/*
    * Copyright (c) 2006 JMockit developers
    * This file is subject to the terms of the MIT license (see LICENSE.txt).
    */
   package mockit.internal.faking;
   
   import static java.lang.reflect.Modifier.isNative;
   
   import static mockit.internal.util.ObjectMethods.isMethodFromObject;
  
  import edu.umd.cs.findbugs.annotations.NonNull;
  import edu.umd.cs.findbugs.annotations.Nullable;
  
  import java.lang.annotation.Annotation;
  import java.lang.reflect.Method;
  import java.lang.reflect.Modifier;
  import java.lang.reflect.Type;
  import java.util.ArrayList;
  import java.util.List;
  
  import mockit.internal.ClassLoadingBridge;
  import mockit.internal.reflection.GenericTypeReflection;
  import mockit.internal.reflection.GenericTypeReflection.GenericSignature;
  import mockit.internal.state.TestRun;
  import mockit.internal.util.TypeDescriptor;
  import mockit.internal.util.Utilities;
  
  /**
   * A container for the fake methods "collected" from a fake class.
   */
  final class FakeMethods {
      @NonNull
      private final Class<?> realClass;
      private final boolean targetTypeIsAClass;
      private final boolean reentrantRealClass;
      @NonNull
      private final List<FakeMethod> methods;
      @Nullable
      private FakeMethod adviceMethod;
      @NonNull
      private final GenericTypeReflection typeParametersToTypeArguments;
      @NonNull
      private String fakeClassInternalName;
      @Nullable
      private List<FakeState> fakeStates;
  
      final class FakeMethod {
          private final int access;
          @NonNull
          final String name;
          @NonNull
          final String desc;
          private final boolean isByNameOnly;
          final boolean isAdvice;
          @NonNull
          final String fakeDescWithoutInvocationParameter;
          private boolean hasMatchingRealMethod;
          @Nullable
          private GenericSignature fakeSignature;
          private int indexForFakeState;
          private boolean nativeRealMethod;
  
          private FakeMethod(int access, @NonNull String name, @NonNull String desc) {
              this.access = access;
              this.name = name;
              this.desc = desc;
  
              if (desc.contains("Lmockit/Invocation;")) {
                  fakeDescWithoutInvocationParameter = '(' + desc.substring(20);
                  isByNameOnly = name.charAt(0) != '$' && fakeDescWithoutInvocationParameter.startsWith("()");
                  isAdvice = "$advice".equals(name) && "()Ljava/lang/Object;".equals(fakeDescWithoutInvocationParameter);
              } else {
                  fakeDescWithoutInvocationParameter = desc;
                  isByNameOnly = false;
                  isAdvice = false;
              }
  
              hasMatchingRealMethod = false;
              indexForFakeState = -1;
          }
  
          @SuppressWarnings("StringEquality")
          boolean hasInvocationParameter() {
              return desc != fakeDescWithoutInvocationParameter;
          }
  
          boolean hasInvocationParameterOnly() {
              return isByNameOnly || isAdvice;
          }
  
          boolean isMatch(int realAccess, @NonNull String realName, @NonNull String realDesc,
                  @Nullable String signature) {
              if (name.equals(realName) && hasMatchingParameters(realDesc, signature)) {
                  hasMatchingRealMethod = true;
                  nativeRealMethod = isNative(realAccess);
                  return true;
              }
  
              return false;
         }
 
         private boolean hasMatchingParameters(@NonNull String methodDesc, @Nullable String signature) {
             boolean sameParametersIgnoringGenerics = fakeDescWithoutInvocationParameter.equals(methodDesc);
 
             if (sameParametersIgnoringGenerics || signature == null) {
                 return sameParametersIgnoringGenerics;
             }
 
             if (fakeSignature == null) {
                 fakeSignature = typeParametersToTypeArguments.parseSignature(fakeDescWithoutInvocationParameter);
             }
 
             return fakeSignature.satisfiesGenericSignature(signature);
         }
 
         boolean isMatchByName(@NonNull String realName) {
             return isByNameOnly && name.equals(realName);
         }
 
         @NonNull
         Class<?> getRealClass() {
             return realClass;
         }
 
         int getIndexForFakeState() {
             return indexForFakeState;
         }
 
         boolean isStatic() {
             return Modifier.isStatic(access);
         }
 
         boolean isPublic() {
             return Modifier.isPublic(access);
         }
 
         boolean isForGenericMethod() {
             return fakeSignature != null;
         }
 
         boolean isForNativeMethod() {
             return nativeRealMethod;
         }
 
         boolean requiresFakeState() {
             return hasInvocationParameter() || reentrantRealClass;
         }
 
         boolean canBeReentered() {
             return targetTypeIsAClass && !nativeRealMethod;
         }
     }
 
     FakeMethods(@NonNull Class<?> realClass, @Nullable Type targetType) {
         this.realClass = realClass;
 
         if (targetType == null || realClass == targetType) {
             targetTypeIsAClass = true;
         } else {
             Class<?> targetClass = Utilities.getClassType(targetType);
             targetTypeIsAClass = !targetClass.isInterface();
         }
 
         reentrantRealClass = targetTypeIsAClass
                 && ClassLoadingBridge.instanceOfClassThatParticipatesInClassLoading(realClass);
         methods = new ArrayList<>();
         typeParametersToTypeArguments = new GenericTypeReflection(realClass, targetType);
         fakeClassInternalName = "";
     }
 
     @NonNull
     Class<?> getRealClass() {
         return realClass;
     }
 
     @Nullable
     FakeMethod addMethod(boolean fromSuperClass, int access, @NonNull String name, @NonNull String desc) {
         if (fromSuperClass && isMethodAlreadyAdded(name, desc)) {
             return null;
         }
 
         FakeMethod fakeMethod = new FakeMethod(access, name, desc);
 
         if (fakeMethod.isAdvice) {
             adviceMethod = fakeMethod;
         } else {
             methods.add(fakeMethod);
         }
 
         return fakeMethod;
     }
 
     private boolean isMethodAlreadyAdded(@NonNull String name, @NonNull String desc) {
         int p = desc.lastIndexOf(')');
         String params = desc.substring(0, p + 1);
 
         for (FakeMethod fakeMethod : methods) {
             if (fakeMethod.name.equals(name) && fakeMethod.desc.startsWith(params)) {
                 return true;
             }
         }
 
         return false;
     }
 
     void addFakeState(@NonNull FakeState fakeState) {
         if (fakeStates == null) {
             fakeStates = new ArrayList<>(4);
         }
 
         fakeState.fakeMethod.indexForFakeState = fakeStates.size();
         fakeStates.add(fakeState);
     }
 
     /**
      * Finds a fake method with the same signature of a given real method, if previously collected from the fake class.
      * Also handles "match-by-name-only" fake methods with only the <code>Invocation</code> parameter, and the
      * <code>$advice</code> fake method.
      * <p>
      * This operation can be performed only once for any given fake method in this container, so that after the last
      * real method is processed there should be no fake methods left unused in the container.
      */
     @Nullable
     FakeMethod findMethod(int access, @NonNull String name, @NonNull String desc, @Nullable String signature) {
         FakeMethod fakeMethodMatchingByNameOnly = null;
 
         for (FakeMethod fakeMethod : methods) {
             if (fakeMethod.isMatch(access, name, desc, signature)) {
                 // Mocking native methods with IntrinsicCandidate annotations will cause the VM to terminate illegally.
                 if (isNative(access) && hasIntrinsicCandidateAnnotation(getRealClass(), name, desc)) {
                     throw new UnsupportedOperationException(
                             "Native methods annotated with IntrinsicCandidate cannot be mocked: "
                                     + getRealClass().getSimpleName() + "#" + name);
                 }
                 return fakeMethod;
             }
 
             if (fakeMethod.isMatchByName(name)) {
                 fakeMethodMatchingByNameOnly = fakeMethod;
             }
         }
 
         if (fakeMethodMatchingByNameOnly != null) {
             return fakeMethodMatchingByNameOnly;
         }
 
         if (adviceMethod != null && !isNative(access) && !isConstructorOrClassInitialization(name)
                 && !isMethodFromObject(name, desc)) {
             return adviceMethod;
         }
 
         return null;
     }
 
     private boolean hasIntrinsicCandidateAnnotation(Class<?> clazz, String methodName, String methodDescriptor) {
         Class<?>[] parameterTypes = TypeDescriptor.getParameterTypes(methodDescriptor);
 
         try {
             // All access modifiers
             Method method = clazz.getDeclaredMethod(methodName, parameterTypes);
             Annotation[] annotations = method.getAnnotations();
 
             for (Annotation annotation : annotations) {
                 String annotationName = annotation.annotationType().getSimpleName();
                 // JDK11: jdk.internal.HotSpotIntrinsicCandidate
                 // JDK17, 21: jdk.internal.vm.annotation.IntrinsicCandidate
                 if (annotationName.contains("IntrinsicCandidate")) {
                     return true;
                 }
             }
         } catch (NoSuchMethodException e) {
             return false;
         }
         return false;
     }
 
     private static boolean isConstructorOrClassInitialization(@NonNull String memberName) {
         return "$init".equals(memberName) || "$clinit".equals(memberName);
     }
 
     @NonNull
     String getFakeClassInternalName() {
         return fakeClassInternalName;
     }
 
     void setFakeClassInternalName(@NonNull String fakeClassInternalName) {
         this.fakeClassInternalName = fakeClassInternalName.intern();
     }
 
     boolean hasUnusedFakes() {
         if (adviceMethod != null) {
             return true;
         }
 
         for (FakeMethod method : methods) {
             if (!method.hasMatchingRealMethod) {
                 return true;
             }
         }
 
         return false;
     }
 
     void registerFakeStates(@NonNull Object fake, boolean forStartupFake) {
         if (fakeStates != null) {
             FakeStates allFakeStates = TestRun.getFakeStates();
 
             if (forStartupFake) {
                 allFakeStates.addStartupFakeAndItsFakeStates(fake, fakeStates);
             } else {
                 allFakeStates.addFakeAndItsFakeStates(fake, fakeStates);
             }
         }
     }
 }