Even more abilities

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

@@ -0,0 +1,57 @@
+namespace PkmnLib.Plugin.Gen7.Scripts.Abilities;
+
+/// <summary>
+/// Shields Down is an ability that changes Minior's form depending on its HP.
+///
+/// <see href="https://bulbapedia.bulbagarden.net/wiki/Shields_Down_(Ability)">Bulbapedia - Shields Down</see>
+/// </summary>
+[Script(ScriptCategory.Ability, "shields_down")]
+public class ShieldsDown : Script
+{
+    private IPokemon? _owningPokemon;
+
+    /// <inheritdoc />
+    public override void OnAddedToParent(IScriptSource source)
+    {
+        if (source is not IPokemon pokemon)
+            throw new ArgumentException("ShieldsDown script must be added to a Pokemon.", nameof(source));
+        _owningPokemon = pokemon;
+    }
+
+    /// <inheritdoc />
+    public override void OnSwitchIn(IPokemon pokemon, byte position) => ChangeFormIfNeeded(pokemon);
+
+    /// <inheritdoc />
+    public override void OnEndTurn(IBattle battle) => ChangeFormIfNeeded(_owningPokemon);
+
+    private static void ChangeFormIfNeeded(IPokemon? pokemon)
+    {
+        if (pokemon is null)
+            return;
+
+        if (pokemon.Species.Name != "minior" || pokemon.BattleData?.Battle == null)
+            return;
+        if (pokemon.CurrentHealth < pokemon.MaxHealth / 2 && pokemon.Form.Name.ToString().EndsWith("-meteor"))
+        {
+            var coreForm = pokemon.Form.Name.ToString().Replace("-meteor", "");
+            if (coreForm == "blue")
+                coreForm = "default";
+            if (pokemon.Species.TryGetForm(coreForm, out var coreFormData))
+            {
+                pokemon.ChangeForm(coreFormData);
+            }
+        }
+        else if (pokemon.CurrentHealth >= pokemon.MaxHealth / 2 &&
+                 pokemon.Form.Name.ToString().EndsWith("-meteor") == false)
+        {
+            var baseFormName = pokemon.Form.Name;
+            if (baseFormName == "default")
+                baseFormName = "blue";
+            var meteorFormName = baseFormName + "-meteor";
+            if (pokemon.Species.TryGetForm(meteorFormName, out var meteorFormData))
+            {
+                pokemon.ChangeForm(meteorFormData);
+            }
+        }
+    }
+}