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.quota;
  
  import java.util.Optional;
  
  import com.google.common.annotations.VisibleForTesting;
  
  import org.apache.aurora.scheduler.resources.ResourceBag;
  import org.apache.aurora.scheduler.resources.ResourceType;
  
  import static java.util.Objects.requireNonNull;
  
  import static org.apache.aurora.scheduler.resources.ResourceBag.IS_NEGATIVE;
  
  /**
   * Calculates and formats detailed quota comparison result.
   */
  public class QuotaCheckResult {
  
    /**
     * Quota check result.
     */
    public enum Result {
      /**
       * There is sufficient quota for the requested operation.
       */
      SUFFICIENT_QUOTA,
  
      /**
       * There is not enough allocated quota for the requested operation.
       */
      INSUFFICIENT_QUOTA
    }
  
    private final Optional<String> details;
    private final Result result;
  
    @VisibleForTesting
    public QuotaCheckResult(Result result) {
      this(result, Optional.empty());
    }
  
    private QuotaCheckResult(Result result, Optional<String> details) {
      this.result = requireNonNull(result);
      this.details = requireNonNull(details);
    }
  
    /**
     * Gets quota check result.
     *
     * @return Quota check result.
     */
    public Result getResult() {
      return result;
    }
  
    /**
     * Gets detailed quota violation description in case quota check fails.
     *
     * @return Quota check details.
     */
    public Optional<String> getDetails() {
      return details;
    }
  
    static QuotaCheckResult greaterOrEqual(ResourceBag a, ResourceBag b) {
      StringBuilder details = new StringBuilder();
      ResourceBag difference = a.subtract(b);
      difference.filter(IS_NEGATIVE).streamResourceVectors().forEach(
          entry -> addMessage(entry.getKey(), Math.abs(entry.getValue()), details));
  
      return new QuotaCheckResult(
          details.length() > 0 ? Result.INSUFFICIENT_QUOTA : Result.SUFFICIENT_QUOTA,
          Optional.of(details.toString()));
    }
  
    private static void addMessage(ResourceType resourceType, Double overage, StringBuilder details) {
      details
          .append(details.length() > 0 ? "; " : "")
          .append(resourceType.getAuroraName())
          .append(" quota exceeded by ")
          .append(String.format("%.2f", overage))
          .append(" ")
          .append(resourceType.getAuroraUnit());
    }
  }
  