using System;
using System.Collections.Generic;
using Server.Items;
using Server.Misc;
using Server.Mobiles;
using Server.Targeting;

namespace Server.Spells.Fifth
{
  public class PoisonFieldSpell : MagerySpell, ISpellTargetingPoint3D
  {
    private static readonly SpellInfo m_Info = new SpellInfo(
      "Poison Field", "In Nox Grav",
      230,
      9052,
      false,
      Reagent.BlackPearl,
      Reagent.Nightshade,
      Reagent.SpidersSilk);

    public PoisonFieldSpell(Mobile caster, Item scroll = null) : base(caster, scroll, m_Info)
    {
    }

    public override SpellCircle Circle => SpellCircle.Fifth;

    public override void OnCast()
    {
      Caster.Target = new SpellTargetPoint3D(this, TargetFlags.None, Core.ML ? 10 : 12, false);
    }

    public void Target(IPoint3D p)
    {
      if (!Caster.CanSee(p))
      {
        Caster.SendLocalizedMessage(500237); // Target can not be seen.
      }
      else if (SpellHelper.CheckTown(p, Caster) && CheckSequence())
      {
        SpellHelper.Turn(Caster, p);

        SpellHelper.GetSurfaceTop(ref p);

        int dx = Caster.Location.X - p.X;
        int dy = Caster.Location.Y - p.Y;
        int rx = (dx - dy) * 44;
        int ry = (dx + dy) * 44;

        bool eastToWest;

        if (rx >= 0 && ry >= 0)
          eastToWest = false;
        else if (rx >= 0)
          eastToWest = true;
        else if (ry >= 0)
          eastToWest = true;
        else
          eastToWest = false;

        Effects.PlaySound(p, Caster.Map, 0x20B);

        int itemID = eastToWest ? 0x3915 : 0x3922;

        TimeSpan duration = TimeSpan.FromSeconds(3 + Caster.Skills.Magery.Fixed / 25);

        for (int i = -2; i <= 2; ++i)
        {
          Point3D loc = new Point3D(eastToWest ? p.X + i : p.X, eastToWest ? p.Y : p.Y + i, p.Z);

          new InternalItem(itemID, loc, Caster, Caster.Map, duration, i);
        }
      }

      FinishSequence();
    }

    [DispellableField]
    public class InternalItem : Item
    {
      private Mobile m_Caster;
      private DateTime m_End;
      private Timer m_Timer;

      public InternalItem(int itemID, Point3D loc, Mobile caster, Map map, TimeSpan duration, int val) : base(itemID)
      {
        bool canFit = SpellHelper.AdjustField(ref loc, map, 12, false);

        Visible = false;
        Movable = false;
        Light = LightType.Circle300;

        MoveToWorld(loc, map);

        m_Caster = caster;

        m_End = DateTime.UtcNow + duration;

        m_Timer = new InternalTimer(this, TimeSpan.FromSeconds(Math.Abs(val) * 0.2), caster.InLOS(this), canFit);
        m_Timer.Start();
      }

      public InternalItem(Serial serial) : base(serial)
      {
      }

      public override bool BlocksFit => true;

      public override void OnAfterDelete()
      {
        base.OnAfterDelete();

        m_Timer?.Stop();
      }

      public override void Serialize(IGenericWriter writer)
      {
        base.Serialize(writer);

        writer.Write(1); // version

        writer.Write(m_Caster);
        writer.WriteDeltaTime(m_End);
      }

      public override void Deserialize(IGenericReader reader)
      {
        base.Deserialize(reader);

        int version = reader.ReadInt();

        switch (version)
        {
          case 1:
            {
              m_Caster = reader.ReadMobile();

              goto case 0;
            }
          case 0:
            {
              m_End = reader.ReadDeltaTime();

              m_Timer = new InternalTimer(this, TimeSpan.Zero, true, true);
              m_Timer.Start();

              break;
            }
        }
      }

      public void ApplyPoisonTo(Mobile m)
      {
        if (m_Caster == null)
          return;

        Poison p;

        if (Core.AOS)
        {
          int total = (m_Caster.Skills.Magery.Fixed + m_Caster.Skills.Poisoning.Fixed) / 2;

          if (total >= 1000)
            p = Poison.Deadly;
          else if (total > 850)
            p = Poison.Greater;
          else if (total > 650)
            p = Poison.Regular;
          else
            p = Poison.Lesser;
        }
        else
        {
          p = Poison.Regular;
        }

        if (m.ApplyPoison(m_Caster, p) == ApplyPoisonResult.Poisoned)
          if (SpellHelper.CanRevealCaster(m))
            m_Caster.RevealingAction();

        (m as BaseCreature)?.OnHarmfulSpell(m_Caster);
      }

      public override bool OnMoveOver(Mobile m)
      {
        if (Visible && m_Caster != null && (!Core.AOS || m != m_Caster) &&
            SpellHelper.ValidIndirectTarget(m_Caster, m) && m_Caster.CanBeHarmful(m, false))
        {
          m_Caster.DoHarmful(m);

          ApplyPoisonTo(m);
          m.PlaySound(0x474);
        }

        return true;
      }

      private class InternalTimer : Timer
      {
        private static readonly Queue<Mobile> m_Queue = new Queue<Mobile>();
        private readonly bool m_InLOS;
        private readonly bool m_CanFit;
        private readonly InternalItem m_Item;

        public InternalTimer(InternalItem item, TimeSpan delay, bool inLOS, bool canFit) : base(delay,
          TimeSpan.FromSeconds(1.5))
        {
          m_Item = item;
          m_InLOS = inLOS;
          m_CanFit = canFit;

          Priority = TimerPriority.FiftyMS;
        }

        protected override void OnTick()
        {
          if (m_Item.Deleted)
            return;

          if (!m_Item.Visible)
          {
            if (m_InLOS && m_CanFit)
              m_Item.Visible = true;
            else
              m_Item.Delete();

            if (!m_Item.Deleted)
            {
              m_Item.ProcessDelta();
              Effects.SendLocationParticles(
                EffectItem.Create(m_Item.Location, m_Item.Map, EffectItem.DefaultDuration), 0x376A, 9, 10,
                5040);
            }
          }
          else if (DateTime.UtcNow > m_Item.m_End)
          {
            m_Item.Delete();
            Stop();
          }
          else
          {
            Map map = m_Item.Map;
            Mobile caster = m_Item.m_Caster;

            if (map != null && caster != null)
            {
              bool eastToWest = m_Item.ItemID == 0x3915;
              IPooledEnumerable<Mobile> eable = map.GetMobilesInBounds(
                new Rectangle2D(m_Item.X - (eastToWest ? 0 : 1), m_Item.Y - (eastToWest ? 1 : 0),
                  eastToWest ? 1 : 2, eastToWest ? 2 : 1));

              foreach (Mobile m in eable)
                if (m.Z + 16 > m_Item.Z && m_Item.Z + 12 > m.Z && (!Core.AOS || m != caster) &&
                    SpellHelper.ValidIndirectTarget(caster, m) && caster.CanBeHarmful(m, false))
                  m_Queue.Enqueue(m);

              eable.Free();

              while (m_Queue.Count > 0)
              {
                Mobile m = m_Queue.Dequeue();

                caster.DoHarmful(m);

                m_Item.ApplyPoisonTo(m);
                m.PlaySound(0x474);
              }
            }
          }
        }
      }
    }
  }
}