/*
    * 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;
  
  import javax.inject.Named;
  import javax.inject.Singleton;
  
  import java.io.File;
  import java.io.IOException;
  import java.io.InputStream;
  import java.io.OutputStream;
  import java.io.UncheckedIOException;
  import java.nio.file.Files;
  import java.nio.file.Path;
  import java.util.Map;
  import java.util.Properties;
  
  import org.slf4j.Logger;
  import org.slf4j.LoggerFactory;
  
  /**
   * Manages access to a properties file.
   */
  @Singleton
  @Named
  public final class DefaultTrackingFileManager implements TrackingFileManager {
      private static final Logger LOGGER = LoggerFactory.getLogger(DefaultTrackingFileManager.class);
  
      @Override
      public Properties read(File file) {
          Path filePath = file.toPath();
          if (Files.isReadable(filePath)) {
              try (InputStream stream = Files.newInputStream(filePath)) {
                  Properties props = new Properties();
                  props.load(stream);
                  return props;
              } catch (IOException e) {
                  LOGGER.warn("Failed to read tracking file '{}'", file, e);
                  throw new UncheckedIOException(e);
              }
          }
          return null;
      }
  
      @Override
      public Properties update(File file, Map<String, String> updates) {
          Path filePath = file.toPath();
          Properties props = new Properties();
  
          try {
              Files.createDirectories(filePath.getParent());
          } catch (IOException e) {
              LOGGER.warn("Failed to create tracking file parent '{}'", file, e);
              throw new UncheckedIOException(e);
          }
  
          try {
              if (Files.isReadable(filePath)) {
                  try (InputStream stream = Files.newInputStream(filePath)) {
                      props.load(stream);
                  }
              }
  
              for (Map.Entry<String, String> update : updates.entrySet()) {
                  if (update.getValue() == null) {
                      props.remove(update.getKey());
                  } else {
                      props.setProperty(update.getKey(), update.getValue());
                  }
              }
  
              try (OutputStream stream = Files.newOutputStream(filePath)) {
                  LOGGER.debug("Writing tracking file '{}'", file);
                  props.store(
                          stream,
                          "NOTE: This is a Maven Resolver internal implementation file"
                                  + ", its format can be changed without prior notice.");
              }
          } catch (IOException e) {
              LOGGER.warn("Failed to write tracking file '{}'", file, e);
              throw new UncheckedIOException(e);
          }
  
         return props;
     }
 }