using System;
using System.Runtime.Caching;
using Kreta.Core;
using Kreta.Framework;
using Kreta.Web.Security;

namespace Kreta.Web.Controllers.Logic
{
    public class SessionHandler
    {
        private static readonly CacheItemPolicy DefaultCacheItemPolicy = new CacheItemPolicy { SlidingExpiration = TimeSpan.FromMinutes(60) };

        private static int sessionTimeOut = 0;

        private static string GetCacheKey(string sessionId)
        {
            return $"{nameof(SessionHandler)}_{sessionId}";
        }

        public static int SessionTimeOut
        {
            get
            {
                if (sessionTimeOut < 1)
                {
                    sessionTimeOut = (SDAServer.Instance.Configuration.SessionTimeout - 1) * 60; // A kérés és válasz alatt a mi számlálónk elcsúszik pár másodperccel és a valódi session hamarabb járna le.
                    if (sessionTimeOut < 45)
                    {
                        sessionTimeOut = 45;
                    }
                }

                return sessionTimeOut;
            }
        }

        public static void UpdateSessionTime()
        {
            string sessionId = ClaimData.SessionId;
            if (string.IsNullOrWhiteSpace(sessionId))
            {
                throw new Exception("Invalid Session key");
            }

            Cache.Set(GetCacheKey(sessionId), DateTime.Now, DefaultCacheItemPolicy);
        }

        public static int GetRemainingTime()
        {
            string sessionId = ClaimData.SessionId;
            if (string.IsNullOrWhiteSpace(sessionId))
            {
                throw new Exception("Invalid Session key");
            }

            DateTime lastCallTime = Cache.AddOrGetExisting(GetCacheKey(sessionId), DateTime.Now, DefaultCacheItemPolicy);
            TimeSpan spendTime = DateTime.Now - lastCallTime;
            int remainingTime = SessionTimeOut - (spendTime.Minutes * 60 + spendTime.Seconds);

            PingKretaServerSession(sessionId);

            return remainingTime;
        }

        public static void DropSession(string sessionId)
        {
            Cache.Remove(GetCacheKey(sessionId));
        }

        private static void PingKretaServerSession(string sessionId)
        {
            SDAServer.Instance.SessionManager.PingSession(sessionId);
        }
    }
}