/*
    * 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.eclipse.aether.internal.impl.transport.http;
  
  import javax.inject.Inject;
  import javax.inject.Named;
  import javax.inject.Singleton;
  
  import java.util.Map;
  import java.util.function.Function;
  
  import org.eclipse.aether.spi.connector.transport.http.ChecksumExtractor;
  import org.eclipse.aether.spi.connector.transport.http.ChecksumExtractorStrategy;
  
  import static java.util.Objects.requireNonNull;
  
  /**
   * Checksum extractor.
   */
  @Singleton
  @Named
  public final class DefaultChecksumExtractor implements ChecksumExtractor {
      private final Map<String, ChecksumExtractorStrategy> strategies;
  
      @Inject
      public DefaultChecksumExtractor(Map<String, ChecksumExtractorStrategy> strategies) {
          this.strategies = requireNonNull(strategies, "strategies");
      }
  
      @Override
      public Map<String, String> extractChecksums(Function<String, String> headerGetter) {
          for (ChecksumExtractorStrategy strategy : strategies.values()) {
              Map<String, String> extracted = strategy.extractChecksums(headerGetter);
              if (extracted != null && !extracted.isEmpty()) {
                  return extracted;
              }
          }
          return null;
      }
  }