Adds mimic

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

@@ -1,7 +1,43 @@
+using PkmnLib.Plugin.Gen7.Scripts.Utils;
+
 namespace PkmnLib.Plugin.Gen7.Scripts.Moves;
 
+/// <summary>
+/// Mimic copies the target's last used move into the move slot Mimic occupies, with 5 PP, until the user
+/// leaves the field. It fails if the target has not used a move, if that move is Sketch, Transform, Struggle,
+/// Metronome, or Chatter, or if the user already knows it.
+///
+/// <see href="https://bulbapedia.bulbagarden.net/wiki/Mimic_(move)">Bulbapedia - Mimic</see>
+/// </summary>
 [Script(ScriptCategory.Move, "mimic")]
-public class Mimic : Script
+public class Mimic : Script, IScriptOnSecondaryEffect
 {
-    // FIXME: support for temporarily copying moves to a move slot.
+    /// <inheritdoc />
+    public void OnSecondaryEffect(IExecutingMove move, IPokemon target, byte hit)
+    {
+        var moveSlot = move.User.Moves.IndexOf(move.ChosenMove);
+        if (moveSlot == -1)
+        {
+            move.GetHitData(target, hit).Fail();
+            return;
+        }
+
+        var lastMove = target.BattleData?.LastMoveChoice;
+        if (lastMove == null || !lastMove.ChosenMove.MoveData.CanCopyMove())
+        {
+            move.GetHitData(target, hit).Fail();
+            return;
+        }
+
+        var copiedMoveName = lastMove.ChosenMove.MoveData.Name;
+        if (move.User.Moves.Any(m => m?.MoveData.Name == copiedMoveName))
+        {
+            move.GetHitData(target, hit).Fail();
+            return;
+        }
+
+        move.User.LearnTemporaryMove(copiedMoveName, MoveLearnMethod.Mimic, (byte)moveSlot);
+        // The copied move only has 5 PP, or its own maximum PP if that is lower.
+        move.User.Moves[moveSlot]?.SetCurrentPP(5);
+    }
 }