Merge pull request #825 from eduardosmaniotto/feature/configurable-npc-buffs

feature: configurable npc buffs
(cherry picked from commit 6a061fcad756e644dadf3721e84e3cce2a25bceb)

src/Persistence/Initialization/Updates/AddElfSoldierBuffPlugIn.cs

@@ -0,0 +1,106 @@
+// <copyright file="AddElfSoldierBuffPlugIn.cs" company="MUnique">
+// Licensed under the MIT License. See LICENSE file in the project root for full license information.
+// </copyright>
+
+namespace MUnique.OpenMU.Persistence.Initialization.Updates;
+
+using System.Runtime.InteropServices;
+using MUnique.OpenMU.AttributeSystem;
+using MUnique.OpenMU.DataModel.Attributes;
+using MUnique.OpenMU.DataModel.Configuration;
+using MUnique.OpenMU.GameLogic.Attributes;
+using MUnique.OpenMU.Persistence.Initialization.Skills;
+using MUnique.OpenMU.PlugIns;
+
+/// <summary>
+/// This update adds the Elf Soldier buff to the existing Elf Soldier NPC.
+/// </summary>
+[PlugIn]
+[Display(Name = PlugInName, Description = PlugInDescription)]
+[Guid("9BCFC8B1-6A6E-48F9-AE7C-0D34FA6D706B")]
+public class AddElfSoldierBuffPlugIn : UpdatePlugInBase
+{
+    /// <summary>
+    /// The plug in name.
+    /// </summary>
+    internal const string PlugInName = "Add Elf Soldier Buff";
+
+    /// <summary>
+    /// The plug in description.
+    /// </summary>
+    internal const string PlugInDescription = "This update adds the Elf Soldier buff (defense and damage boost) as a configurable Buff.";
+
+    /// <inheritdoc />
+    public override string Name => PlugInName;
+
+    /// <inheritdoc />
+    public override string Description => PlugInDescription;
+
+    /// <inheritdoc />
+    public override UpdateVersion Version => UpdateVersion.AddElfSoldierBuff;
+
+    /// <inheritdoc />
+    public override string DataInitializationKey => VersionSeasonSix.DataInitialization.Id;
+
+    /// <inheritdoc />
+    public override bool IsMandatory => true;
+
+    /// <inheritdoc />
+    public override DateTime CreatedAt => new(2026, 07, 11, 17, 10, 0, DateTimeKind.Utc);
+
+    /// <inheritdoc />
+    protected override async ValueTask ApplyAsync(IContext context, GameConfiguration gameConfiguration)
+    {
+        var elfSoldier = gameConfiguration.Monsters.FirstOrDefault(m => m.Number == 257);
+        if (elfSoldier is null)
+        {
+            return;
+        }
+
+        if (elfSoldier.Buffs.Any())
+        {
+            return;
+        }
+
+        var buffEffect = context.CreateNew<MagicEffectDefinition>();
+        gameConfiguration.MagicEffects.Add(buffEffect);
+        buffEffect.Number = (short)MagicEffectNumber.ElfSoldierBuff;
+        buffEffect.Name = "Elf Soldier Buff";
+        buffEffect.InformObservers = true;
+        buffEffect.StopByDeath = true;
+
+        // Duration: 60 minutes
+        buffEffect.Duration = context.CreateNew<PowerUpDefinitionValue>();
+        buffEffect.Duration.ConstantValue.Value = 3600;
+
+        // Defense boost: 50 + (Level / 5)
+        var defensePowerUp = context.CreateNew<PowerUpDefinition>();
+        defensePowerUp.TargetAttribute = Stats.DefenseFinal.GetPersistent(gameConfiguration);
+        defensePowerUp.Boost = context.CreateNew<PowerUpDefinitionValue>();
+        defensePowerUp.Boost.ConstantValue.Value = 50;
+        defensePowerUp.Boost.ConstantValue.AggregateType = AggregateType.AddFinal;
+        var defensePerLevel = context.CreateNew<AttributeRelationship>();
+        defensePerLevel.InputAttribute = Stats.Level.GetPersistent(gameConfiguration);
+        defensePerLevel.InputOperand = 1f / 5;
+        defensePerLevel.InputOperator = InputOperator.Multiply;
+        defensePowerUp.Boost.RelatedValues.Add(defensePerLevel);
+        buffEffect.PowerUpDefinitions.Add(defensePowerUp);
+
+        // Damage boost: 45 + (Level / 3)
+        var damagePowerUp = context.CreateNew<PowerUpDefinition>();
+        damagePowerUp.TargetAttribute = Stats.GreaterDamageBonus.GetPersistent(gameConfiguration);
+        damagePowerUp.Boost = context.CreateNew<PowerUpDefinitionValue>();
+        damagePowerUp.Boost.ConstantValue.Value = 45;
+        var damagePerLevel = context.CreateNew<AttributeRelationship>();
+        damagePerLevel.InputAttribute = Stats.Level.GetPersistent(gameConfiguration);
+        damagePerLevel.InputOperand = 1f / 3;
+        damagePerLevel.InputOperator = InputOperator.Multiply;
+        damagePowerUp.Boost.RelatedValues.Add(damagePerLevel);
+        buffEffect.PowerUpDefinitions.Add(damagePowerUp);
+
+        var buff = context.CreateNew<Buff>();
+        buff.MagicEffectDefinition = buffEffect;
+        buff.MaximumLevel = 220;
+        elfSoldier.Buffs.Add(buff);
+    }
+}