using Microsoft.Extensions.Configuration;
using MP.Core.Conf;
using MP.Data.DbModels;
using Newtonsoft.Json;
using NLog;
using StackExchange.Redis;
using System;
using System.Collections.Generic;
using System.ComponentModel.DataAnnotations;
using System.Data;
using System.Diagnostics;
using System.IO;
using System.Linq;
using System.Text;
using System.Threading.Tasks;

namespace MP.Data.Services
{
    /// <summary>
    /// Classe accesso processi traduzione
    /// </summary>
    public class TranslateSrv : BaseServ
    {
        #region Public Constructors

        public TranslateSrv(IConfiguration configuration, IConnectionMultiplexer redConn) : base(configuration, redConn)
        {
            Stopwatch sw = new Stopwatch();
            sw.Start();
            // conf DB
            string connStr = _configuration.GetConnectionString("MP.Voc");
            if (string.IsNullOrEmpty(connStr))
            {
                Log.Error("MP.Voc: ConnString empty!");
            }
            else
            {
                dbController = new Controllers.MpVocController(configuration);
                InitDict();
                sw.Stop();
                Log.Info($"TranslateSrv | MpVocController OK | {sw.Elapsed.TotalMilliseconds} ms");
            }
        }

        #endregion Public Constructors

        #region Public Properties

        public static Controllers.MpVocController dbController { get; set; } = null!;

        #endregion Public Properties

        #region Public Methods

        /// <summary>
        /// Recupero elenco config
        /// </summary>
        /// <returns></returns>
        public async Task<List<ConfigModel>> ConfigGetAll()
        {
            string source = "DB";
            Stopwatch sw = new Stopwatch();
            sw.Start();
            List<ConfigModel>? result = new List<ConfigModel>();
            // cerco in _redisConn...
            string currKey = $"{redisBaseKey}:Conf";
            RedisValue rawData = await _redisDb.StringGetAsync(currKey);
            //if (!string.IsNullOrEmpty($"{rawData}"))
            if (rawData.HasValue)
            {
                result = JsonConvert.DeserializeObject<List<ConfigModel>>($"{rawData}");
                source = "REDIS";
            }
            else
            {
                result = dbController.ConfigGetAll();
                // serializzo e salvo...
                rawData = JsonConvert.SerializeObject(result);
                _redisDb.StringSet(currKey, rawData, LongCache);
            }
            if (result == null)
            {
                result = new List<ConfigModel>();
            }
            sw.Stop();
            Log.Debug($"ConfigGetAll | {source} | {sw.Elapsed.TotalMilliseconds}ms");
            return result;
        }

        /// <summary>
        /// Pulizia cache Redis (tutta)
        /// </summary>
        /// <returns></returns>
        public async Task<bool> FlushCache()
        {
            RedisValue pattern = new RedisValue($"{redisBaseKey}:*");
            bool answ = await ExecFlushRedisPattern(pattern);
            // rileggo vocabolario!
            var rawData = await VocabolarioGetAll();
            DictVocab = rawData.ToDictionary(kvp => $"{kvp.Lingua}_{kvp.Lemma}".ToUpper(), kvp => kvp.Traduzione);
            return answ;
        }

        /// <summary>
        /// Pulizia cache Redis per chiave specifica (da redisBaseKey...)
        /// </summary>
        /// <returns></returns>
        public async Task<bool> FlushCache(string KeyReq)
        {
            RedisValue pattern = new RedisValue($"{redisBaseKey}:{KeyReq}:*");
            bool answ = await ExecFlushRedisPattern(pattern);
            return answ;
        }

        /// <summary>
        /// Recupero elenco config
        /// </summary>
        /// <returns></returns>
        public async Task<List<LingueModel>> LingueGetAll()
        {
            string source = "DB";
            Stopwatch sw = new Stopwatch();
            sw.Start();
            List<LingueModel>? result = new List<LingueModel>();
            // cerco in _redisConn...
            string currKey = $"{redisBaseKey}:Lang";
            RedisValue rawData = await _redisDb.StringGetAsync(currKey);
            //if (!string.IsNullOrEmpty($"{rawData}"))
            if (rawData.HasValue)
            {
                result = JsonConvert.DeserializeObject<List<LingueModel>>($"{rawData}");
                source = "REDIS";
            }
            else
            {
                result = dbController.LingueGetAll();
                // serializzo e salvo...
                rawData = JsonConvert.SerializeObject(result);
                _redisDb.StringSet(currKey, rawData, UltraLongCache);
            }
            if (result == null)
            {
                result = new List<LingueModel>();
            }
            sw.Stop();
            Log.Debug($"LingueGetAll | {source} | {sw.Elapsed.TotalMilliseconds}ms");
            return result;
        }

        /// <summary>
        /// Traduzione termine
        /// </summary>
        /// <param name="lemma"></param>
        /// <param name="lingua"></param>
        /// <returns></returns>
        public string Traduci(string lemma, string lingua = "IT")
        {
            string answ = $"[{lemma}.{lingua}]";
            string key = $"{lingua}_{lemma}".ToUpper();
            if (DictVocab.ContainsKey(key))
            {
                answ = DictVocab[key];
            }
            return answ;
        }

        /// <summary>
        /// Recupero elenco config
        /// </summary>
        /// <returns></returns>
        public async Task<List<VocabolarioModel>> VocabolarioGetAll()
        {
            string source = "DB";
            Stopwatch sw = new Stopwatch();
            sw.Start();
            List<VocabolarioModel>? result = new List<VocabolarioModel>();
            // cerco in _redisConn...
            string currKey = $"{redisBaseKey}:Voc";
            RedisValue rawData = await _redisDb.StringGetAsync(currKey);
            //if (!string.IsNullOrEmpty($"{rawData}"))
            if (rawData.HasValue)
            {
                result = JsonConvert.DeserializeObject<List<VocabolarioModel>>($"{rawData}");
                source = "REDIS";
            }
            else
            {
                result = dbController.VocabolarioGetAll();
                // serializzo e salvo...
                rawData = JsonConvert.SerializeObject(result);
                _redisDb.StringSet(currKey, rawData, UltraLongCache);
            }
            if (result == null)
            {
                result = new List<VocabolarioModel>();
            }
            sw.Stop();
            Log.Debug($"VocabolarioGetAll | {source} | {sw.Elapsed.TotalMilliseconds}ms");
            return result;
        }

        #endregion Public Methods

        #region Protected Fields

        /// <summary>
        /// Vocabolario x recupero rapido traduzioni
        /// </summary>
        protected static Dictionary<string, string> DictVocab = new Dictionary<string, string>();

        #endregion Protected Fields

        #region Protected Methods

        protected override void Dispose(bool disposing)
        {
            if (!_disposed)
            {
                if (disposing)
                {
                    // Free managed resources here
                    DictVocab.Clear();
                    dbController.Dispose();
                }

                // Free unmanaged resources here
                _disposed = true;
            }

            // Call base class implementation.
            base.Dispose(disposing);
        }

        #endregion Protected Methods

        #region Private Fields

        private static Logger Log = LogManager.GetCurrentClassLogger();
        private bool _disposed = false;
        private string redisBaseKey = "MP:Voc:Cache";

        #endregion Private Fields

        #region Private Methods

        /// <summary>
        /// Inizializzazione dict vari
        /// </summary>
        private static void InitDict()
        {
            // inizializzo dizionario vocabolario
            var rawData = dbController.VocabolarioGetAll();
            DictVocab = rawData.ToDictionary(kvp => $"{kvp.Lingua}_{kvp.Lemma}".ToUpper(), kvp => kvp.Traduzione);
        }

        /// <summary>
        /// Esegue flush memoria _redisConn dato pat2Flush
        /// </summary>
        /// <param name="pat2Flush"></param>
        /// <returns></returns>
        private async Task<bool> ExecFlushRedisPattern(RedisValue pat2Flush)
        {
            bool answ = false;
            var masterEndpoint = _redisConn.GetEndPoints()
                                          .Where(ep => _redisConn.GetServer(ep).IsConnected && !_redisConn.GetServer(ep).IsReplica)
                                          .FirstOrDefault();

            // sepattern è "*" elimino intero DB...
            if (masterEndpoint != null && (pat2Flush.Equals(new RedisValue("*")) || pat2Flush == RedisValue.Null))
            {
                _redisConn.GetServer(masterEndpoint).FlushDatabase(database: _redisDb.Database);
            }
            else
            {
                var server = _redisConn.GetServer(masterEndpoint);
                var keys = server.Keys(database: _redisDb.Database, pattern: pat2Flush, pageSize: 1000);

                var deleteTasks = new List<Task>();
                foreach (var key in keys)
                {
                    deleteTasks.Add(_redisDb.KeyDeleteAsync(key));
                    if (deleteTasks.Count >= 1000)
                    {
                        await Task.WhenAll(deleteTasks);
                        deleteTasks.Clear();
                    }
                }
                if (deleteTasks.Count > 0)
                {
                    await Task.WhenAll(deleteTasks);
                }
            }
            answ = true;
#if false
            var listEndpoints = redisConn.GetEndPoints();
            foreach (var endPoint in listEndpoints)
            {
                //var server = redisConnAdmin.GetServer(listEndpoints[0]);
                var server = redisConn.GetServer(endPoint);
                if (server != null)
                {
                    var keyList = server.Keys(redisDb.Database, pattern);
                    foreach (var item in keyList)
                    {
                        await redisDb.KeyDeleteAsync(item);
                    }
                    answ = true;
                }
            } 
#endif

            return answ;
        }

        #endregion Private Methods
    }
}