/* Copyright (c) Citrix Systems Inc. 
 * All rights reserved. 
 * 
 * Redistribution and use in source and binary forms, 
 * with or without modification, are permitted provided 
 * that the following conditions are met: 
 * 
 * *   Redistributions of source code must retain the above 
 *     copyright notice, this list of conditions and the 
 *     following disclaimer. 
 * *   Redistributions in binary form must reproduce the above 
 *     copyright notice, this list of conditions and the 
 *     following disclaimer in the documentation and/or other 
 *     materials provided with the distribution. 
 * 
 * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND 
 * CONTRIBUTORS "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, 
 * INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF 
 * MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE 
 * DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT HOLDER OR 
 * CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, 
 * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, 
 * BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR 
 * SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS 
 * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, 
 * WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING 
 * NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE 
 * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 
 * SUCH DAMAGE.
 */

using System;
using System.Collections.Generic;
using System.ComponentModel;
using System.Configuration;
using System.Diagnostics;
using System.Globalization;
using System.IO;
using System.Net;
using System.Reflection;
using System.Windows.Forms;
using System.Threading;
using System.Drawing;
using XenAdmin.Core;
using XenAdmin.Network;
using XenAdmin.Dialogs;
using XenAdmin.XenSearch;
using XenAPI;
using System.Runtime.InteropServices;
using XenAdmin.Network.StorageLink;
using XenAdmin.Actions;


namespace XenAdmin
{
    public static class Program
    {
        public const int DEFAULT_WLB_PORT = 8012;



        /// <summary>
        /// A UUID for the current instance of XenCenter.  Used to identify our own task instances.
        /// </summary>
        public static readonly string XenCenterUUID = Guid.NewGuid().ToString();

        private static NamedPipes.Pipe pipe;
        private const string PIPE_PATH_PATTERN = @"\\.\pipe\XenCenter-{0}-{1}-{2}";

        /// <summary>
        /// Color.Transparent on most platforms; SystemColors.Window when ClearType is enabled.
        /// This is to work around a bug in TextRenderer.DrawText which causes text written to a double-buffer
        /// using ClearType to anti-alias onto black rather than onto the background colour.  In this case,
        /// we use Window, because by luck those labels are always on top of that colour on Vista and XP.
        /// We indicate that we're writing to a buffer (rather than the screen) by setting Graphics.TextContrast
        /// to 5 (the default is 4). This hack was needed because there's no easy way to add info to
        /// a Graphics object. (CA-22938).
        /// </summary>
        public static Color TransparentUsually = Color.Transparent;

        public static readonly Color ErrorForeColor = Color.White;
        public static readonly Color ErrorBackColor = Color.Firebrick;

        public static Font DefaultFont = FormFontFixer.DefaultFont;
        public static Font DefaultFontBold;
        public static Font DefaultFontUnderline;
        public static Font DefaultFontBoldUnderline;
        public static Font DefaultFontItalic;
        public static Font DefaultFontHeader;

        // Also set in Main() AFTER we call EnableVisualStyles().
        // We set them here only so something decent shows up in the Designer.
        public static Color TitleBarStartColor = ProfessionalColors.OverflowButtonGradientBegin;
        public static Color TitleBarEndColor = ProfessionalColors.OverflowButtonGradientEnd;
        public static Color TitleBarBorderColor = TitleBarEndColor;
        public static Color TitleBarForeColor = Color.White;

        public static Color HeaderGradientStartColor = Color.FromArgb(57, 109, 140);
        public static Color HeaderGradientEndColor = Color.FromArgb(63, 139, 137);
        public static Color HeaderGradientForeColor = Color.White;
        public static Font HeaderGradientFont = new Font(DefaultFont.FontFamily, 11.25f);
        public static Font HeaderGradientFontSmall = DefaultFont;
        public static Font TabbedDialogHeaderFont = HeaderGradientFont;

        public static Color TabPageRowBorder = Color.DarkGray;
        public static Color TabPageRowHeader = Color.Silver;

        public static readonly XenAdmin.Core.PropertyManager PropertyManager = new XenAdmin.Core.PropertyManager();

        public static MainWindow MainWindow = null;


        private static StorageLinkConnectionManager _storageLinkConnections;
        public static StorageLinkConnectionManager StorageLinkConnections
        {
            get
            {
                if (_storageLinkConnections == null)
                {
                    _storageLinkConnections = new StorageLinkConnectionManager(() => MainWindow, ConnectionsManager.XenConnections, ConnectionsManager.ConnectionsLock);
                }
                return _storageLinkConnections;
            }
        }


        public static CollectionChangeEventHandler ProgramInvokeHandler(CollectionChangeEventHandler handler)
        {
            return delegate(object s, CollectionChangeEventArgs args)
                       {
                           if (Program.MainWindow != null)
                           {
                               Program.BeginInvoke(Program.MainWindow, delegate()
                                                                           {
                                                                               if (handler != null)
                                                                                   handler(s, args);
                                                                           });
                           }
                       };
        }


        /// <summary>
        /// The secure hash of the master password used to load the client session.
        /// If this is null then no prior session existed and the user should be prompted
        /// to save his session when the UI is quit.
        /// </summary>
        public static byte[] MasterPassword = null;

        /// <summary>
        /// A true value here indicates the user does not want to save session information for this
        /// particular instance of the UI; but when the UI is restarted he should be prompted again.
        /// </summary>
        public static bool SkipSessionSave = false;

        public static bool RunInAutomatedTestMode = false;
        public static string TestExceptionString = null;  // an exception passed back to the test framework
        private static log4net.ILog log = null;

        public static volatile bool Exiting = false;

        public static readonly string AssemblyDir = Path.GetDirectoryName(Assembly.GetExecutingAssembly().Location);

        public static readonly DateTime ApplicationStartTime = DateTime.Now;

        private static readonly System.Threading.Timer dailyTimer;

        public static bool IsThemed = false;

        [DllImport("uxtheme", ExactSpelling = true)]
        public extern static int IsAppThemed();

        static Program()
        {
            XenAdminConfigManager.Provider = new WinformsXenAdminConfigProvider();
            // Start timer to record resource usage every 24hrs
            dailyTimer = new System.Threading.Timer((TimerCallback)delegate(object state)
            {
                Program.logApplicationStats();
            }, null, new TimeSpan(24, 0, 0), new TimeSpan(24, 0, 0));

            log4net.Config.XmlConfigurator.ConfigureAndWatch(new FileInfo(Assembly.GetCallingAssembly().Location + ".config"));
            log = log4net.LogManager.GetLogger(MethodBase.GetCurrentMethod().DeclaringType);

            IsThemed = IsAppThemed() > 0 ? true : false;
            SetDefaultFonts();
        }

        /// <summary>
        /// The main entry point for the application.
        /// </summary>
        [STAThread]
        static public void Main(string[] Args)
        {
            //Upgrade settings
            System.Reflection.Assembly a = System.Reflection.Assembly.GetExecutingAssembly();
            Version appVersion = a.GetName().Version;
            string appVersionString = appVersion.ToString();
            log.DebugFormat("Application version of new settings {0}", appVersionString);

            try
            {
                if (Properties.Settings.Default.ApplicationVersion != appVersion.ToString())
                {
                    log.Debug("Upgrading settings...");
                    Properties.Settings.Default.Upgrade();
                    Properties.Settings.Default.ApplicationVersion = appVersionString;
                }
            }
            catch (ConfigurationErrorsException ex)
            {
                log.Error("Could not load settings.", ex);
                var msg = string.Format("{0}\n\n{1}", Messages.MESSAGEBOX_LOAD_CORRUPTED_TITLE,
                                        string.Format(Messages.MESSAGEBOX_LOAD_CORRUPTED, Settings.GetUserConfigPath()));
                var dlog = new ThreeButtonDialog(new ThreeButtonDialog.Details(SystemIcons.Error,msg,Messages.XENCENTER))
                               {
                                   StartPosition = FormStartPosition.CenterScreen,
                                   //For reasons I do not fully comprehend at the moment, the runtime
                                   //overrides the above StartPosition with WindowsDefaultPosition if
                                   //ShowInTaskbar is false. However it's a good idea anyway to show it
                                   //in the taskbar since the main form is not launcched at this point.
                                   ShowInTaskbar = true
                               };
                dlog.ShowDialog();
                Application.Exit();
                return;
            }

            // Reset statics, because XenAdminTests likes to call Main() twice.
            TestExceptionString = null;
            Exiting = false;
            // Clear XenConnections and History so static classes like OtherConfigAndTagsWatcher 
            // listening to changes still work when Main is called more than once.
            ConnectionsManager.XenConnections.Clear();
            ConnectionsManager.History.Clear();

            Search.InitSearch(() => Program.StorageLinkConnections.GetCopy());
            TreeSearch.InitSearch();
            
            ArgType argType = ArgType.None;
            AppDomain.CurrentDomain.UnhandledException -= CurrentDomain_UnhandledException;
            AppDomain.CurrentDomain.UnhandledException += CurrentDomain_UnhandledException;
            Application.ThreadException -= Application_ThreadException;
            Application.ThreadException += Application_ThreadException;
            Application.EnableVisualStyles();
            Application.SetCompatibleTextRenderingDefault(false);

            try
            {
                if (SystemInformation.FontSmoothingType == 2) // ClearType
                    TransparentUsually = SystemColors.Window;
            }
            catch (NotSupportedException)
            {
                // Leave TransparentUsually == Color.Transparent.  This is an old platform
                // without FontSmoothingType support.
            }

            switch (Environment.OSVersion.Version.Major)
            {
                case 6: // Vista, 2K8, Win7.
                    if (Application.RenderWithVisualStyles)
                    {
                        // Vista, Win7 with styles.
                        TitleBarStartColor = Color.FromArgb(242, 242, 242);
                        TitleBarEndColor = Color.FromArgb(207, 207, 207);
                        TitleBarBorderColor = Color.FromArgb(160, 160, 160);
                        TitleBarForeColor = Color.FromArgb(60, 60, 60);
                        HeaderGradientForeColor = Color.White;
                        HeaderGradientFont = new Font(DefaultFont.FontFamily, 11.25f);
                        HeaderGradientFontSmall = DefaultFont;
                        TabbedDialogHeaderFont = HeaderGradientFont;
                        TabPageRowBorder = Color.Gainsboro;
                        TabPageRowHeader = Color.WhiteSmoke;
                    }
                    else
                    {
                        // 2K8, and Vista, Win7 without styles.
                        TitleBarForeColor = SystemColors.ControlText;
                        HeaderGradientForeColor = SystemColors.ControlText;
                        HeaderGradientFont = new Font(DefaultFont.FontFamily, DefaultFont.Size + 1f, FontStyle.Bold);
                        HeaderGradientFontSmall = DefaultFontBold;
                        TabbedDialogHeaderFont = HeaderGradientFont;
                        TabPageRowBorder = Color.DarkGray;
                        TabPageRowHeader = Color.Silver;
                    }
                    break;

                default:
                    TitleBarStartColor = ProfessionalColors.OverflowButtonGradientBegin;
                    TitleBarEndColor = ProfessionalColors.OverflowButtonGradientEnd;
                    TitleBarBorderColor = TitleBarEndColor;
                    TitleBarForeColor = Application.RenderWithVisualStyles ? Color.White : SystemColors.ControlText;
                    HeaderGradientForeColor = TitleBarForeColor;
                    HeaderGradientFont = new Font(DefaultFont.FontFamily, DefaultFont.Size + 1f, FontStyle.Bold);
                    HeaderGradientFontSmall = DefaultFontBold;
                    TabbedDialogHeaderFont = new Font(DefaultFont.FontFamily, DefaultFont.Size + 1.75f, FontStyle.Bold);
                    TabPageRowBorder = Color.DarkGray;
                    TabPageRowHeader = Color.Silver;
                    break;
            }

            // Force the current culture, to make the layout the same whatever the culture of the underlying OS (CA-46983).
            Thread.CurrentThread.CurrentUICulture = Thread.CurrentThread.CurrentCulture = new CultureInfo(InvisibleMessages.LOCALE, false);

            if (string.IsNullOrEmpty(Thread.CurrentThread.Name))
                Thread.CurrentThread.Name = "Main program thread";

            ServicePointManager.DefaultConnectionLimit = 20;
            ServicePointManager.ServerCertificateValidationCallback = SSL.ValidateServerCertificate;
            XenAPI.Session.UserAgent = string.Format("XenCenter/{0}", ClientVersion());
            ReconfigureConnectionSettings();

            log.Info("Application started");
            logSystemDetails();
            OptionsDialog.Log();

            if (Args.Length > 0)
                log.InfoFormat("Args[0]: {0}", Args[0]);

            List<string> sanitizedArgs = new List<string>(Args);
            // Remove the '--wait' argument, which may have been passed to the splash screen
            sanitizedArgs.Remove("--wait");
            string[] args = null;
            if (sanitizedArgs.Count > 1)
            {
                argType = ParseFileArgs(sanitizedArgs, out args);

                if (argType == ArgType.Passwords)
                {
                    log.DebugFormat("Handling password request using '{0}'", args[0]);
                    try
                    {
                        PasswordsRequest.HandleRequest(args[0]);
                    }
                    catch (Exception exn)
                    {
                        log.Fatal(exn, exn);
                    }
                    Application.Exit();
                    return;
                }
            }
            else if (sanitizedArgs.Count == 1 && sanitizedArgs[0] == "messageboxtest")
            {
                new Dialogs.MessageBoxTest().ShowDialog();
                Application.Exit();
                return;
            }
            else if (sanitizedArgs.Count > 0)
            {
                log.Warn("Unrecognised command line options");
            }

            try
            {
                ConnectPipe();
            }
            catch (System.ComponentModel.Win32Exception exn)
            {
                log.Error("Creating named pipe failed. Continuing to launch XenCenter.", exn);
            }

            Application.ApplicationExit -= Application_ApplicationExit;
            Application.ApplicationExit += Application_ApplicationExit;

            MainWindow mainWindow = new MainWindow(argType, args);

            Application.Run(mainWindow);

            log.Info("Application main thread exited");
        }

        private static ArgType ParseFileArgs(List<string> args, out string[] filePath)
        {
            filePath = new string[args.Count - 1];
            for (int i = 0; i < filePath.Length; i++)
                filePath[i] = args[i + 1];

            switch (args[0])
            {
                case "import":
                    return ArgType.Import;
                case "license":
                    return ArgType.License;
                case "restore":
                    return ArgType.Restore;
                case "update":
                    return ArgType.Update;
                case "xensearch":
                    return ArgType.XenSearch;
                case "passwords":
                    return ArgType.Passwords;
                case "connect":
                    return ArgType.Connect;
                default:
                    log.Warn("Unrecognised command line options");
                    return ArgType.None;
            }
        }

        /// <summary>
        /// Connects to the XenCenter named pipe. If the pipe didn't already exist, a new thread is started
        /// that listens for incoming data on the pipe (from new invocations of XenCenter) and deals
        /// with the command line arguments of those instances. If the pipe does exist, a Win32Exception is thrown.
        /// </summary>
        /// <exception cref="Win32Exception">If creating the pipe failed for any reason.</exception>
        private static void ConnectPipe()
        {
            string pipe_path = string.Format(PIPE_PATH_PATTERN, Process.GetCurrentProcess().SessionId, Environment.UserName, Assembly.GetExecutingAssembly().Location.Replace('\\', '-'));

            // Pipe path must be limited to 256 characters in length
            if (pipe_path.Length > 256)
            {
                pipe_path = pipe_path.Substring(0, 256);
            }

            log.InfoFormat(@"Connecting to pipe '{0}'", pipe_path);
            // Line below may throw Win32Exception
            pipe = new NamedPipes.Pipe(pipe_path);

            log.InfoFormat(@"Successfully created pipe '{0}' - proceeding to launch XenCenter", pipe_path);
            pipe.Read += new EventHandler<NamedPipes.PipeReadEventArgs>(delegate(object sender, NamedPipes.PipeReadEventArgs e)
            {
                MainWindow m = Program.MainWindow;
                if (m == null || RunInAutomatedTestMode)
                {
                    return;
                }
                Program.Invoke(m, delegate
                {
                    log.InfoFormat(@"Received data from pipe '{0}': {1}", pipe_path, e.Message);

                    ArgType argType = ArgType.None;
                    string[] other_args;
                    string file_arg = "";
                    string[] bits = e.Message.Split(new char[] { ' ' }, 3);
                    if (bits.Length == 2)
                    {
                        List<string> args = new List<string>();
                        args.Add(bits[0]);
                        args.Add(bits[1]);
                        argType = ParseFileArgs(args, out other_args);
                        file_arg = other_args[0];

                        if (argType == ArgType.Passwords)
                        {
                            log.Error("Refusing to accept passwords request down pipe.  Use XenCenterMain.exe directly");
                            return;
                        }
                        else if (argType == ArgType.Connect)
                        {
                            log.Error("Connect not supported down pipe. Use XenCenterMain.exe directly");
                            return;
                        }
                        else if (argType == ArgType.None)
                        {
                            return;
                        }
                    }
                    else if (e.Message.Length > 0)
                    {
                        log.Error("Could not process data received from pipe.");
                        return;
                    }

                    m.WindowState = FormWindowState.Normal;

                    // Note slight hack: the C++ splash screen passes its command line as a
                    // literal string. This means we will get an e.Message e.g.
                    //      open "C:\Documents and Settings\foo.xva"
                    // INCLUDING double quotes. Thus we trim the quotes below.
                    if (file_arg.Length > 1 && file_arg.StartsWith("\"") && file_arg.EndsWith("\""))
                    {
                        file_arg = file_arg.Substring(1, file_arg.Length - 2);
                    }

                    m.ProcessCommand(argType, new string[] { file_arg });
                });
            });
            pipe.BeginRead();
            // We created the pipe successfully - i.e. nobody was listening, so go ahead and start XenCenter
        }

        internal static void DisconnectPipe()
        {
            if (pipe != null)
            {
                log.Debug("Disconnecting from named pipe in Program.DisconnectPipe()");
                System.Threading.ThreadPool.QueueUserWorkItem((WaitCallback)delegate(object o)
                {
                    pipe.Disconnect();
                });
            }
        }

        private static void logSystemDetails()
        {
            log.Info("Version: " + Assembly.GetExecutingAssembly().GetName().Version.ToString());
            log.Info(".NET runtime version: " + Environment.Version.ToString(4));
            log.Info("OS version: " + Environment.OSVersion.ToString());
            log.Info("UI Culture: " + Thread.CurrentThread.CurrentUICulture.EnglishName);
            log.Info(string.Format("Bitness: {0}-bit", IntPtr.Size * 8));
        }

        static void Application_ApplicationExit(object sender, EventArgs e)
        {
            Exiting = true;

            logApplicationStats();

            Clip.UnregisterClipboardViewer();

            try
            {
                // Lets save the connections first, so we can save their connected state
                Settings.SaveIfRequired();
            }
            catch (Exception)
            {
                // Ignore here
            }
            // The application is about to exit - gracefully close connections to
            // avoid a bunch of WinForms related race conditions...
            foreach (Network.IXenConnection conn in ConnectionsManager.XenConnectionsCopy)
                conn.EndConnect(false);
        }

        private static void logApplicationStats()
        {
            Process p = Process.GetCurrentProcess();

            log.Info("Log Application State");
            log.InfoFormat("ExitCode: {0}", Environment.ExitCode);

            log.InfoFormat("Time since process started: {0}", (DateTime.Now - Process.GetCurrentProcess().StartTime).ToString());

            log.InfoFormat("Handles open: {0}", p.HandleCount.ToString());
            log.InfoFormat("USER handles open: {0}", Win32.GetGuiResourcesUserCount(p.Handle));
            log.InfoFormat("GDI handles open: {0}", Win32.GetGuiResourcesGDICount(p.Handle));
            log.InfoFormat("Thread count: {0}", p.Threads.Count);

            log.InfoFormat("Virtual memory size: {0}", Util.MemorySizeString(p.VirtualMemorySize64));
            log.InfoFormat("Working set: {0}", Util.MemorySizeString(p.WorkingSet64));
            log.InfoFormat("Private memory size: {0}", Util.MemorySizeString(p.PrivateMemorySize64));
            log.InfoFormat("Nonpaged system memory size: {0}", Util.MemorySizeString(p.NonpagedSystemMemorySize64));
            log.InfoFormat("Paged memory size: {0}", Util.MemorySizeString(p.PagedMemorySize64));
            log.InfoFormat("Paged system memory size: {0}", Util.MemorySizeString(p.PagedSystemMemorySize64));

            log.InfoFormat("Peak paged memory size: {0}", Util.MemorySizeString(p.PeakPagedMemorySize64));
            log.InfoFormat("Peak virtual memory size: {0}", Util.MemorySizeString(p.PeakVirtualMemorySize64));
            log.InfoFormat("Peak working set: {0}", Util.MemorySizeString(p.PeakWorkingSet64));

            log.InfoFormat("Process priority class: {0}", p.PriorityClass.ToString());
            log.InfoFormat("Privileged processor time: {0}", p.PrivilegedProcessorTime.ToString());

            log.InfoFormat("Total processor time: {0}", p.TotalProcessorTime.ToString());
            log.InfoFormat("User processor time: {0}", p.UserProcessorTime.ToString());
        }

        static void Application_ThreadException(object sender, System.Threading.ThreadExceptionEventArgs e)
        {
            ProcessUnhandledException(sender, e.Exception, false);
        }

        static void CurrentDomain_UnhandledException(object sender, UnhandledExceptionEventArgs e)
        {
            ProcessUnhandledException(sender, (Exception)e.ExceptionObject, e.IsTerminating);
        }

        private static void ProcessUnhandledException(object sender, Exception e, bool isTerminating)
        {
            try
            {
                if (e != null)
                {
                    log.Fatal("Uncaught exception", e);
                    if (e.InnerException != null)
                        log.Fatal("Inner exception", e.InnerException);
                }
                else
                {
                    log.Fatal("Fatal error");
                }
                logSystemDetails();
                logApplicationStats();

                if (!RunInAutomatedTestMode)
                {
                    string filepath = GetLogFile();

                    ThreeButtonDialog d = new ThreeButtonDialog(
                       new ThreeButtonDialog.Details(
                           SystemIcons.Error,
                           String.Format(Messages.MESSAGEBOX_PROGRAM_UNEXPECTED, HelpersGUI.DateTimeToString(DateTime.Now, "yyyy-MM-dd HH:mm:ss", false), filepath),
                           Messages.MESSAGEBOX_PROGRAM_UNEXPECTED_TITLE));

                    // CA-44733
                    if (MainWindow != null && !IsExiting(MainWindow) && !MainWindow.InvokeRequired)
                        d.ShowDialog(MainWindow);
                    else
                        d.ShowDialog();
                }
            }
            catch (Exception exception)
            {
                try
                {
                    log.Fatal("Fatal error while handling fatal error!", exception);
                }
                catch (Exception)
                {
                }
                if (!RunInAutomatedTestMode)
                {
                    new ThreeButtonDialog(new ThreeButtonDialog.Details(SystemIcons.Error, exception.ToString(), Messages.XENCENTER)).ShowDialog();
                    // To be handled by WER
                    throw;
                }
            }
            if (RunInAutomatedTestMode && TestExceptionString == null)
                TestExceptionString = e.GetBaseException().ToString();
        }

        private static void SetDefaultFonts()
        {
            // Set the default font.
            //
            // Some locales have a known correct font, which we just use.
            //
            // Otherwise (e.g. English), we need to make sure that our fonts fit in with
            // our panel layout.  This can be a problem on far-Eastern platforms in particular, because the default fonts there are wider in the
            // English range than Tahoma / Segoe UI.  Anything bigger than them is going to cause us to overflow on the panels, so we force it back
            // to an appropriate font.
            // We need to be careful not to override the user's settings if they've deliberately scaled up the text for readability reasons,
            // so we only override if the font size is 9pt or smaller, which is the usual default.
            //
            // We also define a registry key to turn this off, just in case someone in the field complains.

            if (Registry.ForceSystemFonts)
            {
                log.Debug("ForceSystemFonts registry key is defined");
            }
            else if (InvisibleMessages.LOCALE.StartsWith("ja-"))
            {
                Font new_font =
                    (Environment.OSVersion.Version.Major < 6 || Environment.OSVersion.Version.Major == 6 && Environment.OSVersion.Version.Minor == 0) ?
                        new Font("MS UI Gothic", 9.0f) : // 2K (5.0), XP (5.1), 2K3 and XP Pro (5.2), Vista and 2K8 (6.0)
                        new Font("Meiryo UI", 9.0f); // Win 7 and 2K8R2 (6.1) and above
                log.DebugFormat("Running on localized resources with Japanese fonts; switching the font from {0} {1}pt to {2} {3}pt.",
                                DefaultFont.Name, DefaultFont.Size, new_font.Name, new_font.Size);
                SetDefaultFonts(new_font);
                return;
            }
            else if (InvisibleMessages.LOCALE.StartsWith("zh-"))
            {
                Font new_font =
                        Environment.OSVersion.Version.Major < 6 ?
                        new Font("MS Shell Dlg", 9.0f) : // 2K (5.0), XP (5.1), 2K3 and XP Pro (5.2)
                        new Font("Microsoft YaHei", 9.0f); // Vista and above
                log.DebugFormat("Running on localized resources with Simplified Chinese fonts; switching the font from {0} {1}pt to {2} {3}pt.",
                                DefaultFont.Name, DefaultFont.Size, new_font.Name, new_font.Size);
                SetDefaultFonts(new_font);
                return;
            }
            else
            {
                if (DefaultFont.Size <= 9.0f)
                {
                    Size s = Drawing.MeasureText("Lorum ipsum", DefaultFont);
                    // Segoe UI 9pt gives 78x15 here.  Tahoma 8pt gives 66x13.
                    // We allow a bit of slop just in case antialias or hinting settings make a small difference.
                    if (s.Width > 80 || s.Height > 16)
                    {
                        Font new_font =
                            Environment.OSVersion.Version.Major < 6 ?
                                new Font("Tahoma", 8.0f) : // 2K (5.0), XP (5.1), 2K3 and XP Pro (5.2)
                                new Font("Segoe UI", 9.0f); // Vista and above

                        log.DebugFormat("Running on default resources with large default font; switching the font from {0} {1}pt to {2} {3}pt.",
                            DefaultFont.Name, DefaultFont.Size, new_font.Name, new_font.Size);
                        SetDefaultFonts(new_font);
                        return;
                    }
                    else
                    {
                        log.Debug("Running on default resources and happy with the font.");
                    }
                }
                else
                {
                    log.Debug("Running on default resources but the font is bigger than usual.");
                }
            }
            log.DebugFormat("Leaving the default font as {0} {1}pt.", DefaultFont.Name, DefaultFont.Size);
            SetDefaultFonts(DefaultFont);
        }

        private static void SetDefaultFonts(Font f)
        {
            DefaultFont = f;
            DefaultFontBold = new Font(f, FontStyle.Bold);
            DefaultFontUnderline = new Font(f, FontStyle.Underline);
            DefaultFontBoldUnderline = new Font(f, FontStyle.Bold | FontStyle.Underline);
            DefaultFontItalic = new Font(f, FontStyle.Italic);
            DefaultFontHeader = new Font(f.FontFamily, 9.75f, FontStyle.Bold);

            FormFontFixer.DefaultFont = f;
        }

        internal static void AssertOffEventThread()
        {
            if (Program.MainWindow.Visible && !Program.MainWindow.InvokeRequired)
            {
                FatalError();
            }
        }

        internal static void AssertOnEventThread()
        {
            if (Program.MainWindow != null && Program.MainWindow.Visible && Program.MainWindow.InvokeRequired)
            {
                FatalError();
            }
        }

        private static void FatalError()
        {
            string msg = String.Format(Messages.MESSAGEBOX_PROGRAM_UNEXPECTED,
                HelpersGUI.DateTimeToString(DateTime.Now, "yyyy-MM-dd HH:mm:ss", false), GetLogFile_());
            log.Fatal(msg + "\n" + Environment.StackTrace);
            MainWindow m = Program.MainWindow;
            if (m == null)
            {
                log.Fatal("Program.MainWindow is null");
            }
            else
            {
                log.FatalFormat("Program.MainWindow.Visible == {0}", m.Visible);
                log.FatalFormat("Program.MainWindow.InvokeRequired == {0}", m.InvokeRequired);
                log.FatalFormat("CurrentThread.Name == {0}", Thread.CurrentThread.Name);
            }

            if (RunInAutomatedTestMode)
            {
                if (TestExceptionString == null)
                    TestExceptionString = msg + "\n" + Environment.StackTrace;
            }
            else
            {
                new ThreeButtonDialog(new ThreeButtonDialog.Details(SystemIcons.Error, msg, Messages.MESSAGEBOX_PROGRAM_UNEXPECTED_TITLE)).ShowDialog();
            }
        }

        public static void ViewLogFiles()
        {
            string s = GetLogFile_();
            if (s == null)
            {
                new ThreeButtonDialog(new ThreeButtonDialog.Details(SystemIcons.Error, Messages.MESSAGEBOX_LOGFILE_MISSING, Messages.XENCENTER)).ShowDialog();
            }
            else
            {
                System.Diagnostics.Process.Start(Path.GetDirectoryName(s));
            }
        }

        private static string GetLogFile()
        {
            string s = GetLogFile_();
            return s == null ? "MISSING LOG FILE!" : s;
        }

        public static string GetLogFile_()
        {
            foreach (log4net.Appender.IAppender appender in log.Logger.Repository.GetAppenders())
            {
                if (appender is log4net.Appender.FileAppender)
                {
                    // Assume that the first FileAppender is the primary log file.
                    return ((log4net.Appender.FileAppender)appender).File;
                }
            }
            return null;
        }

        private static readonly List<string> HiddenObjects = new List<string>();

        internal static void HideObject(string opaqueRef)
        {
            lock (HiddenObjects)
            {
                HiddenObjects.Add(opaqueRef);
            }
            if (MainWindow != null)
            {
                MainWindow.RequestRefreshTreeView();
            }
        }

        internal static void ShowObject(string opaqueRef)
        {
            lock (HiddenObjects)
            {
                HiddenObjects.Remove(opaqueRef);
            }
            if (MainWindow != null)
            {
                MainWindow.RequestRefreshTreeView();
            }
        }

        internal static bool ObjectIsHidden(string opaqueRef)
        {
            lock (HiddenObjects)
            {
                return HiddenObjects.Contains(opaqueRef);
            }
        }

        /// <summary>
        /// Safely invoke the given delegate on the given control.
        /// </summary>
        public static void Invoke(Control c, MethodInvoker f)
        {
            try
            {
                if (!IsExiting(c))
                {
                    if (c.InvokeRequired)
                    {
                        MethodInvoker exceptionLogger = () =>
                            {
                                try
                                {
                                    f();
                                }
                                catch (Exception e)
                                {
                                    log.Error("Exception in Invoke", e);
                                    throw;
                                }
                            };

                        try
                        {
                            c.Invoke(exceptionLogger);
                        }
                        catch (Exception e)
                        {
                            log.Error(string.Format("Exception in Invoke (ControlType={0}, MethodName={1})", c.GetType(),
                                                    f.Method.Name), e);
                            throw;
                        }
                    }
                    else
                    {
                        f();
                    }
                }
            }
            catch (ObjectDisposedException)
            {
                if (!IsExiting(c)) throw;
            }
            catch (InvalidAsynchronousStateException)
            {
                if (!IsExiting(c)) throw;
            }
            catch (InvalidOperationException)
            {
                if (!IsExiting(c)) throw;
            }
        }

        private static bool IsExiting(Control c)
        {
            return Exiting || c.Disposing || c.IsDisposed || !c.IsHandleCreated;
        }

        /// <summary>
        /// Safely invoke the given delegate on the given control.
        /// </summary>
        /// <returns>The result of the function call, or null if c is being disposed.</returns>
        public static object Invoke(Control c, Delegate f, params object[] p)
        {
            try
            {
                if (!IsExiting(c))
                {
                    if (c.InvokeRequired)
                    {
                        Func<object> exceptionLogger = () =>
                            {
                                try
                                {
                                    return f.DynamicInvoke(p);
                                }
                                catch (Exception e)
                                {
                                    log.Error("Exception in Invoke", e);
                                    throw;
                                }
                            };

                        return c.Invoke(exceptionLogger);
                    }
                    else
                    {
                        return f.DynamicInvoke(p);
                    }
                }
            }
            catch (ObjectDisposedException)
            {
                if (!IsExiting(c)) throw;
            }
            catch (InvalidAsynchronousStateException)
            {
                if (!IsExiting(c)) throw;
            }
            catch (InvalidOperationException)
            {
                if (!IsExiting(c)) throw;
            }
            return null;
        }

        public static IAsyncResult BeginInvoke(Control c, Delegate f, params object[] p)
        {
            try
            {
                if (!IsExiting(c))
                {
                    return c.BeginInvoke(f, p);
                }
            }
            catch (ObjectDisposedException)
            {
                if (!IsExiting(c)) throw;
            }
            catch (InvalidAsynchronousStateException)
            {
                if (!IsExiting(c)) throw;
            }
            catch (InvalidOperationException)
            {
                if (!IsExiting(c)) throw;
            }
            return null;
        }

        public static void BeginInvoke(Control c, MethodInvoker f)
        {
            try
            {
                if (!IsExiting(c))
                {
                    c.BeginInvoke(f);
                }
            }
            catch (ObjectDisposedException)
            {
                if (!IsExiting(c)) throw;
            }
            catch (InvalidAsynchronousStateException)
            {
                if (!IsExiting(c)) throw;
            }
            catch (InvalidOperationException)
            {
                if (!IsExiting(c)) throw;
            }
        }

        public static string ClientVersion()
        {
            foreach (object o in Assembly.GetExecutingAssembly().GetCustomAttributes(true))
            {
                if (o is XSVersionAttribute)
                {
                    string result = ((XSVersionAttribute)o).Version;
                    return result == "@PRODUCT_VERSION@" ? "PRIVATE" : result;
                }
            }
            return "MISSING";
        }

        public static void ReconfigureConnectionSettings()
        {
            XenAPI.Session.Proxy = XenAdminConfigManager.Provider.GetProxyFromSettings(null);
        }

        private const string SplashWindowClass = "XenCenterSplash0001";

        internal static void CloseSplash()
        {
            IntPtr hWnd = Win32.FindWindow(SplashWindowClass, null);

            if (hWnd == IntPtr.Zero)
            {
                //log.Warn("Couldn't find splash screen in CloseSplash()", new System.ComponentModel.Win32Exception());
                return;
            }

            if (!Win32.PostMessage(hWnd, Win32.WM_DESTROY, IntPtr.Zero, IntPtr.Zero))
            {
                log.Warn("PostMessage WM_DESTROY failed in CloseSplash()", new System.ComponentModel.Win32Exception());
            }
        }

        public static void OpenURL(string url)
        {
            if (RunInAutomatedTestMode)
                return;
            try
            {
                System.Diagnostics.Process.Start(url);
            }
            catch (Exception e)
            {
                log.Debug(string.Format("Exception while opening url {0}:", url), e);
            }
        }

        /// <summary>
        /// If true action threads will close themselves instantly...
        /// </summary>
        public static bool ForcedExiting = false;

        public static Version Version
        {
            get
            {
                return Assembly.GetExecutingAssembly().GetName().Version;
            }
        }

		/// <summary>
		/// Gets the version in the form "a.b.c"
		/// </summary>
		public static string VersionThreePart
		{
			get
			{
				var version = Version;

				//The release version is obtained from branding.hg. From a
				//private build we get 0.0.0.0 so we should look out for
				//it and return it as is (or alternatively return 99.99.99)
				if (version.ToString() == "0.0.0.0")
					return "0.0.0.0";

				return string.Format("{0}.{1}.{2}", version.Major, version.Minor, version.Build);
			}
		}

        public static string CurrentLanguage
        {
            get
            {
                return Thread.CurrentThread.CurrentCulture.TwoLetterISOLanguageName;
            }
        }

        public static string VersionAndLanguage
        {
            get
            {
                return string.Format("{0}.{1}", Version.ToString(), CurrentLanguage);
            }
        }

        public static CultureInfo CurrentCulture
        {
            get
            {
                return Thread.CurrentThread.CurrentCulture;
            }
        }
    }

    public enum ArgType { Import, License, Restore, Update, None, XenSearch, Passwords, Connect };
}