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

namespace MP.Data.Services
{
    /// <summary>
    /// Classe accesso dati filtrati per operatore
    /// </summary>
    public class ListSelectDataSrv : BaseServ
    {
        #region Public Constructors

        public ListSelectDataSrv(IConfiguration configuration, IConnectionMultiplexer redConn) : base(configuration, redConn)
        {
            // conf DB
            string connStr = _configuration.GetConnectionString("MP.All");
            if (string.IsNullOrEmpty(connStr))
            {
                Log.Error("ConnString empty!");
            }
            else
            {
                StringBuilder sb = new StringBuilder();
                dbController = new Controllers.MpSpecController(configuration);
                sb.AppendLine($"ListSelectDataSrv | MpSpecController OK");
                Log.Info(sb.ToString());
            }
        }

        #endregion Public Constructors

        #region Public Properties

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

        #endregion Public Properties

        #region Public Methods

        /// <summary>
        /// Elenco tabella Articoli da filtro
        /// </summary>
        /// <param name="numRecord">Numero record max da recuperare</param>
        /// <param name="azienda">cod azienda, * = tutte</param>
        /// <param name="searchVal">Ricerca testuale</param>
        /// <returns></returns>
        public async Task<List<AnagArticoliModel>> ArticoliGetSearch(int numRecord, string azienda, string searchVal)
        {
            string source = "DB";
            Stopwatch sw = new Stopwatch();
            sw.Start();
            List<AnagArticoliModel>? result = new List<AnagArticoliModel>();
            // cerco in _redisConn...
            string currKey = $"{redisBaseKey}:Art:{azienda}:{searchVal}:{numRecord}";
            RedisValue rawData = await _redisDb.StringGetAsync(currKey);
            if (rawData.HasValue)
            {
                result = JsonConvert.DeserializeObject<List<AnagArticoliModel>>($"{rawData}");
                source = "REDIS";
            }
            else
            {
                result = dbController.ArticoliGetSearch(numRecord, azienda, searchVal);
#if false
                result = await Task.FromResult(dbController.ArticoliGetSearch(numRecord, azienda, searchVal));
#endif
                // serializzp e salvo...
                rawData = JsonConvert.SerializeObject(result);
                await _redisDb.StringSetAsync(currKey, rawData, LongCache);
            }
            if (result == null)
            {
                result = new List<AnagArticoliModel>();
            }
            sw.Stop();
            Log.Debug($"ArticoliGetSearch | azienda: {azienda} | searchVal: {searchVal} | numRecord: {numRecord} | {source} | {sw.Elapsed.TotalMilliseconds}ms");
            return result;
        }

        /// <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 = $"{redisBaseKey}:Conf";
            RedisValue rawData = await _redisDb.StringGetAsync(currKey);
            if (rawData.HasValue)
            {
                result = JsonConvert.DeserializeObject<List<ConfigModel>>($"{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);
            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>
        /// Elenco link JQM (totale)
        /// </summary>
        /// <returns></returns>
        public async Task<List<LinkMenuModel>> ListLinkAll()
        {
            string source = "DB";
            Stopwatch sw = new Stopwatch();
            sw.Start();
            List<LinkMenuModel>? result = new List<LinkMenuModel>();
            // cerco in _redisConn...
            string currKey = $"{redisBaseKey}:Menu:ALL";
            RedisValue rawData = await _redisDb.StringGetAsync(currKey);
            if (rawData.HasValue)
            {
                result = JsonConvert.DeserializeObject<List<LinkMenuModel>>($"{rawData}");
                source = "REDIS";
            }
            else
            {
                result = await Task.FromResult(dbController.ListLinkAll());
                // serializzp e salvo...
                rawData = JsonConvert.SerializeObject(result);
                await _redisDb.StringSetAsync(currKey, rawData, UltraLongCache);
            }
            if (result == null)
            {
                result = new List<LinkMenuModel>();
            }
            sw.Stop();
            Log.Debug($"ListLinkAll | tipoLink: * | {source} | {sw.Elapsed.TotalMilliseconds}ms");
            return result;
        }

        /// <summary>
        /// Elenco link JQM dato filtro tipo
        /// </summary>
        /// <param name="tipoLink"></param>
        /// <returns></returns>
        public async Task<List<LinkMenuModel>> ListLinkFilt(string tipoLink)
        {
            string source = "DB";
            Stopwatch sw = new Stopwatch();
            sw.Start();
            List<LinkMenuModel>? result = new List<LinkMenuModel>();
            // cerco in _redisConn...
            string currKey = $"{redisBaseKey}:Menu:{tipoLink}";
            RedisValue rawData = await _redisDb.StringGetAsync(currKey);
            //if (!string.IsNullOrEmpty($"{rawData}"))
            if (rawData.HasValue)
            {
                result = JsonConvert.DeserializeObject<List<LinkMenuModel>>($"{rawData}");
                source = "REDIS";
            }
            else
            {
                result = await Task.FromResult(dbController.ListLinkFilt(tipoLink));
                // serializzp e salvo...
                rawData = JsonConvert.SerializeObject(result);
                await _redisDb.StringSetAsync(currKey, rawData, UltraLongCache);
            }
            if (result == null)
            {
                result = new List<LinkMenuModel>();
            }
            sw.Stop();
            Log.Debug($"ListLinkFilt | tipoLink: {tipoLink} | {source} | {sw.Elapsed.TotalMilliseconds}ms");
            return result;
        }

        /// <summary>
        /// Elenco Macchine dato operatore secondo gruppi (macchine/operatore)
        /// </summary>
        /// <param name="MatrOpr"></param>
        /// <returns></returns>
        public async Task<List<MacchineModel>> MacchineByMatrOper(int MatrOpr)
        {
            string source = "DB";
            Stopwatch sw = new Stopwatch();
            sw.Start();
            List<MacchineModel>? result = new List<MacchineModel>();
            // cerco in _redisConn...
            string currKey = $"{redisBaseKey}:Macc:{MatrOpr}";
            RedisValue rawData = await _redisDb.StringGetAsync(currKey);
            //if (!string.IsNullOrEmpty($"{rawData}"))
            if (rawData.HasValue)
            {
                result = JsonConvert.DeserializeObject<List<MacchineModel>>($"{rawData}");
                source = "REDIS";
            }
            else
            {
                result = await Task.FromResult(dbController.MacchineByMatrOper(MatrOpr));
                // serializzp e salvo...
                rawData = JsonConvert.SerializeObject(result);
                await _redisDb.StringSetAsync(currKey, rawData, UltraLongCache);
            }
            if (result == null)
            {
                result = new List<MacchineModel>();
            }
            sw.Stop();
            Log.Debug($"MacchineGetFilt | MatrOpr: {MatrOpr} | {source} | {sw.Elapsed.TotalMilliseconds}ms");
            return result;
        }

        #endregion Public Methods

        #region Protected Methods

        protected override void Dispose(bool disposing)
        {
            if (!_disposed)
            {
                if (disposing)
                {
                    // Free managed resources here
                    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:ALL:Cache";

        #endregion Private Fields

        #region Private Methods

        /// <summary>
        /// Esegue flush memoria _redisConn dato pattern
        /// </summary>
        /// <param name="pattern"></param>
        /// <returns></returns>
        private async Task<bool> ExecFlushRedisPattern(RedisValue pattern)
        {
            Log.Debug($"Richiesta flush pattern: {pattern}");

            // 1. Target ONLY master (le replica sono in read-only)
            var master = _redisConn.GetEndPoints()
                                        .Where(ep => _redisConn.GetServer(ep).IsConnected && !_redisConn.GetServer(ep).IsReplica)
                                        .FirstOrDefault();

            if (master == null)
            {
                Log.Warn($"Nessun master Redis raggiungibile per il pattern {pattern}");
                return false;
            }

            // 2. Flush intero DB se richiesto
            if (pattern.ToString() == "*")
            {
                Log.Debug($"Full DB reset da pattern {pattern}");
                if (master != null)
                {
                    _redisConn.GetServer(master).FlushDatabase(_redisDb.Database);
                    Log.Info($"Flush database {_redisDb.Database} completato");
                }
                return true;
            }
            // altrimenti faccio ciclo!
            var server = _redisConn.GetServer(master);
            var db = _redisConn.GetDatabase(_redisDb.Database);
            const int batchSize = 500;
            var batch = new List<RedisKey>(batchSize);
            int deletedCount = 0;

            try
            {
                // KeysAsync usa SCAN automaticamente quando i risultati sono grandi
                await foreach (var key in server.KeysAsync(
                    database: _redisDb.Database,
                    pattern: pattern.ToString(),
                    pageSize: batchSize))
                {
                    batch.Add(key);
                    if (batch.Count >= batchSize)
                    {
                        // Esecuzione batch in parallelo controllato
                        await Task.WhenAll(batch.Select(k => db.KeyDeleteAsync(k)));
                        batch.Clear();
                        deletedCount += batchSize;
                    }
                }

                // Restanti
                if (batch.Count > 0)
                {
                    await Task.WhenAll(batch.Select(k => db.KeyDeleteAsync(k)));
                    deletedCount += batch.Count;
                }

                Log.Info("Flush pattern {Pattern}: eliminate {Count} chiavi", pattern, deletedCount);
                return true;
            }
            catch (RedisConnectionException ex)
            {
                Log.Error(ex, "Connessione Redis persa durante il flush di {pattern}", pattern);
                return false;
            }
            catch (Exception ex)
            {
                Log.Error(ex, "Errore imprevisto nel flush pattern {pattern}", pattern);
                throw;
            }
#if false
            bool answ = false;
            var masterEndpoint = _redisConn.GetEndPoints()
                                            .Where(ep => _redisConn.GetServer(ep).IsConnected && !_redisConn.GetServer(ep).IsReplica)
                                            .FirstOrDefault();

            // se pattern 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;
            }
            return answ; 
#endif
        }

        #endregion Private Methods
    }
}