/*
    * 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 java.lang.reflect.Modifier.PRIVATE;
   import static java.lang.reflect.Modifier.PROTECTED;
   import static java.lang.reflect.Modifier.PUBLIC;
  
  import static mockit.internal.injection.InjectionPoint.getQualifiedName;
  import static mockit.internal.injection.InjectionPoint.getTypeOfInjectionPointFromVarargsParameter;
  import static mockit.internal.injection.InjectionPoint.kindOfInjectionPoint;
  
  import edu.umd.cs.findbugs.annotations.NonNull;
  import edu.umd.cs.findbugs.annotations.Nullable;
  
  import java.lang.annotation.Annotation;
  import java.lang.reflect.Constructor;
  import java.lang.reflect.Type;
  import java.util.ArrayList;
  import java.util.Arrays;
  import java.util.Comparator;
  import java.util.List;
  
  import mockit.asm.types.JavaType;
  import mockit.internal.injection.InjectionPoint;
  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.TestedClass;
  import mockit.internal.state.ParameterNames;
  import mockit.internal.util.ParameterNameExtractor;
  
  public final class ConstructorSearch {
      private static final int CONSTRUCTOR_ACCESS = PUBLIC + PROTECTED + PRIVATE;
  
      @NonNull
      private final InjectionState injectionState;
      @NonNull
      private final TestedClass testedClass;
      @NonNull
      private final String testedClassDesc;
      @NonNull
      public List<InjectionProvider> parameterProviders;
      private final boolean withFullInjection;
      @Nullable
      private Constructor<?> constructor;
      @Nullable
      private StringBuilder searchResults;
  
      public ConstructorSearch(@NonNull InjectionState injectionState, @NonNull TestedClass testedClass,
              boolean withFullInjection) {
          this.injectionState = injectionState;
          this.testedClass = testedClass;
          Class<?> declaredClass = testedClass.getDeclaredClass();
          testedClassDesc = ParameterNameExtractor.extractNames(declaredClass);
          parameterProviders = new ArrayList<>();
          this.withFullInjection = withFullInjection;
      }
  
      @Nullable
      public Constructor<?> findConstructorToUse() {
          constructor = null;
          Class<?> declaredClass = testedClass.targetClass;
          Constructor<?>[] constructors = declaredClass.getDeclaredConstructors();
  
          if (!findSingleAnnotatedConstructor(constructors)) {
              findSatisfiedConstructorWithMostParameters(constructors);
          }
  
          return constructor;
      }
  
      private boolean findSingleAnnotatedConstructor(@NonNull Constructor<?>[] constructors) {
          for (Constructor<?> c : constructors) {
              if (kindOfInjectionPoint(c) != KindOfInjectionPoint.NotAnnotated) {
                  List<InjectionProvider> providersFound = findParameterProvidersForConstructor(c);
  
                  if (providersFound != null) {
                      parameterProviders = providersFound;
                      constructor = c;
                  }
  
                  return true;
              }
          }
  
          return false;
      }
  
      private void findSatisfiedConstructorWithMostParameters(@NonNull Constructor<?>[] constructors) {
          sortConstructorsWithMostAccessibleFirst(constructors);
  
          Constructor<?> unresolvedConstructor = null;
          List<InjectionProvider> incompleteProviders = null;
  
          for (Constructor<?> candidateConstructor : constructors) {
             List<InjectionProvider> providersFound = findParameterProvidersForConstructor(candidateConstructor);
 
             if (providersFound != null) {
                 if (withFullInjection && containsUnresolvedProvider(providersFound)) {
                     if (unresolvedConstructor == null || isLargerConstructor(candidateConstructor, providersFound,
                             unresolvedConstructor, incompleteProviders)) {
                         unresolvedConstructor = candidateConstructor;
                         incompleteProviders = providersFound;
                     }
                 } else if (constructor == null
                         || isLargerConstructor(candidateConstructor, providersFound, constructor, parameterProviders)) {
                     constructor = candidateConstructor;
                     parameterProviders = providersFound;
                 }
             }
         }
 
         selectConstructorWithUnresolvedParameterIfMoreAccessible(unresolvedConstructor, incompleteProviders);
     }
 
     private static void sortConstructorsWithMostAccessibleFirst(@NonNull Constructor<?>[] constructors) {
         if (constructors.length > 1) {
             Arrays.sort(constructors, CONSTRUCTOR_COMPARATOR);
         }
     }
 
     private static final Comparator<Constructor<?>> CONSTRUCTOR_COMPARATOR = ConstructorSearch::compareAccessibility;
 
     private static int compareAccessibility(@NonNull Constructor<?> c1, @NonNull Constructor<?> c2) {
         int m1 = getModifiers(c1);
         int m2 = getModifiers(c2);
         if (m1 == m2) {
             return 0;
         }
         if (m1 == PUBLIC) {
             return -1;
         }
         if (m2 == PUBLIC) {
             return 1;
         }
         if (m1 == PROTECTED) {
             return -1;
         }
         if (m2 == PROTECTED) {
             return 1;
         }
         if (m2 == PRIVATE) {
             return -1;
         }
         return 1;
     }
 
     private static boolean containsUnresolvedProvider(@NonNull List<InjectionProvider> providersFound) {
         for (InjectionProvider provider : providersFound) {
             if (provider instanceof ConstructorParameter && provider.getValue(null) == null) {
                 return true;
             }
         }
 
         return false;
     }
 
     private static boolean isLargerConstructor(@NonNull Constructor<?> candidateConstructor,
             @NonNull List<InjectionProvider> providersFound, @NonNull Constructor<?> previousSatisfiableConstructor,
             @NonNull List<InjectionProvider> previousProviders) {
         return getModifiers(candidateConstructor) == getModifiers(previousSatisfiableConstructor)
                 && providersFound.size() >= previousProviders.size();
     }
 
     private static int getModifiers(@NonNull Constructor<?> c) {
         return CONSTRUCTOR_ACCESS & c.getModifiers();
     }
 
     @Nullable
     private List<InjectionProvider> findParameterProvidersForConstructor(@NonNull Constructor<?> candidate) {
         Type[] parameterTypes = candidate.getGenericParameterTypes();
         Annotation[][] parameterAnnotations = candidate.getParameterAnnotations();
         int n = parameterTypes.length;
         List<InjectionProvider> providersFound = new ArrayList<>(n);
         boolean varArgs = candidate.isVarArgs();
 
         if (varArgs) {
             n--;
         }
 
         printCandidateConstructorNameIfRequested(candidate);
 
         String constructorDesc = "<init>" + JavaType.getConstructorDescriptor(candidate);
         InjectionProviders injectionProviders = injectionState.injectionProviders;
         KindOfInjectionPoint kindOfInjectionPoint = kindOfInjectionPoint(candidate);
 
         for (int i = 0; i < n; i++) {
             Type parameterType = parameterTypes[i];
             injectionProviders.setTypeOfInjectionPoint(parameterType, kindOfInjectionPoint);
 
             String parameterName = ParameterNames.getName(testedClassDesc, constructorDesc, i);
             Annotation[] appliedAnnotations = parameterAnnotations[i];
             InjectionProvider provider = findOrCreateInjectionProvider(parameterType, parameterName,
                     appliedAnnotations);
 
             if (provider == null || providersFound.contains(provider)) {
                 printParameterOfCandidateConstructorIfRequested(parameterName, provider);
                 return null;
             }
 
             providersFound.add(provider);
         }
 
         if (varArgs) {
             Type parameterType = parameterTypes[n];
             InjectionProvider injectable = hasInjectedValuesForVarargsParameter(parameterType, kindOfInjectionPoint,
                     injectionProviders);
 
             if (injectable != null) {
                 providersFound.add(injectable);
             }
         }
 
         return providersFound;
     }
 
     @Nullable
     private InjectionProvider findOrCreateInjectionProvider(@NonNull Type parameterType, @Nullable String parameterName,
             @NonNull Annotation[] parameterAnnotations) {
         String qualifiedName = getQualifiedName(parameterAnnotations);
 
         if (parameterName == null && qualifiedName == null) {
             return null;
         }
 
         boolean qualified = qualifiedName != null;
         String targetName = qualified ? qualifiedName : parameterName;
         InjectionProvider provider = injectionState.injectionProviders.getProviderByTypeAndOptionallyName(targetName,
                 testedClass);
 
         if (provider != null) {
             return provider;
         }
 
         InjectionPoint injectionPoint = new InjectionPoint(parameterType, targetName, qualifiedName);
         Object valueForParameter = injectionState.getTestedValue(testedClass, injectionPoint);
 
         if (valueForParameter == null && !withFullInjection) {
             return null;
         }
 
         return new ConstructorParameter(parameterType, parameterAnnotations, targetName, valueForParameter);
     }
 
     @Nullable
     private InjectionProvider hasInjectedValuesForVarargsParameter(@NonNull Type parameterType,
             @NonNull KindOfInjectionPoint kindOfInjectionPoint, @NonNull InjectionProviders injectionProviders) {
         Type varargsElementType = getTypeOfInjectionPointFromVarargsParameter(parameterType);
         injectionProviders.setTypeOfInjectionPoint(varargsElementType, kindOfInjectionPoint);
         return injectionProviders.findNextInjectableForInjectionPoint(testedClass);
     }
 
     private void selectConstructorWithUnresolvedParameterIfMoreAccessible(
             @Nullable Constructor<?> unresolvedConstructor, List<InjectionProvider> incompleteProviders) {
         if (unresolvedConstructor != null
                 && (constructor == null || compareAccessibility(unresolvedConstructor, constructor) < 0)) {
             constructor = unresolvedConstructor;
             parameterProviders = incompleteProviders;
         }
     }
 
     // Methods used only when no satisfiable constructor is found //////////////////////////////////////////////////////
 
     @NonNull
     public String getDescription() {
         searchResults = new StringBuilder();
         findConstructorToUse();
         String contents = searchResults.toString();
         searchResults = null;
         return contents;
     }
 
     @SuppressWarnings("DynamicRegexReplaceableByCompiledPattern")
     private void printCandidateConstructorNameIfRequested(@NonNull Constructor<?> candidate) {
         if (searchResults != null) {
             String constructorDesc = candidate.toGenericString().replace("java.lang.", "").replace(",", ", ");
             searchResults.append("\r\n  ").append(constructorDesc).append("\r\n");
         }
     }
 
     private void printParameterOfCandidateConstructorIfRequested(@Nullable String parameterName,
             @Nullable InjectionProvider injectableFound) {
         if (searchResults != null) {
             searchResults.append("    disregarded because ");
 
             if (parameterName == null) {
                 searchResults.append("parameter names are not available");
             } else {
                 searchResults.append("no tested/injectable value was found for parameter \"").append(parameterName)
                         .append('"');
 
                 if (injectableFound != null) {
                     searchResults.append(" that hadn't been used already");
                 }
             }
         }
     }
 }