/*
    * Copyright (c) 2006 JMockit developers
    * This file is subject to the terms of the MIT license (see LICENSE.txt).
    */
   package mockit.internal.injection;
   
   import static mockit.internal.injection.InjectionPoint.getQualifiedName;
   
   import edu.umd.cs.findbugs.annotations.NonNull;
  import edu.umd.cs.findbugs.annotations.Nullable;
  
  import java.lang.reflect.Field;
  import java.lang.reflect.Type;
  import java.util.LinkedHashMap;
  import java.util.List;
  import java.util.Map;
  import java.util.Map.Entry;
  import java.util.concurrent.ConcurrentHashMap;
  
  import mockit.internal.reflection.FieldReflection;
  import mockit.internal.reflection.GenericTypeReflection;
  
  /**
   * Holds state used throughout the injection process while it's in progress for a given set of tested objects.
   */
  public final class InjectionState {
      @NonNull
      private static final Map<InjectionPoint, Object> globalObjects = new ConcurrentHashMap<>(2);
  
      @NonNull
      private final Map<InjectionPoint, Object> testedObjects;
      @NonNull
      private final Map<InjectionPoint, Object> instantiatedDependencies;
      @NonNull
      public final InjectionProviders injectionProviders;
      @NonNull
      public final LifecycleMethods lifecycleMethods;
      @NonNull
      final InterfaceResolution interfaceResolution;
      @Nullable
      private BeanExporter beanExporter;
      private Object currentTestClassInstance;
  
      InjectionState() {
          testedObjects = new LinkedHashMap<>();
          instantiatedDependencies = new LinkedHashMap<>();
          lifecycleMethods = new LifecycleMethods();
          injectionProviders = new InjectionProviders(lifecycleMethods);
          interfaceResolution = new InterfaceResolution();
      }
  
      void setInjectables(@NonNull Object testClassInstance, @NonNull List<? extends InjectionProvider> injectables) {
          currentTestClassInstance = testClassInstance;
          injectionProviders.setInjectables(injectables);
          lifecycleMethods.getServletConfigForInitMethodsIfAny(injectables, testClassInstance);
      }
  
      void addInjectables(@NonNull Object testClassInstance,
              @NonNull List<? extends InjectionProvider> injectablesToAdd) {
          currentTestClassInstance = testClassInstance;
          List<InjectionProvider> injectables = injectionProviders.addInjectables(injectablesToAdd);
          lifecycleMethods.getServletConfigForInitMethodsIfAny(injectables, testClassInstance);
      }
  
      Object getCurrentTestClassInstance() {
          return currentTestClassInstance;
      }
  
      @Nullable
      public Object getValueToInject(@NonNull InjectionProvider injectionProvider) {
          return injectionProviders.getValueToInject(injectionProvider, currentTestClassInstance);
      }
  
      void saveTestedObject(@NonNull InjectionPoint key, @NonNull Object testedObject, boolean global) {
          Map<InjectionPoint, Object> objects = global ? globalObjects : testedObjects;
          objects.put(key, testedObject);
      }
  
      @Nullable
      Object getTestedInstance(@NonNull InjectionPoint injectionPoint, boolean global) {
          Object testedInstance = instantiatedDependencies.isEmpty() ? null
                  : findPreviouslyInstantiatedDependency(injectionPoint);
  
          if (testedInstance == null) {
              testedInstance = testedObjects.isEmpty() ? null : getValueFromExistingTestedObject(injectionPoint);
          }
  
          if (testedInstance == null && global) {
              testedInstance = globalObjects.get(injectionPoint);
          }
  
          return testedInstance;
      }
  
      @Nullable
      private Object findPreviouslyInstantiatedDependency(@NonNull InjectionPoint injectionPoint) {
          Object dependency = instantiatedDependencies.get(injectionPoint);
  
          if (dependency == null) {
             InjectionPoint injectionPointWithTypeOnly = new InjectionPoint(injectionPoint.type);
             dependency = instantiatedDependencies.get(injectionPointWithTypeOnly);
 
             if (dependency == null) {
                 dependency = findMatchingObject(instantiatedDependencies, null, injectionPointWithTypeOnly);
             }
         }
 
         return dependency;
     }
 
     @Nullable
     private Object getValueFromExistingTestedObject(@NonNull InjectionPoint injectionPoint) {
         for (Object testedObject : testedObjects.values()) {
             Object fieldValue = getValueFromFieldOfEquivalentTypeAndName(injectionPoint, testedObject);
 
             if (fieldValue != null) {
                 return fieldValue;
             }
         }
 
         return null;
     }
 
     @Nullable
     private static Object getValueFromFieldOfEquivalentTypeAndName(@NonNull InjectionPoint injectionPoint,
             @NonNull Object testedObject) {
         for (Field internalField : testedObject.getClass().getDeclaredFields()) {
             Type fieldType = internalField.getGenericType();
             String qualifiedName = getQualifiedName(internalField.getDeclaredAnnotations());
             boolean qualified = qualifiedName != null;
             String fieldName = qualified ? qualifiedName : internalField.getName();
             InjectionPoint internalInjectionPoint = new InjectionPoint(fieldType, fieldName, qualified);
 
             if (internalInjectionPoint.equals(injectionPoint)) {
                 return FieldReflection.getFieldValue(internalField, testedObject);
             }
         }
 
         return null;
     }
 
     @Nullable
     @SuppressWarnings("unchecked")
     public static <D> D getGlobalDependency(@NonNull InjectionPoint key) {
         return (D) globalObjects.get(key);
     }
 
     @Nullable
     public Object getTestedValue(@NonNull TestedClass testedClass, @NonNull InjectionPoint injectionPoint) {
         Object testedValue = testedObjects.get(injectionPoint);
 
         if (testedValue == null) {
             testedValue = findMatchingObject(testedObjects, testedClass, injectionPoint);
         }
 
         return testedValue;
     }
 
     @Nullable
     public Object getInstantiatedDependency(@Nullable TestedClass testedClass, @NonNull InjectionPoint dependencyKey) {
         Object dependency = testedObjects.get(dependencyKey);
 
         if (dependency == null) {
             dependency = findMatchingObject(testedObjects, testedClass, dependencyKey);
 
             if (dependency == null) {
                 dependency = instantiatedDependencies.get(dependencyKey);
 
                 if (dependency == null) {
                     dependency = findMatchingObject(instantiatedDependencies, testedClass, dependencyKey);
 
                     if (dependency == null) {
                         dependency = findMatchingObject(globalObjects, testedClass, dependencyKey);
                     }
                 }
             }
         }
 
         return dependency;
     }
 
     @Nullable
     private static Object findMatchingObject(@NonNull Map<InjectionPoint, Object> availableObjects,
             @Nullable TestedClass testedClass, @NonNull InjectionPoint injectionPoint) {
         if (availableObjects.isEmpty()) {
             return null;
         }
 
         GenericTypeReflection reflection = testedClass == null ? null : testedClass.reflection;
         Type dependencyType = injectionPoint.type;
         Object found = null;
 
         for (Entry<InjectionPoint, Object> injectionPointAndObject : availableObjects.entrySet()) {
             InjectionPoint dependencyIP = injectionPointAndObject.getKey();
             Object dependencyObject = injectionPointAndObject.getValue();
 
             if (injectionPoint.equals(dependencyIP)) {
                 return dependencyObject;
             }
 
             if (reflection != null) {
                 if (!reflection.areMatchingTypes(dependencyType, dependencyIP.type)) {
                     continue;
                 }
                 found = dependencyObject;
             }
 
             if (injectionPoint.hasSameName(dependencyIP)) {
                 return dependencyObject;
             }
         }
 
         return injectionPoint.qualified ? null : found;
     }
 
     public void saveInstantiatedDependency(@NonNull InjectionPoint dependencyKey, @NonNull Object dependency) {
         instantiatedDependencies.put(dependencyKey, dependency);
     }
 
     public static void saveGlobalDependency(@NonNull InjectionPoint dependencyKey, @NonNull Object dependency) {
         globalObjects.put(dependencyKey, dependency);
     }
 
     void clearTestedObjectsAndInstantiatedDependencies() {
         testedObjects.clear();
         instantiatedDependencies.clear();
     }
 
     @NonNull
     BeanExporter getBeanExporter() {
         if (beanExporter == null) {
             beanExporter = new BeanExporter(this);
         }
 
         return beanExporter;
     }
 
     @Nullable
     public Class<?> resolveInterface(@NonNull Class<?> anInterface) {
         return interfaceResolution.resolveInterface(anInterface, currentTestClassInstance);
     }
 }