ModernUO/Projects/Scripts/Spells/Necromancy/Strangle.cs

using System;
using System.Collections.Generic;
using Server.Targeting;

namespace Server.Spells.Necromancy
{
  public class StrangleSpell : NecromancerSpell, ISpellTargetingMobile
  {
    private static SpellInfo m_Info = new SpellInfo(
      "Strangle", "In Bal Nox",
      209,
      9031,
      Reagent.DaemonBlood,
      Reagent.NoxCrystal
    );

    private static readonly Dictionary<Mobile, InternalTimer> m_Table = new Dictionary<Mobile, InternalTimer>();

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

    public override TimeSpan CastDelayBase => TimeSpan.FromSeconds(2.0);

    public override double RequiredSkill => 65.0;
    public override int RequiredMana => 29;

    public override void OnCast()
    {
      Caster.Target = new SpellTargetMobile(this, TargetFlags.Harmful, Core.ML ? 10 : 12);
    }

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

      if (CheckHSequence(m))
      {
        SpellHelper.Turn(Caster, m);

        //SpellHelper.CheckReflect( (int)this.Circle, Caster, ref m );	//Irrelevent after AoS

        /* Temporarily chokes off the air suply of the target with poisonous fumes.
         * The target is inflicted with poison damage over time.
         * The amount of damage dealt each "hit" is based off of the caster's Spirit Speak skill and the Target's current Stamina.
         * The less Stamina the target has, the more damage is done by Strangle.
         * Duration of the effect is Spirit Speak skill level / 10 rounds, with a minimum number of 4 rounds.
         * The first round of damage is dealt after 5 seconds, and every next round after that comes 1 second sooner than the one before, until there is only 1 second between rounds.
         * The base damage of the effect lies between (Spirit Speak skill level / 10) - 2 and (Spirit Speak skill level / 10) + 1.
         * Base damage is multiplied by the following formula: (3 - (target's current Stamina / target's maximum Stamina) * 2).
         * Example:
         * For a target at full Stamina the damage multiplier is 1,
         * for a target at 50% Stamina the damage multiplier is 2 and
         * for a target at 20% Stamina the damage multiplier is 2.6
         */

        m.Spell?.OnCasterHurt();

        m.PlaySound(0x22F);
        m.FixedParticles(0x36CB, 1, 9, 9911, 67, 5, EffectLayer.Head);
        m.FixedParticles(0x374A, 1, 17, 9502, 1108, 4, (EffectLayer)255);

        if (!m_Table.TryGetValue(m, out InternalTimer timer))
        {
          m_Table[m] = timer = new InternalTimer(m, Caster);
          timer.Start();
        }

        HarmfulSpell(m);
      }

      //Calculations for the buff bar
      double spiritlevel = Caster.Skills.SpiritSpeak.Value / 10;
      if (spiritlevel < 4)
        spiritlevel = 4;
      int d_MinDamage = 4;
      int d_MaxDamage = ((int)spiritlevel + 1) * 3;
      string args = $"{d_MinDamage}\t{d_MaxDamage}";

      int i_Count = (int)spiritlevel;
      int i_MaxCount = i_Count;
      int i_HitDelay = 5;
      int i_Length = i_HitDelay;

      while (i_Count > 1)
      {
        --i_Count;
        if (i_HitDelay > 1)
        {
          if (i_MaxCount < 5)
          {
            --i_HitDelay;
          }
          else
          {
            int delay = (int)Math.Ceiling((1.0 + 5 * i_Count) / i_MaxCount);

            i_HitDelay = delay <= 5 ? delay : 5;
          }
        }

        i_Length += i_HitDelay;
      }

      TimeSpan t_Duration = TimeSpan.FromSeconds(i_Length);
      BuffInfo.AddBuff(m, new BuffInfo(BuffIcon.Strangle, 1075794, args, t_Duration, m));

      FinishSequence();
    }

    public static bool RemoveCurse(Mobile m)
    {
      if (!m_Table.TryGetValue(m, out InternalTimer timer))
        return false;

      timer.Stop();
      m.SendLocalizedMessage(1061687); // You can breath normally again.

      m_Table.Remove(m);
      return true;
    }

    private class InternalTimer : Timer
    {
      private int m_Count, m_MaxCount;
      private int m_HitDelay;
      private double m_MinBaseDamage, m_MaxBaseDamage;

      private DateTime m_NextHit;
      private Mobile m_Target, m_From;

      public InternalTimer(Mobile target, Mobile from) : base(TimeSpan.FromSeconds(0.1), TimeSpan.FromSeconds(0.1))
      {
        Priority = TimerPriority.FiftyMS;

        m_Target = target;
        m_From = from;

        double spiritLevel = from.Skills.SpiritSpeak.Value / 10;

        m_MinBaseDamage = spiritLevel - 2;
        m_MaxBaseDamage = spiritLevel + 1;

        m_HitDelay = 5;
        m_NextHit = DateTime.UtcNow + TimeSpan.FromSeconds(m_HitDelay);

        m_Count = (int)spiritLevel;

        if (m_Count < 4)
          m_Count = 4;

        m_MaxCount = m_Count;
      }

      protected override void OnTick()
      {
        if (!m_Target.Alive)
        {
          m_Table.Remove(m_Target);
          Stop();
        }

        if (!m_Target.Alive || DateTime.UtcNow < m_NextHit)
          return;

        --m_Count;

        if (m_HitDelay > 1)
        {
          if (m_MaxCount < 5)
          {
            --m_HitDelay;
          }
          else
          {
            int delay = (int)Math.Ceiling((1.0 + 5 * m_Count) / m_MaxCount);

            if (delay <= 5)
              m_HitDelay = delay;
            else
              m_HitDelay = 5;
          }
        }

        if (m_Count == 0)
        {
          m_Target.SendLocalizedMessage(1061687); // You can breath normally again.
          m_Table.Remove(m_Target);
          Stop();
        }
        else
        {
          m_NextHit = DateTime.UtcNow + TimeSpan.FromSeconds(m_HitDelay);

          double damage = m_MinBaseDamage + Utility.RandomDouble() * (m_MaxBaseDamage - m_MinBaseDamage);

          damage *= 3 - (double)m_Target.Stam / m_Target.StamMax * 2;

          if (damage < 1)
            damage = 1;

          if (!m_Target.Player)
            damage *= 1.75;

          AOS.Damage(m_Target, m_From, (int)damage, 0, 0, 0, 100, 0);

          if (0.60 <= Utility.RandomDouble()
          ) // OSI: randomly revealed between first and third damage tick, guessing 60% chance
            m_Target.RevealingAction();
        }
      }
    }
  }
}