ModernUO/Projects/UOContent/Spells/Necromancy/BloodOathSpell.cs

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

namespace Server.Spells.Necromancy;

public class BloodOathSpell : NecromancerSpell, ISpellTargetingMobile
{
    private static readonly SpellInfo _info = new(
        "Blood Oath",
        "In Jux Mani Xen",
        203,
        9031,
        Reagent.DaemonBlood
    );

    private static readonly Dictionary<Mobile, Mobile> _oathTable = new();
    private static readonly Dictionary<Mobile, ExpireTimer> _table = new();

    public BloodOathSpell(Mobile caster, Item scroll = null) : base(caster, scroll, _info)
    {
    }

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

    public override double RequiredSkill => 20.0;
    public override int RequiredMana => 13;

    public void Target(Mobile m)
    {
        if (m == null)
        {
            Caster.SendLocalizedMessage(1060508); // You can't curse that.
        }
        // only PlayerMobile and BaseCreature implement blood oath checking
        else if (Caster == m || m is not (PlayerMobile or BaseCreature))
        {
            Caster.SendLocalizedMessage(1060508); // You can't curse that.
        }
        else if (_oathTable.ContainsKey(Caster))
        {
            Caster.SendLocalizedMessage(1061607); // You are already bonded in a Blood Oath.
        }
        else if (_oathTable.ContainsKey(m))
        {
            if (m.Player)
            {
                Caster.SendLocalizedMessage(1061608); // That player is already bonded in a Blood Oath.
            }
            else
            {
                Caster.SendLocalizedMessage(1061609); // That creature is already bonded in a Blood Oath.
            }
        }
        else if (CheckHSequence(m))
        {
            SpellHelper.Turn(Caster, m);

            /* Temporarily creates a dark pact between the caster and the target.
             * Any damage dealt by the target to the caster is increased, but the target receives the same amount of damage.
             * The effect lasts for ((Spirit Speak skill level - target's Resist Magic skill level) / 80 ) + 8 seconds.
             *
             * NOTE: The above algorithm must be fixed point, it should be:
             * ((ss-rm)/8)+8
             */

            RemoveCurse(m);

            _oathTable[Caster] = Caster;
            _oathTable[m] = Caster;

            m.Spell?.OnCasterHurt();

            Caster.PlaySound(0x175);

            Caster.FixedParticles(0x375A, 1, 17, 9919, 33, 7, EffectLayer.Waist);
            Caster.FixedParticles(0x3728, 1, 13, 9502, 33, 7, (EffectLayer)255);

            m.FixedParticles(0x375A, 1, 17, 9919, 33, 7, EffectLayer.Waist);
            m.FixedParticles(0x3728, 1, 13, 9502, 33, 7, (EffectLayer)255);

            var duration = TimeSpan.FromSeconds((GetDamageSkill(Caster) - GetResistSkill(m)) / 8 + 8);
            m.CheckSkill(SkillName.MagicResist, 0.0, 120.0); // Skill check for gain

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

            BuffInfo.AddBuff(Caster, new BuffInfo(BuffIcon.BloodOathCaster, 1075659, duration, Caster, m.Name));
            BuffInfo.AddBuff(m, new BuffInfo(BuffIcon.BloodOathCurse, 1075661, duration, m, Caster.Name));

            _table[m] = timer;
            HarmfulSpell(m);
        }

        FinishSequence();
    }

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

    public static bool RemoveCurse(Mobile target)
    {
        if (_table.Remove(target, out var timer))
        {
            var caster = timer.Caster;
            if (_oathTable.Remove(caster))
            {
                caster.SendLocalizedMessage(1061620); // Your Blood Oath has been broken.
            }

            if (_oathTable.Remove(target))
            {
                target.SendLocalizedMessage(1061620); // Your Blood Oath has been broken.
            }

            timer.Stop();

            BuffInfo.RemoveBuff(caster, BuffIcon.BloodOathCaster);
            BuffInfo.RemoveBuff(target, BuffIcon.BloodOathCurse);

            return true;
        }

        return false;
    }

    public static Mobile GetBloodOath(Mobile m) =>
        m == null || _oathTable.TryGetValue(m, out var oath) && oath == m ? null : oath;

    private class ExpireTimer : Timer
    {
        private Mobile _target;
        private DateTime _end;

        public Mobile Caster { get; }

        public ExpireTimer(Mobile caster, Mobile target, TimeSpan delay) : base(
            TimeSpan.FromSeconds(1.0),
            TimeSpan.FromSeconds(1.0)
        )
        {
            Caster = caster;
            _target = target;
            _end = Core.Now + delay;
        }

        protected override void OnTick()
        {
            if (Caster.Deleted || _target.Deleted || !Caster.Alive || !_target.Alive ||
                Core.Now >= _end)
            {
                RemoveCurse(_target);
            }
        }
    }
}