/*
    * Copyright 2018 the original author or authors.
    *
    *  Licensed 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.openehealth.ipf.commons.ihe.fhir.support;
  
  
  import org.hl7.fhir.dstu3.model.Bundle;
  import org.hl7.fhir.dstu3.model.NamingSystem;
  
  import java.util.HashMap;
  import java.util.HashSet;
  import java.util.Map;
  import java.util.Set;
  import java.util.function.Predicate;
  import java.util.stream.Collectors;
  import java.util.stream.Stream;
  
  /**
   * Abstract Implementation that holds naming systems in memory as a map of {@link NamingSystem} sets. Before an
   * instance can be used, one of the adder methods of implementations must be called to initialize the
   * bundle.
   *
   * @author Christian Ohr
   * @since 3.4
   */
  public class AbstractNamingSystemServiceImpl implements NamingSystemService {
  
      protected transient Map<String, Set<NamingSystem>> namingSystems = new HashMap<>();
  
      public void addNamingSystems(Bundle bundle) {
          this.namingSystems.merge(bundle.getId(), setOfNamingSystems(bundle), (set1, set2) -> {
              Set<NamingSystem> result = new HashSet<>(set1);
              result.addAll(set2);
              return result;
          });
      }
  
      @Override
      public Stream<NamingSystem> findNamingSystems(String id, Predicate<? super NamingSystem> predicate) {
          if (!namingSystems.containsKey(id)) {
              throw new IllegalArgumentException("No NamingSystem known with ID " + id);
          }
          return namingSystems.get(id).stream().filter(predicate);
      }
  
      private Set<NamingSystem> setOfNamingSystems(Bundle bundle) {
          return bundle.getEntry().stream()
                  .map(bec -> (NamingSystem) bec.getResource())
                  .collect(Collectors.toSet());
      }
  
  }