ModernUO/Projects/UOContent/Items/Weapons/Abilities/TalonStrike.cs

using System;
using System.Collections.Generic;

namespace Server.Items
{
    /// <summary>
    ///     Attack with increased damage with additional damage over time.
    /// </summary>
    public class TalonStrike : WeaponAbility
    {
        private static readonly HashSet<Mobile> _defenders = new();

        public override int BaseMana => 30;
        public override double DamageScalar => 1.2;

        public override bool CheckSkills(Mobile from)
        {
            if (GetSkill(from, SkillName.Ninjitsu) < 50.0)
            {
                // You need ~1_SKILL_REQUIREMENT~ Ninjitsu skill to perform that attack!
                from.SendLocalizedMessage(1063352, "50");
                return false;
            }

            return base.CheckSkills(from);
        }

        public override void OnHit(Mobile attacker, Mobile defender, int damage)
        {
            if (_defenders.Contains(defender) || !Validate(attacker) || !CheckMana(attacker, true))
            {
                return;
            }

            ClearCurrentAbility(attacker);

            attacker.SendLocalizedMessage(1063358); // You deliver a talon strike!
            defender.SendLocalizedMessage(1063359); // Your attacker delivers a talon strike!

            defender.FixedParticles(0x373A, 1, 17, 0x26BC, 0x662, 0, EffectLayer.Waist);

            var timer = new InternalTimer(
                defender,
                (int)(10.0 * (attacker.Skills.Ninjitsu.Value - 50.0) / 70.0 + 5)
            ); // 5 - 15 damage

            timer.Start();

            _defenders.Add(defender);
        }

        private class InternalTimer : Timer
        {
            private readonly double DamagePerTick;
            private readonly Mobile m_Defender;
            private double m_DamageRemaining;
            private double m_DamageToDo;

            // 3 seconds at 0.25 seconds apart = 12.  Confirm delay in between of 0.25 each.
            public InternalTimer(Mobile defender, int totalDamage) : base(
                TimeSpan.Zero,
                TimeSpan.FromSeconds(0.25),
                12
            )
            {
                m_Defender = defender;
                m_DamageRemaining = totalDamage;

                DamagePerTick = (double)totalDamage / 12 + .01;
            }

            protected override void OnTick()
            {
                if (!m_Defender.Alive || m_DamageRemaining <= 0)
                {
                    Stop();
                    _defenders.Remove(m_Defender);
                    return;
                }

                m_DamageRemaining -= DamagePerTick;
                m_DamageToDo += DamagePerTick;

                if (m_DamageRemaining <= 0 && m_DamageToDo < 1)
                {
                    m_DamageToDo = 1.0; // Confirm this 'round up' at the end
                }

                var damage = (int)m_DamageToDo;

                if (damage > 0)
                {
                    // m_Defender.Damage( damage, m_Attacker, false );
                    m_Defender.Hits -= damage; // Don't show damage, don't disrupt
                    m_DamageToDo -= damage;
                }

                if (!m_Defender.Alive || m_DamageRemaining <= 0)
                {
                    Stop();
                    _defenders.Remove(m_Defender);
                }
            }
        }
    }
}