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.util.Map;
  import java.util.Optional;
  
  import javax.inject.Inject;
  
  import com.google.common.annotations.VisibleForTesting;
  import com.google.common.base.Strings;
  import com.google.common.collect.ImmutableMap;
  
  import org.apache.aurora.scheduler.storage.entities.ITaskConfig;
  import org.codehaus.jackson.annotate.JsonCreator;
  import org.codehaus.jackson.annotate.JsonProperty;
  
  import static java.util.Objects.requireNonNull;
  
  import static com.google.common.base.Preconditions.checkArgument;
  
  /**
   * Translates job tier configuration into a set of task traits/attributes.
   */
  public interface TierManager {
  
    /**
     * Gets {@link TierInfo} instance representing task's tier details.
     *
     * @param taskConfig Task configuration to get tier for.
     * @return {@link TierInfo} for the given {@code taskConfig}.
     */
    TierInfo getTier(ITaskConfig taskConfig);
  
    /**
     * Gets name of the default tier.
     *
     * @return Name for the default tier.
     */
    String getDefaultTierName();
  
    /**
     * Gets the map of tier name to {@link TierInfo} instance.
     *
     * @return A readonly view of all tiers.
     */
    Map<String, TierInfo> getTiers();
  
    class TierManagerImpl implements TierManager {
      private final TierConfig tierConfig;
  
      @VisibleForTesting
      public static class TierConfig {
        private final String defaultTier;
        private final Map<String, TierInfo> tiers;
  
        @VisibleForTesting
        @JsonCreator
        public TierConfig(
            @JsonProperty("default") String defaultTier,
            @JsonProperty("tiers") Map<String, TierInfo> tiers) {
  
          checkArgument(!Strings.isNullOrEmpty(defaultTier), "Default tier name cannot be empty.");
          checkArgument(!tiers.isEmpty(), "Tiers cannot be empty.");
          checkArgument(
              tiers.containsKey(defaultTier),
              "Default tier name should match supplied tiers.");
          this.defaultTier = defaultTier;
          this.tiers = ImmutableMap.copyOf(tiers);
        }
  
        @VisibleForTesting
        public String getDefault() {
          return defaultTier;
        }
  
        @VisibleForTesting
        public Map<String, TierInfo> getTiers() {
          return tiers;
        }
      }
  
      @VisibleForTesting
      @Inject
      public TierManagerImpl(TierConfig tierConfig) {
        this.tierConfig = requireNonNull(tierConfig);
      }
  
      @Override
      public TierInfo getTier(ITaskConfig taskConfig) {
        checkArgument(
            !taskConfig.isSetTier() || tierConfig.tiers.containsKey(taskConfig.getTier()),
            "Invalid tier '%s' in TaskConfig.", taskConfig.getTier());
  
        return tierConfig.tiers.get(
            Optional.ofNullable(taskConfig.getTier()).orElse(tierConfig.defaultTier));
      }
  
      @Override
      public String getDefaultTierName() {
        return tierConfig.defaultTier;
      }
  
      @Override
      public Map<String, TierInfo> getTiers() {
        return tierConfig.tiers;
      }
    }
  }
  