using Microsoft.Extensions.Configuration;
using MP.Core.Objects;
using Newtonsoft.Json;
using NLog;
using StackExchange.Redis;
using System;
using System.Collections.Generic;
using System.Diagnostics;
using System.Linq;
using System.Runtime.CompilerServices;
using System.Threading.Tasks;

namespace MP.Data.Services
{
    /// <summary>
    /// Classe di partenza x costruzione servizi di accesso dati + cache
    /// </summary>
    public class BaseServ : IDisposable
    {
        #region Public Constructors

        public BaseServ(IConfiguration configuration, IConnectionMultiplexer redConn)
        {
            _configuration = configuration;

            // Verifica conf trace...
            _traceEnabled = _configuration.GetValue<bool>("Otel:EnableTracing", false);

            // setup componenti REDIS
            _redisConn = redConn;
            _redisDb = _redisConn.GetDatabase();

            // 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
            };

            // recupero conf speciali
            MpIoNS = _configuration.GetValue<string>("ServerConf:MpIoNS");
        }

        #endregion Public Constructors

        #region Public Methods

        public void Dispose()
        {
            Dispose(true);
            GC.SuppressFinalize(this);
        }

        /// <summary>
        /// Recupero info IOB x TAB (da info registrate IOB-WIN--&gt; MP-IO)
        /// </summary>
        /// <param name="IdxMacchina"></param>
        /// <returns></returns>
        public IOB_data IobInfo(string IdxMacchina)
        {
            string source = "DB";
            Stopwatch sw = new Stopwatch();
            sw.Start();
            IOB_data? result = new IOB_data();
            // cerco in _redisConn...
            string currKey = RedHashMpIO($"hM2IOB:{IdxMacchina}");
            RedisValue rawData = _redisDb.StringGet(currKey);
            //if (!string.IsNullOrEmpty($"{rawData}"))
            if (rawData.HasValue)
            {
                result = JsonConvert.DeserializeObject<IOB_data>($"{rawData}");
                source = "REDIS";
            }
            else
            {
                Log.Error($"Errore: non trovato valore <IOB_data> valido in REDIS | key: {currKey}");
                Log.Info($"REDIS | conf: {_redisConn.Configuration}");
                Log.Info($"  --> Valore trovato:{Environment.NewLine}{rawData}");
            }
            if (result == null)
            {
                result = new IOB_data();
                Log.Debug($"Init valore default <IOB_data> | IdxMacchina: {IdxMacchina}");
            }
            sw.Stop();
            Log.Debug($"IobInfo per {IdxMacchina} | {source} | {sw.Elapsed.TotalMilliseconds}ms");
            return result;
        }

        /// <summary>
        /// Recupero info Machine-IOB x TAB (da info registrate IOB-WIN --&gt; MP-IO)
        /// </summary>
        /// <param name="IdxMacchina"></param>
        /// <returns></returns>
        public Dictionary<string, string> MachIobConf(string IdxMacchina)
        {
            string source = "NA";
            Stopwatch sw = new Stopwatch();
            sw.Start();
            Dictionary<string, string> result = new Dictionary<string, string>();
            // cerco in _redisConn...
            string currKey = RedHashMpIO($"IOB:{IdxMacchina}:MachIobConf");
            try
            {
                result = _redisDb
                            .HashGetAll(currKey)
                            .ToDictionary(x => $"{x.Name}", x => $"{x.Value}");
                source = "REDIS";
            }
            catch (Exception exc)
            {
                Log.Error($"Errore in MachIobConf{Environment.NewLine}{exc}");
            }
            if (result == null)
            {
                result = new Dictionary<string, string>();
                Log.Debug($"Init valore default MachIobConf | IdxMacchina: {IdxMacchina}");
            }
            sw.Stop();
            Log.Debug($"MachIobConf per {IdxMacchina} | {source} | {sw.Elapsed.TotalMilliseconds}ms");
            return result;
        }

        /// <summary>
        /// Recupero Conf Yaml Machine-IOB
        /// </summary>
        /// <param name="IdxMacchina"></param>
        /// <returns></returns>
        public string MachIobYamlConf(string IdxMacchina)
        {
            string source = "NA";
            Stopwatch sw = new Stopwatch();
            sw.Start();
            string result = "";
            // cerco in _redisConn...
            string currKey = RedHashMpIO($"IOB:{IdxMacchina}:ConfYaml");
            try
            {
                result = _redisDb.StringGet(currKey);
                source = "REDIS";
            }
            catch (Exception exc)
            {
                Log.Error($"Errore in MachIobYamlConf{Environment.NewLine}{exc}");
            }
            if (result == null)
            {
                result = "";
                Log.Debug($"Init valore default MachIobYamlConf | IdxMacchina: {IdxMacchina}");
            }
            sw.Stop();
            Log.Debug($"MachIobYamlConf per {IdxMacchina} | {source} | {sw.Elapsed.TotalMilliseconds}ms");
            return result;
        }

        #endregion Public Methods

        #region Protected Fields

        /// <summary>
        /// Oggetto per collezione dati Activity (span in Uptrace)
        /// </summary>
        protected static readonly ActivitySource ActivitySource = new ActivitySource("MP.IOC");

        protected static IConfiguration _configuration = null!;

        /// <summary>
        /// Abilitazione operazioni tracing generiche
        /// </summary>
        protected readonly bool _traceEnabled = false;

        /// <summary>
        /// Oggetto per connessione a REDIS
        /// </summary>
        protected IConnectionMultiplexer _redisConn = null!;

        //ISubscriber sub = _redisConn.GetSubscriber();
        /// <summary>
        /// Oggetto DB redis da impiegare x chiamate R/W
        /// </summary>
        protected IDatabase _redisDb = null!;

        protected JsonSerializerSettings? JSSettings;
        protected string MpIoNS = "";

        #endregion Protected Fields

        #region Protected Properties

        /// <summary>
        /// Durata cache breve (1 min circa + perturbazione percentuale +/-10%)
        /// </summary>
        protected TimeSpan FastCache
        {
            get => TimeSpan.FromSeconds(cacheTtlShort * rnd.Next(900, 1100) / 1000);
        }

        /// <summary>
        /// Durata cache lunga (+ perturbazione percentuale +/-10%)
        /// </summary>
        protected TimeSpan LongCache
        {
            get => TimeSpan.FromSeconds(cacheTtlLong * rnd.Next(900, 1100) / 1000);
        }

        /// <summary>
        /// Durata cache MOLTO breve (10 sec circa + perturbazione percentuale +/-10%)
        /// </summary>
        protected TimeSpan UltraFastCache
        {
            get => TimeSpan.FromSeconds(cacheTtlShort / 6 * rnd.Next(900, 1100) / 1000);
        }

        /// <summary>
        /// Durata cache MOLTO lunga (+ perturbazione percentuale +/-10%)
        /// </summary>
        protected TimeSpan UltraLongCache
        {
            get => TimeSpan.FromSeconds(cacheTtlLong * 10 * rnd.Next(900, 1100) / 1000);
        }

        #endregion Protected Properties

        #region Protected Methods

        /// <summary>
        /// Helper avvio attività per la funzione tracciata
        /// </summary>
        /// <param name="methodName"></param>
        /// <returns></returns>
        protected static Activity? StartActivity([CallerMemberName] string? methodName = null)
        {
            var activity = ActivitySource.StartActivity(methodName ?? "UNDEF");
            activity?.SetTag("host.name", Environment.MachineName);
            return activity;
        }

        /// <summary>
        /// Invalida una o più chiavi/pattern in Redis
        /// </summary>
        protected async Task ClearCacheAsync(params string[] patterns)
        {
            foreach (var pattern in patterns)
            {
                // Chiamata al tuo metodo esistente
                await ExecFlushRedisPatternAsync((RedisValue)pattern);
            }
        }

        protected virtual void Dispose(bool disposing)
        {
            if (!_disposed)
            {
                if (disposing)
                {
                    // Free managed resources here
                    _redisDb = null;
                }

                // Free unmanaged resources here
                _disposed = true;
            }
        }

        /// <summary>
        /// Metodo di flush dati cache Redis
        /// </summary>
        /// <param name="pattern"></param>
        /// <returns></returns>
        protected async Task ExecFlushRedisPatternAsync(RedisValue pattern)
        {
            // Qui inserisci la tua logica attuale (es. via Lua script o Keys/Scan)
            // Esempio rapido via server scan:
            var endpoints = _redisConn.GetEndPoints();
            foreach (var endpoint in endpoints)
            {
                var server = _redisConn.GetServer(endpoint);
                await foreach (var key in server.KeysAsync(_redisDb.Database, pattern))
                {
                    await _redisDb.KeyDeleteAsync(key);
                }
            }
        }

        /// <summary>
        /// Helper generale di lettura da cache o da funzione (DB) con caching successivo
        /// </summary>
        /// <typeparam name="T"></typeparam>
        /// <param name="key"></param>
        /// <param name="factory"></param>
        /// <param name="expiration"></param>
        /// <returns></returns>
        protected async Task<T> GetOrSetCacheAsync<T>(string key, Func<Task<T>> factory, TimeSpan? expiration = null, [CallerMemberName] string? caller = null)
        {
            using var activity = StartActivity();
            string source = "DB";

            // 1. Provo Redis
            var cached = await _redisDb.StringGetAsync(key);
            if (cached.HasValue)
            {
                source = "REDIS";
                var cachedResult = JsonConvert.DeserializeObject<T>(cached!)!;

                activity?.SetTag("data.source", source);
                LogTrace($"{source} | trace: {activity?.TraceId} | {activity?.Duration.TotalMilliseconds}ms", NLog.LogLevel.Trace, caller);

                return cachedResult;
            }

            // 2. Chiamo il factory (DB)
            T result = await factory();

            if (result != null)
            {
                // 3. Salva in Redis per la prossima volta
                var serialized = JsonConvert.SerializeObject(result, JSSettings);
                await _redisDb.StringSetAsync(key, serialized, expiration ?? LongCache);
            }

            // sistemo activity tracking data
            activity?.SetTag("data.source", source);
            activity?.Stop();

            // log in console
            LogTrace($"GetOrSetCacheAsync | {source} | trace: {activity?.TraceId} | {activity?.Duration.TotalMilliseconds:N3}ms", NLog.LogLevel.Trace, caller);

            return result!;
        }

        /// <summary>
        /// Helper trace messaggio log (SE abilitato)
        /// </summary>
        /// <param name="traceMsg"></param>
        /// <param name="reqLevel"></param>
        /// <param name="methodName"></param>
        protected void LogTrace(string traceMsg, NLog.LogLevel? reqLevel = null, [CallerMemberName] string? methodName = null)
        {
            if (!_traceEnabled)
                return;

            reqLevel ??= NLog.LogLevel.Debug;

            // Loggo!
            Log.Log(reqLevel, $"{methodName} | {traceMsg}");
        }

        protected string RedHashMpIO(string keyName)
        {
            string result = keyName;
            try
            {
                result = $"{MpIoNS}:{keyName}".Replace("\\", "_");
            }
            catch (Exception exc)
            {
                Log.Error($"Errore in RedHashMpIO{Environment.NewLine}{exc}");
            }

            return result;
        }

        /// <summary>
        /// Helper generale per la telemetria e gestione eccezioni
        /// </summary>
        /// <typeparam name="T"></typeparam>
        /// <param name="name"></param>
        /// <param name="body"></param>
        /// <param name="parameters"></param>
        /// <returns></returns>
        protected async Task<T> TraceAsync<T>(string name, Func<Activity?, Task<T>> body, object? parameters = null)
        {
            using var activity = ActivitySource.StartActivity(name);
            try
            {
                if (parameters != null)
                {
                    activity?.SetTag("params", JsonConvert.SerializeObject(parameters));
                }
                var result = await body(activity);
                activity?.SetStatus(ActivityStatusCode.Ok);
                activity?.Stop();
                LogTrace($"TraceAsync | trace: {activity?.TraceId} | {activity?.Duration.TotalMilliseconds}ms", methodName: name);
                return result;
            }
            catch (Exception ex)
            {
                activity?.SetStatus(ActivityStatusCode.Error, ex.Message);
                //Log.Error(ex, "Errore in {MethodName}", name);
                LogTrace($"Errore in {name}", NLog.LogLevel.Error, name);
                throw; // Riesponi l'eccezione per il tracking globale
            }
        }

        #endregion Protected Methods

        #region Private Fields

        private static Logger Log = LogManager.GetCurrentClassLogger();
        private bool _disposed = false;

        /// <summary>
        /// Durata cache lunga IN SECONDI
        /// </summary>
        private int cacheTtlLong = 60 * 5;

        /// <summary>
        /// Durata cache breve IN SECONDI
        /// </summary>
        private int cacheTtlShort = 60 * 1;

        private Random rnd = new Random();

        /// <summary>
        /// Path base chiavi REDIS
        /// </summary>
        protected readonly string _redisBaseKey = "MP:IOC";

        #endregion Private Fields
    }
}