using Microsoft.Extensions.Caching.Distributed;
using Microsoft.Extensions.Caching.Memory;
using Newtonsoft.Json;
using NKC.Data.DbModels;
using NKC.Data.DTO;
using NLog;
using System.Diagnostics;
using System.Text;

namespace REMAN.Data
{
    public class RDataService : IDisposable
    {
        #region Private Fields

        private static IConfiguration _configuration = null!;
        private static ILogger<RDataService> _logger = null!;
        private static JsonSerializerSettings? JSSettings;

        private static NLog.Logger Log = LogManager.GetCurrentClassLogger();

        //private readonly IEmailSender _emailSender;
        //private readonly UserManager<IdentityUser> _userManager;
        private readonly IDistributedCache distributedCache;

        private readonly IMemoryCache memoryCache;
        private List<string> cachedDataList = new List<string>();

        /// <summary>
        /// Durata assoluta massima della cache IN SECONDI
        /// </summary>
        private int chAbsExp = 60 * 5;

        /// <summary>
        /// Durata della cache IN SECONDI in modalità inattiva (non acceduta) prima di venire rimossa
        /// NON estende oltre il tempo massimo di validità della cache (chAbsExp)
        /// </summary>
        private int chSliExp = 60 * 1;

        #endregion Private Fields

        #region Protected Fields

        protected const string rKeyMaterials = "Cache:Materials";
        protected const string rKeyQrRemnants = "Cache:QrRemnants";
        protected const string rKeyRemnants = "Cache:Remnants";
        protected static string connStringBBM = "";

        #endregion Protected Fields

        #region Public Fields

        public static NKC.Data.Controllers.NKCController dbController = null!;

        #endregion Public Fields

        #region Public Constructors

        public RDataService(IConfiguration configuration, ILogger<RDataService> logger, IMemoryCache memoryCache, IDistributedCache distributedCache)
        {
            _logger = logger;
            _configuration = configuration;
            // conf cache
            this.memoryCache = memoryCache;
            this.distributedCache = distributedCache;

            // json serializer...
            // FIX errore loop circolare
            // https://www.ryadel.com/en/jsonserializationexception-self-referencing-loop-detected-error-fix-entity-framework-asp-net-core/
            JSSettings = new JsonSerializerSettings()
            {
                ReferenceLoopHandling = ReferenceLoopHandling.Ignore
            };
            // conf DB
            string connStr = _configuration.GetConnectionString("NKC.DB");
            if (string.IsNullOrEmpty(connStr))
            {
                _logger.LogError("ConnString empty!");
            }
            else
            {
                dbController = new NKC.Data.Controllers.NKCController(configuration);
            }
        }

        #endregion Public Constructors

        #region Private Methods

        private DistributedCacheEntryOptions cacheOpt(bool fastCache)
        {
            var numSecAbsExp = fastCache ? chAbsExp : chAbsExp * 10;
            var numSecSliExp = fastCache ? chSliExp : chSliExp * 10;
            return new DistributedCacheEntryOptions().SetAbsoluteExpiration(DateTime.Now.AddSeconds(numSecAbsExp)).SetSlidingExpiration(TimeSpan.FromSeconds(numSecSliExp));
        }

        #endregion Private Methods

        #region Public Methods

        public void Dispose()
        {
            // Clear database controller
            dbController.Dispose();
        }

        /// <summary>
        /// invalida tutta la cache in caso di update
        /// </summary>
        /// <returns></returns>
        public async Task InvalidateAllCache()
        {
            await distributedCache.RemoveAsync(rKeyMaterials);
            await distributedCache.RemoveAsync(rKeyRemnants);
            foreach (var item in cachedDataList)
            {
                await distributedCache.RemoveAsync(item);
            }
            cachedDataList = new List<string>();
        }

        public async Task<List<MaterialDTO>> MaterialsGetAll()
        {
            List<MaterialDTO>? dbResult = new List<MaterialDTO>();
            string rawData;
            var redisDataList = await distributedCache.GetAsync(rKeyMaterials);
            if (redisDataList != null)
            {
                rawData = Encoding.UTF8.GetString(redisDataList);
                dbResult = JsonConvert.DeserializeObject<List<MaterialDTO>>(rawData);
            }
            else
            {
                Stopwatch stopWatch = new Stopwatch();
                stopWatch.Start();
                dbResult = dbController.MaterialsGetAll();
                rawData = JsonConvert.SerializeObject(dbResult, JSSettings);
                redisDataList = Encoding.UTF8.GetBytes(rawData);
                await distributedCache.SetAsync(rKeyMaterials, redisDataList, cacheOpt(false));
                stopWatch.Stop();
                TimeSpan ts = stopWatch.Elapsed;
                Log.Trace($"Effettuata lettura da DB + caching per GetMaterials: {ts.TotalMilliseconds} ms");
            }
            if (dbResult == null)
            {
                dbResult = new List<MaterialDTO>();
            }
            return await Task.FromResult(dbResult);
        }

        public async Task<List<MovMagModel>> MovMagGetFilt(int RemnId, int numShow)
        {
            List<MovMagModel> dbResult = new List<MovMagModel>();
            Stopwatch stopWatch = new Stopwatch();
            stopWatch.Start();
            dbResult = dbController.MovMagGetFilt(RemnId, numShow);
            stopWatch.Stop();
            TimeSpan ts = stopWatch.Elapsed;
            Log.Trace($"Effettuata lettura da DB + caching per MovMagGetFilt: {ts.TotalMilliseconds} ms");
            return await Task.FromResult(dbResult);
        }

        public async Task<bool> AddPrintJob(int RemnId)
        {
            bool answ = dbController.AddPrintJob("docRemnant", $"{RemnId}", "queueRemnants");
            return await Task.FromResult(answ);
        }

        public async Task<List<RemnantsModel>> RemnantsGetFilt(int matId, int minQty)
        {
            List<RemnantsModel>? dbResult = new List<RemnantsModel>();
            string rawData;
            string cacheKey = $"{rKeyRemnants}:{matId}:{minQty}";
            if (!cachedDataList.Contains(cacheKey))
            {
                cachedDataList.Add(cacheKey);
            }

            var redisDataList = await distributedCache.GetAsync(cacheKey);
            if (redisDataList != null)
            {
                rawData = Encoding.UTF8.GetString(redisDataList);
                dbResult = JsonConvert.DeserializeObject<List<RemnantsModel>>(rawData);
            }
            else
            {
                Stopwatch stopWatch = new Stopwatch();
                stopWatch.Start();
                var rawList = dbController.RemnantsGetFilt(matId, minQty);
                dbResult = rawList.OrderBy(r => r.RemDtmx).ThenBy(o => o.Area).ToList();
                rawData = JsonConvert.SerializeObject(dbResult, JSSettings);
                redisDataList = Encoding.UTF8.GetBytes(rawData);
                await distributedCache.SetAsync(cacheKey, redisDataList, cacheOpt(false));
                stopWatch.Stop();
                TimeSpan ts = stopWatch.Elapsed;
                Log.Trace($"Effettuata lettura da DB + caching per RemnantsGetAll: {ts.TotalMilliseconds} ms");
            }
            if (dbResult == null)
            {
                dbResult = new List<RemnantsModel>();
            }
            return await Task.FromResult(dbResult);
        }

        public async Task<bool> RemnantsIsDupl(RemnantsModel currItem)
        {
            bool answ = false;
            var rawList = dbController.RemnantsGetFilt(currItem.MatID, 0);
            var duplicati = rawList
                            .Where(x => x.RemnID != currItem.RemnID && x.LMm == currItem.LMm && x.WMm == currItem.WMm && x.TMm == currItem.TMm)
                            .ToList();
            answ = duplicati.Count > 0;
            return await Task.FromResult(answ);
        }

        public async Task<bool> RemnantsMovMag(RemnantsModel currItem, string userId, int deltaQty)
        {
            bool done = false;
            try
            {
                // recupero item da DB
                var currRecord = dbController.RemnantGetByid(currItem.RemnID);
                if (currRecord != null && currRecord.RemnID == currItem.RemnID)
                {
                    // modifico qty entro limiti >=0..
                    if (currRecord.QtyAvail + deltaQty >= 0)
                    {
                        currRecord.QtyAvail = currRecord.QtyAvail + deltaQty;
                        done = dbController.RemnantsUpsert(currRecord, userId);
                        await InvalidateAllCache();
                    }
                }
            }
            catch (Exception exc)
            {
                Log.Error($"Eccezione in RemnantsMovMag:{Environment.NewLine}{exc}");
            }
            return await Task.FromResult(done);
        }

        public async Task<bool> RemnantsUpsert(RemnantsModel currItem, string userId)
        {
            bool done = false;
            try
            {
                done = dbController.RemnantsUpsert(currItem, userId);
                await InvalidateAllCache();
            }
            catch (Exception exc)
            {
                Log.Error($"Eccezione in RemnantsUpsert:{Environment.NewLine}{exc}");
            }
            return await Task.FromResult(done);
        }

        public void rollBackEdit(object item)
        {
            dbController.rollBackEntity(item);
        }

        public async Task<RemnantsModel> SearchQrRemnant(string QrCode)
        {
            RemnantsModel? answ = new RemnantsModel();
            string rawData = "";
            string cacheKey = $"{rKeyQrRemnants}:{QrCode}";
            // cerco in redis
            var redisData = await distributedCache.GetAsync(cacheKey);
            if (redisData != null)
            {
                rawData = Encoding.UTF8.GetString(redisData);
                answ = JsonConvert.DeserializeObject<RemnantsModel>(rawData);
            }
            // se non trovo cerco su DB
            else
            {
                Stopwatch stopWatch = new Stopwatch();
                stopWatch.Start();
                var foundItem = dbController.RemnantGetByQr(QrCode);
                if (foundItem != null && foundItem.RemDtmx == QrCode)
                {
                    rawData = JsonConvert.SerializeObject(foundItem, JSSettings);
                    redisData = Encoding.UTF8.GetBytes(rawData);
                    await distributedCache.SetAsync(cacheKey, redisData, cacheOpt(false));
                    answ = foundItem;
                }
                stopWatch.Stop();
                TimeSpan ts = stopWatch.Elapsed;
                Log.Trace($"Effettuata lettura da DB + caching per SearchQrRemnant: {ts.TotalMilliseconds} ms");
            }
            if (answ == null)
            {
                answ = new RemnantsModel();
            }
            return await Task.FromResult(answ);
        }

        #endregion Public Methods
    }
}