content: /**
   * 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.apache.aurora.scheduler;
  
  import java.io.File;
  import java.io.IOException;
  import java.nio.charset.StandardCharsets;
  
  import com.beust.jcommander.Parameter;
  import com.beust.jcommander.Parameters;
  import com.google.common.annotations.VisibleForTesting;
  import com.google.common.base.Strings;
  import com.google.common.io.Files;
  import com.google.common.io.Resources;
  import com.google.inject.AbstractModule;
  
  import org.apache.aurora.scheduler.TierManager.TierManagerImpl;
  import org.apache.aurora.scheduler.TierManager.TierManagerImpl.TierConfig;
  import org.apache.aurora.scheduler.config.validators.ReadableFile;
  import org.codehaus.jackson.map.ObjectMapper;
  import org.slf4j.Logger;
  import org.slf4j.LoggerFactory;
  
  import static java.util.Objects.requireNonNull;
  
  import static com.google.common.base.Preconditions.checkArgument;
  
  /**
   * Binding module for tier management.
   */
  public class TierModule extends AbstractModule {
    private static final Logger LOG = LoggerFactory.getLogger(TierModule.class);
  
    @VisibleForTesting
    static final String TIER_CONFIG_PATH = "org/apache/aurora/scheduler/tiers.json";
  
    @Parameters(separators = "=")
    public static class Options {
      @Parameter(names = "-tier_config",
          validateValueWith = ReadableFile.class,
          description =
              "Configuration file defining supported task tiers, task traits and behaviors.")
      public File tierConfigFile;
    }
  
    private final TierConfig tierConfig;
  
    public TierModule(Options options) {
      this(parseTierConfig(readTierFile(options)));
    }
  
    @VisibleForTesting
    public TierModule(TierConfig tierConfig) {
      this.tierConfig = requireNonNull(tierConfig);
    }
  
    @Override
    protected void configure() {
      bind(TierManager.class).toInstance(new TierManagerImpl(tierConfig));
    }
  
    static String readTierFile(Options options) {
      try {
        File tierConfig = options.tierConfigFile;
        return tierConfig == null
            ? Resources.toString(
                TierModule.class.getClassLoader().getResource(TIER_CONFIG_PATH),
                StandardCharsets.UTF_8)
            : Files.asCharSource(tierConfig, StandardCharsets.UTF_8).read();
      } catch (IOException e) {
        LOG.error("Error loading tier configuration file.");
        throw new RuntimeException(e);
      }
    }
  
    @VisibleForTesting
    static TierConfig parseTierConfig(String config) {
      checkArgument(!Strings.isNullOrEmpty(config), "configuration cannot be empty");
      try {
        return new ObjectMapper().readValue(config, TierConfig.class);
      } catch (IOException e) {
        LOG.error("Error parsing tier configuration file.");
        throw new RuntimeException(e);
      }
    }
  }
  