using System;
using System.Collections.Generic;
using System.Linq;
using System.Reflection;
using DTS.Common;
using DTS.Common.Base;
using DTS.Common.Classes;
using DTS.Common.Core.PluginLib;
using DTS.Common.Interface;
using Microsoft.Practices.Prism.Events;
using Microsoft.Practices.Prism.Modularity;
using Microsoft.Practices.Prism.Regions;
using Microsoft.Practices.ServiceLocation;
using Microsoft.Practices.Unity;
using System.IO;

namespace DTS.Viewer.Loader
{
    /// <summary>
    /// I think we need it...
    /// </summary>
    public class ViewerLoaderSession
    {
        /// <summary>
        /// Custom Bootstrapper
        /// </summary>
        ///<remarks>
        /// Do not try to re-create the bootstrapper.  Once modules are loaded, they will be be loaded into the DirectoryModuleCatalog and each
        /// Module initialization will not be called (thus no registered types).
        /// It appears that the current bootstrapper loads around 40 MB into memory. 
        /// To completely unload the bootstrapper would take same research and effort.
        /// </remarks>
        private Bootstrapper _bootstrapper;

        public IUnityContainer _unityContainer { get; private set; }
        public IServiceLocator ServiceLocator { get; private set; }
        public IEventAggregator EventAggregator { get; private set; }
        public IRegionManager RegionManager { get; private set; }

        public ViewerLoaderSession()
        {

        }

        public void CreateSession()
        {
            CreateBootstrapper();
            if (_bootstrapper == null) return;
            _unityContainer = _bootstrapper.Container;
            EventAggregator = _unityContainer.Resolve<IEventAggregator>();
            ServiceLocator = _unityContainer.Resolve<IServiceLocator>();
            RegionManager = _unityContainer.Resolve<IRegionManager>();

            var shellVviewmodel = _unityContainer.Resolve<IShellViewModel>();
            var viewerModule = _unityContainer.Resolve<IViewerModule>();
            viewerModule.StartSession(true, @"C:\devDTS\RunTimeModules\DTS.Viewer.dll.config");
            var viewModel = _unityContainer.Resolve<IViewerMainViewModel>();

            shellVviewmodel.ContextMainRegion = viewModel.View;

            //var assemblyList = LoadPlugins();
            //if (assemblyList.Count == 1)
            //{
            //    var assembly = assemblyList[0];
            //    if (assembly.ManifestModule.Name.StartsWith("DTS.Viewer"))
            //    {


            //    }
            //}


            //var viewDefinition = new ViewDefinition(RegionNames.MainRegion, typeof(IMainView), typeof(IMainViewModel));
            //var viewModel = (IBaseViewModel)Container.Resolve(viewDefinition.ViewModelInterfaceType);
            //var view = (IBaseView)Container.Resolve(viewDefinition.ViewInterfaceType);
            //view.DataContext = viewModel;
            //RegionManager.Regions[RegionNames.MainRegion].Add(view);
            //RegionManager.ActivateViewIfExists(viewDefinition.RegionName, viewDefinition.ViewInterfaceType);
        }
        /// <summary>
        /// Return type of View/ViewModel registered with Unity Container
        /// </summary>
        /// <param name="name">Name of the selected assembly (plug-in)</param>
        /// <returns>interface type</returns>
        private Type GetRegisteredViewType(string name)
        {
            return (from v in _unityContainer.Registrations where v.RegisteredType.Name.EndsWith(name) select v.RegisteredType).FirstOrDefault();
        }
        private List<Assembly> LoadPlugins()
        {
            var pluginManager = PluginManager.GetPluginManager(Path.Combine(Environment.CurrentDirectory, @"DTS.Viewer.Loader.exe.config"));
            return pluginManager.GetPluginList<IModule>();
        }

        /// <summary>
        /// Create bootstrapper for prism-based modules and views.
        /// </summary>
        /// <remarks>
        /// Currently, there is no course of action for destroying the bootstrapper.
        /// </remarks>
        private void CreateBootstrapper()
        {
            if (_bootstrapper == null)
            {
                try
                {
                    _bootstrapper = new Bootstrapper();
                    _bootstrapper.Run();
                }
                catch (ApplicationException ex)
                {
                    throw new Exception("Failed to create bootstrapper ", ex);
                }
            }

            if (_bootstrapper == null)
            {
                throw new Exception("Failed to create Bootstrapper!");
            }
        }

        /// <summary>
        /// The Terminate method is called only when JMPS is in the process of shutting down. 
        /// If a component is just being closed, only the class destructor will be called.
        /// Part of IComponent implementation.
        /// </summary>
        public void Terminate()
        {

        }
    }
}