/*
    * 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.maven.shared.jar.identification.hash;
  
  import javax.inject.Named;
  import javax.inject.Singleton;
  
  import java.io.IOException;
  import java.io.InputStream;
  import java.nio.file.Files;
  
  import org.apache.commons.codec.digest.DigestUtils;
  import org.apache.maven.shared.jar.JarAnalyzer;
  import org.apache.maven.shared.jar.JarData;
  import org.slf4j.Logger;
  import org.slf4j.LoggerFactory;
  
  /**
   * Analyzer that calculates the hash code for the entire file. Can be used to detect an exact copy of the file.
   */
  @Singleton
  @Named("file")
  public class JarFileHashAnalyzer implements JarHashAnalyzer {
      private final Logger logger = LoggerFactory.getLogger(getClass());
  
      @Override
      public String computeHash(JarAnalyzer jarAnalyzer) {
          JarData jarData = jarAnalyzer.getJarData();
  
          String result = jarData.getFileHash();
          if (result == null) {
              try {
                  try (InputStream inputStream =
                          Files.newInputStream(jarData.getFile().toPath())) {
                      jarData.setFileHash(DigestUtils.sha1Hex(inputStream));
                  }
              } catch (IOException e) {
                  logger.warn("Unable to calculate the hashcode.", e);
              }
          }
          return result;
      }
  }