More abilities, refactor stealing held items

Plugins/PkmnLib.Plugin.Gen7/Scripts/Abilities/StormDrain.cs

@@ -0,0 +1,34 @@
+namespace PkmnLib.Plugin.Gen7.Scripts.Abilities;
+
+/// <summary>
+/// Storm Drain is an ability that draws in all Water-type moves to up its Special Attack.
+///
+/// <see href="https://bulbapedia.bulbagarden.net/wiki/Storm_Drain_(Ability)">Bulbapedia - Storm Drain</see>
+/// </summary>
+[Script(ScriptCategory.Ability, "storm_drain")]
+public class StormDrain : Script
+{
+    /// <inheritdoc />
+    public override void ChangeIncomingTargets(IMoveChoice moveChoice, ref IReadOnlyList<IPokemon?> targets)
+    {
+        if (moveChoice.ChosenMove.MoveData.MoveType.Name == "water" && targets.Count == 1)
+        {
+            targets = [moveChoice.User];
+        }
+    }
+
+    /// <inheritdoc />
+    public override void ChangeEffectiveness(IExecutingMove move, IPokemon target, byte hit, ref float effectiveness)
+    {
+        if (move.GetHitData(target, hit).Type?.Name != "water")
+            return;
+
+        effectiveness = 0f;
+        EventBatchId batchId = new();
+        move.Battle.EventHook.Invoke(new AbilityTriggerEvent(move.User)
+        {
+            BatchId = batchId,
+        });
+        move.User.ChangeStatBoost(Statistic.SpecialAttack, 1, true, true, batchId);
+    }
+}