/*
    * 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.plugin.surefire.booterclient;
  
  import java.io.File;
  import java.security.MessageDigest;
  import java.security.NoSuchAlgorithmException;
  import java.util.ArrayList;
  import java.util.List;
  import java.util.Map;
  
  import org.apache.maven.artifact.Artifact;
  
  import static java.nio.charset.StandardCharsets.UTF_8;
  
  /**
   * @author Kristian Rosenvold
   */
  public class ChecksumCalculator {
      private static final String HEX = "0123456789ABCDEF";
  
      private final List<Object> checksumItems = new ArrayList<>();
  
      private void appendObject(Object item) {
          checksumItems.add(item);
      }
  
      public void add(boolean value) {
          checksumItems.add(value);
      }
  
      public void add(int value) {
          checksumItems.add(value);
      }
  
      public void add(double value) {
          checksumItems.add(value);
      }
  
      public void add(Map<?, ?> map) {
          if (map != null) {
              appendObject(map.toString());
          }
      }
  
      public void add(String string) {
          appendObject(string);
      }
  
      public void add(File workingDirectory) {
          appendObject(workingDirectory);
      }
  
      public void add(List<?> items) {
          if (items != null) {
              for (Object item : items) {
                  appendObject(item);
              }
          } else {
              appendObject(null);
          }
      }
  
      public void add(Object[] items) {
          if (items != null) {
              for (Object item : items) {
                  appendObject(item);
              }
          } else {
              appendObject(null);
          }
      }
  
      public void add(Artifact artifact) {
          appendObject(artifact != null ? artifact.getId() : null);
      }
  
      public void add(Boolean aBoolean) {
          appendObject(aBoolean);
      }
  
      @SuppressWarnings("checkstyle:magicnumber")
      private static String asHexString(byte[] bytes) {
         if (bytes == null) {
             return null;
         }
         final StringBuilder result = new StringBuilder(2 * bytes.length);
         for (byte b : bytes) {
             result.append(HEX.charAt((b & 0xF0) >> 4)).append(HEX.charAt((b & 0x0F)));
         }
         return result.toString();
     }
 
     private String getConfig() {
         StringBuilder result = new StringBuilder();
         for (Object checksumItem : checksumItems) {
             result.append(checksumItem != null ? checksumItem.toString() : "null");
         }
         return result.toString();
     }
 
     public String getSha1() {
         try {
             MessageDigest md = MessageDigest.getInstance("SHA-1");
             String configValue = getConfig();
             byte[] configBytes = configValue.getBytes(UTF_8);
             md.update(configBytes);
             byte[] sha1hash = md.digest();
             return asHexString(sha1hash);
         } catch (NoSuchAlgorithmException e) {
             throw new RuntimeException(e);
         }
     }
 }