using Applications.FDC;
using AutoMapper;
using Edge.Core.Database;
using Edge.Core.Processor;
using Edge.Core.IndustryStandardInterface.ATG;
using Edge.Core.UniversalApi;
using Dfs.WayneChina.FairbanksRTData.Support;
using Dfs.WayneChina.FairbanksRTData.UniversalApiModels;
using FdcServerHost;
using Microsoft.Extensions.DependencyInjection;
using Microsoft.Extensions.Logging;
using Microsoft.Extensions.Logging.Abstractions;
using System;
using System.Collections.Concurrent;
using System.Collections.Generic;
using System.IO;
using System.IO.Compression;
using System.Linq;
using System.Reflection;
using System.Text;
using System.Text.Json;
using System.Text.RegularExpressions;
using System.Threading;
using System.Threading.Tasks;
using System.Timers;
using Edge.Core.Database.Models;
using Edge.Core.Processor.Dispatcher.Attributes;

namespace Dfs.WayneChina.FairbanksRTData
{
    [MetaPartsDescriptor(
        "lang-zh-cn:Fairbanks实时数据上传应用lang-en-us:Fairbank real time data App",
        "lang-zh-cn:用于传输加油站实时数据，如：加油、液位仪、告警等数据到Fairbanks服务器" +
        "lang-en-us:Used for uploading real time data in specified format to Fairbanks server",
        new[] { "lang-zh-cn:Fairbankslang-en-us:Fairbanks" })]
    public class FairbanksRealTimeDataApp : IAppProcessor
    {
        #region Fields

        public string MetaConfigName { get; set; }

        private ILogger appLogger = NullLogger.Instance;
        private IServiceProvider services;

        private FdcServerHostApp fdcServer;

        private System.Timers.Timer tankReadTimer;
        private System.Timers.Timer uploadTimer;

        private string host;
        private int port;
        private string username;
        private string password;
        private string deviceId;
        private string siteName;
        private int tankReadInterval;
        private int uploadInterval;
        private string hostUploadFolder;

        private IEnumerable<IAutoTankGaugeController> autoTankGaugeControllers;

        private string transactionsFileName = "transactions";
        private string transactionsFilePath;

        private string tankReadingFileName = "stockLevels";
        private string stockLevelsFilePath;

        private string alarmsFileName = "alarms";
        private string alarmsFilePath;

        private string deliveriesFileName = "deliveries";
        private string deliveriesFilePath;

        private string requiredFolder;
        private string tempFolder;
        private string uploadedFilesFolder;
        private string folderSeperator = "/";

        private FairbanksSftpClient fbSftpClient;

        // Persistence
        private IMapper objMapper;
        private readonly SqliteDbContext dbContext;
        private AppConfig appConfig;
        private DbHelper dbHelper;

        private ConcurrentQueue<string> csvFileQueue = new ConcurrentQueue<string>();

        private ReaderWriterLockSlim fileLocker = new ReaderWriterLockSlim();

        private int sortToken = 0;

        #endregion

        #region Tank State Dictionary

        private Dictionary<int, TankState> tankStateDict = new Dictionary<int, TankState>();

        #endregion

        #region Logger

        NLog.Logger logger = NLog.LogManager.LoadConfiguration("NLog.config").GetLogger("Fairbanks");

        #endregion

        #region Constructor

        [ParamsJsonSchemas("appCtorParamsJsonSchema")]
        public FairbanksRealTimeDataApp(IServiceProvider services, FairbanksAppConfigV1 config)
        {
            this.services = services;
            var loggerFactory = services.GetRequiredService<ILoggerFactory>();
            appLogger = loggerFactory.CreateLogger("Application");
            objMapper = services.GetRequiredService<IMapper>();
            dbContext = services.GetRequiredService<SqliteDbContext>();

            if (services != null)
                dbHelper = new DbHelper(services);

            host = config.Host;
            port = config.Port;
            username = config.Username;
            password = config.Password;
            deviceId = config.DeviceId;
            siteName = config.SiteName;
            tankReadInterval = config.Interval;
            uploadInterval = config.UploadInterval;
            hostUploadFolder = config.HostUploadFolder;

            fbSftpClient = new FairbanksSftpClient(host, username, password);
        }

        public FairbanksRealTimeDataApp(IServiceProvider services, string host, int port, string username, string password,
            string deviceId, string siteName, int interval, int uploadInterval, string hostUploadFolder)
        {
            this.services = services;
            var loggerFactory = services.GetRequiredService<ILoggerFactory>();
            appLogger = loggerFactory.CreateLogger("Application");
            objMapper = services.GetRequiredService<IMapper>();
            dbContext = services.GetRequiredService<SqliteDbContext>();

            if (services != null)
                dbHelper = new DbHelper(services);

            this.host = host;
            this.port = port;
            this.username = username;
            this.password = password;
            this.deviceId = deviceId;
            this.siteName = siteName;
            this.tankReadInterval = interval;
            this.uploadInterval = uploadInterval;
            this.hostUploadFolder = hostUploadFolder;

            fbSftpClient = new FairbanksSftpClient(host, username, password);
        }

        #endregion

        #region Init

        public void Init(IEnumerable<IProcessor> processors)
        {
            //get the FdcServer instance during init
            foreach (dynamic processor in processors)
            {
                if (processor is IAppProcessor)
                {
                    FdcServerHostApp fdcServer = processor as FdcServerHostApp;
                    if (fdcServer != null)
                    {
                        logger.Info("FdcServerHostApp retrieved as an IApplication instance!");
                        this.fdcServer = processor;
                    }

                    continue;
                }
            }

            if (fdcServer != null)
                logger.Info("Fdc Server instance alive");

            var atgControllers = processors.WithHandlerOrApp<IAutoTankGaugeController>()
                .Select(p => p.ProcessorDescriptor().DeviceHandlerOrApp)
                .Cast<IAutoTankGaugeController>();

            autoTankGaugeControllers = atgControllers;

            if (autoTankGaugeControllers != null)
            {
                foreach (var controller in autoTankGaugeControllers)
                {
                    controller.OnStateChange += Controller_OnStateChange;
                    controller.OnAlarm += Controller_OnAlarm;
                }
            }
        }

        #region Alarms

        private async void Controller_OnAlarm(object sender, AtgAlarmEventArg e)
        {
            logger.Info("Incoming alarm");

            var currentGauge = sender as IAutoTankGaugeController;
            if (currentGauge != null)
            {
                var alarms = new List<FbAlarm>();
                foreach (var alarm in e.Alarms)
                {
                    logger.Info($"Gauge: {currentGauge.DeviceId}");
                    logger.Info($"  tank number: {alarm.TankNumber}, description: {alarm.Description}");
                    logger.Info($"  alarm id: {alarm.Id}, priority: {alarm.Priority}, type: {alarm.Type}");
                    logger.Info($"  created time: {alarm.CreatedTimeStamp}, cleared time: {alarm.ClearedTimeStamp}");

                    var fbAlarm = new FbAlarm();
                    fbAlarm.ibank = deviceId;
                    fbAlarm.DateTime = alarm.CreatedTimeStamp;
                    fbAlarm.CodedAlarm = "1";
                    fbAlarm.Category = "TLS_ALARM";
                    fbAlarm.Type = ""; // can be left blank or null
                    fbAlarm.AlarmCode = string.Concat("TLS_", "02_", ((byte)alarm.Type).ToString().PadLeft(2, '0'));
                    fbAlarm.TankAlarm = "1"; //1=tank alarm, 0=other device alarm or things
                    fbAlarm.Tank = alarm.TankNumber;
                    fbAlarm.State = 0; // active = 0, cleared = 1
                    fbAlarm.Note = alarm.Description;

                    alarms.Add(fbAlarm);
                }

                await RecordAlarmsAsync(alarms);
            }
        }

        private async Task RecordAlarmsAsync(IEnumerable<FbAlarm> alarms)
        {
            try
            {
                fileLocker.TryEnterReadLock(500);
                SetAlarmsFile(requiredFolder);
            }
            catch (Exception ex)
            {
                logger.Error(ex.ToString());
            }
            finally
            {
                fileLocker.ExitReadLock();
            }

            if (!File.Exists(alarmsFilePath))
            {
                logger.Info("Creating alarms file path");
                await WriteCsvAsync(new List<FbAlarm>(), alarmsFilePath);
            }

            logger.Info("Writing alarms info into file");
            await WriteCsvAsync(alarms, alarmsFilePath);
        }

        #endregion

        #region Fuel deliveries

        private async void Controller_OnStateChange(object sender, AtgStateChangeEventArg e)
        {
            if (e.State == AtgState.TanksReloaded)
            {
                logger.Info("Tank reloaded, ready for use");
            }

            if (e.TargetTank != null)
            {
                if (e.TargetTank.State == TankState.Delivering)
                {
                    logger.Info("Delivering fuel...");

                    if (!tankStateDict.ContainsKey(e.TargetTank.TankNumber))
                    {
                        logger.Info($"Adding tank {e.TargetTank.TankNumber.ToString()} to the tank state dict");
                        tankStateDict.Add(e.TargetTank.TankNumber, e.TargetTank.State);
                    }
                }
                else if (e.TargetTank.State == TankState.Idle)
                {
                    logger.Info("Tank state: Idle");

                    var currentTankState = tankStateDict[e.TargetTank.TankNumber];
                    if (currentTankState == TankState.Delivering && e.TargetTank.State == TankState.Idle)
                    {
                        logger.Info($"Tank {e.TargetTank.TankNumber.ToString()} state changed, Delivering -> Idle, check fuel delivery");
                        tankStateDict[e.TargetTank.TankNumber] = TankState.Idle;
                        var currentAtg = sender as IAutoTankGaugeController;

                        if (currentAtg != null)
                        {
                            await RecordFuelDelivery(currentAtg, e.TargetTank.TankNumber);
                        }
                    }
                }
            }
        }

        private async Task RecordFuelDelivery(IAutoTankGaugeController autoTankGauge, int tankNumber)
        {
            var deliveries = await autoTankGauge.GetTankDeliveryAsync(tankNumber);
            var fbFuelDeliveries = new List<FbFuelDelivery>();

            foreach (var delivery in deliveries)
            {
                logger.Info($"Tank: {delivery.TankNumber}, FuelHeight, start: {delivery.StartingFuelHeight}, end: {delivery.EndingFuelHeight}");
                logger.Info($"  Fuel TC Volume, start: {delivery.StartingFuelTCVolume}, end: {delivery.EndingFuelTCVolume}");
                logger.Info($"  Fuel Volume, start: {delivery.StartingFuelVolume}, end: {delivery.EndingFuelVolume}");

                var fbFuelDelivery = new FbFuelDelivery();
                fbFuelDelivery.ibank = deviceId;
                fbFuelDelivery.Tank = delivery.TankNumber;
                fbFuelDelivery.StartDateTime = delivery.StartingDateTime;
                fbFuelDelivery.StartVolume = (decimal)delivery.StartingFuelVolume;
                fbFuelDelivery.StartWater = (decimal)delivery.StartingWaterHeight;
                fbFuelDelivery.StartTemperature = (decimal)delivery.StartingTemperture;
                fbFuelDelivery.EndDateTime = (DateTime)delivery.EndingDateTime;
                fbFuelDelivery.EndVolume = (decimal)delivery.EndingFuelVolume;
                fbFuelDelivery.EndWater = (decimal)delivery.EndingWaterHeight;
                fbFuelDelivery.EndTemperature = (decimal)delivery.EndingTemperture;
                fbFuelDelivery.Quantity = 0m;
                fbFuelDelivery.ConfirmedQuantity = 0m;

                fbFuelDeliveries.Add(fbFuelDelivery);
            }

            try
            {
                fileLocker.TryEnterReadLock(500);
                SetDeliveriesFile(requiredFolder);
            }
            catch (Exception ex)
            {
                logger.Error(ex.ToString());
            }
            finally
            {
                fileLocker.ExitReadLock();
            }

            if (!File.Exists(deliveriesFilePath))
            {
                logger.Info("Creating deliveries file path");
                await WriteCsvAsync(new List<FbFuelDelivery>(), deliveriesFilePath);
            }

            logger.Info("Writing deliveries info into file");
            await WriteCsvAsync(fbFuelDeliveries, deliveriesFilePath);
        }

        #endregion

        #endregion

        #region Folder and file name handling

        private void EnsureFolder()
        {
            string path = Directory.GetCurrentDirectory();
            requiredFolder = path + folderSeperator + "RealTimeData";

            if (!Directory.Exists(requiredFolder))
                Directory.CreateDirectory(requiredFolder);

            tempFolder = requiredFolder + folderSeperator + "temp";
            if (!Directory.Exists(requiredFolder + folderSeperator + "temp"))
            {
                Directory.CreateDirectory(tempFolder);
            }

            uploadedFilesFolder = requiredFolder + folderSeperator + "archives";

            if (!Directory.Exists(uploadedFilesFolder))
                Directory.CreateDirectory(uploadedFilesFolder);

            SetAlarmsFile(requiredFolder);
            SetDeliveriesFile(requiredFolder);
            SetTransactionFile(requiredFolder);
            SetTankReadingFile(requiredFolder);
        }

        private string CreateFileNameWithoutExt(string fileTypeName, string dateSection, string hourSection)
        {
            return string.Concat(requiredFolder, folderSeperator, /*deviceId, "_",*/ fileTypeName, "_", dateSection, "_", hourSection);
        }

        private void SetAlarmsFile(string requiredFolder)
        {
            var dateSection = DateTime.Now.Date.ToString("yyyy-MM-dd");
            var hourSection = DateTime.Now.Hour.ToString("D2");
            var fileNameWithoutExtension = CreateFileNameWithoutExt(alarmsFileName, dateSection, hourSection);

            logger.Debug($"FileNameWithoutExt: {fileNameWithoutExtension}");

            var filesInProcessing = csvFileQueue.Where(f => f.Contains(dateSection + "_" + hourSection)).ToList();
            foreach (var file in filesInProcessing)
            {
                logger.Debug($"     Alarms files in queue: {file}");
            }

            var candidateFiles = GetMatchingFilesFromFolder(alarmsFileName, uploadedFilesFolder)
                .Concat(filesInProcessing);

            foreach (var cf in candidateFiles)
            {
                logger.Debug($"\tcdi: {cf}");
            }

            if (candidateFiles.Any(f => f.Contains('[')))
            {
                Interlocked.Increment(ref sortToken);
                var currentSortToken = sortToken;

                logger.Info($"Sort [{currentSortToken}] the candidates to find last Alarms file name");
                var lastFile = candidateFiles.OrderBy(f => f, new FileNameSuffixComparer()).Last();
                logger.Info($"Sort [{currentSortToken}] done, Last alarms file full name: {lastFile}");

                int startIndex = lastFile.IndexOf('[');
                int endIndex = lastFile.IndexOf(']');
                int number = Convert.ToInt32(lastFile.Substring(startIndex + 1, endIndex - startIndex - 1));

                alarmsFilePath = fileNameWithoutExtension + "[" + Convert.ToString(number + 1) + "]" + ".csv";
                logger.Debug($"Expected new alarms file: {alarmsFilePath}");
            }
            else if (candidateFiles.Any(f => Path.GetFileNameWithoutExtension(f) == Path.GetFileNameWithoutExtension(fileNameWithoutExtension)
                    || Path.GetFileNameWithoutExtension(f) == Path.GetFileNameWithoutExtension(fileNameWithoutExtension + ".csv")))
            {
                logger.Info("Found a alarms file in `processing file`");
                alarmsFilePath = fileNameWithoutExtension + "[0]" + ".csv";
            }
            else
            {
                logger.Info("No previous alarms file");
                alarmsFilePath = fileNameWithoutExtension + ".csv";
            }

            if (csvFileQueue.Count > 5)
            {
                string dqFile;
                if (csvFileQueue.TryDequeue(out dqFile))
                    logger.Info($"Dequeued alarms file: {dqFile}");
            }
        }

        private void SetDeliveriesFile(string requiredFolder)
        {
            //It's not possible that within an hour there are multiple fuel deliveries, is it?
            var dateSection = DateTime.Now.Date.ToString("yyyy-MM-dd");
            var hourSection = DateTime.Now.Hour.ToString("D2");
            var fileNameWithoutExtension = requiredFolder + folderSeperator + /*deviceId + "_" +*/ deliveriesFileName + "_" + dateSection + "_" + hourSection;
            deliveriesFilePath = fileNameWithoutExtension + ".csv";
        }

        private void SetTransactionFile(string requiredFolder)
        {
            var dateSection = DateTime.Now.Date.ToString("yyyy-MM-dd");
            var hourSection = DateTime.Now.Hour.ToString("D2");
            var fileNameWithoutExtension = requiredFolder + folderSeperator + /*deviceId + "_" +*/ transactionsFileName + "_" + dateSection + "_" + hourSection;

            logger.Debug($"FileNameWithoutExt: {fileNameWithoutExtension}");

            var filesInProcessing = csvFileQueue.Where(f => f.Contains(dateSection + "_" + hourSection)).ToList();
            foreach (var file in filesInProcessing)
            {
                logger.Debug($"     Transaction files in queue: {file}");
            }

            var candidateFiles = GetMatchingFilesFromFolder(transactionsFileName, uploadedFilesFolder)
                .Concat(filesInProcessing);

            foreach (var cf in candidateFiles)
            {
                logger.Debug($"\tcdi: {cf}");
            }

            if (candidateFiles.Any(f => f.Contains('[')))
            {
                Interlocked.Increment(ref sortToken);
                var currentSortToken = sortToken;

                logger.Info($"Sort [{currentSortToken}] the candidates to find last transaction file name");
                var lastFile = candidateFiles.OrderBy(f => f, new FileNameSuffixComparer()).Last();
                logger.Info($"Sort [{currentSortToken}] done, Last transaction file full name: {lastFile}");

                int startIndex = lastFile.IndexOf('[');
                int endIndex = lastFile.IndexOf(']');
                int number = Convert.ToInt32(lastFile.Substring(startIndex + 1, endIndex - startIndex - 1));

                transactionsFilePath = fileNameWithoutExtension + "[" + Convert.ToString(number + 1) + "]" + ".csv";
                logger.Debug($"Expected new transaction file: {stockLevelsFilePath}");
            }
            else if (candidateFiles.Any(f => Path.GetFileNameWithoutExtension(f) == Path.GetFileNameWithoutExtension(fileNameWithoutExtension)
                    || Path.GetFileNameWithoutExtension(f) == Path.GetFileNameWithoutExtension(fileNameWithoutExtension + ".csv")))
            {
                logger.Info("Found a transaction file in `processing file`");
                transactionsFilePath = fileNameWithoutExtension + "[0]" + ".csv";
            }
            else
            {
                logger.Info("No previous transaction file");
                transactionsFilePath = fileNameWithoutExtension + ".csv";
            }

            if (csvFileQueue.Count > 5)
            {
                string dqFile;
                if (csvFileQueue.TryDequeue(out dqFile))
                    logger.Info($"Dequeued transaction file: {dqFile}");
            }
        }

        private void SetTankReadingFile(string folder)
        {
            logger.Debug($"Determining TankReading file name, operating folder is: {folder}");

            var dateSection = DateTime.Now.Date.ToString("yyyy-MM-dd");
            var hourSection = DateTime.Now.Hour.ToString("D2");
            var fileNameWithoutExtension = folder + folderSeperator + /*deviceId + "_" +*/ tankReadingFileName + "_" + dateSection + "_" + hourSection;

            logger.Debug($"FileNameWithoutExt: {fileNameWithoutExtension}");

            var filesInProcessing = csvFileQueue.Where(f => f.Contains(dateSection + "_" + hourSection)).ToList();
            foreach (var file in filesInProcessing)
            {
                logger.Debug($"     file in queue: {file}");
            }

            var candidateFiles = GetMatchingFilesFromFolder(tankReadingFileName, uploadedFilesFolder).Concat(filesInProcessing);

            foreach (var cf in candidateFiles)
            {
                logger.Debug($"\tcdi: {cf}");
            }

            if (candidateFiles.Any(f => f.Contains('[')))
            {
                Interlocked.Increment(ref sortToken);
                var currentSortToken = sortToken;

                logger.Info($"Sort [{currentSortToken}] the candidates to find last stock reading file name");
                var lastFile = candidateFiles.OrderBy(f => f, new FileNameSuffixComparer()).Last();
                logger.Info($"Sort [{currentSortToken}] done, Last stock reading file full name: {lastFile}");

                int startIndex = lastFile.IndexOf('[');
                int endIndex = lastFile.IndexOf(']');
                int number = Convert.ToInt32(lastFile.Substring(startIndex + 1, endIndex - startIndex - 1));

                stockLevelsFilePath = fileNameWithoutExtension + "[" + Convert.ToString(number + 1) + "]" + ".csv";
                logger.Debug($"Expected new stock reading file: {stockLevelsFilePath}");
            }
            else if (candidateFiles.Any(f => Path.GetFileNameWithoutExtension(f) == Path.GetFileNameWithoutExtension(fileNameWithoutExtension)
                    || Path.GetFileNameWithoutExtension(f) == Path.GetFileNameWithoutExtension(fileNameWithoutExtension + ".csv")))
            {
                logger.Info("Found an in processing file");
                stockLevelsFilePath = fileNameWithoutExtension + "[0]" + ".csv";
            }
            else
            {
                logger.Info("No previous tank reading file");
                stockLevelsFilePath = fileNameWithoutExtension + ".csv";
            }

            if (csvFileQueue.Count > 5)
            {
                string dqFile;
                if (csvFileQueue.TryDequeue(out dqFile))
                    logger.Info($"Dequeued file: {dqFile}");
            }
        }

        private void CleanOldFiles(string folder, string fileName)
        {
            var di = new DirectoryInfo(folder);
            var files = di.GetFiles().Where(f => f.Name.Contains(fileName)).OrderByDescending(f => f.LastAccessTime);
            var oldFiles = files.Skip(10);
            foreach (var file in oldFiles)
            {
                logger.Debug($"Deleting file: {file.FullName}");
                file.Delete();
            }
        }

        private List<string> GetMatchingFilesFromFolder(string fileName, string folder)
        {
            logger.Info($"Finding matching {fileName} in folder: {folder}");

            var dateSection = DateTime.Now.Date.ToString("yyyy-MM-dd");
            var hourSection = DateTime.Now.Hour.ToString("D2");

            CleanOldFiles(folder, fileName);

            var archivedFiles = Directory.GetFiles(folder, "*.zip");
            logger.Info($"Archived files count = {archivedFiles.Length}");

            var matchedFileNames = archivedFiles
                .Where(f => f.Contains(dateSection + "_" + hourSection) && f.Contains(fileName)
                            && Regex.IsMatch(Path.GetFileNameWithoutExtension(f), @"[a-zA-Z]{11}_\d{4}-\d{2}-\d{2}_\d{2}\[(.*?)\]"));

            logger.Info($"Matched files count = {matchedFileNames.Count()}");

            if (!matchedFileNames.Any())
            {
                var fileNameWithoutExtension = folder + folderSeperator + fileName + "_" + dateSection + "_" + hourSection;
                if (File.Exists(fileNameWithoutExtension + ".zip"))
                    return new List<string> { fileNameWithoutExtension };
            }

            return matchedFileNames.ToList();
        }

        private List<string> GetMatchingTransactionFilesFromFolder(string fileName, string folder)
        {
            logger.Info($"Finding matching {fileName} in folder: {folder}");

            var dateSection = DateTime.Now.Date.ToString("yyyy-MM-dd");
            var hourSection = DateTime.Now.Hour.ToString("D2");

            CleanOldFiles(folder, fileName);

            var archivedFiles = Directory.GetFiles(folder, "*.zip");
            logger.Info($"Archived files count = {archivedFiles.Length}");

            var matchedFileNames = archivedFiles
                .Where(f => f.Contains(dateSection + "_" + hourSection) && f.Contains(fileName)
                            && Regex.IsMatch(Path.GetFileNameWithoutExtension(f), @"[a-zA-Z]{11}_\d{4}-\d{2}-\d{2}_\d{2}\[(.*?)\]"));

            logger.Info($"Matched files count = {matchedFileNames.Count()}");

            if (!matchedFileNames.Any())
            {
                var fileNameWithoutExtension = folder + folderSeperator + transactionsFileName + "_" + dateSection + "_" + hourSection;
                if (File.Exists(fileNameWithoutExtension + ".zip"))
                    return new List<string> { fileNameWithoutExtension };
            }

            return matchedFileNames.ToList();
        }

        #endregion

        #region Start

        public Task<bool> Start()
        {
            EnsureFolder();

            if (fdcServer != null)
                fdcServer.OnCurrentFuellingStatusChange += FdcServer_OnCurrentFuellingStatusChange;

            uploadTimer = new System.Timers.Timer();
            uploadTimer.Interval = uploadInterval * 60 * 1000;
            uploadTimer.Elapsed += Timer_Elapsed;
            uploadTimer.Enabled = true;

            tankReadTimer = new System.Timers.Timer();
            tankReadTimer.Interval = tankReadInterval * 1000;
            tankReadTimer.Elapsed += TankReadTimer_Elapsed;
            tankReadTimer.Enabled = true;

            logger.Info("\n");
            logger.Info("Fairbanks real time data client started");

            var config = GetAppConfig();
            RefreshConfig(config);
            return Task.FromResult(true);
        }

        #endregion

        #region Process records

        //Tank reading

        private async void TankReadTimer_Elapsed(object sender, ElapsedEventArgs e)
        {
            if (autoTankGaugeControllers != null)
            {
                var readings = new List<FbTankReading>();
                var atgController = autoTankGaugeControllers.First();

                if (atgController.Tanks == null)
                    return;

                foreach (var tank in atgController.Tanks)
                {
                    try
                    {
                        var inventory = await atgController.GetTankInventoryAsync(tank.TankNumber, 1);

                        if (inventory != null)
                        {
                            var record = inventory.First();

                            logger.Info($"Tank No: {record.TankNumber}, Time stamp: {record.TimeStamp}, " +
                                $"Fuel Volume: {record.FuelVolume}, Fuel TCVolume: {record.FuelTCVolume}, " +
                                $"Fuel Height: {record.FuelHeight}, Temperature: {record.Temperture}," +
                                $"Water Height: {record.WaterHeight}, Fuel Height: {record.FuelHeight}");

                            var reading = new FbTankReading();
                            reading.ibank = deviceId;
                            reading.DateTime = record.TimeStamp;
                            reading.Tank = record.TankNumber;
                            reading.QTY = Math.Round(Convert.ToDecimal(record.FuelVolume), 2);
                            reading.Temperature = Math.Round(Convert.ToDecimal(record.Temperture), 2);
                            reading.Water = Math.Round(Convert.ToDecimal(record.WaterHeight), 2);
                            reading.Height = Math.Round(Convert.ToDecimal(record.FuelHeight), 2);

                            readings.Add(reading);
                        }
                    }
                    catch (Exception ex)
                    {
                        logger.Error($"Exception in getting tank inventory on Tank {tank.TankNumber}, ex: " + ex.ToString());
                    }
                }

                if (readings.Count > 0)
                {
                    await AddTankReadingsAsync(readings);
                }
            }
        }

        //Fuelling transactions

        private async void FdcServer_OnCurrentFuellingStatusChange(object sender, FdcServerTransactionDoneEventArg e)
        {
            if (e.Transaction.Finished)
            {
                logger.Info("A finished filling arrived and block the upload timer");
                
                await AddFillingTransactionAsync(e);
            }
        }

        private async Task AddTankReadingsAsync(List<FbTankReading> readings)
        {
            try
            {
                fileLocker.TryEnterReadLock(500);
                SetTankReadingFile(requiredFolder);
            }
            catch (Exception ex)
            {
                logger.Error(ex.ToString());
            }
            finally
            {
                fileLocker.ExitReadLock();
            }

            if (!File.Exists(stockLevelsFilePath))
                await WriteCsvAsync(new List<FbTankReading>(), stockLevelsFilePath);

            await WriteCsvAsync(readings, stockLevelsFilePath);
        }

        private async Task AddFillingTransactionAsync(FdcServerTransactionDoneEventArg e)
        {
            var filling = new FbFillingTransaction();
            filling.ibank = deviceId;
            filling.StartDateTime = DateTime.Now;
            filling.EndDateTime = e.FuelingEndTime.HasValue ? e.FuelingEndTime.Value : DateTime.Now;
            filling.Pump = e.Transaction.Nozzle.PumpId;
            filling.Nozzle = e.Transaction.Nozzle.LogicalId;
            filling.QTY = Convert.ToDecimal(e.Transaction.Volumn) / 100;

            var fillings = new List<FbFillingTransaction>();
            fillings.Add(filling);

            logger.Info("Converted fueling transaction");

            try
            {
                fileLocker.TryEnterReadLock(500);
                SetTransactionFile(requiredFolder);
            }
            catch (Exception ex)
            {
                logger.Error("Exception in adding filling transaction, ex: " + ex.ToString());
            }
            finally
            {
                fileLocker.ExitReadLock();
            }

            if (!File.Exists(transactionsFilePath))
                await WriteCsvAsync(new List<FbFillingTransaction>(), transactionsFilePath);

            await WriteCsvAsync(fillings, transactionsFilePath);
        }

        public async Task WriteCsvAsync<T>(IEnumerable<T> objInstances, string fileName)
        {
            logger.Debug($"Started to write record to file, File name: {fileName}");

            Type itemType = typeof(T);
            var props = itemType.GetProperties(BindingFlags.Public | BindingFlags.Instance);

            using (FileStream fs = new FileStream(fileName, FileMode.Append, FileAccess.Write))
            using (var writer = new StreamWriter(fs, Encoding.UTF8))
            {
                if (objInstances.Count() == 0)
                {
                    logger.Debug($"Formatting Header");
                    await writer.WriteLineAsync(string.Join(",", props.Select(p => p.Name)));
                }
                else
                {
                    foreach (var obj in objInstances)
                    {
                        var propertyValues = props.Select(p => p.GetValue(obj, null)).ToList();
                        StringBuilder sb = new StringBuilder();
                        for (int i = 0; i < propertyValues.Count(); i++)
                        {
                            if (propertyValues[i] is DateTime)
                                sb.Append(((DateTime)propertyValues[i]).ToString("yyyy-MM-dd HH:mm:ss"));
                            else
                                sb.Append(propertyValues[i]);

                            if (i <= propertyValues.Count() - 2)
                                sb.Append(",");
                        }
                        //sb.Append("\r");

                        await writer.WriteLineAsync(sb.ToString());
                    }
                }
            }

            logger.Debug("Writing done");
        }

        private async void Timer_Elapsed(object sender, ElapsedEventArgs e)
        {
            List<string> files = new List<string>();

            try
            {
                fileLocker.TryEnterReadLock(500);
                files = Directory.GetFiles(requiredFolder, "*.csv").ToList();
                foreach (var file in files)
                {
                    if (!csvFileQueue.Contains(file))
                    {
                        logger.Debug($" Enqueuing CSV file: {file}");
                        csvFileQueue.Enqueue(file);
                    }
                }
            }
            catch (Exception ex)
            {
                logger.Error(ex.ToString());
            }
            finally
            {
                fileLocker.ExitReadLock();
            }

            var fileCount = files.Count();
            logger.Debug($"File count: {fileCount}");

            fbSftpClient.Connect();

            foreach (var currentFile in files)
            {
                logger.Info($"File full name: {currentFile}");

                File.Move(currentFile, tempFolder + folderSeperator + Path.GetFileName(currentFile));

                var zippedFileName = Path.GetFileNameWithoutExtension(currentFile) + ".zip";
                ZipFile.CreateFromDirectory(tempFolder, requiredFolder + folderSeperator + zippedFileName);

                File.Delete(tempFolder + folderSeperator + Path.GetFileName(currentFile));

                var sendResult = fbSftpClient.UploadSingleFile(requiredFolder + folderSeperator + zippedFileName, hostUploadFolder);

                await SaveUploadHistory(zippedFileName, sendResult);

                ArchiveFile(requiredFolder + folderSeperator + zippedFileName);
            }

            fbSftpClient.Disconnect();
        }

        private void ArchiveFile(string currentFile)
        {
            logger.Info($"Archiving file: {currentFile}");

            try
            {
                File.Move(currentFile, uploadedFilesFolder + folderSeperator + Path.GetFileName(currentFile));
            }
            catch (IOException ex)
            {
                logger.Error("Error in archiving file: " + currentFile + "\n" + ex.ToString());
            }
        }

        #endregion

        #region Upload history

        [UniversalApi(Description = "Leave input <b>null</b> to retrieve latest Day's(24 hours) upload history" +
            "</br>input parameters are as follows, " +
            "</br>para.Name==\"startTime\", format should be yyyyMMddHHmmss")]
        public async Task<IEnumerable<UploadRecord>> GetUploadHistoryAsync(ApiData input)
        {
            if (input == null || (input?.IsEmpty() ?? false))
            {
                return await dbHelper.GetLatestUploadHistoryAsync(DateTime.Now.Subtract(new TimeSpan(24, 0, 0)));
            }
            else
            {
                var startTime = input.Get("starttime", DateTime.Now.Subtract(new TimeSpan(24, 0, 0)));
                return await dbHelper.GetLatestUploadHistoryAsync(startTime);
            }
        }

        #endregion

        #region Stop

        public Task<bool> Stop()
        {
            return Task.FromResult(true);
        }

        #endregion

        #region Config handling

        [UniversalApi(Description = "Leave input <b>null</b> to retrieve Fairbanks related Config" +
            "</br>First para.Name==\"template\" will return an sample Config for reference.")]
        public async Task<object> GetAppConfigAsync(ApiData input)
        {
            var uploadingConfig = new AppConfig();
            if (input?.Get("template") != null)
            {
                logger.Info($"GetAppConfigAsync with template");
            }
            else
            {
                uploadingConfig = GetAppConfig();
            }

            logger.Info($"GetConfigAsync, Fairbanks app config: {uploadingConfig.ToString()}");

            return await Task.FromResult(new[] { new { Name = "FairbanksAppConfig", Value = uploadingConfig } });
        }

        [UniversalApi(Description = "First para.Name is the updating config name, such as: FairbanksAppConfig, " +
            "</br>First para.Value is the new config's json serialized string value")]
        public async Task<object> PutConfigAsync(ApiData input)
        {
            //Check input
            if (input == null || input.Parameters == null || !input.Parameters.Any())
            {
                throw new ArgumentException(nameof(input));
            }

            try
            {
                AppConfig appConfig = GetConfig(input.Parameters.First().Name, input.Parameters.First().Value, new JsonSerializerOptions
                {
                    PropertyNameCaseInsensitive = true,
                });

                bool appConfigExists = objMapper
                    .Map<IEnumerable<AppConfig>>(dbContext.GenericDatas
                        .Where(gd => gd.Type == AutoMapperProfile.UploadConfig && gd.Owner == AutoMapperProfile.AppDataOwner))
                        .FirstOrDefault() != null;

                if (!appConfigExists)
                {
                    //Create the config record
                    await SaveDbAsync(appConfig);
                    logger.Info($"PutConfigAsync created config type: {appConfig.GetType().Name}, details: {appConfig.ToString()}");
                }
                else
                {
                    //Update the config record
                    await UpdateDbAsync(appConfig);
                    logger.Info($"PutConfigAsync updated config type: {appConfig.GetType().Name}, details: {appConfig.ToString()}");
                }

                RefreshConfig(appConfig);
            }
            catch (Exception ex)
            {
                logger.Error(ex.ToString());
                return await Task.FromResult(new { Name = "FairbanksAppConfig", Value = false });
            }

            return await Task.FromResult(new { Name = "FairbanksAppConfig", Value = true });
        }

        static AppConfig GetConfig(string name, string value, JsonSerializerOptions options) => name switch
        {
            "FairbanksAppConfig" => JsonSerializer.Deserialize<AppConfig>(value, options),
            _ => throw new InvalidOperationException("Unknown Config name: " + (name ?? ""))
        };

        public AppConfig GetAppConfig()
        {
            return objMapper
                .Map<IEnumerable<AppConfig>>(dbContext.GenericDatas
                    .Where(d => d.Type == AutoMapperProfile.UploadConfig && d.Owner == AutoMapperProfile.AppDataOwner))
                    .FirstOrDefault() ?? new AppConfig
                    {
                        DeviceId = this.deviceId,
                        Host = this.host,
                        Port = this.port,
                        UserName = this.username,
                        Password = this.password,
                        SiteId = this.siteName,
                        TankReadInterval = this.tankReadInterval,
                        UploadInterval = this.uploadInterval
                    };
        }

        #endregion

        #region Private methods

        private void RefreshConfig(AppConfig config)
        {
            if (config == null)
                return;

            logger.Info("Refreshing config");

            deviceId = config.DeviceId;
            siteName = config.SiteId;

            tankReadTimer.Stop();
            tankReadTimer.Interval = config.TankReadInterval * 1000;
            tankReadTimer.Start();

            uploadTimer.Stop();
            uploadTimer.Interval = config.UploadInterval * 60 * 1000;
            uploadTimer.Start();

            fbSftpClient.RefreshConfig(config.Host, config.UserName, config.Password);
        }

        private async Task SaveUploadHistory(string fileName, bool status)
        {
            var currentUploadRecord = new UploadRecord();
            currentUploadRecord.TimeStamp = DateTime.Now;
            currentUploadRecord.FileName = fileName;
            currentUploadRecord.Status = status ? "成功" : "失败";
            currentUploadRecord.Remark = dbHelper.RecordUploadTried(fileName) ? "重试" : "首次上传";
            await SaveDbAsync(currentUploadRecord);
        }

        private async Task SaveDbAsync<T>(T data)
        {
            var dbModel = objMapper.Map<GenericData>(data);
            dbContext.GenericDatas.Add(dbModel);
            await dbContext.SaveChangesAsync();
        }

        private async Task UpdateDbAsync<T>(T data)
        {
            var dbModel = objMapper.Map<GenericData>(data);
            dbContext.GenericDatas.Update(dbModel);
            await dbContext.SaveChangesAsync();
        }

        #endregion
    }

    public class FairbanksAppConfigV1
    {
        /// <summary>
        /// FTP host
        /// </summary>
        public string Host { get; set; }

        /// <summary>
        /// FTP port
        /// </summary>
        public int Port { get; set; }

        /// <summary>
        /// FTP user name
        /// </summary>
        public string Username { get; set; }

        /// <summary>
        /// FTP user password
        /// </summary>
        public string Password { get; set; }

        /// <summary>
        /// Device ID
        /// </summary>
        public string DeviceId { get; set; }

        /// <summary>
        /// Site name
        /// </summary>
        public string SiteName { get; set; }

        /// <summary>
        /// Tank reading interval, in seconds.
        /// </summary>
        public int Interval { get; set; }

        /// <summary>
        /// Upload interval, in minutes.
        /// </summary>
        public int UploadInterval { get; set; }

        /// <summary>
        /// Host folder path
        /// </summary>
        public string HostUploadFolder { get; set; }
    }
}