using System;
using System.Linq;
using System.Threading.Tasks;
using GenCycleVDP.Resources;
using DbCycleVDP;

namespace GenCycleVDP
{
    internal class GenCycle(int vdp)
    {
        private readonly int vdp = vdp;

        private CycleStatus currCycle = CycleStatus.EndTechCycle;
        private DateTime factStart = DateTime.Now;
        private DateTime factEnd = DateTime.Now;
        private DateTime thinkEnd = DateTime.Now;

        private bool cycle = false;
        private Task taskCycle = Task.CompletedTask;

        public void Start()
        {
            cycle = true;
            taskCycle = this.Cycle();
        }
        public void Stop()
        {
            cycle = false;
            taskCycle.Wait();
        }

        async public Task Cycle()
        {
            while (cycle)
            {
                if (GetCurrCycle()) //Can get info form DB.
                {
                    if (DateTime.Now >= factEnd)
                    {
                        GetNextCycle();
                        GetTimeStart();
                        GetTimeThinkEnd();
                        GetTimeFactEnd();
                        while (!SaveToDB())
                        {
                            Console.WriteLine("VDP " + vdp.ToString("D2") + ": Can't connect to DB.");
                            await Task.Delay(5000);
                        }
                    }
                }
                else //It's new Cycle.
                {
                    GetTimeStart();
                    GetTimeThinkEnd();
                    GetTimeFactEnd();
                    while (!SaveToDB())
                    {
                        Console.WriteLine("VDP " + vdp.ToString("D2") + ": Can't connect to DB.");
                        await Task.Delay(5000);
                    }
                }

                while (cycle && (DateTime.Now < factEnd))
                {
                    var secAwait = (factEnd - DateTime.Now).TotalSeconds;
                    if (secAwait >= 5)
                    {
                        await Task.Delay(5000);
                    }
                    else
                    {
                        await Task.Delay(Convert.ToInt32(Math.Ceiling(secAwait)) * 1000);
                    }
                }
            }
        }

        public bool GetCurrCycle()
        {
            try
            {
                using var db = new DbFurnace();
                var tmp = (from u in db.Cycles
                           where
                              u.NumVdp == vdp
                           orderby u.FactStart descending
                           select u).FirstOrDefault();
                if (tmp == null)
                {
                    currCycle = CycleStatus.EndTechCycle;
                    return false;
                }
                currCycle = Enum.IsDefined(typeof(CycleStatus), tmp.NumCycle)
                    ? (CycleStatus)tmp.NumCycle
                    : CycleStatus.EndTechCycle;
                factStart = tmp.FactStart;
                factEnd = tmp.FactEnd;
            }
            catch (Exception e)
            {
                Console.WriteLine(e.Message);
                return false;
            }
            return true;
        }
        public void GetNextCycle()
        {
            currCycle = GenData.GetNextCycle(currCycle);
        }
        public void GetTimeStart()
        {
            factStart = factEnd;
        }
        public void GetTimeThinkEnd()
        {
            thinkEnd = factStart.AddMinutes(GenData.GetDuration(currCycle));
        }
        public void GetTimeFactEnd()
        {
            factEnd = thinkEnd.AddSeconds(GenData.GetDeviation(currCycle));
        }
        public bool SaveToDB()
        {
            try
            {
                using var db = new DbFurnace();
                var tmp = new TableCycle()
                {
                    NumVdp = vdp,
                    NumCycle = (int)currCycle,
                    FactStart = factStart,
                    FactEnd = factEnd,
                    ThinkEnd = thinkEnd
                };
                db.Cycles.Add(tmp);
                db.SaveChanges();
            }
            catch (Exception e)
            {
                Console.WriteLine(e.Message);
                return false;
            }
            return true;
        }

        public string GetStatus()
        {
            return vdp.ToString("D2") + "-" + currCycle.ToString();
        }
    }
}