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

namespace Server.Spells.Necromancy
{
  public class CorpseSkinSpell : NecromancerSpell
  {
    private static SpellInfo m_Info = new SpellInfo(
      "Corpse Skin", "In Agle Corp Ylem",
      203,
      9051,
      Reagent.BatWing,
      Reagent.GraveDust
    );

    private static Hashtable m_Table = new Hashtable();

    public CorpseSkinSpell(Mobile caster, Item scroll) : base(caster, scroll, m_Info)
    {
    }

    public override TimeSpan CastDelayBase => TimeSpan.FromSeconds(1.5);

    public override double RequiredSkill => 20.0;
    public override int RequiredMana => 11;

    public override void OnCast()
    {
      Caster.Target = new InternalTarget(this);
    }

    public void Target(Mobile m)
    {
      if (CheckHSequence(m))
      {
        SpellHelper.Turn(Caster, m);

        /* Transmogrifies the flesh of the target creature or player to resemble rotted corpse flesh,
         * making them more vulnerable to Fire and Poison damage,
         * but increasing their resistance to Physical and Cold damage.
         *
         * The effect lasts for ((Spirit Speak skill level - target's Resist Magic skill level) / 25 ) + 40 seconds.
         *
         * NOTE: Algorithm above is fixed point, should be:
         * ((ss-mr)/2.5) + 40
         *
         * NOTE: Resistance is not checked if targeting yourself
         */

        ExpireTimer timer = (ExpireTimer)m_Table[m];

        if (timer != null)
          timer.DoExpire();
        else
          m.SendLocalizedMessage(1061689); // Your skin turns dry and corpselike.

        m.Spell?.OnCasterHurt();

        m.FixedParticles(0x373A, 1, 15, 9913, 67, 7, EffectLayer.Head);
        m.PlaySound(0x1BB);

        double ss = GetDamageSkill(Caster);
        double mr = Caster == m ? 0.0 : GetResistSkill(m);
        m.CheckSkill(SkillName.MagicResist, 0.0, 120.0); //Skill check for gain

        TimeSpan duration = TimeSpan.FromSeconds((ss - mr) / 2.5 + 40.0);

        ResistanceMod[] mods = new ResistanceMod[4]
        {
          new ResistanceMod(ResistanceType.Fire, -15),
          new ResistanceMod(ResistanceType.Poison, -15),
          new ResistanceMod(ResistanceType.Cold, +10),
          new ResistanceMod(ResistanceType.Physical, +10)
        };

        timer = new ExpireTimer(m, mods, duration);
        timer.Start();

        BuffInfo.AddBuff(m, new BuffInfo(BuffIcon.CorpseSkin, 1075663, duration, m));

        m_Table[m] = timer;

        for (int i = 0; i < mods.Length; ++i)
          m.AddResistanceMod(mods[i]);

        HarmfulSpell(m);
      }

      FinishSequence();
    }

    public static bool RemoveCurse(Mobile m)
    {
      ExpireTimer t = (ExpireTimer)m_Table[m];

      if (t == null)
        return false;

      m.SendLocalizedMessage(1061688); // Your skin returns to normal.
      t.DoExpire();
      return true;
    }

    private class ExpireTimer : Timer
    {
      private Mobile m_Mobile;
      private ResistanceMod[] m_Mods;

      public ExpireTimer(Mobile m, ResistanceMod[] mods, TimeSpan delay) : base(delay)
      {
        m_Mobile = m;
        m_Mods = mods;
      }

      public void DoExpire()
      {
        for (int i = 0; i < m_Mods.Length; ++i)
          m_Mobile.RemoveResistanceMod(m_Mods[i]);

        Stop();
        BuffInfo.RemoveBuff(m_Mobile, BuffIcon.CorpseSkin);
        m_Table.Remove(m_Mobile);
      }

      protected override void OnTick()
      {
        m_Mobile.SendLocalizedMessage(1061688); // Your skin returns to normal.
        DoExpire();
      }
    }

    private class InternalTarget : Target
    {
      private CorpseSkinSpell m_Owner;

      public InternalTarget(CorpseSkinSpell owner) : base(Core.ML ? 10 : 12, false, TargetFlags.Harmful)
      {
        m_Owner = owner;
      }

      protected override void OnTarget(Mobile from, object o)
      {
        if (o is Mobile)
          m_Owner.Target((Mobile)o);
      }

      protected override void OnTargetFinish(Mobile from)
      {
        m_Owner.FinishSequence();
      }
    }
  }
}