using BeWoLauncher.Logic.Utils;
using BeWoLauncher.ServiceProxy;
using BS.SharedLauncher.Information;
using System;
using System.Diagnostics;
using System.IO;
using System.IO.Pipes;
using System.Threading;
using System.Windows;
using System.Windows.Threading;

namespace BeWoLauncher.Logic.Controller
{
    public static class ProcessController
    {
        private static Process PlanerProcess { get; set; }

        public static Application Current => Application.Current;
        public static LauncherApp CurrentLauncher => Current as LauncherApp;

        public static bool Running { get; set; }

        internal static void CheckForOtherInstance()
        {
            string procName = Process.GetCurrentProcess().ProcessName;

            Process[] processes = Process.GetProcessesByName(procName);

            if (processes.Length > 1)
            {
                HandleProzessAlreadyRunning(false);
                return;
            }

            Process[] processes2 = Process.GetProcessesByName("BeWoPlaner");

            if (processes2.Length > 0)
            {
                HandleProzessAlreadyRunning(false);
                return;
            }
        }

        internal static void HandleProzessAlreadyRunning(bool letUserKill)
        {
#if DEBUG
            letUserKill = true;
#endif

            if (letUserKill)
            {
                string message = "Möchten Sie es schließen? Dadurch können nicht gespeicherte Daten verloren gehen.";
                string caption = "BeWo Anwendung läuft bereits. ";

                var result = MessageBox.Show(message, caption, MessageBoxButton.YesNo);

                if (result == MessageBoxResult.Yes)
                {
                    var own_process_id = Process.GetCurrentProcess().Id;

                    GenericTextLogger.Post($"Beende alle BeWo Prozesse außer PID {own_process_id}");

                    KillAllPlanerProcess(own_process_id);
                }
                else
                {
                    StartLauncherShutdown();
                }
            }
            else
            {
                string message = "Möchten Sie es schließen? Dadurch können nicht gespeicherte Daten verloren gehen.";
                string caption = "BeWo Anwendung läuft bereits. ";

                MessageBox.Show(message, caption);

                StartLauncherShutdown();
            }
        }

        internal static void StartLauncher()
        {
            CheckForOtherInstance();

            LauncherServiceFacade.UpdateServerAddresses();

            Running = true;
        }
        
        internal static void StartLauncherShutdown()
        {
            if (!Running)
                return;

            Running = false;

            GenericTextLogger.Post("Schließe Launcher Prozess...");

            Current.Shutdown();
        }

        internal static void StartPlanerProcess()
        {
            // based on https://docs.microsoft.com/en-us/dotnet/standard/io/how-to-use-anonymous-pipes-for-local-interprocess-communication?redirectedfrom=MSDN
            PlanerProcess = new Process();

            PlanerProcess.StartInfo.FileName = LauncherPaths.GetPlanerExePath();
            PlanerProcess.EnableRaisingEvents = true;
            PlanerProcess.Exited += PlanerProcess_Exit;

            using (AnonymousPipeServerStream pipeServer = new AnonymousPipeServerStream(PipeDirection.Out, HandleInheritability.Inheritable))
            {
                PlanerProcess.StartInfo.Arguments = pipeServer.GetClientHandleAsString();
                PlanerProcess.StartInfo.UseShellExecute = false;
                PlanerProcess.StartInfo.CreateNoWindow = false;
                PlanerProcess.StartInfo.RedirectStandardOutput = true;
                PlanerProcess.OutputDataReceived += MessageFromPlanerClient;

                PlanerProcess.Start();
                GenericTextLogger.Post($"Launcher Start: {PlanerProcess.StartInfo.FileName}");

                PlanerProcess.BeginOutputReadLine();

                pipeServer.DisposeLocalCopyOfClientHandle();

                try
                {
                    using (StreamWriter sw = new StreamWriter(pipeServer))
                    {
                        var signal = new string[] { "C-137", "C-131" };

                        sw.AutoFlush = true;
                        
                        SendInfo(sw, signal[0], pipeServer);

                        SessionInformation.Connection.ToList().ForEach(info => SendInfo(sw, info, pipeServer));
                        SessionInformation.Login.ToList().ForEach(info => SendInfo(sw, info, pipeServer));
                        SessionInformation.Session.ToList().ForEach(info => SendInfo(sw, info, pipeServer));

                        SendInfo(sw, signal[1], pipeServer);
                    }
                }
                catch (IOException ex)
                {

                }
            }
        }
        internal static void SendInfo(StreamWriter sw, string info, AnonymousPipeServerStream pipe)
        {
            sw.WriteLine(info);
            pipe.WaitForPipeDrain();
        }
        internal static void KillOwnPlanerProcess()
        {
            if (PlanerProcess is null)
                return;

            if (PlanerProcess.HasExited)
                return;

            PlanerProcess.CloseMainWindow();
            PlanerProcess.Close();

            PlanerProcess = null;
        }
        internal static void KillAllPlanerProcess(int? own_id)
        {
            foreach (var process in Process.GetProcesses())
            {
                if (own_id.HasValue)
                {
                    if (process.Id == own_id.Value)
                        continue;
                }

                if (process.ProcessName.Contains("BeWoPlaner"))
                {
                    process.Kill();
                }
            }
        }

        internal static void PlanerProcess_Exit(object sender, EventArgs e)
        {
            // ExitCode Übersicht:
            // 100 - Nutzer hat Logout in Core gedrückt
            // 0 - Nutzer hat Fenster geschlossen
            // 1 - Proess über TaskManager gekillt

            if (PlanerProcess.ExitCode == 100)
            {
                GenericTextLogger.Post("Planer Prozess beendet mit ExitCode 100. Starte Launcher neu.");

                CurrentLauncher.Dispatcher.BeginInvoke(DispatcherPriority.Render, (Action)delegate
                {
                    Thread.Sleep(500);
                    ViewController.RestartView();
                });
                return;
            }

            CurrentLauncher.Dispatcher.BeginInvoke(DispatcherPriority.Normal, (Action)StartLauncherShutdown);
        }

        private static void MessageFromPlanerClient(object sender, DataReceivedEventArgs args)
        {
            var data = args.Data;

            if (data == "GUI geladen")
            {
                ViewController.CurrentWindow.Dispatcher.BeginInvoke(DispatcherPriority.Render, (Action)(() => ViewController.CurrentWindow.Hide()));
            }
        }
    }
}