Implement basic AI check for whether a move would fail

Plugins/PkmnLib.Plugin.Gen7/AI/AIMoveScoreFunctionAttribute.cs

@@ -5,4 +5,9 @@ namespace PkmnLib.Plugin.Gen7.AI;
 [AttributeUsage(AttributeTargets.Method), MeansImplicitUse]
 public class AIMoveScoreFunctionAttribute : Attribute
 {
+}
+
+[AttributeUsage(AttributeTargets.Method), MeansImplicitUse]
+public class AIMoveFailureFunctionAttribute : Attribute
+{
 }

Plugins/PkmnLib.Plugin.Gen7/AI/ExplicitAIFunctions.cs

@@ -20,18 +20,37 @@ public static class ExplicitAIFunctions
 
             if (attribute.Category == ScriptCategory.Move)
             {
-                // Check if the move type has a static function in the following format:
+                var failureMethod = type.GetMethods(BindingFlags.Public | BindingFlags.Static).FirstOrDefault(m =>
-                // public static void AIMoveEffectScore(MoveOption option, ref int score);
+                    m.GetCustomAttribute<AIMoveFailureFunctionAttribute>() != null);
-                var method = type.GetMethods(BindingFlags.Public | BindingFlags.Static).FirstOrDefault(m =>
+                if (failureMethod != null)
-                    m.GetCustomAttribute<AIMoveScoreFunctionAttribute>() != null && m.ReturnType == typeof(void) &&
-                    m.GetParameters().Length == 2 && m.GetParameters()[0].ParameterType == typeof(MoveOption) &&
-                    m.GetParameters()[1].ParameterType == typeof(int).MakeByRefType());
-                if (method != null)
                 {
+                    if (failureMethod.ReturnType != typeof(bool) || failureMethod.GetParameters().Length != 1 ||
+                        failureMethod.GetParameters()[0].ParameterType != typeof(MoveOption))
+                    {
+                        throw new InvalidOperationException(
+                            $"Method {failureMethod.Name} in {type.Name} must return bool and take a single MoveOption parameter.");
+                    }
+                    var optionParam = Expression.Parameter(typeof(MoveOption), "option");
+                    var functionExpression = Expression.Lambda<AIBoolHandler>(
+                        Expression.Call(null, failureMethod, optionParam), optionParam).Compile();
+                    handlers.MoveFailureCheck.Add(attribute.Name, functionExpression);
+                }
+
+                var scoreMethod = type.GetMethods(BindingFlags.Public | BindingFlags.Static).FirstOrDefault(m =>
+                    m.GetCustomAttribute<AIMoveScoreFunctionAttribute>() != null);
+                if (scoreMethod != null)
+                {
+                    if (scoreMethod.ReturnType != typeof(void) || scoreMethod.GetParameters().Length != 2 ||
+                        scoreMethod.GetParameters()[0].ParameterType != typeof(MoveOption) ||
+                        scoreMethod.GetParameters()[1].ParameterType != typeof(int).MakeByRefType())
+                    {
+                        throw new InvalidOperationException(
+                            $"Method {scoreMethod.Name} in {type.Name} must return void and take a MoveOption and an int by reference parameter.");
+                    }
                     var optionParam = Expression.Parameter(typeof(MoveOption), "option");
                     var scoreParam = Expression.Parameter(typeof(int).MakeByRefType(), "score");
                     var functionExpression = Expression.Lambda<AIScoreMoveHandler>(
-                        Expression.Call(null, method, optionParam, scoreParam), optionParam, scoreParam).Compile();
+                        Expression.Call(null, scoreMethod, optionParam, scoreParam), optionParam, scoreParam).Compile();
                     handlers.MoveEffectScore.Add(attribute.Name, functionExpression);
                 }
             }

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

@@ -35,6 +35,9 @@ public abstract class ChangeUserStats : Script, IScriptOnInitialize, IScriptOnSe
         move.User.ChangeStatBoost(_stat, _amount, true, false);
     }
 
+    protected static bool WouldMoveFail(MoveOption option, Statistic stat) =>
+        option.Move.User.StatBoost.GetStatistic(stat) == StatBoostStatisticSet.MaxStatBoost;
+
     protected static void GetMoveEffectScore(MoveOption option, Statistic stat, ref int score)
     {
         if (option.Move.Move.SecondaryEffect == null ||
@@ -56,6 +59,9 @@ public class ChangeUserAttack : ChangeUserStats
     {
     }
 
+    [AIMoveFailureFunction]
+    public static bool AIMoveWillFail(MoveOption option) => WouldMoveFail(option, Statistic.Attack);
+
     [AIMoveScoreFunction]
     public static void AIMoveEffectScore(MoveOption option, ref int score) =>
         GetMoveEffectScore(option, Statistic.Attack, ref score);
@@ -68,6 +74,9 @@ public class ChangeUserDefense : ChangeUserStats
     {
     }
 
+    [AIMoveFailureFunction]
+    public static bool AIMoveWillFail(MoveOption option) => WouldMoveFail(option, Statistic.Defense);
+
     [AIMoveScoreFunction]
     public static void AIMoveEffectScore(MoveOption option, ref int score) =>
         GetMoveEffectScore(option, Statistic.Defense, ref score);
@@ -80,6 +89,9 @@ public class ChangeUserSpecialAttack : ChangeUserStats
     {
     }
 
+    [AIMoveFailureFunction]
+    public static bool AIMoveWillFail(MoveOption option) => WouldMoveFail(option, Statistic.SpecialAttack);
+
     [AIMoveScoreFunction]
     public static void AIMoveEffectScore(MoveOption option, ref int score) =>
         GetMoveEffectScore(option, Statistic.SpecialAttack, ref score);
@@ -92,6 +104,9 @@ public class ChangeUserSpecialDefense : ChangeUserStats
     {
     }
 
+    [AIMoveFailureFunction]
+    public static bool AIMoveWillFail(MoveOption option) => WouldMoveFail(option, Statistic.SpecialDefense);
+
     [AIMoveScoreFunction]
     public static void AIMoveEffectScore(MoveOption option, ref int score) =>
         GetMoveEffectScore(option, Statistic.SpecialDefense, ref score);
@@ -104,6 +119,9 @@ public class ChangeUserSpeed : ChangeUserStats
     {
     }
 
+    [AIMoveFailureFunction]
+    public static bool AIMoveWillFail(MoveOption option) => WouldMoveFail(option, Statistic.Speed);
+
     [AIMoveScoreFunction]
     public static void AIMoveEffectScore(MoveOption option, ref int score) =>
         GetMoveEffectScore(option, Statistic.Speed, ref score);
@@ -116,6 +134,9 @@ public class ChangeUserAccuracy : ChangeUserStats
     {
     }
 
+    [AIMoveFailureFunction]
+    public static bool AIMoveWillFail(MoveOption option) => WouldMoveFail(option, Statistic.Accuracy);
+
     [AIMoveScoreFunction]
     public static void AIMoveEffectScore(MoveOption option, ref int score) =>
         GetMoveEffectScore(option, Statistic.Accuracy, ref score);
@@ -128,6 +149,9 @@ public class ChangeUserEvasion : ChangeUserStats
     {
     }
 
+    [AIMoveFailureFunction]
+    public static bool AIMoveWillFail(MoveOption option) => WouldMoveFail(option, Statistic.Evasion);
+
     [AIMoveScoreFunction]
     public static void AIMoveEffectScore(MoveOption option, ref int score) =>
         GetMoveEffectScore(option, Statistic.Evasion, ref score);