Implements more abilities

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

@@ -0,0 +1,36 @@
+namespace PkmnLib.Plugin.Gen7.Scripts.Abilities;
+
+/// <summary>
+/// Download is an ability that raises the Pokémon's Attack or Special Attack stat when it enters battle,
+/// depending on which stat is lower on the opposing Pokémon.
+/// This ability is commonly associated with Porygon and its evolutions.
+///
+/// <see href="https://bulbapedia.bulbagarden.net/wiki/Download_(Ability)">Bulbapedia - Download</see>
+/// </summary>
+[Script(ScriptCategory.Ability, "download")]
+public class Download : Script
+{
+    /// <inheritdoc />
+    public override void OnSwitchIn(IPokemon pokemon, byte position)
+    {
+        var battleData = pokemon.BattleData;
+        if (battleData == null)
+            return;
+
+        var opponents = battleData.Battle.Sides.Where(x => x != battleData.BattleSide).SelectMany(x => x.Pokemon)
+            .WhereNotNull().ToArray();
+        if (opponents.Length == 0)
+            return;
+        var opponentAverageDefense = opponents.Average(x => x.BoostedStats.Defense);
+        var opponentAverageSpecialDefense = opponents.Average(x => x.BoostedStats.SpecialDefense);
+
+        EventBatchId batchId = new();
+        battleData.Battle.EventHook.Invoke(new AbilityTriggerEvent(pokemon)
+        {
+            BatchId = batchId,
+        });
+        pokemon.ChangeStatBoost(
+            opponentAverageDefense < opponentAverageSpecialDefense ? Statistic.Attack : Statistic.SpecialAttack, 1,
+            true, batchId);
+    }
+}