using Egw.Core;
using Microsoft.Extensions.Caching.Distributed;
using Microsoft.Extensions.Configuration;
using Microsoft.Extensions.Logging;
using MP.AppAuth.Models;
using Newtonsoft.Json;
using RestSharp;
using StackExchange.Redis;
using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;
using System.Threading.Tasks;
using System.Web;

#nullable enable

namespace MP.Land.Data
{
    /// <summary>
    /// Servizi e dati condivisi a livello applicazione
    /// </summary>
    public class LicenseService
    {
        #region Public Constructors

        /// <summary>
        /// Init classe
        /// </summary>
        /// <param name="configuration"></param>
        /// <param name="logger"></param>
        /// <param name="redisConnMult"></param>
        public LicenseService(IConfiguration configuration, ILogger<LicenseService> logger, IConnectionMultiplexer redisConnMult)
        {
            _logger = logger;
            _configuration = configuration;
            // Conf cache
            redisConn = redisConnMult;
            redisDb = this.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
            };
        }

        #endregion Public Constructors

        #region Public Events

        public event Action EA_InfoUpdated = null!;

        #endregion Public Events

        #region Public Properties

        public List<LiManObj.AttivazioneDTO> ActivList { get; set; } = new List<LiManObj.AttivazioneDTO>();
        public List<AnagKeyValueModel> AKVList { get; set; } = new List<AnagKeyValueModel>();
        public string Applicazione { get; set; } = "";

        public bool HasActivData
        {
            get
            {
                bool answ = ValidData;
                // se ok controllo che ci siano attivazioni
                if (answ)
                {
                    // provo classe locale...
                    answ = ActivList != null && ActivList.Count > 0;
                    // se non le avessi carico!
                    if (!answ)
                    {
                        var pUpd = Task.Run(async () =>
                        {
                            ActivList = await ActivListCache();
                        });
                        pUpd.Wait();
                    }
                }
                return answ;
            }
        }

        public DateTime infoExpiry { get; set; } = DateTime.Today.AddDays(1);

        /// <summary>
        /// Codice cliente/installazione
        /// </summary>
        public string Installazione { get; set; } = "";

        /// <summary>
        /// Master key licenza principale
        /// </summary>
        public string MasterKey { get; set; } = "";

        /// <summary>
        /// Numero licenze da DB
        /// </summary>
        public int NumLicDb { get; set; } = -1;

        /// <summary>
        /// Numero licenze da auth remota
        /// </summary>
        public int NumLicRemote { get; set; } = -1;

        public bool ValidData
        {
            get
            {
                // controllo valori string base
                bool checkData = !string.IsNullOrEmpty(Installazione) && !string.IsNullOrEmpty(Applicazione) && !string.IsNullOrEmpty(MasterKey) && ActivList != null && ActivList.Count > 0;
                return checkData;
            }
        }

        #endregion Public Properties

        #region Public Methods

        public async Task<List<LiManObj.AttivazioneDTO>> ActivListCache()
        {
            List<LiManObj.AttivazioneDTO> dbResult = new List<LiManObj.AttivazioneDTO>();
            string cacheKey = $"{rKeyAttByLic}:{MasterKey}";
            string rawData = await getRSV(cacheKey);
            if (!string.IsNullOrEmpty(rawData))
            {
                var cacheRes = JsonConvert.DeserializeObject<List<LiManObj.AttivazioneDTO>?>(rawData);
                if (cacheRes != null)
                {
                    dbResult = cacheRes;
                }
            }

            return await Task.FromResult(dbResult);
        }

        /// <summary>
        /// Verifica attivazione licenza
        /// </summary>
        /// <param name="authKey"></param>
        /// <returns></returns>
        public bool checkLicenseActive(string authKey)
        {
            bool answ = false;
            //cerco anche nelle info AKV
            if (AKVList != null)
            {
                var recLic = AKVList.Where(x => x.ValString == authKey).FirstOrDefault();
                int numLic = 0;
                //cerco in record
                if (recLic != null && recLic.ValInt != null)
                {
                    numLic = (int)recLic.ValInt;
                    // verifico scadenza licenza!
                    DateTime scadenza = licenseManGLS.expiryDateByAuthKey(Installazione, recLic.NomeVar, numLic, authKey);
                    answ = scadenza > DateTime.Today;
                }
                else
                {
                    _logger.LogInformation($"checkLicenseActive | Record non trovato per {authKey}");
                }
            }
            return answ;
        }

        /// <summary>
        /// Stato server gestione licenze
        /// </summary>
        public async Task<string> checkLimanServer()
        {
            string answ = "ND";
            // cerco online
            RestClient client = new RestClient(apiUrl);
            var request = new RestRequest($"api/health", Method.Get);
            var response = await client.GetAsync(request);
            // controllo risposta
            if (response.StatusCode == System.Net.HttpStatusCode.OK)
            {
                // verifico risposta
                if (response.Content != null)
                {
                    answ = response.Content.Replace("\"", "");
                }
            }
            return await Task.FromResult(answ);
        }

        /// <summary>
        /// Verifica scadenza licenza
        /// </summary>
        /// <param name="authKey"></param>
        /// <returns></returns>
        public DateTime getLicenseExpiry(string authKey)
        {
            DateTime answ = DateTime.Today.AddDays(-1);
            //cerco anche nelle info AKV
            if (AKVList != null)
            {
                var recLic = AKVList.Where(x => x.ValString == authKey).FirstOrDefault();
                int numLic = 0;
                //cerco in record
                if (recLic != null && recLic.ValInt != null)
                {
                    numLic = (int)recLic.ValInt;
                    // verifico scadenza licenza!
                    DateTime scadenza = licenseManGLS.expiryDateByAuthKey(Installazione, recLic.NomeVar, numLic, authKey);
                    answ = scadenza;
                }
                else
                {
                    _logger.LogInformation($"getLicenseExpiry | Record non trovato per {authKey}");
                }
            }
            return answ;
        }

        /// <summary>
        /// Init della classe con variabili di base da Redis/DB
        /// </summary>
        public bool InitAkv()
        {
            bool fatto = false;
            Applicazione = "MAPO";
            Installazione = getAVKStr("Installazione");
            MasterKey = getAVKStr(Applicazione);
            NumLicDb = getAVKInt(Applicazione);
            fatto = !string.IsNullOrEmpty($"{Installazione}{MasterKey}");
            return fatto;
        }

        public async Task<List<LiManObj.ApplicativoDTO>> LicAppCache()
        {
            List<LiManObj.ApplicativoDTO> dbResult = new List<LiManObj.ApplicativoDTO>();
            string cacheKey = $"{rkeyAppInfo}:{MasterKey}";
            string rawData = await getRSV(cacheKey);
            if (!string.IsNullOrEmpty(rawData))
            {
                var cacheRes = JsonConvert.DeserializeObject<List<LiManObj.ApplicativoDTO>?>(rawData);
                if (cacheRes != null)
                {
                    dbResult = cacheRes;
                }
            }

            return await Task.FromResult(dbResult);
        }

        /// <summary>
        /// Init della classe con variabili di base da Redis/DB
        /// </summary>
        public async Task<bool> RefreshLicense()
        {
            bool fatto = false;
            // scadenza info a 15 gg...
            int numDays = 15;

            // dati applicativo
            var appData = await OnlineAppInfo();
            if (appData != null)
            {
                if (appData.Count > 0)
                {
                    fatto = await setAppInfo(appData, numDays);
                    // salvo info licenza...
                    NumLicRemote = appData[0].NumLicenze;
                }
            }

            // dati attivazioni
            var onlineAct = await OnlineActivationList();
            if (onlineAct != null)
            {
                if (onlineAct.Count > 0)
                {
                    infoExpiry = DateTime.Now.AddDays(numDays);
                    ActivList = onlineAct;
                    fatto = await setActivList(onlineAct, numDays);
                }
            }
            await Task.Delay(1);
            return fatto;
        }

        public async Task<bool> setActivList(List<LiManObj.AttivazioneDTO> newActList, int numDays)
        {
            bool fatto = false;
            string cacheKey = $"{rKeyAttByLic}:{MasterKey}";
            var rawData = JsonConvert.SerializeObject(newActList);
            TimeSpan cacheTs = TimeSpan.FromDays(numDays);
            await setRSV(cacheKey, rawData, cacheTs);
            fatto = true;
            if (EA_InfoUpdated != null)
            {
                EA_InfoUpdated?.Invoke();
            }
            return fatto;
        }

        public async Task<bool> setAppInfo(List<LiManObj.ApplicativoDTO> newAppInfo, int numDays)
        {
            bool fatto = false;
            string cacheKey = $"{rkeyAppInfo}:{MasterKey}";
            var rawData = JsonConvert.SerializeObject(newAppInfo);
            TimeSpan cacheTs = TimeSpan.FromDays(numDays);
            await setRSV(cacheKey, rawData, cacheTs);
            fatto = true;
            if (EA_InfoUpdated != null)
            {
                EA_InfoUpdated?.Invoke();
            }
            return fatto;
        }

        #endregion Public Methods

        #region Protected Fields

        /// <summary>
        /// Chiave redis x attivazioni della licenza
        /// </summary>
        protected const string rKeyAttByLic = "LongCache:AttByLic";

        #endregion Protected Fields

        #region Protected Methods

        /// <summary>
        /// Cerca di recuperare valore INT da elenco AKV
        /// </summary>
        /// <param name="varReq">Chiave AKV richiesta</param>
        /// <returns></returns>
        protected int getAVKInt(string varReq)
        {
            int answ = -9999;
            if (AKVList != null && AKVList.Count > 0)
            {
                var currRec = AKVList.Where(x => x.NomeVar == varReq).FirstOrDefault();
                if (currRec != null)
                {
                    answ = currRec.ValInt ?? 0;
                }
            }
            return answ;
        }

        /// <summary>
        /// Cerca di recuperare valore string da elenco AKV
        /// </summary>
        /// <param name="varReq">Chiave AKV richiesta</param>
        /// <returns></returns>
        protected string getAVKStr(string varReq)
        {
            string answ = "";
            if (AKVList != null && AKVList.Count > 0)
            {
                var currRec = AKVList.Where(x => x.NomeVar == varReq).FirstOrDefault();
                if (currRec != null)
                {
                    answ = $"{currRec.ValString}";
                }
            }
            return answ;
        }

        /// <summary>
        /// Recupero chiave da redis
        /// </summary>
        /// <param name="rKey"></param>
        /// <returns></returns>
        protected async Task<string> getRSV(string rKey)
        {
            var rawData = await redisDb.StringGetAsync(rKey);
            string answ = rawData.HasValue ? $"{rawData}" : "";
            return answ;
        }

        /// <summary>
        /// Salvataggio chiave in redis
        /// </summary>
        /// <param name="rKey"></param>
        /// <param name="rVal"></param>
        /// <param name="cacheTS"></param>
        /// <returns></returns>
        protected async Task<bool> setRSV(string rKey, string rVal, TimeSpan cacheTS)
        {
            bool fatto = await redisDb.StringSetAsync(rKey, rVal, cacheTS);
            return fatto;
        }

        /// <summary>
        /// Salvataggio chiave in redis
        /// </summary>
        /// <param name="rKey"></param>
        /// <param name="rValInt"></param>
        /// <param name="cacheTS"></param>
        /// <returns></returns>
        protected async Task<bool> setRSV(string rKey, int rValInt, TimeSpan cacheTS)
        {
            bool fatto = await setRSV(rkeyAppInfo, $"{rValInt}", cacheTS);
            return fatto;
        }

        #endregion Protected Methods

        #region Private Fields

        private static IConfiguration? _configuration;

        /// <summary>
        /// URL dell'API x chiamate gestione licenze
        /// </summary>
        private static string apiUrl = "https://liman.egalware.com/ELM.API/";

        private static JsonSerializerSettings? JSSettings;

        /// <summary>
        /// Chiave redis x info della licenza
        /// </summary>
        private static string rkeyAppInfo = "LongCache:AppInfo";

        /// <summary>
        /// Oggetto per connessione a REDIS
        /// </summary>
        private IConnectionMultiplexer redisConn;

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

        private Random rnd = new Random();

        #endregion Private Fields

        #region Private Properties

        private static ILogger<LicenseService> _logger { get; set; } = null!;

        #endregion Private Properties

        #region Private Methods

        /// <summary>
        /// Elenco attivazioni attuali
        /// </summary>
        private async Task<List<LiManObj.AttivazioneDTO>?> OnlineActivationList()
        {
            List<LiManObj.AttivazioneDTO>? answ = new List<LiManObj.AttivazioneDTO>();
            // cerco online
            RestClient client = new RestClient(apiUrl);
            //client.Authenticator = new HttpBasicAuthenticator("username", "password");
            string MKeyEnc = HttpUtility.UrlEncode(MasterKey);
            var request = new RestRequest($"api/attivazioni/?chiave={MKeyEnc}", Method.Get);
            var response = await client.GetAsync(request);
            // controllo risposta
            if (response.StatusCode == System.Net.HttpStatusCode.OK)
            {
                // salvo in redis contenuto serializzato
                string rawData = $"{response.Content}";
                answ = JsonConvert.DeserializeObject<List<LiManObj.AttivazioneDTO>?>(rawData);
            }
            return await Task.FromResult(answ);
        }

        /// <summary>
        /// Recupera info licenza da remoto
        /// </summary>
        private async Task<List<LiManObj.ApplicativoDTO>> OnlineAppInfo()
        {
            List<LiManObj.ApplicativoDTO>? answ = new List<LiManObj.ApplicativoDTO>();
            // cerco online
            RestClient client = new RestClient(apiUrl);
            string MKeyEnc = HttpUtility.UrlEncode(MasterKey);
            //string mKey = System.Net.WebUtility.UrlEncode(MasterKey);
            string reqUrl = $"api/licenza/{Installazione}?CodApp={Applicazione}&Chiave={MKeyEnc}";
            var request = new RestRequest(reqUrl, Method.Get);
            var response = await client.GetAsync(request);
            // controllo risposta
            if (response.StatusCode == System.Net.HttpStatusCode.OK)
            {
                // verifico risposta
                string rawData = $"{response.Content}";
                answ = JsonConvert.DeserializeObject<List<LiManObj.ApplicativoDTO>?>(rawData);
            }
            // restituisce valori o insieme vuoto
            return await Task.FromResult(answ ?? new List<LiManObj.ApplicativoDTO>());
        }

        private void ReportUpdated()
        {
            if (EA_InfoUpdated != null)
            {
                EA_InfoUpdated?.Invoke();
            }
        }

        #endregion Private Methods
    }
}