Fixes and reworking of item use

PkmnLib.Dynamic/Models/Battle.cs

@@ -351,6 +351,21 @@ public class BattleImpl : ScriptSource, IBattle
             if (switchChoice.SwitchTo == switchChoice.User)
                 return false;
         }
+        else if (choice is IItemChoice itemChoice)
+        {
+            if (!Library.ScriptResolver.TryResolveBattleItemScript(itemChoice.Item, out var itemScript))
+                return false;
+            if (!itemScript.IsItemUsable)
+                return false;
+            if (itemScript.TargetType != ItemTargetType.None)
+            {
+                var target = itemChoice.GetTargetPokemon(this);
+                if (target is null || !itemScript.IsTargetValid(target))
+                    return false;
+                if (!itemScript.TargetType.IsValidTarget(this, choice.User, target))
+                    return false;
+            }
+        }
 
         return true;
 

PkmnLib.Dynamic/Models/Choices/ItemChoice.cs

@@ -11,40 +11,67 @@ public interface IItemChoice : ITurnChoice
     /// <summary>
     /// The item that is used.
     /// </summary>
-    public IItem Item { get; }
+    IItem Item { get; }
 
     /// <summary>
-    /// The side the move is targeted at.
+    /// The target Pokémon of the item, if any.
     /// </summary>
-    byte? TargetSide { get; }
-
-    /// <summary>
-    /// The position the move is targeted at.
-    /// </summary>
-    byte? TargetPosition { get; }
+    IPokemon? GetTargetPokemon(IBattle battle);
 }
 
 /// <inheritdoc cref="IItemChoice"/>
 public class ItemChoice : TurnChoice, IItemChoice
 {
     /// <inheritdoc cref="ItemChoice"/>
-    public ItemChoice(IPokemon user, IItem item, byte? targetSide, byte? targetPosition) : base(user)
+    private ItemChoice(IPokemon user, IItem item, byte? targetSide, byte? targetPosition, IPokemon? targetPokemon) :
+        base(user)
     {
         Item = item;
         TargetSide = targetSide;
         TargetPosition = targetPosition;
+        TargetPokemon = targetPokemon;
     }
 
+    public static ItemChoice CreateWithoutTarget(IPokemon user, IItem item) =>
+        new(user, item, null, null, null);
+
+    public static ItemChoice CreateForOpponent(IPokemon user, IItem item, byte targetSide, byte targetPosition) =>
+        new(user, item, targetSide, targetPosition, null);
+
+    public static ItemChoice CreateForPartyMember(IPokemon user, IItem item, IPokemon targetPokemon) =>
+        new(user, item, null, null, targetPokemon);
+
     /// <summary>
     /// The item that is used.
     /// </summary>
     public IItem Item { get; }
 
     /// <inheritdoc />
-    public byte? TargetSide { get; }
+    public IPokemon? GetTargetPokemon(IBattle battle)
+    {
+        if (TargetPokemon != null)
+            return TargetPokemon;
 
-    /// <inheritdoc />
-    public byte? TargetPosition { get; }
+        if (!TargetSide.HasValue || !TargetPosition.HasValue)
+            return null;
+        var side = battle.Sides[TargetSide.Value];
+        return side.Pokemon[TargetPosition.Value];
+    }
+
+    /// <summary>
+    /// The target side of the item, if any.
+    /// </summary>
+    private byte? TargetSide { get; }
+
+    /// <summary>
+    /// The target position of the item, if any.
+    /// </summary>
+    private byte? TargetPosition { get; }
+
+    /// <summary>
+    /// The target Pokémon of the item, if any. This is used for party members.
+    /// </summary>
+    private IPokemon? TargetPokemon { get; }
 
     /// <inheritdoc />
     public override int ScriptCount => User.ScriptCount;

PkmnLib.Dynamic/Models/ItemTargetType.cs

@@ -0,0 +1,67 @@
+namespace PkmnLib.Dynamic.Models;
+
+/// <summary>
+/// Types of targets an item can have.
+/// </summary>
+[Flags]
+public enum ItemTargetType
+{
+    /// <summary>
+    /// The item does not require a target.
+    /// </summary>
+    None = 0,
+
+    /// <summary>
+    /// The item targets Pokémon that are part of the user's own team.
+    /// </summary>
+    OwnPokemon = 1,
+
+    /// <summary>
+    /// The item targets allied Pokémon.
+    /// </summary>
+    AllyPokemon = 2,
+
+    /// <summary>
+    /// The item targets opposing Pokémon.
+    /// </summary>
+    FoePokemon = 4,
+}
+
+/// <summary>
+/// Helper methods for ItemTargetType.
+/// </summary>
+public static class ItemTargetTypeHelpers
+{
+    /// <summary>
+    /// Determines if the given target is valid based on the ItemTargetType.
+    /// </summary>
+    public static bool IsValidTarget(this ItemTargetType targetType, IBattle battle, IPokemon user, IPokemon target)
+    {
+        if (targetType == ItemTargetType.None)
+            return true;
+
+        if (targetType.HasFlag(ItemTargetType.OwnPokemon))
+        {
+            var userParty = battle.Parties.FirstOrDefault(x => x.Party.Contains(user));
+            var targetParty = battle.Parties.FirstOrDefault(x => x.Party.Contains(target));
+            if (userParty is not null && targetParty is not null && userParty == targetParty)
+                return true;
+        }
+
+        if (targetType.HasFlag(ItemTargetType.AllyPokemon))
+        {
+            if (user.BattleData?.BattleSide == target.BattleData?.BattleSide)
+                return true;
+        }
+
+        if (targetType.HasFlag(ItemTargetType.FoePokemon))
+        {
+            var userParty = battle.Parties.FirstOrDefault(x => x.Party.Contains(user));
+            var targetParty = battle.Parties.FirstOrDefault(x => x.Party.Contains(target));
+            if (userParty is not null && targetParty is not null && userParty != targetParty)
+                return true;
+        }
+
+        return false;
+    }
+}