#region License Information
/* HeuristicLab
 * Copyright (C) 2002-2012 Heuristic and Evolutionary Algorithms Laboratory (HEAL)
 *
 * This file is part of HeuristicLab.
 *
 * HeuristicLab is free software: you can redistribute it and/or modify
 * it under the terms of the GNU General Public License as published by
 * the Free Software Foundation, either version 3 of the License, or
 * (at your option) any later version.
 *
 * HeuristicLab is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 * GNU General Public License for more details.
 *
 * You should have received a copy of the GNU General Public License
 * along with HeuristicLab. If not, see <http://www.gnu.org/licenses/>.
 */
#endregion

using System;
using System.Collections.Generic;
using System.IO;
using System.Linq;
using System.Reflection;
using System.Text;
using HeuristicLab.PluginInfrastructure.Manager;

namespace HeuristicLab.PluginInfrastructure {

  /// <summary>
  /// The SandboxApplicationManager provides properties to retrieve the list of available plugins and applications.
  /// It also provides methods for type discovery and instantiation for types declared in plugins.
  /// The SandboxApplicationManager is used in sandboxed Application Domains where permissions are restricted and
  /// only partially-trusted code can be executed. 
  /// </summary>
  internal class WebApplicationManager : MarshalByRefObject, IApplicationManager {
    // private class to store plugin dependency declarations while reflecting over plugins
    private class PluginDependency {
      public string Name { get; private set; }
      public Version Version { get; private set; }

      public PluginDependency(string name, Version version) {
        this.Name = name;
        this.Version = version;
      }
    }

    /// <summary>
    /// Fired when a plugin is loaded.
    /// </summary>
    internal event EventHandler<PluginInfrastructureEventArgs> PluginLoaded;
    /// <summary>
    /// Fired when a plugin is unloaded (when the application terminates).
    /// </summary>
    internal event EventHandler<PluginInfrastructureEventArgs> PluginUnloaded;

    // cache for the AssemblyResolveEvent 
    // which must be handled when assemblies are loaded dynamically after the application start
    protected internal Dictionary<string, Assembly> loadedAssemblies;

    private List<IPlugin> loadedPlugins;

    private List<PluginDescription> plugins;
    /// <summary>
    /// Gets all plugins.
    /// </summary>
    public IEnumerable<IPluginDescription> Plugins {
      get { return plugins.Cast<IPluginDescription>(); }
    }

    private List<ApplicationDescription> applications;
    /// <summary>
    /// Gets all installed applications.
    /// </summary>
    public IEnumerable<IApplicationDescription> Applications {
      get { return applications.Cast<IApplicationDescription>(); }
    }

    internal WebApplicationManager()
      : base() {
      loadedAssemblies = new Dictionary<string, Assembly>();
      loadedPlugins = new List<IPlugin>();
      plugins = GatherPluginDescriptions();
    }

    static private string AssemblyDirectory {
      get {
        string codeBase = Assembly.GetExecutingAssembly().CodeBase;
        UriBuilder uri = new UriBuilder(codeBase);
        string path = Uri.UnescapeDataString(uri.Path);
        return Path.GetDirectoryName(path);
      }
    }
    // find all types implementing IPlugin in the reflectionOnlyAssemblies and create a list of plugin descriptions
    // the dependencies in the plugin descriptions are not yet set correctly because we need to create
    // the full list of all plugin descriptions first
    private List<PluginDescription> GatherPluginDescriptions() {
      /*List<PluginDescription> pluginDescriptions = new List<PluginDescription>();

      // load all assemblies that are available in the project folders
      var loadedAssemblies = AppDomain.CurrentDomain.GetAssemblies().ToList();
      IList<string> loadedPaths = new List<string>();
      foreach (var asm in loadedAssemblies) {
        try {
          loadedPaths.Add(asm.Location);
        }
        catch (Exception ex) {
        }
      }*/
      /*var assembliePaths = from location in loadedAssemblies                           
                           select location.Location;

      var loadedPaths = loadedAssemblies.Select(a => a.Location).ToArray();*/
      var pv = new PluginValidator() { PluginDir = AssemblyDirectory };
      pv.DiscoverAndCheckPlugins();
      return pv.Plugins.ToList();
      /*var pluginManager = new PluginManager(AssemblyDirectory);
      pluginManager.DiscoverAndCheckPlugins();
      return pluginManager.Plugins.ToList();*/

      /*var referencedPaths = Directory.GetFiles(AssemblyDirectory, "*.dll");
      var toLoad = referencedPaths.Where(r => !loadedPaths.Contains(r, StringComparer.InvariantCultureIgnoreCase)).ToList();
      toLoad.ForEach(path => loadedAssemblies.Add(AppDomain.CurrentDomain.Load(AssemblyName.GetAssemblyName(path))));
      
      foreach (Assembly assembly in loadedAssemblies)
      {
        // GetExportedTypes throws FileNotFoundException when a referenced assembly
        // of the current assembly is missing.
        try {
          // loadedAssemblies.Add(assembly.GetName().Name, assembly);
          // if there is a type that implements IPlugin
          // use AssemblyQualifiedName to compare the types because we can't directly 
          // compare ReflectionOnly types and execution types
          var assemblyPluginDescriptions = from t in assembly.GetExportedTypes()
                                           where !t.IsAbstract && t.GetInterfaces().Any(x => x.AssemblyQualifiedName == typeof(IPlugin).AssemblyQualifiedName)
                                           select GetPluginDescription(t);

          // TODO: Also load all plugin descriptors from assemblies liying in the app domain folder!!!!!
          pluginDescriptions.AddRange(assemblyPluginDescriptions);
        }
        // ignore exceptions. Just don't yield a plugin description when an exception is thrown
        catch (NotSupportedException) {
        }
        catch (FileNotFoundException) {
        }
        catch (FileLoadException) {
        }
        catch (InvalidPluginException) {
        }
        catch (TypeLoadException) {
        }
        catch (MissingMemberException) {
        }
      }
      return pluginDescriptions;*/
    }

    /// <summary>
    /// Extracts plugin information for this type.
    /// Reads plugin name, list and type of files and dependencies of the plugin. This information is necessary for
    /// plugin dependency checking before plugin activation.
    /// </summary>
    /// <param name="pluginType"></param>
    private PluginDescription GetPluginDescription(Type pluginType) {

      string pluginName, pluginDescription, pluginVersion;
      string contactName, contactAddress;
      GetPluginMetaData(pluginType, out pluginName, out pluginDescription, out pluginVersion);
      GetPluginContactMetaData(pluginType, out contactName, out contactAddress);
      var pluginFiles = GetPluginFilesMetaData(pluginType);
      var pluginDependencies = GetPluginDependencyMetaData(pluginType);

      // minimal sanity check of the attribute values
      if (!string.IsNullOrEmpty(pluginName) &&
          pluginFiles.Count() > 0 &&                                 // at least one file
          pluginFiles.Any(f => f.Type == PluginFileType.Assembly)) { // at least one assembly
        // create a temporary PluginDescription that contains the attribute values
        PluginDescription info = new PluginDescription();
        info.Name = pluginName;
        info.Description = pluginDescription;
        info.Version = new Version(pluginVersion);
        info.ContactName = contactName;
        info.ContactEmail = contactAddress;
        info.LicenseText = ReadLicenseFiles(pluginFiles);
        info.AddFiles(pluginFiles);

        //this.pluginDependencies[info] = pluginDependencies;
        return info;
      } else {
        throw new InvalidPluginException("Invalid metadata in plugin " + pluginType.ToString());
      }
    }

    private static string ReadLicenseFiles(IEnumerable<PluginFile> pluginFiles) {
      // combine the contents of all plugin files 
      var licenseFiles = from file in pluginFiles
                         where file.Type == PluginFileType.License
                         select file;
      if (licenseFiles.Count() == 0) return string.Empty;
      StringBuilder licenseTextBuilder = new StringBuilder();
      licenseTextBuilder.AppendLine(File.ReadAllText(licenseFiles.First().Name));
      foreach (var licenseFile in licenseFiles.Skip(1)) {
        licenseTextBuilder.AppendLine().AppendLine(); // leave some empty space between multiple license files
        licenseTextBuilder.AppendLine(File.ReadAllText(licenseFile.Name));
      }
      return licenseTextBuilder.ToString();
    }

    private static IEnumerable<PluginDependency> GetPluginDependencyMetaData(Type pluginType) {
      // get all attributes of type PluginDependency
      var dependencyAttributes = from attr in CustomAttributeData.GetCustomAttributes(pluginType)
                                 where IsAttributeDataForType(attr, typeof(PluginDependencyAttribute))
                                 select attr;

      foreach (var dependencyAttr in dependencyAttributes) {
        string name = (string)dependencyAttr.ConstructorArguments[0].Value;
        Version version = new Version("0.0.0.0"); // default version
        // check if version is given for now
        // later when the constructor of PluginDependencyAttribute with only one argument has been removed
        // this conditional can be removed as well
        if (dependencyAttr.ConstructorArguments.Count > 1) {
          try {
            version = new Version((string)dependencyAttr.ConstructorArguments[1].Value); // might throw FormatException
          }
          catch (FormatException ex) {
            throw new InvalidPluginException("Invalid version format of dependency " + name + " in plugin " + pluginType.ToString(), ex);
          }
        }
        yield return new PluginDependency(name, version);
      }
    }

    private static bool IsAttributeDataForType(CustomAttributeData attributeData, Type attributeType) {
      return attributeData.Constructor.DeclaringType.AssemblyQualifiedName == attributeType.AssemblyQualifiedName;
    }

    private static void GetPluginContactMetaData(Type pluginType, out string contactName, out string contactAddress) {
      // get attribute of type ContactInformation if there is any
      var contactInfoAttribute = (from attr in CustomAttributeData.GetCustomAttributes(pluginType)
                                  where IsAttributeDataForType(attr, typeof(ContactInformationAttribute))
                                  select attr).SingleOrDefault();

      if (contactInfoAttribute != null) {
        contactName = (string)contactInfoAttribute.ConstructorArguments[0].Value;
        contactAddress = (string)contactInfoAttribute.ConstructorArguments[1].Value;
      } else {
        contactName = string.Empty;
        contactAddress = string.Empty;
      }
    }

    // not static because we need the PluginDir property
    private IEnumerable<PluginFile> GetPluginFilesMetaData(Type pluginType) {
      // get all attributes of type PluginFileAttribute
      var pluginFileAttributes = from attr in CustomAttributeData.GetCustomAttributes(pluginType)
                                 where IsAttributeDataForType(attr, typeof(PluginFileAttribute))
                                 select attr;
      foreach (var pluginFileAttribute in pluginFileAttributes) {
        string pluginFileName = (string)pluginFileAttribute.ConstructorArguments[0].Value;
        PluginFileType fileType = (PluginFileType)pluginFileAttribute.ConstructorArguments[1].Value;
        yield return new PluginFile(Path.GetFullPath(Path.Combine(@"C:\dev\Heuristiclab\branches\OaaS\bin", pluginFileName)), fileType);
      }
    }

    private static void GetPluginMetaData(Type pluginType, out string pluginName, out string pluginDescription, out string pluginVersion) {
      // there must be a single attribute of type PluginAttribute
      var pluginMetaDataAttr = (from attr in CustomAttributeData.GetCustomAttributes(pluginType)
                                where IsAttributeDataForType(attr, typeof(PluginAttribute))
                                select attr).Single();

      pluginName = (string)pluginMetaDataAttr.ConstructorArguments[0].Value;

      // default description and version
      pluginVersion = "0.0.0.0";
      pluginDescription = string.Empty;
      if (pluginMetaDataAttr.ConstructorArguments.Count() == 2) {
        // if two arguments are given the second argument is the version
        pluginVersion = (string)pluginMetaDataAttr.ConstructorArguments[1].Value;
      } else if (pluginMetaDataAttr.ConstructorArguments.Count() == 3) {
        // if three arguments are given the second argument is the description and the third is the version
        pluginDescription = (string)pluginMetaDataAttr.ConstructorArguments[1].Value;
        pluginVersion = (string)pluginMetaDataAttr.ConstructorArguments[2].Value;
      }
    }

    /// <summary>
    /// Prepares the application domain for the execution of an HL application.
    /// Pre-loads all <paramref name="plugins"/>.
    /// </summary>
    /// <param name="apps">Enumerable of available HL applications.</param>
    /// <param name="plugins">Enumerable of plugins that should be pre-loaded.</param>  
    internal void PrepareApplicationDomain(IEnumerable<ApplicationDescription> apps, IEnumerable<PluginDescription> plugins) {
      this.plugins = new List<PluginDescription>(plugins);
      this.applications = new List<ApplicationDescription>(apps);
      ApplicationManager.RegisterApplicationManager(this);
      LoadPlugins(plugins);
    }

    /// <summary>
    /// Loads the <paramref name="plugins"/> into this application domain.
    /// </summary>
    /// <param name="plugins">Enumerable of plugins that should be loaded.</param>
    private void LoadPlugins(IEnumerable<PluginDescription> plugins) {
      // load all loadable plugins (all dependencies available) into the execution context
      foreach (var desc in PluginDescriptionIterator.IterateDependenciesBottomUp(plugins.Where(x => x.PluginState != PluginState.Disabled))) {
        foreach (string fileName in desc.AssemblyLocations) {
          // load assembly reflection only first to get the full assembly name
          var reflectionOnlyAssembly = Assembly.ReflectionOnlyLoadFrom(fileName);
          // load the assembly into execution context using full assembly name
          var asm = Assembly.Load(reflectionOnlyAssembly.FullName);
          RegisterLoadedAssembly(asm);
          // instantiate and load all plugins in this assembly
          foreach (var plugin in GetInstances<IPlugin>(asm)) {
            plugin.OnLoad();
            loadedPlugins.Add(plugin);
          }
        }
        OnPluginLoaded(new PluginInfrastructureEventArgs(desc));
        desc.Load();
      }
    }

    /// <summary>
    /// Runs the application declared in <paramref name="appInfo"/>.
    /// This is a synchronous call. When the application is terminated all plugins are unloaded.
    /// </summary>
    /// <param name="appInfo">Description of the application to run</param>
    internal void Run(ApplicationDescription appInfo, ICommandLineArgument[] args) {
      IApplication runnablePlugin = (IApplication)Activator.CreateInstance(appInfo.DeclaringAssemblyName, appInfo.DeclaringTypeName).Unwrap();
      try {
        runnablePlugin.Run(args);
      }
      finally {
        // unload plugins in reverse order
        foreach (var plugin in loadedPlugins.Reverse<IPlugin>()) {
          plugin.OnUnload();
        }
        foreach (var desc in PluginDescriptionIterator.IterateDependenciesBottomUp(plugins.Where(x => x.PluginState != PluginState.Disabled))) {
          desc.Unload();
          OnPluginUnloaded(new PluginInfrastructureEventArgs(desc));
        }
      }
    }

    // register assembly in the assembly cache for the AssemblyResolveEvent
    private void RegisterLoadedAssembly(Assembly asm) {
      if (loadedAssemblies.ContainsKey(asm.FullName) || loadedAssemblies.ContainsKey(asm.GetName().Name)) {
        throw new ArgumentException("An assembly with the name " + asm.GetName().Name + " has been registered already.", "asm");
      }
      loadedAssemblies.Add(asm.FullName, asm);
      loadedAssemblies.Add(asm.GetName().Name, asm); // add short name
    }

    /// <summary>
    /// Creates an instance of all types that are subtypes or the same type of the specified type and declared in <paramref name="plugin"/>
    /// </summary>
    /// <typeparam name="T">Most general type.</typeparam>
    /// <returns>Enumerable of the created instances.</returns>
    internal static IEnumerable<T> GetInstances<T>(IPluginDescription plugin) where T : class {
      List<T> instances = new List<T>();
      foreach (Type t in GetTypes(typeof(T), plugin, onlyInstantiable: true, includeGenericTypeDefinitions: false)) {
        T instance = null;
        try { instance = (T)Activator.CreateInstance(t); }
        catch { }
        if (instance != null) instances.Add(instance);
      }
      return instances;
    }
    /// <summary>
    /// Creates an instance of all types declared in assembly <paramref name="asm"/> that are subtypes or the same type of the specified <typeparamref name="type"/>. 
    /// </summary>
    /// <typeparam name="T">Most general type.</typeparam>
    /// <param name="asm">Declaring assembly.</param>
    /// <returns>Enumerable of the created instances.</returns>
    private static IEnumerable<T> GetInstances<T>(Assembly asm) where T : class {
      List<T> instances = new List<T>();
      foreach (Type t in GetTypes(typeof(T), asm, onlyInstantiable: true, includeGenericTypeDefinitions: false)) {
        T instance = null;
        try { instance = (T)Activator.CreateInstance(t); }
        catch { }
        if (instance != null) instances.Add(instance);
      }
      return instances;
    }
    /// <summary>
    /// Creates an instance of all types that are subtypes or the same type of the specified type
    /// </summary>
    /// <typeparam name="T">Most general type.</typeparam>
    /// <returns>Enumerable of the created instances.</returns>
    internal static IEnumerable<T> GetInstances<T>() where T : class {
      return from i in GetInstances(typeof(T))
             select (T)i;
    }

    /// <summary>
    /// Creates an instance of all types that are subtypes or the same type of the specified type
    /// </summary>
    /// <param name="type">Most general type.</param>
    /// <returns>Enumerable of the created instances.</returns>
    internal static IEnumerable<object> GetInstances(Type type) {
      List<object> instances = new List<object>();
      foreach (Type t in GetTypes(type, onlyInstantiable: true, includeGenericTypeDefinitions: false)) {
        object instance = null;
        try { instance = Activator.CreateInstance(t); }
        catch { }
        if (instance != null) instances.Add(instance);
      }
      return instances;
    }

    /// <summary>
    /// Finds all types that are subtypes or equal to the specified type.
    /// </summary>
    /// <param name="type">Most general type for which to find matching types.</param>
    /// <param name="onlyInstantiable">Return only types that are instantiable 
    /// <param name="includeGenericTypeDefinitions">Specifies if generic type definitions shall be included</param>
    /// (interfaces, abstract classes... are not returned)</param>
    /// <returns>Enumerable of the discovered types.</returns>
    internal static IEnumerable<Type> GetTypes(Type type, bool onlyInstantiable, bool includeGenericTypeDefinitions) {
      return from asm in AppDomain.CurrentDomain.GetAssemblies()
             from t in GetTypes(type, asm, onlyInstantiable, includeGenericTypeDefinitions)
             select t;
    }

    internal static IEnumerable<Type> GetTypes(IEnumerable<Type> types, bool onlyInstantiable, bool includeGenericTypeDefinitions, bool assignableToAllTypes) {
      IEnumerable<Type> result = GetTypes(types.First(), onlyInstantiable, includeGenericTypeDefinitions);
      foreach (Type type in types.Skip(1)) {
        IEnumerable<Type> discoveredTypes = GetTypes(type, onlyInstantiable, includeGenericTypeDefinitions);
        if (assignableToAllTypes) result = result.Intersect(discoveredTypes);
        else result = result.Union(discoveredTypes);
      }
      return result;
    }

    /// <summary>
    /// Finds all types that are subtypes or equal to the specified type if they are part of the given
    /// <paramref name="pluginDescription"/>.
    /// </summary>
    /// <param name="type">Most general type for which to find matching types.</param>
    /// <param name="pluginDescription">The plugin the subtypes must be part of.</param>
    /// <param name="onlyInstantiable">Return only types that are instantiable 
    /// <param name="includeGenericTypeDefinitions">Specifies if generic type definitions shall be included</param>
    /// (interfaces, abstract classes... are not returned)</param>
    /// <returns>Enumerable of the discovered types.</returns>
    internal static IEnumerable<Type> GetTypes(Type type, IPluginDescription pluginDescription, bool onlyInstantiable, bool includeGenericTypeDefinitions) {
      PluginDescription pluginDesc = (PluginDescription)pluginDescription;
      return from asm in AppDomain.CurrentDomain.GetAssemblies()
             where !asm.IsDynamic && !string.IsNullOrEmpty(asm.Location)
             where pluginDesc.AssemblyLocations.Any(location => location.Equals(Path.GetFullPath(asm.Location), StringComparison.CurrentCultureIgnoreCase))
             from t in GetTypes(type, asm, onlyInstantiable, includeGenericTypeDefinitions)
             select t;
    }

    internal static IEnumerable<Type> GetTypes(IEnumerable<Type> types, IPluginDescription pluginDescription, bool onlyInstantiable, bool includeGenericTypeDefinitions, bool assignableToAllTypes) {
      IEnumerable<Type> result = GetTypes(types.First(), pluginDescription, onlyInstantiable, includeGenericTypeDefinitions);
      foreach (Type type in types.Skip(1)) {
        IEnumerable<Type> discoveredTypes = GetTypes(type, pluginDescription, onlyInstantiable, includeGenericTypeDefinitions);
        if (assignableToAllTypes) result = result.Intersect(discoveredTypes);
        else result = result.Union(discoveredTypes);
      }
      return result;
    }

    /// <summary>
    /// Gets types that are assignable (same of subtype) to the specified type only from the given assembly.
    /// </summary>
    /// <param name="type">Most general type we want to find.</param>
    /// <param name="assembly">Assembly that should be searched for types.</param>
    /// <param name="onlyInstantiable">Return only types that are instantiable 
    /// (interfaces, abstract classes...  are not returned)</param>
    /// <param name="includeGenericTypeDefinitions">Specifies if generic type definitions shall be included</param>
    /// <returns>Enumerable of the discovered types.</returns>
    private static IEnumerable<Type> GetTypes(Type type, Assembly assembly, bool onlyInstantiable, bool includeGenericTypeDefinitions) {
      var buildTypes = from t in assembly.GetTypes()
                       where CheckTypeCompatibility(type, t)
                       where !IsNonDiscoverableType(t)
                       where onlyInstantiable == false ||
                             (!t.IsAbstract && !t.IsInterface && !t.HasElementType)
                       select BuildType(t, type);

      return from t in buildTypes
             where includeGenericTypeDefinitions || !t.IsGenericTypeDefinition
             select t;
    }


    private static bool IsNonDiscoverableType(Type t) {
      return t.GetCustomAttributes(typeof(NonDiscoverableTypeAttribute), false).Any();
    }

    private static bool CheckTypeCompatibility(Type type, Type other) {
      if (type.IsAssignableFrom(other))
        return true;
      if (type.IsGenericType && other.IsGenericType) {
        var otherGenericArguments = other.GetGenericArguments();
        var typeGenericArguments = type.GetGenericArguments();

        //check type arguments count
        if (otherGenericArguments.Length != typeGenericArguments.Length)
          return false;

        //check type arguments & constraints
        int i = 0;
        foreach (var genericArgument in typeGenericArguments) {
          if (otherGenericArguments[i].IsGenericParameter) {
            foreach (var constraint in otherGenericArguments[i].GetGenericParameterConstraints())
              if (!constraint.IsAssignableFrom(genericArgument)) return false;
          } else if (genericArgument != otherGenericArguments[i]) return false;
          i++;
        }
        //check types
        try {
          var otherGenericTypeDefinition = other.GetGenericTypeDefinition();
          if (type.IsAssignableFrom(otherGenericTypeDefinition.MakeGenericType(typeGenericArguments)))
            return true;
        }
        catch (Exception) { }
      }
      return false;
    }
    private static Type BuildType(Type type, Type protoType) {
      if (type.IsGenericType && protoType.IsGenericType)
        return type.GetGenericTypeDefinition().MakeGenericType(protoType.GetGenericArguments());
      else
        return type;
    }

    private void OnPluginLoaded(PluginInfrastructureEventArgs e) {
      if (PluginLoaded != null) PluginLoaded(this, e);
    }

    private void OnPluginUnloaded(PluginInfrastructureEventArgs e) {
      if (PluginUnloaded != null) PluginUnloaded(this, e);
    }

    #region IApplicationManager Members

    IEnumerable<T> IApplicationManager.GetInstances<T>() {
      return GetInstances<T>();
    }

    IEnumerable<object> IApplicationManager.GetInstances(Type type) {
      return GetInstances(type);
    }

    IEnumerable<Type> IApplicationManager.GetTypes(Type type, bool onlyInstantiable, bool includeGenericTypeDefinitions) {
      return GetTypes(type, onlyInstantiable, includeGenericTypeDefinitions);
    }
    IEnumerable<Type> IApplicationManager.GetTypes(IEnumerable<Type> types, bool onlyInstantiable, bool includeGenericTypeDefinitions, bool assignableToAllTypes) {
      return GetTypes(types, onlyInstantiable, includeGenericTypeDefinitions, assignableToAllTypes);
    }

    IEnumerable<Type> IApplicationManager.GetTypes(Type type, IPluginDescription plugin, bool onlyInstantiable, bool includeGenericTypeDefinitions) {
      return GetTypes(type, plugin, onlyInstantiable, includeGenericTypeDefinitions);
    }
    IEnumerable<Type> IApplicationManager.GetTypes(IEnumerable<Type> types, IPluginDescription plugin, bool onlyInstantiable, bool includeGenericTypeDefinitions, bool assignableToAllTypes) {
      return GetTypes(types, plugin, onlyInstantiable, includeGenericTypeDefinitions, assignableToAllTypes);
    }

    /// <summary>
    /// Finds the plugin that declares the <paramref name="type">type</paramref>.
    /// </summary>
    /// <param name="type">The type of interest.</param>
    /// <returns>The description of the plugin that declares the given type or null if the type has not been declared by a known plugin.</returns>
    public IPluginDescription GetDeclaringPlugin(Type type) {
      if (type == null) throw new ArgumentNullException("type");
      var name = type.Assembly.GetName().Name;
      foreach (PluginDescription info in Plugins) {
        var f = Path.GetFileNameWithoutExtension(info.Files.ElementAt(0).Name);
        if (f.Contains(name)) return info;
      }
      return null;
    }
    #endregion
  }
}