using System;
using System.Collections.Generic;
using System.Linq;
using Dfs.WayneChina.HengshanFPos.FPosDbManager.Model;

namespace Dfs.WayneChina.HengshanFPos.FPosDbManager
{
    /// <summary>
    /// Sequence number manager
    /// </summary>
    public class FPosDbManager
    {
        //private FPosDbContext _context;
        //private object syncObj = new object();

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

        public FPosDbManager(FPosDbContext context)
        {
            //_context = context;
        }

        public bool ReserveTransaction(ushort fPosSqNo, int fcSqNo)
        {
            using (var _context = new FPosDbContext())
            {
                var trx = _context.FPosTransactions.FirstOrDefault(t => t.FPosSqNo == fPosSqNo && t.FcSqNo == fcSqNo);

                if (trx != null)
                {
                    if (trx.Reserved)
                    {
                        logger.Info($"Current transaction FPosSqNo: {trx.FPosSqNo}, FcSqNo: {trx.FcSqNo} is already reserved by another entity.");
                        return false;
                    }

                    try
                    {
                        trx.Reserved = true;
                        _context.FPosTransactions.Attach(trx);
                        var entry = _context.Entry(trx);
                        entry.Property(p => p.Reserved).IsModified = true;
                        _context.SaveChanges();

                        logger.Info($"FPos SqNo:{fPosSqNo}, FC SqNo:{fcSqNo}, Reserved set to: true");
                        return true;
                    }
                    catch (Exception ex)
                    {
                        logger.Info($"Exception in ReserveTransaction: {ex}");
                        return false;
                    }
                }
                else
                {
                    logger.Info($"ReserveTransaction, FPos SqNo {fPosSqNo}, FC SqNo {fcSqNo}, the trx record not found!");
                }

                return false;
            }
        }

        public bool UnreserveTransaction(ushort fPosSqNo, int fcSqNo)
        {
            using (var _context = new FPosDbContext())
            {
                var trx = _context.FPosTransactions.FirstOrDefault(t => t.FPosSqNo == fPosSqNo && t.FcSqNo == fcSqNo);

                if (trx != null)
                {
                    try
                    {
                        trx.Reserved = false;
                        _context.FPosTransactions.Attach(trx);
                        var entry = _context.Entry(trx);
                        entry.Property(p => p.Reserved).IsModified = true;
                        _context.SaveChanges();

                        logger.Info($"FPos SqNo:{fPosSqNo}, FC SqNo:{fcSqNo}, Reserved set to: false");
                        return true;
                    }
                    catch (Exception ex)
                    {
                        logger.Info($"Exception in ReserveTransaction: {ex}");
                        return false;
                    }
                }
                else
                {
                    logger.Info($"UnreserveTransaction, FPos SqNo {fPosSqNo}, FC SqNo {fcSqNo}, the trx record not found!");
                }

                return false;
            }
        }

        public void AddMapping(ushort epsSqNo, int fcSqNo, int pumpId, int nozzleId, int token, decimal fillingAmount)
        {

            using (var _context = new FPosDbContext())
            {
                var mapper = new FPosTransaction
                {
                    Reserved = false,
                    PumpId = pumpId,
                    NozzleId = nozzleId,
                    FPosSqNo = epsSqNo,
                    FcSqNo = fcSqNo,
                    ReleaseToken = token,
                    FillingAmount = fillingAmount,
                    PosItemId = Guid.Empty,
                    CloudTrxId = Guid.Empty,
                    Submitted = false
                };

                logger.Info($"Adding mapping, FPos SqNo={epsSqNo}, FC SqNo={fcSqNo}, PumpId={pumpId}, NozzleId={nozzleId}");

                try
                {
                    _context.FPosTransactions.Add(mapper);
                    _context.SaveChanges();
                }
                catch (Exception ex)
                {
                    logger.Info($"Exception in inserting a new mapper: {ex.Message}");
                }
            }
            
        }

        #region Un-used

        /// <summary>
        /// Returns the sequence number of the current fueling or a new one for a new fueling.
        /// </summary>
        /// <param name="pumpId">Pump id (fueling point id).</param>
        /// <param name="nozzleId">Nozzle id of the current pump.</param>
        /// <returns>Sequence number.</returns>
        public ushort GetSqNo(int pumpId, int nozzleId)
        {
            using (var _context = new FPosDbContext())
            {
                try
                {
                    logger.Info($"Checking pumpId = {pumpId} and nozzleId = {nozzleId}");

                    var sqNoList = _context.SequenceNumbers
                        .OrderByDescending(s => s.TimeStamp)
                        .ToList();

                    var sqNo = sqNoList
                        .Where(s => s.Ongoing && s.PumpId == pumpId && s.NozzleId == nozzleId)
                        .FirstOrDefault();

                    if (sqNo != null)
                    {
                        return sqNo.SqNo;
                    }

                    logger.Info($"No running transaction for current pumpId: {pumpId} and nozzleId: {nozzleId}, will add a new one.");

                    var newSqNo = new SequenceNumber
                    {
                        PumpId = pumpId,
                        NozzleId = nozzleId,
                        Ongoing = true, //Field value in DB: 1
                        TimeStamp = DateTime.Now
                    };

                    _context.SequenceNumbers.Add(newSqNo);
                    _context.SaveChanges();

                    logger.Info($"The newly-added SqNo is: {newSqNo.SqNo}");

                    return newSqNo.SqNo;
                }
                catch (Exception ex)
                {
                    logger.Info($"Exception in getting new Sequence number: {ex.Message}");

                    return 0;
                }
            }   
        }

        #endregion

        public ushort GetNewSqNo(int pumpId, int nozzleId)
        {
            using (var _context = new FPosDbContext())
            {
                try
                {
                    var newSqNo = new SequenceNumber
                    {
                        PumpId = pumpId,
                        NozzleId = nozzleId,
                        Ongoing = true, //Field value in DB: 1
                        TimeStamp = DateTime.Now
                    };
                    _context.SequenceNumbers.Add(newSqNo);
                    _context.SaveChanges();

                    logger.Info($"Got new SqNo: {newSqNo.SqNo}");
                    return newSqNo.SqNo;
                }
                catch (Exception ex)
                {
                    logger.Info($"Exception in creating new SqNo: {ex.Message}");
                    return 0;
                }
            }
           
        }

        public ushort GetCurrentSqNo(int pumpId, int nozzleId)
        {
            logger.Info($"Retrieving current SqNo for pumpId = {pumpId} and nozzleId = {nozzleId}");

            using (var _context = new FPosDbContext())
            {
                var sqNoList = _context.SequenceNumbers
                    .OrderByDescending(s => s.TimeStamp)
                    .ToList();

                var sqNo = sqNoList
                    .Where(s => s.Ongoing && s.PumpId == pumpId && s.NozzleId == nozzleId)
                    .FirstOrDefault();

                if (sqNo != null)
                {
                    logger.Info($"SqNo for current fueling: {sqNo.SqNo}");
                    return sqNo.SqNo;
                }

                return 0;
            }
        }

        public ushort SetFillingDone(int pumpId, int nozzleId)
        {
            using (var _context = new FPosDbContext())
            {
                try
                {
                    var sqNo = _context.SequenceNumbers
                        .Where(s => s.Ongoing && s.PumpId == pumpId && s.NozzleId == nozzleId)
                        .OrderByDescending(n => n.SqNo)
                        .FirstOrDefault();

                    if (sqNo == null)
                    {
                        logger.Info($"could not get a SqNo for pump id: {pumpId}, nozzle id: {nozzleId} ");
                    }

                    sqNo.Ongoing = false;
                    _context.SequenceNumbers.Attach(sqNo);
                    var entry = _context.Entry(sqNo);
                    entry.Property(p => p.Ongoing).IsModified = true;
                    _context.SaveChanges();

                    logger.Info($"Pump id: {pumpId}, nozzle id: {nozzleId}, filling done, ongoing set to false");

                    return sqNo.SqNo;

                }
                catch (Exception ex)
                {
                    logger.Info($"Exception in setting filling to be done: {ex.Message}");
                    return 0;
                }
            }
        }

        public bool SetCardType(ushort fPosSqNo, int fcSqNo, int cardType)
        {
            using (var _context = new FPosDbContext())
            {
                var trx = _context.FPosTransactions
                    .FirstOrDefault(t => t.FPosSqNo == fPosSqNo && t.FcSqNo == fcSqNo);

                if (trx != null)
                {
                    try
                    {
                        trx.CardType = cardType;
                        _context.FPosTransactions.Attach(trx);
                        var entry = _context.Entry(trx);
                        entry.Property(p => p.CardType).IsModified = true;
                        _context.SaveChanges();

                        logger.Info($"pump id:{trx.PumpId}, nozzle id:{trx.NozzleId}, FPOS SqNo:{fPosSqNo}, FC SqNo:{fcSqNo}, CardType set to {cardType}");
                        return true;
                    }
                    catch (Exception ex)
                    {
                        logger.Info($"Exception in setting card type: {ex}");
                        return false;
                    }
                }
                else
                {
                    logger.Info($"Set card type, Could not find the match in FPos database with FPos SqNo:{fPosSqNo} and FC SqNo:{fcSqNo}");
                    return false;
                }
            }
        }

        public bool SetActualPayAmount(ushort fPosSqNo, int fcSqNo, decimal amount)
        {
            using (var _context = new FPosDbContext())
            {
                var trx = _context.FPosTransactions
                    .FirstOrDefault(t => t.FPosSqNo == fPosSqNo && t.FcSqNo == fcSqNo);

                if (trx != null)
                {
                    try
                    {
                        trx.ActualPayAmount = amount;
                        _context.FPosTransactions.Attach(trx);
                        var entry = _context.Entry(trx);
                        entry.Property(p => p.ActualPayAmount).IsModified = true;
                        _context.SaveChanges();

                        logger.Info($"Entry pump id:{trx.PumpId}, nozzle id:{trx.NozzleId}, FPOS SqNo:{fPosSqNo}, FC SqNo:{fcSqNo}, ActualPayAmount=>{amount}");
                        return true;
                    }
                    catch (Exception ex)
                    {
                        logger.Info($"Exception in setting actual payment amount: {ex}");
                        return false;
                    }
                }
                else
                {
                    logger.Info($"Could not find the match in FPos database with FPos SqNo:{fPosSqNo} and FC SqNo:{fcSqNo}");
                    return false;
                }
            }
        }

        public FPosTransaction GetCurrentTrx(ushort currentFPosSqNo, int currentFdcSqNo)
        {
            using (var _context = new FPosDbContext())
            {
                return _context.FPosTransactions
                    .FirstOrDefault(t => t.Reserved && t.FPosSqNo == currentFPosSqNo && t.FcSqNo == currentFdcSqNo);
            } 
        }

        public bool SetPosItemId(ushort fPosSqNo, int fcSqNo, Guid itemId)
        {
            using (var _context = new FPosDbContext())
            {
                var trx = _context.FPosTransactions
                    .FirstOrDefault(t => t.FPosSqNo == fPosSqNo && t.FcSqNo == fcSqNo);

                if (trx != null)
                {
                    try
                    {
                        trx.PosItemId = itemId;
                        _context.FPosTransactions.Attach(trx);
                        var entry = _context.Entry(trx);
                        entry.Property(p => p.PosItemId).IsModified = true;
                        _context.SaveChanges();

                        logger.Info($"FPos SqNo:{fPosSqNo}, FC SqNo:{fcSqNo}, PosItemId set to {itemId}");
                        return true;
                    }
                    catch (Exception ex)
                    {
                        logger.Info($"Exception in setting PosItemId: {ex}");
                        return false;
                    }
                }
                else
                {
                    logger.Info($"Set PosItemId, FPos SqNo {fPosSqNo}, FC SqNo {fcSqNo}, the trx record not found!");
                }

                return false;
            }
        }

        public bool SetTransactionId(ushort fPosSqNo, int fcSqNo, Guid trxId)
        {
            using (var _context = new FPosDbContext())
            {
                var trx = _context.FPosTransactions
                    .FirstOrDefault(t => t.FPosSqNo == fPosSqNo && t.FcSqNo == fcSqNo);

                if (trx != null)
                {
                    try
                    {
                        trx.CloudTrxId = trxId;
                        _context.FPosTransactions.Attach(trx);
                        var entry = _context.Entry(trx);
                        entry.Property(p => p.CloudTrxId).IsModified = true;
                        _context.SaveChanges();

                        logger.Info($"FPos SqNo:{fPosSqNo}, FC SqNo:{fcSqNo}, CloudTrxId set to {trxId}");
                        return true;
                    }
                    catch (Exception ex)
                    {
                        logger.Info($"Exception in setting CloudTrxId: {ex}");
                        return false;
                    }
                }
                else
                {
                    logger.Info($"Set CloudTrxId, FPos SqNo {fPosSqNo}, FC SqNo {fcSqNo}, the trx record not found!");
                }

                return false;
            }
        }

        public bool SetTransactionSubmitted(ushort fPosSqNo, int fcSqNo, bool submitted)
        {
            using (var _context = new FPosDbContext())
            {
                var trx = _context.FPosTransactions
                    .FirstOrDefault(t => t.FPosSqNo == fPosSqNo && t.FcSqNo == fcSqNo);

                if (trx != null)
                {
                    try
                    {
                        trx.Submitted = submitted;
                        _context.FPosTransactions.Attach(trx);
                        var entry = _context.Entry(trx);
                        entry.Property(p => p.Submitted).IsModified = true;
                        _context.SaveChanges();

                        logger.Info($"FPos SqNo:{fPosSqNo}, FC SqNo:{fcSqNo}, Submitted set to {submitted}");
                        return true;
                    }
                    catch (Exception ex)
                    {
                        logger.Info($"Exception in setting Submitted: {ex}");
                        return false;
                    }
                }
                else
                {
                    logger.Info($"Set Submitted, FPos SqNo {fPosSqNo}, FC SqNo {fcSqNo}, the trx record not found!");
                }

                return false;
            }
        }

        public void CleanSqNo()
        {
            using (var _context = new FPosDbContext())
            {
                try
                {
                    var oldSqNos = _context
                        .SequenceNumbers
                        .Where(sq => sq.TimeStamp < DateTime.Now.Subtract(new TimeSpan(0, 1, 0)));

                    var mappers = new List<FPosTransaction>();

                    foreach (var sqNo in oldSqNos.ToList())
                    {
                        var mapper = _context.FPosTransactions
                            .FirstOrDefault(m => m.FPosSqNo == sqNo.SqNo && m.Submitted);

                        if (mapper != null)
                            mappers.Add(mapper);
                    }

                    _context.SequenceNumbers.RemoveRange(oldSqNos.ToArray());
                    _context.FPosTransactions.RemoveRange(mappers.ToArray());

                    _context.SaveChanges();

                }
                catch (Exception ex)
                {
                    logger.Info($"Exception in deleting submitted trx sequence no: {ex.Message}");
                }
            }
        }

        /// <summary>
        /// Get the POS sequence number.
        /// </summary>
        /// <param name="pumpId">pump id.</param>
        /// <param name="nozzleId">nozzle id.</param>
        /// <param name="fcSqNo">FDC transaction sequence number.</param>
        /// <returns></returns>
        public int GetSqNoByMapping(int pumpId, int nozzleId, int fcSqNo)
        {
            using (var _context = new FPosDbContext())
            {
                try
                {
                    var mapper = _context.FPosTransactions
                        .OrderBy(s => s.Id)
                        .FirstOrDefault(s => s.PumpId == pumpId && s.NozzleId == nozzleId && s.FcSqNo == fcSqNo);

                    if (mapper != null)
                    {
                        return mapper.FPosSqNo;
                    }
                    else
                    {
                        logger.Info($"Could not find the POS SqNo by pumpId={pumpId} and nozzleId={nozzleId} for FcSqNo={fcSqNo}");
                        return 0;
                    }
                }
                catch (Exception ex)
                {
                    logger.Info($"Exception in get SqNo by FcSqNo={fcSqNo} from mapping table: {ex.Message}");
                    return 0;
                }
            }
        }
    }
}