using System;
using System.Collections.Generic;
using System.Linq;
using System.Threading.Tasks;
using System.Configuration;
using System.Text;
using Microsoft.Extensions.Configuration;
using Microsoft.Extensions.Logging;
using BlaServApp.Data;
using Microsoft.Extensions.Caching.Distributed;
using Microsoft.Extensions.Caching.Memory;
using Newtonsoft.Json;
using System.Diagnostics;
using NLog;

namespace BlaServApp.UI.Data
{
    public class BlaServAppDataService
    {
        #region Private Fields

        private static IConfiguration _configuration;
        private static ILogger<BlaServAppDataService> _logger;

        private static NLog.Logger Log = LogManager.GetCurrentClassLogger();
        private readonly IDistributedCache distributedCache;
        private readonly IMemoryCache memoryCache;

        /// <summary>
        /// Durata assoluta massima della cache
        /// </summary>
        private int chAbsExp = 15;

        /// <summary>
        /// Durata della cache in modalità inattiva (non acceduta) prima di venire rimossa
        /// NON estende oltre il tempo massimo di validità della cache (chAbsExp)
        /// </summary>
        private int chSliExp = 5;

        #endregion Private Fields

        #region Protected Fields

        protected static string connStringBBM = "";

        #endregion Protected Fields

        #region Public Fields

        public static BlaServApp.Data.Controllers.BlaServAppController dbController;

        #endregion Public Fields

        #region Public Constructors

        public BlaServAppDataService(IConfiguration configuration, ILogger<BlaServAppDataService> logger, IMemoryCache memoryCache, IDistributedCache distributedCache)
        {
            _logger = logger;
            _configuration = configuration;
            // conf cache
            this.memoryCache = memoryCache;
            this.distributedCache = distributedCache;
            // conf DB
            string connStr = _configuration.GetConnectionString("BlaServApp.Data");
            if (string.IsNullOrEmpty(connStr))
            {
                _logger.LogError("ConnString empty!");
            }
            else
            {
                dbController = new BlaServApp.Data.Controllers.BlaServAppController(configuration);
                StringBuilder sb = new StringBuilder();
                sb.AppendLine($"DbController OK");
                _logger.LogInformation(sb.ToString());
            }
        }

        #endregion Public Constructors

        #region Private Properties

        private DistributedCacheEntryOptions cacheOpt
        {
            get
            {
                return new DistributedCacheEntryOptions().SetAbsoluteExpiration(DateTime.Now.AddMinutes(chAbsExp)).SetSlidingExpiration(TimeSpan.FromMinutes(chSliExp));
            }
        }

        #endregion Private Properties

        #region Protected Methods

        protected string getCacheKey(string TableName, SelectData CurrFilter)
        {
            string answ = $"{TableName}:M_{CurrFilter.IdxMacchina}:A_{CurrFilter.CodArticolo}:K_{CurrFilter.KeyRichiesta}:O_{CurrFilter.IdxOdl}:D_{CurrFilter.DateStart:yyyyMMddHHmm}_{CurrFilter.DateEnd:yyyyMMddHHmm}";
            return answ;
        }

        #endregion Protected Methods

        #region Public Methods

        public async Task<List<BlaServApp.Data.DatabaseModels.Articoli>> ArticoliGetAll()
        {
            //return Task.FromResult(dbController.ActionsGetAll());
            List<BlaServApp.Data.DatabaseModels.Articoli> dbResult = new List<BlaServApp.Data.DatabaseModels.Articoli>();
            string cacheKey = "BlaServApp:DATA:ARTICOLI";
            string rawData;
            var redisDataList = await distributedCache.GetAsync(cacheKey);
            if (redisDataList != null)
            {
                rawData = Encoding.UTF8.GetString(redisDataList);
                dbResult = JsonConvert.DeserializeObject<List<BlaServApp.Data.DatabaseModels.Articoli>>(rawData);
            }
            else
            {
                Stopwatch stopWatch = new Stopwatch();
                stopWatch.Start();
                dbResult = dbController.getArticoli();
                rawData = JsonConvert.SerializeObject(dbResult);
                redisDataList = Encoding.UTF8.GetBytes(rawData);
                await distributedCache.SetAsync(cacheKey, redisDataList, cacheOpt);
                stopWatch.Stop();
                TimeSpan ts = stopWatch.Elapsed;
                Log.Info($"Effettuata lettura da DB + caching per ArticoliGetAll: {ts.TotalMilliseconds} ms");
            }
            return await Task.FromResult(dbResult);
        }

        public async Task<List<BlaServApp.Data.DatabaseModels.Config>> ConfigGetAll()
        {
            //return Task.FromResult(dbController.ActionsGetAll());
            List<BlaServApp.Data.DatabaseModels.Config> dbResult = new List<BlaServApp.Data.DatabaseModels.Config>();
            string cacheKey = "BlaServApp:DATA:CONFIG";
            string rawData;
            var redisDataList = await distributedCache.GetAsync(cacheKey);
            if (redisDataList != null)
            {
                rawData = Encoding.UTF8.GetString(redisDataList);
                dbResult = JsonConvert.DeserializeObject<List<BlaServApp.Data.DatabaseModels.Config>>(rawData);
            }
            else
            {
                Stopwatch stopWatch = new Stopwatch();
                stopWatch.Start();
                dbResult = dbController.getConfig();
                rawData = JsonConvert.SerializeObject(dbResult);
                redisDataList = Encoding.UTF8.GetBytes(rawData);
                await distributedCache.SetAsync(cacheKey, redisDataList, cacheOpt);
                stopWatch.Stop();
                TimeSpan ts = stopWatch.Elapsed;
                Log.Info($"Effettuata lettura da DB + caching per ConfigGetAll: {ts.TotalMilliseconds} ms");
            }
            return await Task.FromResult(dbResult);
        }

        #endregion Public Methods
    }
}