AlertGrouperFactory.java

package com.linkedin.thirdeye.anomaly.alert.grouping;

import java.util.Collections;
import java.util.Map;
import org.apache.commons.collections.MapUtils;
import org.apache.commons.lang3.StringUtils;

public class AlertGrouperFactory {
  public static final String GROUPER_TYPE_KEY = "type";
  private static final AlertGrouper DUMMY_ALERT_GROUPER = new DummyAlertGrouper();

  public enum GrouperType {
    DUMMY, DIMENSIONAL, HORIZONTAL_DIMENSIONAL
  }

  public static AlertGrouper fromSpec(Map<String, String> spec) {
    if (MapUtils.isEmpty(spec)) {
      spec = Collections.emptyMap();
    }
    AlertGrouper alertGrouper = fromStringType(spec.get(GROUPER_TYPE_KEY));
    alertGrouper.setParameters(spec);

    return alertGrouper;
  }

  private static AlertGrouper fromStringType(String type) {
    if (StringUtils.isBlank(type)) { // backward compatibility
      return DUMMY_ALERT_GROUPER;
    }

    GrouperType filterType = GrouperType.DUMMY;
    for (GrouperType enumFilterType : GrouperType.values()) {
      if (enumFilterType.name().compareToIgnoreCase(type) == 0) {
        filterType = enumFilterType;
        break;
      }
    }

    switch (filterType) {
    case DUMMY: // speed optimization for most use cases
      return DUMMY_ALERT_GROUPER;
    case DIMENSIONAL:
      return new DimensionalAlertGrouper();
    case HORIZONTAL_DIMENSIONAL:
      return new HorizontalDimensionalAlertGrouper();
    default:
      return DUMMY_ALERT_GROUPER;
    }
  }
}