using System;
using System.Collections.Generic;
using System.Diagnostics;
using System.Globalization;
using System.IO;
using System.ServiceModel;
using System.Threading;

using log4net;
using log4net.Appender;
using log4net.Layout;
using log4net.Repository.Hierarchy;

using NHibernate;
using NHibernate.Cfg;


namespace BeWo.Data
{
    public class DefaultHibernateSessionManager
    {
        private static Dictionary<string, ISessionFactory> _SessionFactories = new Dictionary<string, ISessionFactory>();
        private static object _Lock = string.Empty;


        private static ISession currentSession;

        public static ISession CurrentSession
        {
            get
            {
                var frame = new StackFrame(1);
                var method = frame.GetMethod();
                var callingMethodName = method.Name;

                return currentSession ?? OpenSession();
            }
            set
            {
                currentSession = value;
            }
        }

        public static string CurrentTenant { get; set; }

        private static ISessionFactory SessionFactory
        {
            get
            {
                try
                {
                    Monitor.Enter(_Lock);
                    if (!_SessionFactories.ContainsKey(CurrentTenant))
                    {
#if DEBUG
                        //TODO: wieder einkommentieren!
                        //var hierarchy = (Hierarchy)LogManager.GetRepository();
                        //var logger = (Logger)hierarchy.GetLogger("NHibernate.SQL");
                        //logger.AddAppender(new TraceAppender { Layout = new SimpleLayout() });
                        //hierarchy.Configured = true;
#endif

                        var baseDirectory = AppDomain.CurrentDomain.BaseDirectory;
                        var splittedBaseDirectory = baseDirectory.Split('\\'); // 0 -3
                        var correctBaseDirectory = string.Empty;

                        for(var i = 0; i < 4; i++)
                        {
                            correctBaseDirectory += splittedBaseDirectory[i] + "\\";
                        }
                        
                        _SessionFactories[CurrentTenant] = new Configuration().Configure(BS.Shared.Core.Utils.CreateSavePath(correctBaseDirectory, @"Multitenancy\" + CurrentTenant + ".config")).BuildSessionFactory();
                    }

                    return _SessionFactories[CurrentTenant];
                }
                catch (Exception e)
                {
                    //String path = System.IO.Path.Combine(AppDomain.CurrentDomain.BaseDirectory, "SessionFactoryError.txt");
                    //System.IO.File.AppendAllText(path, String.Format("{0:dd.MM.yyyy HH:mm:ss}", DateTime.Now) + "\n" + e.Message + "\n" + e.StackTrace);
                    Debug.WriteLine("<<<<< " + e.StackTrace + e.InnerException?.Message ?? string.Empty);
                    throw new FaultException(e.StackTrace + e.InnerException?.Message ?? string.Empty);
                }
                finally
                {
                    Monitor.Exit(_Lock);
                }
            }
        }

        private static ISessionFactory RebuildSessionFactory()
        {
            ResetSessionFactory(CurrentTenant);

            return SessionFactory;
        }

        public static void ResetAllSessionFactories()
        {
            try
            {
                var tenants = new string[_SessionFactories.Keys.Count];

                _SessionFactories.Keys.CopyTo(tenants, 0);

                foreach (var item in tenants)
                {
                    ResetSessionFactory(item);
                }

                _SessionFactories = new Dictionary<string, ISessionFactory>();
            }
            catch (Exception)
            {
                //ignore?
            }
        }

        public static void ResetSessionFactory(string tenant)
        {
            var t = tenant;
            if (string.IsNullOrEmpty(t))
            {
                t = CurrentTenant;
            }

            if (_SessionFactories.ContainsKey(t))
            {
                try
                {
                    var fact = _SessionFactories[t];
                    if (!fact.IsClosed)
                    {
                        fact.Close();
                    }

                    fact.Dispose();
                }
                catch (Exception)
                {
                    //ignore exception??
                }

                _SessionFactories.Remove(t);
            }
        }

        public static void CloseSession()
        {
            if (currentSession != null)
            {
                currentSession.Close();
                currentSession.Dispose();
                currentSession = null;
            }
        }

        public static ISession OpenSession()
        {
            try
            {
                Thread.CurrentThread.CurrentCulture = new CultureInfo("de-DE");

                CloseSession();
                var session = SessionFactory.OpenSession(new UpdInsInterceptor()) ?? RebuildSessionFactory().OpenSession(new UpdInsInterceptor());

                currentSession = session;
                
                return currentSession;
            }
            catch (Exception e)
            {
                //throw new FaultException("ttttt" + e.ToString());
                throw new FaultException(e.StackTrace + e.InnerException?.Message ?? string.Empty);
            }
        }

        public static bool TenantExists()
        {
            var path = BS.Shared.Core.Utils.CreateSavePath(AppDomain.CurrentDomain.BaseDirectory, @"Multitenancy\" + CurrentTenant + ".config");

            return File.Exists(path);
        }
    }
}