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

using System;
using System.Collections.Generic;

namespace Server.Items
{
    /// <summary>
    ///     The assassin's friend.
    ///     A successful Mortal Strike will render its victim unable to heal any damage for several seconds.
    ///     Use a gruesome follow-up to finish off your foe.
    /// </summary>
    public class MortalStrike : WeaponAbility
    {
        public static readonly TimeSpan PlayerDuration = TimeSpan.FromSeconds(6.0);
        public static readonly TimeSpan NPCDuration = TimeSpan.FromSeconds(12.0);

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

        public override int BaseMana => 30;

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

            ClearCurrentAbility(attacker);

            attacker.SendLocalizedMessage(1060086); // You deliver a mortal wound!
            defender.SendLocalizedMessage(1060087); // You have been mortally wounded!

            defender.PlaySound(0x1E1);
            defender.FixedParticles(0x37B9, 244, 25, 9944, 31, 0, EffectLayer.Waist);

            // Do not reset timer if one is already in place.
            if (!IsWounded(defender))
            {
                BeginWound(defender, defender.Player ? PlayerDuration : NPCDuration);
            }
        }

        public static bool IsWounded(Mobile m) => _table.ContainsKey(m);

        private static bool StopTimer(Mobile m)
        {
            if (_table.Remove(m, out var timerToken))
            {
                timerToken.Cancel();
                return true;
            }

            return false;
        }

        public static void BeginWound(Mobile m, TimeSpan duration)
        {
            StopTimer(m);
            Timer.StartTimer(duration, () => EndWound(m), out var timerToken);
            _table[m] = timerToken;

            m.YellowHealthbar = true;
        }

        public static bool EndWound(Mobile m)
        {
            if (StopTimer(m))
            {
                m.YellowHealthbar = false;
                m.SendLocalizedMessage(1060208); // You are no longer mortally wounded.
                return true;
            }

            return false;
        }
    }
}