/*
    * Copyright (c) 2006 JMockit developers
    * This file is subject to the terms of the MIT license (see LICENSE.txt).
    */
   package mockit.internal.expectations.invocation;
   
   import static mockit.internal.util.Utilities.JAVA8;
   
   import edu.umd.cs.findbugs.annotations.NonNull;
  import edu.umd.cs.findbugs.annotations.Nullable;
  
  import java.lang.reflect.Array;
  import java.util.ArrayList;
  import java.util.Collection;
  import java.util.Iterator;
  import java.util.LinkedHashMap;
  import java.util.LinkedHashSet;
  import java.util.List;
  import java.util.ListIterator;
  import java.util.Map;
  import java.util.Set;
  import java.util.SortedMap;
  import java.util.SortedSet;
  import java.util.TreeMap;
  import java.util.TreeSet;
  import java.util.stream.Stream;
  
  import org.checkerframework.checker.index.qual.NonNegative;
  
  final class MultiValuedConversion {
      @NonNull
      private final InvocationResults invocationResults;
      @NonNull
      private final Class<?> returnType;
      @NonNull
      private final Object valueToReturn;
  
      MultiValuedConversion(@NonNull InvocationResults invocationResults, @NonNull Class<?> returnType,
              @NonNull Object valueToReturn) {
          this.invocationResults = invocationResults;
          this.returnType = returnType;
          this.valueToReturn = valueToReturn;
      }
  
      void addMultiValuedResultBasedOnTheReturnType(boolean valueIsArray) {
          if (returnType == void.class) {
              addMultiValuedResult(valueIsArray);
          } else if (returnType == Object.class) {
              invocationResults.addReturnValueResult(valueToReturn);
          } else if (valueIsArray && addCollectionOrMapWithElementsFromArray()) {
              // Do nothing
          } else if (hasReturnOfDifferentType()) {
              addMultiValuedResult(valueIsArray);
          } else {
              invocationResults.addReturnValueResult(valueToReturn);
          }
      }
  
      @SuppressWarnings("Since15")
      private void addMultiValuedResult(boolean valueIsArray) {
          if (valueIsArray) {
              invocationResults.addResults(valueToReturn);
          } else if (valueToReturn instanceof Iterable<?>) {
              if (JAVA8 && valueToReturn instanceof Collection && returnType.isAssignableFrom(Stream.class)) {
                  invocationResults.addReturnValueResult(((Collection<?>) valueToReturn).stream());
              } else {
                  invocationResults.addResults((Iterable<?>) valueToReturn);
              }
          } else {
              invocationResults.addDeferredResults((Iterator<?>) valueToReturn);
          }
      }
  
      private boolean hasReturnOfDifferentType() {
          return !returnType.isArray() && !Iterable.class.isAssignableFrom(returnType)
                  && !Iterator.class.isAssignableFrom(returnType)
                  && !returnType.isAssignableFrom(valueToReturn.getClass());
      }
  
      @SuppressWarnings("Since15")
      private boolean addCollectionOrMapWithElementsFromArray() {
          @NonNegative
          int n = Array.getLength(valueToReturn);
          Object values = null;
  
          if (returnType.isAssignableFrom(ListIterator.class)) {
              List<Object> list = new ArrayList<>(n);
              addArrayElements(list, n);
              values = list.listIterator();
          } else if (returnType.isAssignableFrom(List.class)) {
              values = addArrayElements(new ArrayList<>(n), n);
          } else if (returnType.isAssignableFrom(Set.class)) {
              values = addArrayElements(new LinkedHashSet<>(n), n);
          } else if (returnType.isAssignableFrom(SortedSet.class)) {
              values = addArrayElements(new TreeSet<>(), n);
          } else if (returnType.isAssignableFrom(Map.class)) {
              values = addArrayElements(new LinkedHashMap<>(n), n);
          } else if (returnType.isAssignableFrom(SortedMap.class)) {
              values = addArrayElements(new TreeMap<>(), n);
         } else if (JAVA8 && returnType.isAssignableFrom(Stream.class)) {
             values = addArrayElements(new ArrayList<>(n), n).stream();
         }
 
         if (values != null) {
             invocationResults.addReturnValue(values);
             return true;
         }
 
         return false;
     }
 
     @NonNull
     private Collection<?> addArrayElements(@NonNull Collection<Object> values, @NonNegative int elementCount) {
         for (int i = 0; i < elementCount; i++) {
             Object element = Array.get(valueToReturn, i);
             values.add(element);
         }
 
         return values;
     }
 
     @Nullable
     private Object addArrayElements(@NonNull Map<Object, Object> values, @NonNegative int elementPairCount) {
         for (int i = 0; i < elementPairCount; i++) {
             Object keyAndValue = Array.get(valueToReturn, i);
 
             if (keyAndValue == null || !keyAndValue.getClass().isArray()) {
                 return null;
             }
 
             Object key = Array.get(keyAndValue, 0);
             Object element = Array.getLength(keyAndValue) > 1 ? Array.get(keyAndValue, 1) : null;
             values.put(key, element);
         }
 
         return values;
     }
 }