// Sample TekGuard MailServer database driven configuration code
// Contact Vector Information Systems, Inc (www.VInfo.com) for
// information regarding our commercial and SQL Server versions.
using System;
using System.Diagnostics;
using System.ServiceProcess;
using System.Threading;
using System.Windows.Forms;
using TGMSupport;

namespace TGMailServer
{
   public class AppMain : System.ServiceProcess.ServiceBase
   {
      // Component members
      private        System.ComponentModel.IContainer components     = null;
//    private        AppMain                       m_AppMain      = null;  // Main application object
      private        string[]                   m_StartupArgs  = null;  // Save any startup parameters
      private        MailServer                    m_MailServer   = null;  // MailServer main component
      private static ManualResetEvent              m_evtMainDone  = new ManualResetEvent(false);   // Reset the semaphore to wait state
      private  static   ServiceStatus                 m_ServiceStatus   = new ServiceStatus(AppInstaller.TGMSERVICE_NAME);
      private  static   bool                       m_IsService    = false;
      private        bool                       m_OnStartOK    = false;
      private const  string                        STARTUP_ASAPP  = "Application";
      private const  int                           COMMAND_COCKPIT = 128 + 8;
      private const  Int32                      SCM_STARTMS    = 60000;
      private const  Int32                      SCM_STOPMS     = 30000;

      #region Constructors / Destructors

      public AppMain()
      {
         // This call is required by the Windows.Forms Component Designer.
         InitializeComponent();
      }

      /// <summary>
      /// Clean up any resources being used.
      /// </summary>
      protected override void Dispose( bool disposing )
      {
         if( disposing )
         {
            if (components != null)
            {
               components.Dispose();
            }
         }
         base.Dispose( disposing );
      }

      #endregion

      #region Component Designer generated code
      /// <summary> 
      /// Required method for Designer support - do not modify 
      /// the contents of this method with the code editor.
      /// </summary>
      private void InitializeComponent()
      {
         // 
         // AppMain
         // 
         this.CanShutdown = true;
         this.ServiceName = AppInstaller.TGMSERVICE_NAME;

      }
      #endregion

      #region Main Entry Point
      //Application main entry point
      [MTAThread]
      public static void Main(string[] args)
      {
         // Create initial application object
         AppMain AppMain = new AppMain();

         // Run as an application or a service?
         m_IsService = (args.Length == 0) || (args[0].ToLower() != STARTUP_ASAPP.ToLower());

         // Note: Allow either one service or multiple application instances
         if (m_IsService)
         {
            // Run as a service; return (exit) to SCM on successful execution
            if (AppMain.RunAsService(AppMain)) return;

            // Failed Service startup - already running?
            if (AppMain.IsRunning())
            {
               // Already running as a service?
               ServiceController Controller = GetActiveService();
               if (Controller != null)
               {
                  // Yes, simply activate the Controller window
                  Controller.ExecuteCommand(COMMAND_COCKPIT);

                  // Don't run a second instance if a service
                  return;
               }
            }

            // Service execution failed; try running as an application?
            string Msg = "Would you like to run this as an application?\n\nNote: Specify 'Application' on the command\nline when not running as a service.";
            if (DialogResult.No == MessageBox.Show (Msg, AppInstaller.TGMDISPLAY_NAME, MessageBoxButtons.YesNo)) return;

            // Try running as an application
            m_IsService = false;
         }

         // Run as an application; emulate service startup sequence
         AppMain.OnStart(new string[] {STARTUP_ASAPP});

         // Wait until read is completed before continuing.
         AppMain.m_evtMainDone.WaitOne();

         // End Mail processing
         AppMain.OnStop();

         // Exit application (after all threads complete)
         Application.Exit();
      }
      #endregion

      #region RunAsService
      private bool RunAsService(AppMain AppMain)
      {
         // More than one user Service may run within the same process.
         System.ServiceProcess.ServiceBase[] ServicesToRun;

         // Force ability to interact with the desktop
         // Note: .Net 1.1 ignores this parameter
         // Controller.ServiceType = System.ServiceProcess.ServiceType.InteractiveProcess;

         // Service: Register Service Status Handler with SCM
         string ErrorText;
         if ((ErrorText = m_ServiceStatus.Register(new ServiceCustomEventHandler(AppMain.OnCustomCommand), new ServiceStopEventHandler(AppMain.OnStop))) != null)
         {
            MessageBox.Show (ErrorText, AppInstaller.TGMSERVICE_NAME);
         }
         else
         {
            // Let the SCM know we are starting this process
            if (m_ServiceStatus.IsRegistered) m_ServiceStatus.SendStatus(ServiceControllerStatus.StartPending, 0, SCM_STARTMS);
         }

         // Install application as a Service Control Manager (SCM) service
         // Calls OnStart() and OnStop()
         ServicesToRun = new System.ServiceProcess.ServiceBase[] { AppMain };
         System.ServiceProcess.ServiceBase.Run(ServicesToRun);

         // Successfully run as a service?
         return (m_OnStartOK);
      }

      #endregion

      #region OnStart / OnStop
      protected override void OnStart(string[] args)
      {
         // Save the startup parameters for future reference
         m_StartupArgs = args;

         // Create the TekGuard Mail Server
         m_MailServer = new MailServer();

         // Initialize internal settings
         m_MailServer.Initialize();

         // Begin Mail processing
         m_MailServer.Enabled = true;

         // Let the SCM know we have started
         if (m_ServiceStatus.IsRegistered) m_ServiceStatus.SendStatus(ServiceControllerStatus.Running);

         // Indicate that OnStart was called successfully
         m_OnStartOK = true;
      }
      /// <summary>Stop this service</summary>
      protected override void OnStop()
      {
         // Let the SCM know we are stopping this process
         if (m_ServiceStatus.IsRegistered) m_ServiceStatus.SendStatus(ServiceControllerStatus.StopPending, 0, SCM_STOPMS);

         // End Mail processing
         m_MailServer.Enabled = false;

         // Terminate internal processing
         m_MailServer.Terminate();
      }
      #endregion

      #region OnCustomCommand
      protected override void OnCustomCommand (int command)
      {
         // Open or close the Cockpit window
         if (command == COMMAND_COCKPIT) m_MailServer.Visible = true;
      }
      #endregion

      #region IsRunning
      private bool IsRunning()
      {
         // GetProcessesByName() returns array of processes with the specified name
         Process[] processes = Process.GetProcessesByName(AppInstaller.TGMSERVICE_NAME);

         // Running?       
         if (processes.Length > 1)
            return true;   // Another copy is running
         else
            return false;  // No instance exists
      }
      #endregion

      #region IsApplication
      internal static bool IsApplication
      {
         get {return (!m_IsService);}
      }
      #endregion

      #region GetActiveService
      internal static ServiceController GetActiveService()
      {
         // Installed as a service?
         ServiceController Controller = new ServiceController(AppInstaller.TGMSERVICE_NAME);

         try
         {
            // Catch Security Error: "Service TGMailServer was not found on computer '.'"
            ServiceControllerStatus Status = Controller.Status;
            bool bActive = (Status != ServiceControllerStatus.StopPending) && (Status != ServiceControllerStatus.Stopped);
            return (bActive ? Controller : null);
         }
         catch
         {
            // Not an installed service
            return (null);
         }
      }
      #endregion

      #region ServiceStartUpdate
      internal static void ServiceStartUpdate()
      {
         // Let the SCM know what is happening with the process
         if (m_ServiceStatus.IsRegistered) m_ServiceStatus.SendStatus(ServiceControllerStatus.StartPending);
      }
      #endregion

      #region SignalMainDone
      internal static ManualResetEvent SignalMainDone
      {
         get {return m_evtMainDone;}
      }
      #endregion

   }

}