using Microsoft.Owin.Hosting;
using Step.Config;
using Step.Core;
using Step.Database;
using Step.Listeners;
using Step.Model;
using Step.NC;
using Step.UI;
using Step.Utils;
using System;
using System.Net;
using System.Net.Sockets;
using System.Threading;
using System.Windows.Forms;
using TeamDev.SDK.MVVM;
using static Step.Config.ServerConfig;
using static Step.Model.Constants;
using static Step.Utils.StepLogger;

namespace Step
{
    public class Application
    {
        public static readonly ManualResetEvent StopRequest = new ManualResetEvent(false);
        
        public static int MessageService { get; private set; }

        public static void Main()
        {
            LogInfo("Application started");

            //Check if is already running an instance of this application
            string AppName = System.IO.Path.GetFileNameWithoutExtension(System.Reflection.Assembly.GetEntryAssembly().Location);
            if (System.Diagnostics.Process.GetProcessesByName(AppName).Length > 1)
            {
                MessageBox.Show("Only one istance of "+ AppName +" can be executed!", AppName, MessageBoxButtons.OK, MessageBoxIcon.Error);
                return;
            }
            
            // Create unhandled exception handler
            AppDomain.CurrentDomain.UnhandledException += new UnhandledExceptionEventHandler(ExceptionHandler);

            // Read config
            ServerConfigController.ReadStartupConfig();

            // Start WinForm
            ServerControlWindow.Start();


            DatabaseContext.SetUpDbConnectionAndDbConfig();

            // Register listener to "close application" messages
            MessageServices.Current.Subscribe(SEND_STOP_SERVER, (a, b) =>
            {
                StopRequest.Set();
                if (NcConfig.NcVendor.ToUpper() == NC_VENDOR.SIEMENS)
                    ThreadSiemensHmi.StopThread();
            });
            
            // Stop threads and disconnect from NC
            MessageServices.Current.Subscribe(SEND_STOP_THREADS, (a, b) =>
            {
                using (NcHandler ncHandler = new NcHandler())
                    ncHandler.Disconnect();

                // Stop Threads
                ThreadsHandler.Close();
                // Stop messageservice listeners
                ListenersHandler.Stop();
            });

            // Start server services
            if (!ValidateAddress(ServerStartupConfig.ServerAddress))
                ExceptionManager.Manage(ERROR_LEVEL.FATAL, "IP Address not valid (must be one configured in Windows-OS)!");

            StartOptions opt = new StartOptions();
            opt.Urls.Add("http://localhost:" + ServerStartupConfig.ServerPort.ToString());
            opt.Urls.Add("http://127.0.0.1:" + ServerStartupConfig.ServerPort.ToString());

            if (!string.IsNullOrWhiteSpace(ServerStartupConfig.ServerAddress.ToString()))
                opt.Urls.Add("http://" + ServerStartupConfig.ServerAddress.ToString() + ":" + ServerStartupConfig.ServerPort.ToString());

            using (WebApp.Start<App_Start.Startup>(opt))
            {
                // Start Threads
                ThreadsHandler.Start();
                // Start listeners
                ListenersHandler.Start();


                // Wait interrupt from client
                StopRequest.WaitOne();
                
                using (NcHandler ncHandler = new NcHandler())
                    ncHandler.Disconnect();

                LogInfo("Application closed");
            }

            // Stop Threads
            ThreadsHandler.Close();
            // Stop messageservice listeners
            ListenersHandler.Stop();
            // Close WinForm
            ServerControlWindow.Stop();
        }

        private static bool ValidateAddress(string Addr)
        {
            //If is an asterisk is OK
            if (string.IsNullOrWhiteSpace(Addr) || Addr == "*")
                return true;

            //Find an IP Address
            foreach (IPAddress ipAddr in Array.FindAll(Dns.GetHostEntry(string.Empty).AddressList, a => a.AddressFamily == AddressFamily.InterNetwork))
            {
                if (ipAddr.ToString() == Addr)
                    return true;
            }

            return false;
        }

        private static void ExceptionHandler(object sender, UnhandledExceptionEventArgs args)
        {
            using (NcHandler ncHandler = new NcHandler())
            {
                if (ncHandler.numericalControl.NC_IsConnected()) 
                {
                    ncHandler.Disconnect();
                }
            }

            LogException((Exception)args.ExceptionObject, ERROR_LEVEL.FATAL);
        }
    }
}