/*
    * SPDX-FileCopyrightText: none
    * SPDX-License-Identifier: CC0-1.0
    */
   
   package dev.metaschema.databind.model;
   
   import java.lang.reflect.Field;
   import java.lang.reflect.ParameterizedType;
  import java.lang.reflect.Type;
  import java.util.Collection;
  import java.util.List;
  import java.util.Map;
  
  import dev.metaschema.core.model.IBoundObject;
  import dev.metaschema.core.model.IModelInstanceAbsolute;
  import dev.metaschema.core.util.ObjectUtils;
  import dev.metaschema.databind.io.BindingException;
  import dev.metaschema.databind.model.info.IModelInstanceCollectionInfo;
  import edu.umd.cs.findbugs.annotations.NonNull;
  import edu.umd.cs.findbugs.annotations.Nullable;
  
  /**
   * Represents an assembly or field instance bound to Java data.
   *
   * @param <ITEM>
   *          the Java type for associated bound objects
   */
  public interface IBoundInstanceModel<ITEM>
      extends IBoundInstance<ITEM>, IModelInstanceAbsolute {
    /**
     * Get the collection Java item type for the Java field associated with this
     * instance.
     *
     * @param field
     *          the Java field for the instance
     * @return the Java item type
     */
    @NonNull
    static Class<?> getItemType(@NonNull Field field) {
      Type fieldType = field.getGenericType();
      Class<?> rawType = ObjectUtils.notNull(
          (Class<?>) (fieldType instanceof ParameterizedType ? ((ParameterizedType) fieldType).getRawType() : fieldType));
  
      Class<?> itemType;
      if (Map.class.isAssignableFrom(rawType)) {
        // this is a Map so the second generic type is the value
        itemType = ObjectUtils.notNull((Class<?>) ((ParameterizedType) fieldType).getActualTypeArguments()[1]);
      } else if (List.class.isAssignableFrom(rawType)) {
        // this is a List so there is only a single generic type
        itemType = ObjectUtils.notNull((Class<?>) ((ParameterizedType) fieldType).getActualTypeArguments()[0]);
      } else {
        // non-collection
        itemType = rawType;
      }
      return itemType;
    }
  
    /**
     * Get the collection Java item type for the Java field associated with this
     * instance.
     *
     * @param <TYPE>
     *          the item's expected Java type
     * @param field
     *          the Java field for the instance
     * @param expectedItemType
     *          the item's expected Java type, which may be a super type of the
     *          item's type
     * @return the Java item type
     */
    @NonNull
    static <TYPE> Class<? extends TYPE> getItemType(@NonNull Field field, @NonNull Class<TYPE> expectedItemType) {
      Type fieldType = field.getGenericType();
      Class<?> rawType = ObjectUtils.notNull(
          (Class<?>) (fieldType instanceof ParameterizedType ? ((ParameterizedType) fieldType).getRawType() : fieldType));
  
      Class<?> itemType;
      if (Map.class.isAssignableFrom(rawType)) {
        // this is a Map so the second generic type is the value
        itemType = ObjectUtils.notNull((Class<?>) ((ParameterizedType) fieldType).getActualTypeArguments()[1]);
      } else if (List.class.isAssignableFrom(rawType)) {
        // this is a List so there is only a single generic type
        itemType = ObjectUtils.notNull((Class<?>) ((ParameterizedType) fieldType).getActualTypeArguments()[0]);
      } else {
        // non-collection
        itemType = rawType;
      }
      return ObjectUtils.notNull(itemType.asSubclass(expectedItemType));
    }
  
    @Override
    @NonNull
    IBoundDefinitionModelAssembly getContainingDefinition();
  
    @Override
    default Object getResolvedDefaultValue() {
      return getMaxOccurs() == 1 ? getEffectiveDefaultValue() : getCollectionInfo().emptyValue();
    }
 
   /**
    * Get the item values associated with the provided value.
    *
    * @param value
    *          the value which may be a singleton or a collection
    * @return the ordered collection of values
    */
   @Override
   @NonNull
   default Collection<? extends Object> getItemValues(Object value) {
     return getCollectionInfo().getItemsFromValue(value);
   }
 
   /**
    * Get the Java binding information for the collection type supported by this
    * instance.
    *
    * @return the collection Java binding information
    */
   @NonNull
   IModelInstanceCollectionInfo<ITEM> getCollectionInfo();
 
   /**
    * Get the JSON key flag for the provided item.
    *
    * @param item
    *          the item to get the JSON key flag for
    * @return the JSON key flag
    */
   @Nullable
   IBoundInstanceFlag getItemJsonKey(@NonNull Object item);
 
   @Override
   default void deepCopy(@NonNull IBoundObject fromInstance, @NonNull IBoundObject toInstance) throws BindingException {
     Object value = getValue(fromInstance);
     if (value != null) {
       value = getCollectionInfo().deepCopyItems(fromInstance, toInstance);
     }
     setValue(toInstance, value);
   }
 }