/*
    * Licensed to the Apache Software Foundation (ASF) under one
    * or more contributor license agreements.  See the NOTICE file
    * distributed with this work for additional information
    * regarding copyright ownership.  The ASF licenses this file
    * to you under the Apache License, Version 2.0 (the
    * "License"); you may not use this file except in compliance
    * with the License.  You may obtain a copy of the License at
    *
   *   http://www.apache.org/licenses/LICENSE-2.0
   *
   * Unless required by applicable law or agreed to in writing,
   * software distributed under the License is distributed on an
   * "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY
   * KIND, either express or implied.  See the License for the
   * specific language governing permissions and limitations
   * under the License.
   */
  package org.apache.syncope.core.provisioning.java.utils;
  
  import java.util.ArrayList;
  import java.util.HashSet;
  import java.util.List;
  import java.util.Map;
  import java.util.Optional;
  import java.util.Set;
  import java.util.concurrent.ConcurrentHashMap;
  import java.util.stream.Stream;
  import org.apache.commons.lang3.ArrayUtils;
  import org.apache.commons.lang3.StringUtils;
  import org.apache.syncope.common.lib.to.Item;
  import org.apache.syncope.common.lib.to.Mapping;
  import org.apache.syncope.common.lib.to.Provision;
  import org.apache.syncope.common.lib.types.MappingPurpose;
  import org.apache.syncope.core.persistence.api.entity.Implementation;
  import org.apache.syncope.core.provisioning.api.data.ItemTransformer;
  import org.apache.syncope.core.provisioning.api.data.JEXLItemTransformer;
  import org.apache.syncope.core.provisioning.java.data.JEXLItemTransformerImpl;
  import org.apache.syncope.core.spring.ApplicationContextProvider;
  import org.apache.syncope.core.spring.implementation.ImplementationManager;
  import org.identityconnectors.framework.common.objects.Name;
  import org.identityconnectors.framework.common.objects.OperationOptions;
  import org.identityconnectors.framework.common.objects.OperationOptionsBuilder;
  import org.identityconnectors.framework.common.objects.OperationalAttributes;
  import org.identityconnectors.framework.common.objects.Uid;
  import org.slf4j.Logger;
  import org.slf4j.LoggerFactory;
  import org.springframework.beans.factory.support.AbstractBeanDefinition;
  
  public final class MappingUtils {
  
      private static final Logger LOG = LoggerFactory.getLogger(MappingUtils.class);
  
      private static final Map<String, ItemTransformer> PER_CONTEXT_ITEM_TRANSFORMERS = new ConcurrentHashMap<>();
  
      public static Optional<Item> getConnObjectKeyItem(final Provision provision) {
          Mapping mapping = null;
          if (provision != null) {
              mapping = provision.getMapping();
          }
  
          return mapping == null
                  ? Optional.empty()
                  : mapping.getConnObjectKeyItem();
      }
  
      public static Stream<Item> getPropagationItems(final Stream<Item> items) {
          return items.filter(
                  item -> item.getPurpose() == MappingPurpose.PROPAGATION || item.getPurpose() == MappingPurpose.BOTH);
      }
  
      public static Stream<Item> getPullItems(final Stream<Item> items) {
          return items.filter(
                  item -> item.getPurpose() == MappingPurpose.PULL || item.getPurpose() == MappingPurpose.BOTH);
      }
  
      public static List<ItemTransformer> getItemTransformers(
              final Item item,
              final List<Implementation> transformers) {
  
          List<ItemTransformer> result = new ArrayList<>();
  
          // First consider the JEXL transformation expressions
          if (StringUtils.isNotBlank(item.getPropagationJEXLTransformer())
                  || StringUtils.isNotBlank(item.getPullJEXLTransformer())) {
  
              JEXLItemTransformer jexlTransformer = (JEXLItemTransformer) ApplicationContextProvider.getBeanFactory().
                      createBean(JEXLItemTransformerImpl.class, AbstractBeanDefinition.AUTOWIRE_BY_NAME, false);
  
              jexlTransformer.setPropagationJEXL(item.getPropagationJEXLTransformer());
              jexlTransformer.setPullJEXL(item.getPullJEXLTransformer());
              result.add(jexlTransformer);
          }
  
          // Then other custom transformers
          transformers.forEach(impl -> {
              try {
                  result.add(ImplementationManager.build(
                          impl,
                         () -> PER_CONTEXT_ITEM_TRANSFORMERS.get(impl.getKey()),
                         instance -> PER_CONTEXT_ITEM_TRANSFORMERS.put(impl.getKey(), instance)));
             } catch (Exception e) {
                 LOG.error("While building {}", impl, e);
             }
         });
 
         return result;
     }
 
     /**
      * Build options for requesting all mapped connector attributes.
      *
      * @param items items
      * @param moreAttrsToGet additional attributes to get
      * @return options for requesting all mapped connector attributes
      * @see OperationOptions
      */
     public static OperationOptions buildOperationOptions(
             final Stream<Item> items,
             final String... moreAttrsToGet) {
 
         OperationOptionsBuilder builder = new OperationOptionsBuilder();
 
         Set<String> attrsToGet = new HashSet<>();
         attrsToGet.add(Name.NAME);
         attrsToGet.add(Uid.NAME);
         attrsToGet.add(OperationalAttributes.ENABLE_NAME);
         if (!ArrayUtils.isEmpty(moreAttrsToGet)) {
             attrsToGet.addAll(List.of(moreAttrsToGet));
         }
 
         items.filter(item -> item.getPurpose() != MappingPurpose.NONE).
                 forEach(item -> attrsToGet.add(item.getExtAttrName()));
 
         builder.setAttributesToGet(attrsToGet);
         // -------------------------------------
 
         return builder.build();
     }
 
     /**
      * Private default constructor, for static-only classes.
      */
     private MappingUtils() {
     }
 }