/*
    * Copyright (c) 2006 JMockit developers
    * This file is subject to the terms of the MIT license (see LICENSE.txt).
    */
   package mockit.internal.injection.constructor;
   
   import static mockit.internal.injection.InjectionPoint.getQualifiedName;
   import static mockit.internal.injection.InjectionPoint.getTypeOfInjectionPointFromVarargsParameter;
   import static mockit.internal.injection.InjectionPoint.kindOfInjectionPoint;
  import static mockit.internal.injection.InjectionPoint.wrapInProviderIfNeeded;
  import static mockit.internal.injection.InjectionProvider.NULL;
  import static mockit.internal.reflection.ConstructorReflection.invokeAccessible;
  import static mockit.internal.util.Utilities.NO_ARGS;
  import static mockit.internal.util.Utilities.ensureThatMemberIsAccessible;
  import static mockit.internal.util.Utilities.getClassType;
  
  import edu.umd.cs.findbugs.annotations.NonNull;
  import edu.umd.cs.findbugs.annotations.Nullable;
  
  import java.lang.reflect.Array;
  import java.lang.reflect.Constructor;
  import java.lang.reflect.Type;
  import java.util.ArrayList;
  import java.util.List;
  
  import mockit.asm.types.JavaType;
  import mockit.internal.injection.InjectionPoint.KindOfInjectionPoint;
  import mockit.internal.injection.InjectionProvider;
  import mockit.internal.injection.InjectionProviders;
  import mockit.internal.injection.InjectionState;
  import mockit.internal.injection.Injector;
  import mockit.internal.injection.TestedClass;
  import mockit.internal.injection.full.FullInjection;
  import mockit.internal.state.ParameterNames;
  import mockit.internal.state.TestRun;
  import mockit.internal.util.MethodFormatter;
  import mockit.internal.util.StackTrace;
  
  public final class ConstructorInjection extends Injector {
      @NonNull
      private final Constructor<?> constructor;
  
      public ConstructorInjection(@NonNull InjectionState injectionState, @Nullable FullInjection fullInjection,
              @NonNull Constructor<?> constructor) {
          super(injectionState, fullInjection);
          ensureThatMemberIsAccessible(constructor);
          this.constructor = constructor;
      }
  
      @Nullable
      public Object instantiate(@NonNull List<InjectionProvider> parameterProviders, @NonNull TestedClass testedClass,
              boolean required, boolean needToConstruct) {
          Type[] parameterTypes = constructor.getGenericParameterTypes();
          int n = parameterTypes.length;
          List<InjectionProvider> consumedInjectables = n == 0 ? null
                  : injectionState.injectionProviders.saveConsumedInjectionProviders();
          Object[] arguments = n == 0 ? NO_ARGS : new Object[n];
          boolean varArgs = constructor.isVarArgs();
  
          if (varArgs) {
              n--;
          }
  
          for (int i = 0; i < n; i++) {
              @NonNull
              InjectionProvider parameterProvider = parameterProviders.get(i);
              Object value;
  
              if (parameterProvider instanceof ConstructorParameter) {
                  value = createOrReuseArgumentValue((ConstructorParameter) parameterProvider, required);
  
                  if (value == null && !needToConstruct) {
                      return null;
                  }
              } else {
                  value = getArgumentValueToInject(parameterProvider, i);
              }
  
              if (value != NULL) {
                  Type parameterType = parameterTypes[i];
                  arguments[i] = wrapInProviderIfNeeded(parameterType, value);
              }
          }
  
          if (varArgs) {
              Type parameterType = parameterTypes[n];
              arguments[n] = obtainInjectedVarargsArray(parameterType, testedClass);
          }
  
          if (consumedInjectables != null) {
              injectionState.injectionProviders.restoreConsumedInjectionProviders(consumedInjectables);
          }
  
          return invokeConstructor(arguments);
      }
  
      @Nullable
      private Object createOrReuseArgumentValue(@NonNull ConstructorParameter constructorParameter, boolean required) {
          Object givenValue = constructorParameter.getValue(null);
 
         if (givenValue != null) {
             return givenValue;
         }
 
         assert fullInjection != null;
 
         Class<?> parameterClass = constructorParameter.getClassOfDeclaredType();
         Object newOrReusedValue = null;
 
         if (FullInjection.isInstantiableType(parameterClass)) {
             Type parameterType = constructorParameter.getDeclaredType();
             KindOfInjectionPoint kindOfInjectionPoint = kindOfInjectionPoint(constructor);
             injectionState.injectionProviders.setTypeOfInjectionPoint(parameterType, kindOfInjectionPoint);
             String qualifiedName = getQualifiedName(constructorParameter.getAnnotations());
             TestedClass nextTestedClass = new TestedClass(parameterType, parameterClass);
 
             newOrReusedValue = fullInjection.createOrReuseInstance(nextTestedClass, this, constructorParameter,
                     qualifiedName);
         } else {
             fullInjection.setInjectionProvider(constructorParameter);
         }
 
         if (newOrReusedValue == null && required) {
             String parameterName = constructorParameter.getName();
             String message = "Missing @Tested or @Injectable" + missingValueDescription(parameterName)
                     + "\r\n  when initializing " + fullInjection;
             IllegalStateException injectionFailure = new IllegalStateException(message);
             StackTrace.filterStackTrace(injectionFailure);
             throw injectionFailure;
         }
 
         return newOrReusedValue;
     }
 
     @NonNull
     private Object getArgumentValueToInject(@NonNull InjectionProvider injectable, int parameterIndex) {
         Object argument = injectionState.getValueToInject(injectable);
 
         if (argument == null) {
             String classDesc = getClassDesc();
             String constructorDesc = getConstructorDesc();
             String parameterName = ParameterNames.getName(classDesc, constructorDesc, parameterIndex);
 
             if (parameterName == null) {
                 parameterName = injectable.getName();
             }
 
             throw new IllegalArgumentException(
                     "No injectable value available" + missingValueDescription(parameterName));
         }
 
         return argument;
     }
 
     @NonNull
     private String getClassDesc() {
         return JavaType.getInternalName(constructor.getDeclaringClass());
     }
 
     @NonNull
     private String getConstructorDesc() {
         return "<init>" + JavaType.getConstructorDescriptor(constructor);
     }
 
     @NonNull
     private Object obtainInjectedVarargsArray(@NonNull Type parameterType, @NonNull TestedClass testedClass) {
         Type varargsElementType = getTypeOfInjectionPointFromVarargsParameter(parameterType);
         KindOfInjectionPoint kindOfInjectionPoint = kindOfInjectionPoint(constructor);
         InjectionProviders injectionProviders = injectionState.injectionProviders;
         injectionProviders.setTypeOfInjectionPoint(varargsElementType, kindOfInjectionPoint);
 
         List<Object> varargValues = new ArrayList<>();
         InjectionProvider injectable;
 
         while ((injectable = injectionProviders.findNextInjectableForInjectionPoint(testedClass)) != null) {
             Object value = injectionState.getValueToInject(injectable);
 
             if (value != null) {
                 value = wrapInProviderIfNeeded(varargsElementType, value);
                 varargValues.add(value);
             }
         }
 
         return newArrayFromList(varargsElementType, varargValues);
     }
 
     @NonNull
     private static Object newArrayFromList(@NonNull Type elementType, @NonNull List<Object> values) {
         Class<?> componentType = getClassType(elementType);
         int elementCount = values.size();
         Object array = Array.newInstance(componentType, elementCount);
 
         for (int i = 0; i < elementCount; i++) {
             Array.set(array, i, values.get(i));
         }
 
         return array;
     }
 
     @NonNull
     private String missingValueDescription(@NonNull String name) {
         String classDesc = getClassDesc();
         String constructorDesc = getConstructorDesc();
         String constructorDescription = new MethodFormatter(classDesc, constructorDesc).toString();
         int p = constructorDescription.indexOf('#');
         // noinspection DynamicRegexReplaceableByCompiledPattern
         String friendlyConstructorDesc = constructorDescription.substring(p + 1).replace("java.lang.", "");
 
         return " for parameter \"" + name + "\" in constructor " + friendlyConstructorDesc;
     }
 
     @NonNull
     private Object invokeConstructor(@NonNull Object[] arguments) {
         TestRun.exitNoMockingZone();
 
         try {
             return invokeAccessible(constructor, arguments);
         } finally {
             TestRun.enterNoMockingZone();
         }
     }
 }