPackageItem dllItem, IPackageItem? pdbItem)
+    {
+        if (_loadContext is null)
+            throw new InvalidOperationException("Load Context should be initialized before calling the method");
+
+        Log.Trace("Loading {0}", key);
+        await using var dll = await dllItem.OpenFileAsync();
+        if (pdbItem is null)
+            return _loadContext.LoadFromStream(dll);
+
+        await using var pdb = await pdbItem.OpenFileAsync();
+        return _loadContext.LoadFromStream(dll, pdb);
+    }
+
+    private async Task ResolvePackagesAsync(IReadOnlyDictionary<string, string> requestedPackages)
+    {
+        Log.Info("Resolving packages");
+        var packages = await _packageResolver!.ResolvePackagesAsync(requestedPackages);
+
+        _packages = packages.ToImmutableHashSet();
+        Log.Info("Got {0} packages", _packages.Count);
+    }
+}