ModernUO/Projects/UOContent/Spells/Ninjitsu/SurpriseAttack.cs

using System;
using System.Collections.Generic;
using Server.SkillHandlers;

namespace Server.Spells.Ninjitsu;

public class SurpriseAttack : NinjaMove
{
    private static readonly Dictionary<Mobile, SurpriseAttackTimer> _table = new();

    public override int BaseMana => 20;
    public override double RequiredSkill => Core.ML ? 60.0 : 30.0;

    public override TextDefinition AbilityMessage { get; } = 1063128; // You prepare to surprise your prey.

    public override bool ValidatesDuringHit => false;

    public override bool Validate(Mobile from)
    {
        if (!from.Hidden || from.AllowedStealthSteps <= 0)
        {
            from.SendLocalizedMessage(1063087); // You must be in stealth mode to use this ability.
            return false;
        }

        return base.Validate(from);
    }

    public override bool OnBeforeSwing(Mobile attacker, Mobile defender)
    {
        var valid = Validate(attacker) && CheckMana(attacker, true);

        if (valid)
        {
            attacker.BeginAction<Stealth>();
            Timer.StartTimer(TimeSpan.FromSeconds(5.0), attacker.EndAction<Stealth>);
        }

        return valid;
    }

    public override void OnHit(Mobile attacker, Mobile defender, int damage)
    {
        // Validates before swing

        ClearCurrentMove(attacker);

        attacker.SendLocalizedMessage(1063129); // You catch your opponent off guard with your Surprise Attack!
        defender.SendLocalizedMessage(1063130); // Your defenses are lowered as your opponent surprises you!

        defender.FixedParticles(0x37B9, 1, 5, 0x26DA, 0, 3, EffectLayer.Head);

        attacker.RevealingAction();

        StopTimer(defender);

        var ninjitsu = attacker.Skills.Ninjitsu.Fixed;

        var malus = ninjitsu / 60 + (int)Tracking.GetStalkingBonus(attacker, defender);

        var timer = new SurpriseAttackTimer(defender, malus);
        timer.Start();

        _table[defender] = timer;

        CheckGain(attacker);
    }

    public override void OnMiss(Mobile attacker, Mobile defender)
    {
        ClearCurrentMove(attacker);

        attacker.SendLocalizedMessage(1063161); // You failed to properly use the element of surprise.

        attacker.RevealingAction();
    }

    public static bool GetMalus(Mobile target, ref int malus)
    {
        if (!_table.TryGetValue(target, out var info))
        {
            return false;
        }

        malus = info.Malus;
        return true;
    }

    private static void StopTimer(Mobile m)
    {
        if (_table.Remove(m, out var timer))
        {
            timer.Stop();
        }
    }

    private static void EndSurprise(SurpriseAttackTimer info)
    {
        StopTimer(info.Target);
        info.Target.SendLocalizedMessage(1063131); // Your defenses have returned to normal.
    }

    private class SurpriseAttackTimer : Timer
    {
        public int Malus;
        public Mobile Target;

        public SurpriseAttackTimer(Mobile target, int effect) : base(TimeSpan.FromSeconds(8.0))
        {
            Target = target;
            Malus = effect;
        }

        protected override void OnTick()
        {
            StopTimer(Target);
            Target.SendLocalizedMessage(1063131); // Your defenses have returned to normal.
        }
    }
}