using System;
using System.Threading;
using System.Drawing;
using System.Windows.Forms;

namespace EthernetSwitcher
{
    public class EthernetSwitcherService
    {
        private Thread _workerThread;
        private bool _isRunning;
        private NotifyIcon _trayIcon;
        private string _lastSelectedInterface = "";

        public void Start(NotifyIcon trayIcon)
        {
            _trayIcon = trayIcon;
            _isRunning = true;
            _workerThread = new Thread(WorkerLoop);
            _workerThread.IsBackground = true;
            _workerThread.Start();
        }

        public void Stop()
        {
            _isRunning = false;
            if (_workerThread != null && _workerThread.IsAlive)
            {
                _workerThread.Join(1000); // Wait up to 1 second for thread to finish
            }
        }

        public void UpdateMode(EthernetMode newMode)
        {
            // Force immediate execution of the new mode
            var settings = CurrentSettings.Instance;
            
            switch (newMode)
            {
                case EthernetMode.Primary:
                    SelectInterface(settings.PrimaryName);
                    UpdateIconFromResource("icon_yellow.ico");
                    break;
                    
                case EthernetMode.Secondary:
                    SelectInterface(settings.SecondaryName);
                    UpdateIconFromResource("icon_yellow.ico");
                    break;
                    
                case EthernetMode.Auto:
                    HandleAutoMode(settings);
                    break;
                    
                case EthernetMode.Disabled:
                    UpdateIconFromResource("icon_yellow.ico");
                    _lastSelectedInterface = "Нет активного интерфейса";
                    break;
            }
            
            UpdateTrayTooltip(newMode, _lastSelectedInterface);
        }

        private void WorkerLoop()
        {
            while (_isRunning)
            {
                try
                {
                    var settings = CurrentSettings.Instance;
                    
                    switch (settings.Mode)
                    {
                        case EthernetMode.Primary:
                            SelectInterface(settings.PrimaryName);
                            UpdateIconFromResource("icon_yellow.ico");
                            break;
                            
                        case EthernetMode.Secondary:
                            SelectInterface(settings.SecondaryName);
                            UpdateIconFromResource("icon_yellow.ico");
                            break;
                            
                        case EthernetMode.Auto:
                            HandleAutoMode(settings);
                            break;
                            
                        case EthernetMode.Disabled:
                            // Do nothing
                            UpdateIconFromResource("icon_yellow.ico");
                            _lastSelectedInterface = "Нет активного интерфейса";
                            break;
                    }
                    
                    // Update tray tooltip after all operations
                    UpdateTrayTooltip(settings.Mode, _lastSelectedInterface);
                    
                    // Wait for the specified interval
                    Thread.Sleep(settings.CheckInterval * 1000);
                }
                catch (Exception ex)
                {
                    Thread.Sleep(5000); // Wait 5 seconds on error before retrying
                }
            }
        }

        private void UpdateIconFromResource(string resourceName)
        {
            try
            {
                var icon = new Icon(System.Reflection.Assembly.GetExecutingAssembly().GetManifestResourceStream($"EthernetSwitcher.{resourceName}"));
                if (_trayIcon.Icon?.Handle != icon.Handle)
                {
                    _trayIcon.Icon = icon;
                }
            }
            catch (Exception ex)
            {
                // Fallback to default icon
                var defaultIcon = Icon.FromHandle(System.Drawing.SystemIcons.WinLogo.Handle);
                if (_trayIcon.Icon?.Handle != defaultIcon.Handle)
                {
                    _trayIcon.Icon = defaultIcon;
                }
            }
        }

        private void HandleAutoMode(Settings settings)
        {
            bool primaryLinkExists = CheckInterfaceLink(settings.PrimaryName);
            
            // Update tray icon based on link status
            if (primaryLinkExists)
            {
                UpdateIconFromResource("icon_green.ico");
            }
            else
            {
                UpdateIconFromResource("icon_red.ico");
            }
            
            if (primaryLinkExists)
            {
                SelectInterface(settings.PrimaryName);
                DeselectInterface(settings.SecondaryName);
            }
            else
            {
                SelectInterface(settings.SecondaryName);
                DeselectInterface(settings.PrimaryName);
            }
        }

        private bool CheckInterfaceLink(string interfaceName)
        {
            try
            {
                return NetworkManager.GetInterfaceStatus(interfaceName);
            }
            catch (Exception ex)
            {
                return false;
            }
        }

        private void DeselectInterface(string interfaceName)
        {
            if (string.IsNullOrEmpty(interfaceName))
                return;

            try
            {
                var settings = CurrentSettings.Instance;
                
                if (!NetworkManager.InterfaceExists(interfaceName))
                {
                    _lastSelectedInterface = $"Интерфейс не найден: {interfaceName}";
                    UpdateIconFromResource("icon_red.ico");
                    return;
                }

                switch (settings.Protocol)
                {
                    case IpProtocol.IPv4:
                        NetworkManager.SetIPv4Status(interfaceName, false);
                        break;
                    case IpProtocol.IPv6:
                        NetworkManager.SetIPv6Status(interfaceName, false);
                        break;
                    case IpProtocol.IPv4_IPv6:
                        NetworkManager.SetIPv4Status(interfaceName, false);
                        NetworkManager.SetIPv6Status(interfaceName, false);
                        break;
                }
            }
            catch (Exception ex)
            {
                // Error handling without logging
            }
        }

        private void SelectInterface(string interfaceName)
        {
            if (string.IsNullOrEmpty(interfaceName))
                return;

            try
            {
                var settings = CurrentSettings.Instance;
                
                if (!NetworkManager.InterfaceExists(interfaceName))
                {
                    _lastSelectedInterface = $"Интерфейс не найден: {interfaceName}";
                    UpdateIconFromResource("icon_red.ico");
                    return;
                }

                switch (settings.Protocol)
                {
                    case IpProtocol.IPv4:
                        NetworkManager.SetIPv4Status(interfaceName, true);
                        break;
                    case IpProtocol.IPv6:
                        NetworkManager.SetIPv6Status(interfaceName, true);
                        break;
                    case IpProtocol.IPv4_IPv6:
                        NetworkManager.SetIPv4Status(interfaceName, true);
                        NetworkManager.SetIPv6Status(interfaceName, true);
                        break;
                }

                _lastSelectedInterface = interfaceName;
            }
            catch (Exception ex)
            {
                // Error handling without logging
            }
        }

        private void UpdateTrayTooltip(EthernetMode mode, string interfaceName)
        {
            try
            {
                var tooltip = $"Режим: {mode}";
                
                if (!string.IsNullOrEmpty(interfaceName))
                {
                    // Shorten interface name to fit in tooltip (Windows 64 char limit)
                    var shortInterfaceName = interfaceName.Length > 25 ? interfaceName.Substring(0, 22) + "..." : interfaceName;
                    tooltip += $"\nИнтерфейс: {shortInterfaceName}";
                }
                
                if (_trayIcon.Text != tooltip)
                {
                    _trayIcon.Text = tooltip;
                }
            }
            catch (Exception ex)
            {
                // Error handling without logging
            }
        }
    }
}