private void EnsureModulesDiscovered()
        {
            ModulesConfigurationSection section = this.Store.RetrieveModuleConfigurationSection();

            if (section != null)
            {
                foreach (ModuleConfigurationElement element in section.Modules)
                {
                    IList<string> dependencies = new List<string>();

                    if (element.Dependencies.Count > 0)
                    {
                        foreach (ModuleDependencyConfigurationElement dependency in element.Dependencies)
                        {
                            dependencies.Add(dependency.ModuleName);
                        }
                    }

                    ModuleInfo moduleInfo = new ModuleInfo(element.ModuleName, element.ModuleType)
                    {
                        Ref = GetFileAbsoluteUri(element.AssemblyFile),
                        InitializationMode = element.StartupLoaded ? InitializationMode.WhenAvailable : InitializationMode.OnDemand
                    };
                    moduleInfo.DependsOn.AddRange(dependencies.ToArray());
                    AddModule(moduleInfo);
                }
            }
        }

        public void WhenInitializingAModuleWithNoCatalogPendingToBeLoaded_ThenInitializesTheModule()
        {
            var aggregateCatalog = new AggregateCatalog(new AssemblyCatalog(typeof(MefModuleInitializer).Assembly));
            var compositionContainer = new CompositionContainer(aggregateCatalog);
            compositionContainer.ComposeExportedValue(aggregateCatalog);

            var serviceLocatorMock = new Mock<IServiceLocator>();
            var loggerFacadeMock = new Mock<ILoggerFacade>();

            var serviceLocator = serviceLocatorMock.Object;
            var loggerFacade = loggerFacadeMock.Object;

            compositionContainer.ComposeExportedValue(serviceLocator);
            compositionContainer.ComposeExportedValue(loggerFacade);

            aggregateCatalog.Catalogs.Add(new TypeCatalog(typeof(TestModuleForInitializer)));

            var moduleInitializer = compositionContainer.GetExportedValue<IModuleInitializer>();

            var moduleInfo = new ModuleInfo("TestModuleForInitializer", typeof(TestModuleForInitializer).AssemblyQualifiedName);

            var module = compositionContainer.GetExportedValues<IModule>().OfType<TestModuleForInitializer>().First();

            Assert.IsFalse(module.Initialized);

            moduleInitializer.Initialize(moduleInfo);

            Assert.IsTrue(module.Initialized);
        }

        public void WhenInitializingAModuleWithACatalogPendingToBeLoaded_ThenLoadsTheCatalogInitializesTheModule()
        {
            var aggregateCatalog = new AggregateCatalog(new AssemblyCatalog(typeof(MefModuleInitializer).Assembly));
            var compositionContainer = new CompositionContainer(aggregateCatalog);
            compositionContainer.ComposeExportedValue(aggregateCatalog);

            var serviceLocatorMock = new Mock<IServiceLocator>();
            var loggerFacadeMock = new Mock<ILoggerFacade>();

            var serviceLocator = serviceLocatorMock.Object;
            var loggerFacade = loggerFacadeMock.Object;

            compositionContainer.ComposeExportedValue(serviceLocator);
            compositionContainer.ComposeExportedValue(loggerFacade);

            var moduleInitializer = compositionContainer.GetExportedValue<IModuleInitializer>();
            var repository = compositionContainer.GetExportedValue<DownloadedPartCatalogCollection>();

            var moduleInfo = new ModuleInfo("TestModuleForInitializer", typeof(TestModuleForInitializer).AssemblyQualifiedName);

            repository.Add(moduleInfo, new TypeCatalog(typeof(TestModuleForInitializer)));

            moduleInitializer.Initialize(moduleInfo);

            ComposablePartCatalog existingCatalog;
            Assert.IsFalse(repository.TryGet(moduleInfo, out existingCatalog));

            var module = compositionContainer.GetExportedValues<IModule>().OfType<TestModuleForInitializer>().First();

            Assert.IsTrue(module.Initialized);
        }

        public void WhenItemsInCollection_TryGetReturnsTrueAndCatalog()
        {
            // Prepare
            ModuleInfo moduleInfo1 = new ModuleInfo();
            ModuleInfo moduleInfo2 = new ModuleInfo();
            ModuleInfo moduleInfo3 = new ModuleInfo();

            ComposablePartCatalog catalog1 = new TypeCatalog();
            ComposablePartCatalog catalog2 = new TypeCatalog();
            ComposablePartCatalog catalog3 = new TypeCatalog();

            DownloadedPartCatalogCollection target = new DownloadedPartCatalogCollection();

            target.Add(moduleInfo1, catalog1);
            target.Add(moduleInfo2, catalog2);
            target.Add(moduleInfo3, catalog3);

            // Act
            bool actual = target.TryGet(moduleInfo3, out catalog3);    
        
            // Verify
            Assert.IsTrue(actual);
            Assert.AreSame(catalog3, target.Get(moduleInfo3));
            
        }

		public void Initialize(ModuleInfo moduleInfo)
		{
			if(initialModuleLoadCompleted)
			{
				defaultInitializer.Initialize(moduleInfo);
				return;
			}
			
			// register Module in Module-Config-List
			moduleConfigs.Modules.FirstOrDefault(mc => mc.Name == moduleInfo.ModuleName).Module = moduleInfo;
			
			// All modules pre-loaded?
			if (!(moduleConfigs.Modules.Any(mc => mc.Module == null)))
			{
				// Sort modules
		    	moduleConfigs.Modules = moduleConfigs.Modules.OrderBy(mc => mc.Order).ToList();

				foreach (var config in moduleConfigs.Modules)
				{
					defaultInitializer.Initialize(config.Module);
				}

				initialModuleLoadCompleted = true;
			}
		}

        public void ShouldLoadDownloadedAssemblies()
        {
            // NOTE: This test method uses a resource that is built in a pre-build event when building the project. The resource is a
            // dynamically generated XAP file that is built with the Mocks/Modules/createXap.bat batch file.
            // If this test is failing unexpectedly, it may be that the batch file is not working correctly in the current environment.

            var mockFileDownloader = new MockFileDownloader();
            const string moduleTypeName = "Microsoft.Practices.Prism.Tests.Mocks.Modules.RemoteModule, RemoteModuleA, Version=0.0.0.0";
            var remoteModuleUri = "http://MyModule.xap";
            var moduleInfo = new ModuleInfo() { Ref = remoteModuleUri };
            XapModuleTypeLoader typeLoader = new TestableXapModuleTypeLoader(mockFileDownloader);
            ManualResetEvent callbackEvent = new ManualResetEvent(false);

            typeLoader.LoadModuleCompleted += delegate(object sender, LoadModuleCompletedEventArgs e)
            {
                callbackEvent.Set();
            };

            typeLoader.LoadModuleType(moduleInfo);

            Assert.IsNull(Type.GetType(moduleTypeName));

            Stream xapStream = Assembly.GetExecutingAssembly().GetManifestResourceStream("Microsoft.Practices.Prism.Tests.Mocks.Modules.RemoteModules.xap");
            mockFileDownloader.InvokeOpenReadCompleted(new DownloadCompletedEventArgs(xapStream, null, false, mockFileDownloader.DownloadAsyncArgumentUserToken));
            Assert.IsTrue(callbackEvent.WaitOne(500));

            Assert.IsNotNull(Type.GetType(moduleTypeName));
        }

		public void Initialize(ModuleInfo moduleInfo)
		{
			if(initialModuleLoadCompleted || moduleInfo.ModuleName.EndsWith("Modules.Splash"))
			{
				defaultInitializer.Initialize(moduleInfo);
				return;
			}
			
			moduleConfigs.Modules.FirstOrDefault(mc => mc.Name == moduleInfo.ModuleName).Module = moduleInfo;
			
			// All modules pre-loaded?
			if (!(moduleConfigs.Modules.Any(mc => mc.Module == null)))
			{
				// Sort modules
		    	moduleConfigs.Modules = moduleConfigs.Modules.OrderBy(mc => mc.Order).ToList();

				foreach (var config in moduleConfigs.Modules)
				{
					_eventAggregator.GetEvent<SplashInfoUpdateEvent>().Publish(new SplashInfoUpdateEvent {Info = config.Description});
					Thread.Sleep(1000); // Uncomment as you need ;-)
					defaultInitializer.Initialize(config.Module);
				}

				initialModuleLoadCompleted = true;
			}
		}

        /// <summary>
        /// Uses the container to resolve a new <see cref="IModule"/> by specifying its <see cref="Type"/>.
        /// </summary>
        /// <param name="moduleInfo">The module to create.</param>
        /// <returns>
        /// A new instance of the module specified by <paramref name="moduleInfo"/>.
        /// </returns>
        protected override IModule CreateModule(ModuleInfo moduleInfo)
        {
            // If there is a catalog that needs to be integrated with the AggregateCatalog as part of initialization, I add it to the container's catalog.
            ComposablePartCatalog partCatalog;
            if (this.downloadedPartCatalogs.TryGet(moduleInfo, out partCatalog))
            {
                if (!this.aggregateCatalog.Catalogs.Contains(partCatalog))
                {
                    this.aggregateCatalog.Catalogs.Add(partCatalog);
                }

                this.downloadedPartCatalogs.Remove(moduleInfo);
            }

            if (this.ImportedModules != null && this.ImportedModules.Count() != 0)
            {
                Lazy<IModule, IModuleExport> lazyModule =
                    this.ImportedModules.FirstOrDefault(x => (x.Metadata.ModuleName == moduleInfo.ModuleName));
                if (lazyModule != null)
                {
                    return lazyModule.Value;
                }
            }

            // This does not fall back to the base implementation because the type must be in the MEF container and not just in the application domain.
            throw new ModuleInitializeException(
                string.Format(CultureInfo.CurrentCulture, Properties.Resources.FailedToGetType, moduleInfo.ModuleType));
        }

        /// <summary>
        /// Handles any exception ocurred in the module Initialization process,
        /// logs the error using the <seealso cref="ILoggerFacade"/> and throws a <seealso cref="ModuleInitializeException"/>.
        /// This method can be overriden to provide a different behavior. 
        /// </summary>
        /// <param name="moduleInfo">The module metadata where the error happenened.</param>
        /// <param name="assemblyName">The assembly name.</param>
        /// <param name="exception">The exception thrown that is the cause of the current error.</param>
        /// <exception cref="ModuleInitializeException"></exception>
        public virtual void HandleModuleInitializationError(ModuleInfo moduleInfo, string assemblyName, Exception exception)
        {
            if (moduleInfo == null) throw new ArgumentNullException("moduleInfo");
            if (exception == null) throw new ArgumentNullException("exception");

            Exception moduleException;

            if (exception is ModuleInitializeException)
            {
                moduleException = exception;
            }
            else
            {
                if (!string.IsNullOrEmpty(assemblyName))
                {
                    moduleException = new ModuleInitializeException(moduleInfo.ModuleName, assemblyName, exception.Message, exception);
                }
                else
                {
                    moduleException = new ModuleInitializeException(moduleInfo.ModuleName, exception.Message, exception);
                }
            }

            this.loggerFacade.Log(moduleException.ToString(), Category.Exception, Priority.High);

            throw moduleException;
        }

        public void LoadModuleType(ModuleInfo moduleInfo)
        {
            if (moduleInfo == null)
            {
                throw new System.ArgumentNullException("moduleInfo");
            }

            try
            {
                // If this module has already been downloaded, I fire the completed event.
                if (this.IsSuccessfullyDownloaded(moduleInfo.ModuleType))
                {
                    this.RaiseLoadModuleCompleted(moduleInfo, null);
                }
                else
                {
                    // Although this isn't asynchronous, nor expected to take very long, I raise progress changed for consistency.
                    this.RaiseModuleDownloadProgressChanged(moduleInfo, 0, 100);

                    //

                    // Although this isn't asynchronous, nor expected to take very long, I raise progress changed for consistency.
                    this.RaiseModuleDownloadProgressChanged(moduleInfo, 100, 100);

                    // I remember the downloaded URI.
                    this.RecordDownloadSuccess(moduleInfo.Ref);

                    this.RaiseLoadModuleCompleted(moduleInfo, null);
                }
            }
            catch (Exception ex)
            {
                this.RaiseLoadModuleCompleted(moduleInfo, ex);
            }
        }

        public void CannotRetrieveWithIncorrectRef()
        {
            var retriever = new FileModuleTypeLoader();
            var moduleInfo = new ModuleInfo() { Ref = "NotForLocalRetrieval" };

            Assert.IsFalse(retriever.CanLoadModuleType(moduleInfo));
        }

        public void CanRetrieveWithCorrectRef()
        {
            var retriever = new FileModuleTypeLoader();
            var moduleInfo = new ModuleInfo() { Ref = "file://somefile" };

            Assert.IsTrue(retriever.CanLoadModuleType(moduleInfo));
        }

        public ModuleInfo CreateModuleInfo()
        {
            ModuleInfo info = new ModuleInfo();
            info.ModuleName = "MefModuleOne";
            info.Ref = "file:///MefModulesForTesting.dll";

            return info;
        }

        /// <summary>
        /// Initializes a new instance of the <see cref="LoadModuleCompletedEventArgs"/> class.
        /// </summary>
        /// <param name="moduleInfo">The module info.</param>
        /// <param name="error">Any error that occurred during the call.</param>
        public LoadModuleCompletedEventArgs(ModuleInfo moduleInfo, Exception error)
        {
            if (moduleInfo == null) throw new ArgumentNullException("moduleInfo");
            Contract.EndContractBlock();

            this.ModuleInfo = moduleInfo;
            this.Error = error;
        }

        /// <summary>
        /// Initializes a new instance of the <see cref="LoadModuleCompletedEventArgs"/> class.
        /// </summary>
        /// <param name="moduleInfo">The module info.</param>
        /// <param name="error">Any error that occurred during the call.</param>
        public LoadModuleCompletedEventArgs(ModuleInfo moduleInfo, Exception error)
        {
            if (moduleInfo == null) {
                throw new ArgumentNullException("moduleInfo");
            }

            this.ModuleInfo = moduleInfo;
            this.Error = error;
        }

        /// <summary>
        /// Evaluates the <see cref="ModuleInfo.Ref"/> property to see if the current typeloader will be able to retrieve the <paramref name="moduleInfo"/>.
        /// Returns true if the <see cref="ModuleInfo.Ref"/> property starts with "file://", because this indicates that the file
        /// is a local file. 
        /// </summary>
        /// <param name="moduleInfo">Module that should have it's type loaded.</param>
        /// <returns>
        ///     <see langword="true"/> if the current typeloader is able to retrieve the module, otherwise <see langword="false"/>.
        /// </returns>
        public virtual bool CanLoadModuleType(ModuleInfo moduleInfo)
        {
            if (moduleInfo == null)
            {
                throw new System.ArgumentNullException("moduleInfo");
            }

            return moduleInfo.Ref != null && moduleInfo.Ref.StartsWith(RefFilePrefix, StringComparison.Ordinal);
        }

        public void CanCreateCatalogFromList()
        {
            var moduleInfo = new ModuleInfo("MockModule", "type");
            List<ModuleInfo> moduleInfos = new List<ModuleInfo> { moduleInfo };

            var moduleCatalog = new ModuleCatalog(moduleInfos);

            Assert.AreEqual(1, moduleCatalog.Modules.Count());
            Assert.AreEqual(moduleInfo, moduleCatalog.Modules.ElementAt(0));
        }

        /// <summary>
        /// 
        /// </summary>
        /// <param name="moduleInfo"></param>
        /// <exception cref="System.ArgumentNullException">The <paramref name="moduleInfo"/> is <c>null</c>.</exception>
        public ModuleTemplate(ModuleInfo moduleInfo)
        {
            Argument.IsNotNull(() => moduleInfo);

            _moduleInfo = moduleInfo;

            RaisePropertyChanged(() => ModuleName);
            RaisePropertyChanged(() => Enabled);
            RaisePropertyChanged(() => State);
        }

        /// <summary>
        /// Initializes a new instance of the <see cref="ModuleDownloadProgressChangedEventArgs"/> class.
        /// </summary>
        /// <param name="moduleInfo">The module info.</param>
        /// <param name="bytesReceived">The bytes received.</param>
        /// <param name="totalBytesToReceive">The total bytes to receive.</param>        
        public ModuleDownloadProgressChangedEventArgs(ModuleInfo moduleInfo, long bytesReceived, long totalBytesToReceive)
            : base(CalculateProgressPercentage(bytesReceived, totalBytesToReceive), null)
        {
            if (moduleInfo == null) throw new ArgumentNullException("moduleInfo");
            Contract.EndContractBlock();

            this.ModuleInfo = moduleInfo;
            this.BytesReceived = bytesReceived;
            this.TotalBytesToReceive = totalBytesToReceive;
        }

        public void LoadModuleType(ModuleInfo moduleInfo)
        {
            Task.Factory.StartNew(async() =>
            {
                await Task.Delay(SleepTimeOut);

                this.RaiseLoadModuleCompleted(new LoadModuleCompletedEventArgs(moduleInfo, CallbackArgumentError));
                callbackEvent.Set();
            });
        }