using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;
using System.Threading.Tasks;
using Tango.BL;
using Tango.BL.Entities;
using Tango.Core;
using Tango.Integration.Operation;
using Tango.Integration.ExternalBridge;
using Tango.PMR.Connection;
using Tango.Transport.Adapters;
using Tango.Settings;
using Tango.Logging;
using Tango.BL.Builders;
using Tango.Core.DI;
using Tango.PPC.Common.Messages;
using Tango.Emulations.Emulators;
using Tango.Transport.Transporters;
using Tango.Integration;
using Tango.Transport;
using System.Threading;
using Tango.Core.ExtensionMethods;

namespace Tango.PPC.Common.Connection
{
    /// <summary>
    /// Represents the default <see cref="IMachineProvider"/>.
    /// </summary>
    /// <seealso cref="Tango.Core.ExtendedObject" />
    /// <seealso cref="Tango.PPC.Common.Connection.IMachineProvider" />
    public class DefaultMachineProvider : ExtendedObject, IMachineProvider
    {
        private bool _isInitialized;
        private Thread _connection_thread;
        private ObservablesContext _context;
        private bool disableConnectionFileLogging;

        /// <summary>
        /// Occurs when the machine has connected.
        /// </summary>
        public event EventHandler MachineConnected;

        /// <summary>
        /// Occurs when the machine has disconnected.
        /// </summary>
        public event EventHandler MachineDisconnected;

        private bool _isConnected;
        /// <summary>
        /// Gets a value indicating whether the machine is currently connected.
        /// </summary>
        public bool IsConnected
        {
            get { return _isConnected; }
            private set { _isConnected = value; RaisePropertyChangedAuto(); }
        }

        private Machine _machine;
        /// <summary>
        /// Gets the database machine entity associated with the current machine.
        /// </summary>
        public Machine Machine
        {
            get
            {
                return _machine;
            }
            private set
            {
                _machine = value;
                RaisePropertyChangedAuto();
            }
        }

        private IMachineOperator _machineOperator;
        /// <summary>
        /// Gets the machine operator.
        /// </summary>
        public IMachineOperator MachineOperator
        {
            get
            {
                return _machineOperator;
            }
            private set
            {
                _machineOperator = value;
                RaisePropertyChangedAuto();
            }
        }

        /// <summary>
        /// Initializes a new instance of the <see cref="DefaultMachineProvider"/> class.
        /// </summary>
        public DefaultMachineProvider()
        {
            var settings = SettingsManager.Default.GetOrCreate<PPCSettings>();

            MachineOperator = new MachineOperator();
            MachineOperator.StatusChanged += MachineOperator_StatusChanged;
            MachineOperator.EnableEventsNotification = true;
            MachineOperator.EnableJobResume = true;
            MachineOperator.UseKeepAlive = true;
            MachineOperator.EnableMachineStatusUpdates = true;
            MachineOperator.EnableDiagnostics = true;
            MachineOperator.EnablePowerUpSequence = true;
            MachineOperator.EnableEmbeddedDebugging = settings.EnableEmbeddedDebugLogs;
            MachineOperator.EnableAutomaticThreadLoading = settings.EnableAutomaticThreadLoading;
            MachineOperator.JobRunsLogger.JobSource = BL.Enumerations.JobSource.Local;

            MachineOperator.FirmwareUpgradeMode = Integration.Upgrade.FirmwareUpgradeModes.DFU | Integration.Upgrade.FirmwareUpgradeModes.TFP_PACKAGE;

            MachineOperator.JobUploadStrategy = settings.JobUploadStrategy;
            MachineOperator.JobUnitsMethod = settings.JobUnitsMethod;

            MachineOperator.GradientGenerationConfiguration.IsEnabled = settings.EnableGradientGeneration;
            MachineOperator.GradientGenerationConfiguration.ResolutionCM = settings.GradientGenerationResolution;

            MachineOperator.EmergencyNotificationProvider.Address = settings.EmergencyComPort;
            MachineOperator.EmergencyNotificationProvider.IsEnabled = settings.EnableEmergencyNotifications;

            MachineOperator.EnableJobLiquidQuantityValidation = settings.EnableJobLiquidQuantityValidation;
        }

        private void MachineOperator_StatusChanged(object sender, MachineStatuses status)
        {
            if (status != MachineStatuses.Disconnected)
            {
                if (!IsConnected)
                {
                    OnMachineConnected();
                }
            }
            else
            {
                if (IsConnected)
                {
                    OnMachineConnected();
                }
            }
        }

        private async void ConnectionThreadMethod()
        {
            while (true)
            {
                if (MachineOperator.State != TransportComponentState.Connected)
                {
                    var fileLogger = LogManager.RegisteredLoggers.FirstOrDefault(x => x.GetType() == typeof(FileLogger));

                    try
                    {
                        Thread.Sleep(2000);

                        if (fileLogger != null && disableConnectionFileLogging)
                        {
                            fileLogger.Enabled = false;
                        }

                        LogManager.Log("Starting machine connection procedure...", LogCategory.Info);

                        var settings = SettingsManager.Default.GetOrCreate<PPCSettings>();

                        if (!Machine.IsDemo)
                        {
                            if (String.IsNullOrWhiteSpace(settings.EmbeddedComPort))
                            {
                                TimeSpan timeout = TimeSpan.FromSeconds(SettingsManager.Default.GetOrCreate<PPCSettings>().MachineScanningTimeoutSeconds);

                                LogManager.Log("Scanning for machine on available serial ports...", LogCategory.Info);
                                Transport.Discovery.UsbCommunicationScanner<ConnectRequest, ConnectResponse> scanner = new Transport.Discovery.UsbCommunicationScanner<ConnectRequest, ConnectResponse>(UsbSerialBaudRates.BR_115200);
                                var response = await scanner.Scan(new ConnectRequest() { Password = "1234" }, settings.EmbeddedDeviceHint, timeout);

                                LogManager.Log("Machine discovered on port: " + response.Adapter.Address, LogCategory.Info);
                                LogManager.Log("Device Information:", LogCategory.Debug);
                                LogManager.Log(response.Response.DeviceInformation.ToJsonString(), LogCategory.Info);

                                LogManager.Log("Disconnecting machine operator...", LogCategory.Info);
                                await MachineOperator.Disconnect();
                                MachineOperator.Adapter = response.Adapter;
                                MachineOperator.JobHandlingMode = JobHandlerModes.SettingUp;
                                LogManager.Log("Connecting machine operator...", LogCategory.Info);
                                try
                                {
                                    await MachineOperator.Connect();

                                    if (MachineOperator.DeviceInformation != null)
                                    {
                                        settings.FirmwareVersion = MachineOperator.DeviceInformation.Version;
                                        settings.Save();
                                    }

                                    disableConnectionFileLogging = false;
                                }
                                catch (Exception)
                                {
                                    await response.Adapter.Disconnect();
                                    throw;
                                }


                                await Task.Delay(1000);
                                await MachineOperator.UploadHardwareConfiguration(Machine.Configuration.HardwareVersion, Machine.Configuration);
                                MachineOperator.UseKeepAlive = true;
                            }
                            else
                            {
                                LogManager.Log($"Connecting to machine on {settings.EmbeddedComPort}...", LogCategory.Info);

                                UsbTransportAdapter adapter = new UsbTransportAdapter(settings.EmbeddedComPort, UsbSerialBaudRates.BR_115200);
                                MachineOperator.Adapter = adapter;
                                MachineOperator.JobHandlingMode = JobHandlerModes.SettingUp;
                                try
                                {
                                    await MachineOperator.Connect();

                                    if (MachineOperator.DeviceInformation != null)
                                    {
                                        settings.FirmwareVersion = MachineOperator.DeviceInformation.Version;
                                        settings.Save();
                                    }

                                    disableConnectionFileLogging = false;
                                }
                                catch (Exception)
                                {
                                    await adapter.Disconnect();
                                    throw;
                                }

                                await Task.Delay(1000);
                                await MachineOperator.UploadHardwareConfiguration(Machine.Configuration.HardwareVersion, Machine.Configuration);
                                MachineOperator.UseKeepAlive = true;
                            }
                        }
                        else
                        {
                            LogManager.Log("Application in demo mode!");

                            var emulator_channel_name = "emulator-" + Guid.NewGuid().ToString();

                            LogManager.Log("Starting embedded emulator...");
                            MachineEmulator emulator = new MachineEmulator(new BasicTransporter(new MemoryTransportAdapter(emulator_channel_name)));
                            await emulator.Start();

                            LogManager.Log("Emulator started. Connecting to emulator...");

                            MemoryTransportAdapter adapter = new MemoryTransportAdapter(emulator_channel_name);
                            MachineOperator.Adapter = adapter;
                            MachineOperator.JobHandlingMode = JobHandlerModes.SettingUp;
                            LogManager.Log("Connecting machine operator...");
                            await MachineOperator.Connect();

                            disableConnectionFileLogging = false;

                            if (MachineOperator.DeviceInformation != null)
                            {
                                settings.FirmwareVersion = MachineOperator.DeviceInformation.Version;
                                settings.Save();
                            }

                            await Task.Delay(1000);
                            await MachineOperator.UploadHardwareConfiguration(Machine.Configuration.HardwareVersion, Machine.Configuration);
                        }
                    }
                    catch (Exception ex)
                    {
                        LogManager.Log(ex, "Error while trying to scan and connect to the machine.");
                        LogManager.Log("File logging of further connection attempts is now disabled and will resume when connection is successful.");
                        disableConnectionFileLogging = true;
                    }
                    finally
                    {
                        await Task.Delay(100);

                        if (fileLogger != null)
                        {
                            fileLogger.Enabled = true;
                        }
                    }
                }

                Thread.Sleep(5000);
            }
        }

        /// <summary>
        /// Initializes this machine provider start machine port scanning and connection.
        /// </summary>
        public void Init(Machine machine, ObservablesContext context)
        {
            if (!_isInitialized)
            {
                LogManager.Log("Initializing machine operator...");

                _isInitialized = true;

                LogManager.Log("Retrieving first machine database entry...");

                _context = context;
                Machine = machine;

                if (Machine != null)
                {
                    LogManager.Log("First machine entry found. Machine serial number is: " + Machine.SerialNumber + ".");

                    if (Machine.IsDemo)
                    {
                        LogManager.Log("Machine is in demo mode. Changing firmware upgrade mode to TFP package only.");
                        MachineOperator.FirmwareUpgradeMode = Integration.Upgrade.FirmwareUpgradeModes.TFP_PACKAGE;
                    }

                    ConnectToMachine();
                }
                else
                {
                    LogManager.Log("No machine entry found on database. Could not connect to the embedded device!", LogCategory.Error);
                }
            }
        }

        /// <summary>
        /// Tries to connect to the machine by scanning all available serial ports.
        /// The timeout for a scan cycle is specified on <see cref="PPCSettings.MachineScanningTimeoutSeconds"/>.
        /// </summary>
        private void ConnectToMachine()
        {
            if (_connection_thread == null)
            {
                _connection_thread = new Thread(ConnectionThreadMethod);
                _connection_thread.IsBackground = true;
                _connection_thread.Start();
            }
        }

        /// <summary>
        /// Saves the machine settings.
        /// </summary>
        /// <returns></returns>
        public async Task SaveMachine()
        {
            await _context.SaveChangesAsync();
            Machine = await new MachineBuilder(_context).SetFirst().BuildAsync();
            TangoMessenger.Default.Send(new MachineSettingsSavedMessage() { Machine = Machine });
        }

        /// <summary>
        /// Creates and connects a machine operator with no continuous requests at all.
        /// </summary>
        /// <returns></returns>
        public static async Task<IMachineOperator> CreateMinimalMachineOperator(Action<String> onProgress = null)
        {
            LogManager.Default.Log("Creating minimal machine operator...");

            var machineOperator = new MachineOperator();
            machineOperator.EnableDiagnostics = false;
            machineOperator.EnableEmbeddedDebugging = false;
            machineOperator.EnableEventsNotification = false;
            machineOperator.EnableMachineStatusUpdates = false;
            machineOperator.EnableJobResume = false;

            LogManager.Default.Log("Starting machine connection procedure...");

            var settings = SettingsManager.Default.GetOrCreate<PPCSettings>();

            if (String.IsNullOrWhiteSpace(settings.EmbeddedComPort))
            {
                TimeSpan timeout = TimeSpan.FromSeconds(SettingsManager.Default.GetOrCreate<PPCSettings>().MachineScanningTimeoutSeconds);

                onProgress?.Invoke("Scanning for the machine...");
                LogManager.Default.Log("Scanning for machine on available serial ports...");
                Transport.Discovery.UsbCommunicationScanner<ConnectRequest, ConnectResponse> scanner = new Transport.Discovery.UsbCommunicationScanner<ConnectRequest, ConnectResponse>(UsbSerialBaudRates.BR_115200);
                var response = await scanner.Scan(new ConnectRequest() { Password = "1234" }, timeout);

                onProgress?.Invoke("Machine discovered on port: " + response.Adapter.Address);
                LogManager.Default.Log("Machine discovered on port: " + response.Adapter.Address);
                LogManager.Default.Log("Device Information:");
                LogManager.Default.Log(response.Response.DeviceInformation.ToJsonString());

                machineOperator.Adapter = response.Adapter;
                machineOperator.JobHandlingMode = JobHandlerModes.SettingUp;
                LogManager.Default.Log("Connecting machine operator...");

                onProgress?.Invoke("Connecting machine operator...");
                await machineOperator.Connect();
            }
            else
            {
                LogManager.Default.Log($"Connecting to machine on {settings.EmbeddedComPort}...");

                onProgress?.Invoke($"Connecting to machine on {settings.EmbeddedComPort}...");
                UsbTransportAdapter adapter = new UsbTransportAdapter(settings.EmbeddedComPort, UsbSerialBaudRates.BR_115200);
                machineOperator.Adapter = adapter;
                machineOperator.JobHandlingMode = JobHandlerModes.SettingUp;
                await machineOperator.Connect();
            }

            return machineOperator;
        }

        /// <summary>
        /// Called when the machine has connected.
        /// </summary>
        protected virtual void OnMachineConnected()
        {
            IsConnected = true;
            MachineConnected?.Invoke(this, new EventArgs());
        }

        /// <summary>
        /// Called when the machine has disconnected.
        /// </summary>
        protected virtual void OnMachineDisconnected()
        {
            IsConnected = false;
            MachineDisconnected?.Invoke(this, new EventArgs());
        }
    }
}