Adds effects for after you, assist, and attract

PkmnLib.Dynamic/Models/BattleChoiceQueue.cs

@@ -77,6 +77,9 @@ public class BattleChoiceQueue
     /// <summary>
     /// This moves the choice of a specific Pokémon up to the next choice to be executed.
     /// </summary>
+    /// <returns>
+    /// Returns true if the Pokémon was found and moved, false otherwise.
+    /// </returns>
     public bool MovePokemonChoiceNext(IPokemon pokemon)
     {
         var index = Array.FindIndex(_choices, _currentIndex, choice => choice?.User == pokemon);

Plugins/PkmnLib.Plugin.Gen7/Scripts/Moves/AfterYou.cs

@@ -0,0 +1,32 @@
+using PkmnLib.Dynamic.Models;
+using PkmnLib.Dynamic.ScriptHandling;
+using PkmnLib.Dynamic.ScriptHandling.Registry;
+
+namespace PkmnLib.Plugin.Gen7.Moves;
+
+/// <summary>
+/// The user helps the target and makes it use its move right after the user. 
+/// </summary>
+/// <remarks>
+/// The target will move next on the current turn, ignoring priority. After You bypasses accuracy checks to always hit,
+/// unless the target is in the semi-invulnerable turn of a move such as Dig or Fly. It fails if the target has already
+/// moved on the same turn. After You ignores the effects of Quash.
+/// After You fails if the order remains the same after using After You. 
+/// </remarks>
+[Script(ScriptCategory.Move, "after_you")]
+public class AfterYou : Script
+{
+    /// <inheritdoc />
+    public override void OnSecondaryEffect(IExecutingMove move, IPokemon target, byte hit)
+    {
+        var queue = move.User.BattleData!.Battle.ChoiceQueue;
+        if (queue == null)
+            return;
+        
+        // If the queue doesn't change, the move fails
+        if (!queue.MovePokemonChoiceNext(target))
+        {
+            move.GetHitData(target, hit).Fail();
+        }
+    }
+}

Plugins/PkmnLib.Plugin.Gen7/Scripts/Moves/Assist.cs

@@ -0,0 +1,62 @@
+using System.Collections.Generic;
+using System.Linq;
+using PkmnLib.Dynamic.Models;
+using PkmnLib.Dynamic.Models.Choices;
+using PkmnLib.Dynamic.ScriptHandling;
+using PkmnLib.Dynamic.ScriptHandling.Registry;
+using PkmnLib.Plugin.Gen7.Scripts.Utils;
+using PkmnLib.Static.Moves;
+using PkmnLib.Static.Utils;
+
+namespace PkmnLib.Plugin.Gen7.Moves;
+
+/// <summary>
+/// The user hurriedly and randomly uses a move among those known by ally Pokémon. 
+/// </summary>
+/// <remarks>
+/// The Assist user executes a move that is randomly selected from all the eligible moves known by other Pokémon in the
+/// same party. If the same move is known by multiple Pokémon, each of them counts and therefore the move is more likely
+/// to be called. Assist can call a move that currently has no PP or is known by a fainted Pokémon. It is also able to
+/// call moves that are currently inaccessible to their original users due to Disable, Heal Block, Taunt, or Torment.
+/// If the other Pokémon in the user's party do not know any eligible moves, Assist fails. 
+/// </remarks>
+[Script(ScriptCategory.Move, "assist")]
+public class Assist : Script
+{
+    /// <inheritdoc />
+    public override void ChangeMove(IMoveChoice choice, ref StringKey moveName)
+    {
+        var user = choice.User;
+        if (user.BattleData == null)
+            return;
+        var battle = user.BattleData.Battle;
+        var party = battle.Parties.FirstOrDefault(p => p.Party.Contains(user));
+        if (party == null)
+        {
+            choice.Fail();
+            return;
+        }
+        var moves = GetPartyMoves(party.Party, user).ToList();
+        if (moves.Count == 0)
+        {
+            choice.Fail();
+            return;
+        }
+        var random = battle.Random.GetInt(moves.Count);
+        moveName = moves[random].Name;
+    }
+
+    private static IEnumerable<IMoveData> GetPartyMoves(IPokemonParty party, IPokemon user)
+    {
+        foreach (var pokemon in party.WhereNotNull())
+        {
+            if (pokemon == user)
+                continue;
+            var moves = pokemon.Moves.WhereNotNull().Where(m => m.MoveData.CanCopyMove());
+            foreach (var move in moves)
+            {
+                yield return move.MoveData;
+            }
+        }
+    }
+}

Plugins/PkmnLib.Plugin.Gen7/Scripts/Moves/Attract.cs

@@ -0,0 +1,48 @@
+using PkmnLib.Dynamic.Models;
+using PkmnLib.Dynamic.ScriptHandling;
+using PkmnLib.Dynamic.ScriptHandling.Registry;
+using PkmnLib.Plugin.Gen7.Scripts.Pokemon;
+using PkmnLib.Static.Species;
+
+namespace PkmnLib.Plugin.Gen7.Moves;
+
+/// <summary>
+/// If it is the opposite gender of the user, the target becomes infatuated and less likely to attack. 
+/// </summary>
+/// <remarks>
+/// The target becomes infatuated with the user if they have opposite genders. Attract works regardless of type immunity.
+/// Unlike most status moves, Attract is able to bypass a substitute.
+/// Attract has no effect if the user and target have the same gender, or if either of them is a gender-unknown Pokémon
+/// (such as Magnemite). It also fails when used on a Pokémon that is already infatuated.
+/// Pokémon with the Ability Oblivious or under the protection of Aroma Veil are immune to the effects of Attract. If
+/// a Pokémon is infatuated by Attract while holding a Mental Herb or an Eggant Berry, the item will be consumed and the
+/// infatuation will end. Even if the Pokémon has Oblivious, the item will still be consumed.
+/// If the target Pokémon becomes infatuated while holding a Destiny Knot, the user will also become infatuated with the
+/// target. 
+/// </remarks>
+[Script(ScriptCategory.Move, "attract")]
+public class Attract : Script
+{
+    /// <inheritdoc />
+    public override void OnSecondaryEffect(IExecutingMove move, IPokemon target, byte hit)
+    {
+        if (target.Gender == move.User.Gender)
+        {
+            move.GetHitData(target, hit).Fail();
+            return;
+        }
+
+        if (target.Gender == Gender.Genderless || move.User.Gender == Gender.Genderless)
+        {
+            move.GetHitData(target, hit).Fail();
+            return;
+        }
+        if (target.Volatile.Contains("infatuated"))
+        {
+            move.GetHitData(target, hit).Fail();
+            return;
+        }
+
+        target.Volatile.Add(new Infatuated());
+    }
+}

Plugins/PkmnLib.Plugin.Gen7/Scripts/Pokemon/Infatuated.cs

@@ -0,0 +1,25 @@
+using PkmnLib.Dynamic.Models;
+using PkmnLib.Dynamic.ScriptHandling;
+using PkmnLib.Dynamic.ScriptHandling.Registry;
+
+namespace PkmnLib.Plugin.Gen7.Scripts.Pokemon;
+
+/// <summary>
+/// If an infatuated Pokémon attempts to use a move, it will fail 50% of the time, even when targeting Pokémon other than
+/// the one it is infatuated with. This failed move does not spend PP. 
+/// </summary>
+/// <remarks>
+/// Infatuation is caused when Attract is used on a target of the opposite gender, G-Max Cuddle is used by Gigantamax Eevee
+/// on all opponents of the opposite gender, may be caused when a Pokémon makes contact with a Pokémon of the opposite
+/// gender that has Cute Charm as its Ability, and is caused to a Pokémon that infatuates a Pokémon holding a Destiny Knot. 
+/// </remarks>
+[Script(ScriptCategory.Pokemon, "infatuated")]
+public class Infatuated : Script
+{
+    /// <inheritdoc />
+    public override void PreventMove(IExecutingMove move, ref bool prevent)
+    {
+        if (move.User.BattleData?.Battle?.Random.GetBool() == true)
+            prevent = true;
+    }
+}

Plugins/PkmnLib.Plugin.Gen7/Scripts/Utils/CopyableMoves.cs

@@ -0,0 +1,70 @@
+using System.Collections.Generic;
+using PkmnLib.Static.Moves;
+using PkmnLib.Static.Utils;
+
+namespace PkmnLib.Plugin.Gen7.Scripts.Utils;
+
+public static class CopyableMoves
+{
+    /// <summary>
+    /// Validates if a move can be copied by scripts, such as Assist.
+    /// </summary>
+    public static bool CanCopyMove(this IMoveData move) => !NonCopyable.Contains(move.Name);
+
+    /// <summary>
+    /// The names of moves that cannot be copied by scripts.
+    /// </summary>
+    private static readonly HashSet<StringKey> NonCopyable =
+    [
+        "assist",
+        "baneful_bunker",
+        "beak_blast",
+        "belch",
+        "bestow",
+        "bounce",
+        "celebrate",
+        "chatter",
+        "circle_throw",
+        "copycat",
+        "counter",
+        "covet",
+        "destiny_bond",
+        "detect",
+        "dig",
+        "dive",
+        "dragon_tail",
+        "endure",
+        "feint",
+        "fly",
+        "focus_punch",
+        "follow_me",
+        "helping_hand",
+        "hold_hands",
+        "kings_shield",
+        "mat_block",
+        "me_first",
+        "metronome",
+        "mimic",
+        "mirror_coat",
+        "mirror_move",
+        "nature_power",
+        "phantom_force",
+        "protect",
+        "rage_powder",
+        "roar",
+        "shadow_force",
+        "shell_trap",
+        "sketch",
+        "sky_drop",
+        "sleep_talk",
+        "snatch",
+        "spiky_shield",
+        "spotlight",
+        "struggle",
+        "switcheroo",
+        "thief",
+        "transform",
+        "trick",
+        "whirlwind"
+    ];
+}