using Knoks.CryptoExchanges.Entities;
using System;
using System.Collections.Generic;
using System.Linq;
using System.Threading.Tasks;
using WebSocket.Interfaces;
//using Knoks.CryptoExchanges.Classes;
using Knoks.Framework.DataAccess;
using System.IO;
using Microsoft.Extensions.Configuration;
using Microsoft.Extensions.Logging;
using Knoks.CryptoExchanges.Data.Interfaces;
using Knoks.CryptoExchanges.Data.Dao;
using Knoks.CryptoExchanges.Entities.Args;
using System.Threading;
using System.Text;

namespace Knoks.CryptoExchanges
{
    public class CryptoExchangeManager
    {
        #region Fields
        private List<ExchangeClientHandler> Exchanges { get; set; }
        private UpdateData saveData;
        private readonly List<KnokExchangeData>[] testSet = new List<KnokExchangeData>[2];
        private readonly int last = Convert.ToInt32(false);
        public static IConfiguration Configuration { get; set; }
        private IExchangeDao _exchangeDao;
        private IKnokDao _knokDao;
        private IExchangePairRateDao _exchangePairRateDao;
        private readonly Dictionary<int, List<Tuple<string, string>>> pairs = new Dictionary<int, List<Tuple<string, string>>>();
        //private bool exit = false;
        private Task exchangePairsTracerTask;
        private readonly double mitunteIntervalCheck;
        private readonly Dictionary<int, DateTime> lastExchangesResponse = new Dictionary<int, DateTime>();
        CancellationTokenSource _cancellationTokenSource = new CancellationTokenSource();
        ILogger _logger;
        #endregion

        #region Public
        /// <summary>
        /// ctor
        /// </summary>
        public CryptoExchangeManager() {
            var builder = new ConfigurationBuilder()
            .SetBasePath(Directory.GetCurrentDirectory())
            .AddJsonFile("appsettings.json");

            Configuration = builder.Build();

            if (double.TryParse(Configuration["MinuteIntervalCheck"], out var val))
            {
                this.mitunteIntervalCheck = val;
            }
            else {
                this.mitunteIntervalCheck = 1;
            }

            ILoggerFactory loggerFactory = new LoggerFactory()
                .AddConsole(Configuration.GetSection("Logging"))
                .AddDebug();

            _logger = loggerFactory.CreateLogger<ProcExecutor>();

            Dictionary<string, string> items = Configuration.GetSection("DbConnections").
                GetChildren().ToDictionary(x=>x.Key, x => x.Value);

            var provider = new ProcExecutor(items,
                loggerFactory.CreateLogger<ProcExecutor>());

            _exchangeDao = new ExchangeDao(provider);
            _knokDao = new KnokDao(provider);
            _exchangePairRateDao = new ExchangePairRateDao(provider);
        }

        /// <summary>
        /// Starts initial request to all CryptoExchanges
        /// </summary>
        /// <returns></returns>
        public bool StartExchangesRequest() {
            this.saveData = (exchangeId, exchange, x) => {
                var replaceSymbols = Configuration.GetSection($"{exchange}:ReplaceSymbols").GetChildren()
                    .ToDictionary(s=>s.Key, s=>s.Value);
                this.lastExchangesResponse[exchangeId] = DateTime.Now;
                foreach (var item in x)
                {
                    var pair = item.Key;
                    // Replace TUSD => USDT for Bittrex
                    //if (replaceSymbols != null)
                    //{
                    //    var value = pair.Split('-');
                    //    if (value.Count() == 2)
                    //    {
                    //        var symbol1 = replaceSymbols.FirstOrDefault(rs => rs.Value.Equals(value[0]));
                    //        if (!symbol1.Equals(default(KeyValuePair<string, string>)))
                    //        {
                    //            pair = $"{symbol1.Key}{value[1]}";
                    //        }
                    //    }
                    //}

                    _exchangePairRateDao.UpdateExchangePairRate(exchangeId,
                    new ExchangePairRateArg()
                    {
                        PairSymbol = pair.Replace("-", string.Empty).Replace(":", string.Empty),
                        Open = item.Value.OpenPrice,
                        High = item.Value.HighPrice,
                        Low = item.Value.LowPrice,
                        Close = item.Value.ClosePrice,
                        //Volume = item.Value.Volume,
                        StartDate = item.Value.TimeStamp
                    });
                }

                var sb = new StringBuilder();
                sb.AppendLine($"Exchange: \"{exchange}\"");
                foreach (var item in x)
                {
                    sb.AppendLine($"    Pair: {item.Key}");
                    sb.AppendLine($"        Timestamp: {item.Value.TimeStamp.ToShortDateString()} {item.Value.TimeStamp.ToShortTimeString()}");
                    sb.AppendLine($"        High: {item.Value.HighPrice}");
                    sb.AppendLine($"        Low: {item.Value.LowPrice}");
                    sb.AppendLine();
                }
                DebugInfo(sb.ToString());
            };

            InitExchagesClients().Wait();
            this.exchangePairsTracerTask = Task.Run(() => ExchangePairsTracer(_cancellationTokenSource.Token), _cancellationTokenSource.Token);
            LogInfo($"CryptoExchange service is ran.");
            return true;
        }

        /// <summary>
        /// Stops request to all CryptoExchanges
        /// </summary>
        /// <returns></returns>
        public async Task StopExchangesRequest()
        {
            //this.exit = true;
            LogInfo($"CryptoExchange service is stopping...");
            _cancellationTokenSource.Cancel();
            await Task.WhenAll(this.exchangePairsTracerTask);
            await Task.WhenAll(Exchanges.Select(x=>x.Client.CloseConnection()));
        }
        #endregion

        #region Private
        /// <summary>
        /// Background proccess for the pairs tracing
        /// </summary>
        /// <returns></returns>
        private async Task ExchangePairsTracer(CancellationToken token)
        {
            do //while (!this.exit)
            {
                await CheckPairsChange();
                // Task.Delay(TimeSpan.FromMinutes(this.mitunteIntervalCheck)).Wait();
            } while (!token.WaitHandle.WaitOne(TimeSpan.FromMinutes(this.mitunteIntervalCheck))); // GetRemainRefreshDataIntervalMs(cycleBeginTime, _trackerSettings.ProcessKnoksIntervalMs)));
        }

        /// <summary>
        /// Comparator of the exchange pairs list
        /// </summary>
        /// <returns></returns>
        private async Task CheckPairsChange()
        {
            foreach (var exchange in Exchanges)
            {
                var exchangePairs = await GetActiveKnoksDataByExchange(exchange.ExchangeId);
                var pairsChanged = true;
                if (this.pairs.Keys.Contains(exchange.ExchangeId))
                {
                    var firstNotSecond = this.pairs[exchange.ExchangeId].Except(exchangePairs).ToList();
                    var secondNotFirst = exchangePairs.Except(this.pairs[exchange.ExchangeId]).ToList();

                    pairsChanged = firstNotSecond.Any() || secondNotFirst.Any();
                }

                this.pairs[exchange.ExchangeId] = exchangePairs.ToList();
                if ((pairsChanged && exchangePairs.Any()) || (this.lastExchangesResponse.Keys.Contains(exchange.ExchangeId) && (DateTime.Now - this.lastExchangesResponse[exchange.ExchangeId]).Minutes > 10))
                {
                    UpdateExchangeRequest(exchange);
                }
            }
            await RecalcAggregations();
        }

        /// <summary>
        /// The clients initialization
        /// </summary>
        /// <returns></returns>
        private async Task InitExchagesClients() {
            Exchanges = new List<ExchangeClientHandler>();
            foreach (var item in await GetExchanges())
            {
                var exchange = new ExchangeClientHandler
                {
                    ExchangeId = item.ExchangeId,
                    Client = CryptoExchangeFactory.InitialyzeExchange(item.ExchangeId, item.ExchangeName, CryptoExchangeManager.Configuration)
                };
                Exchanges.Add(exchange);
                if (exchange.Client != null)
                {
                    await exchange.Client.InitClient(saveData);
                }
            }
        }

        /// <summary>
        /// Returns all CeyptoExchanges from DB
        /// </summary>
        /// <returns></returns>
        private async Task<IEnumerable<Exchange>> GetExchanges() {
            return await _exchangeDao.GetExchanges();
        }

        /// <summary>
        /// Get list of active knoks pairs
        /// </summary>
        /// <param name="exchangeId"></param>
        /// <returns></returns>
        private async Task<IEnumerable<Tuple<string, string>>> GetActiveKnoksDataByExchange(int exchangeId)
        {
            return await _knokDao.GetActiveKnoksDataByExchange(exchangeId);
        }

        /// <summary>
        /// Recalculate all aggregations except 1 minute
        /// </summary>
        /// <returns></returns>
        private async Task RecalcAggregations()
        {
            await _knokDao.RecalcAggregations();
        }

        /// <summary>
        /// Reconnect exchanges with new pairs
        /// </summary>
        /// <param name="exchange"></param>
        private void UpdateExchangeRequest(ExchangeClientHandler exchange)
        {
            var requestedExchange = Exchanges.FirstOrDefault(x => x.ExchangeId == exchange.ExchangeId);
            if (requestedExchange != null) {
                if (exchange.TaskHandler != null)
                {
                    requestedExchange.Client.Reconnect().Wait();
                    Task.WaitAll(exchange.TaskHandler);
                }
                var pairs = this.pairs[exchange.ExchangeId]; // await GetActiveKnoksDataByExchange(exchange.ExchangeId); //  await knoks. SelectMany(x => x.TradingPairs).Distinct().ToList();
                if (pairs.Any())
                {
                    var sb = new StringBuilder();
                    sb.AppendLine($"Reconnect for ExchangeId: {exchange.ExchangeId}");
                    foreach (var i in pairs) {
                        sb.AppendLine($"    Pair: {i}");
                    }
                    LogInfo(sb.ToString());
                    // Replace USDT => TUSD for Bittrex
                    //if (requestedExchange.Client.ReplaceSymbols != null)
                    //{
                    //    for (var i = 0; i < pairs.Count; i++)
                    //    {
                    //        if (requestedExchange.Client.ReplaceSymbols.Keys.Contains(pairs[i].Item1))
                    //        {
                    //            pairs[i] = new Tuple<string, string>(requestedExchange.Client.ReplaceSymbols[pairs[i].Item1], pairs[i].Item2);
                    //        }
                    //    }
                    //}
                    exchange.TaskHandler = requestedExchange.Client.RequestPairsData(pairs);
                }
                else {
                    exchange.TaskHandler = null;
                }
            }            
        }

        /// <summary>
        /// Log info
        /// </summary>
        /// <param name="info"></param>
        private void LogInfo(string info)
        {
            _logger.LogInformation($"{DateTime.UtcNow:G} {info}");
        }

        /// <summary>
        /// Log debug info
        /// </summary>
        /// <param name="info"></param>
        /// <param name="timestamp"></param>
        private void DebugInfo(string info, bool timestamp = false)
        {
            if (timestamp)
                _logger.LogDebug($"{DateTime.UtcNow:G} {info}");
            else
                _logger.LogDebug($"{info}");
        }
        #endregion
    }
}