First couple abilities implemented

PkmnLib.Dynamic/Models/BattleSide.cs

@@ -271,18 +271,25 @@ public class BattleSideImpl : ScriptSource, IBattleSide
             pokemon.SetBattleData(Battle, Index);
             pokemon.SetOnBattlefield(true);
             pokemon.SetBattleSidePosition(position);
+            Battle.EventHook.Invoke(new SwitchEvent(Index, position, pokemon));
+            pokemon.RunScriptHook(script => script.OnSwitchIn(pokemon, position));
+
             foreach (var side in Battle.Sides)
             {
                 if (side == this)
                     continue;
+                var scripts = new List<IEnumerable<ScriptContainer>>(10);
                 foreach (var opponent in side.Pokemon.WhereNotNull())
                 {
                     opponent.MarkOpponentAsSeen(pokemon);
                     pokemon.MarkOpponentAsSeen(opponent);
+
+                    scripts.Clear();
+                    opponent.GetOwnScripts(scripts);
+                    opponent.RunScriptHook(script => script.OnOpponentSwitchIn(pokemon, position));
                 }
+                side.RunScriptHook(script => script.OnOpponentSwitchIn(pokemon, position));
             }
-            Battle.EventHook.Invoke(new SwitchEvent(Index, position, pokemon));
-            pokemon.RunScriptHook(script => script.OnSwitchIn(pokemon, position));
         }
         else
         {

PkmnLib.Dynamic/Models/ExecutingMove.cs

@@ -46,6 +46,16 @@ public interface IHitData
     /// Fails the hit.
     /// </summary>
     void Fail();
+
+    /// <summary>
+    /// Sets a flag on the hit data. This is used to mark certain conditions or states
+    /// </summary>
+    void SetFlag(StringKey flag);
+
+    /// <summary>
+    /// Checks whether a flag is set on the hit data.
+    /// </summary>
+    bool HasFlag(StringKey flag);
 }
 
 /// <inheritdoc />
@@ -71,6 +81,18 @@ public record HitData : IHitData
 
     /// <inheritdoc />
     public void Fail() => HasFailed = true;
+
+    private HashSet<StringKey>? _flags;
+
+    /// <inheritdoc />
+    public void SetFlag(StringKey flag)
+    {
+        _flags ??= [];
+        _flags.Add(flag);
+    }
+
+    /// <inheritdoc />
+    public bool HasFlag(StringKey flag) => _flags != null && _flags.Contains(flag);
 }
 
 /// <summary>

PkmnLib.Dynamic/Models/Pokemon.cs

@@ -401,7 +401,7 @@ public interface IPokemon : IScriptSource, IDeepCloneable
     /// <summary>
     /// Changes the ability of the Pokémon.
     /// </summary>
-    void ChangeAbility(IAbility ability);
+    bool ChangeAbility(IAbility ability);
 
     /// <summary>
     /// Whether the Pokémon is levitating. This is used for moves like Magnet Rise, and abilities such as
@@ -1197,8 +1197,10 @@ public class PokemonImpl : ScriptSource, IPokemon
     }
 
     /// <inheritdoc />
-    public void ChangeAbility(IAbility ability)
+    public bool ChangeAbility(IAbility ability)
     {
+        if (!ability.CanBeChanged)
+            return false;
         OverrideAbility = ability;
         if (Library.ScriptResolver.TryResolve(ScriptCategory.Ability, ability.Name, ability.Parameters,
                 out var abilityScript))
@@ -1210,6 +1212,7 @@ public class PokemonImpl : ScriptSource, IPokemon
         {
             AbilityScript.Clear();
         }
+        return true;
     }
 
     /// <inheritdoc />