code: /*
   * 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.apache.skywalking.oap.server.core.query.type;
  
  import java.math.BigInteger;
  import java.util.ArrayList;
  import java.util.Comparator;
  import java.util.List;
  import lombok.Getter;
  import lombok.RequiredArgsConstructor;
  import lombok.Setter;
  import org.apache.commons.lang3.StringUtils;
  import org.apache.skywalking.oap.server.core.analysis.metrics.DataTable;
  
  /**
   * HeatMap represents the value distribution in the defined buckets.
   *
   * @since 8.0.0
   */
  @Getter
  public class HeatMap {
      private List<HeatMapColumn> values = new ArrayList<>(10);
      private List<Bucket> buckets = new ArrayList<>();
  
      public void addBucket(Bucket bucket) {
          this.buckets.add(bucket);
      }
  
      /**
       * Build one heatmap value column based on rawdata in the storage and row id.
       *
       * @param id      of the row
       * @param rawdata literal string, represent a {@link DataTable}
       */
      public void buildColumn(String id, String rawdata, int defaultValue) {
          DataTable dataset = new DataTable(rawdata);
  
          final List<String> sortedKeys = dataset.sortedKeys(new KeyComparator(true));
          if (buckets.isEmpty()) {
              for (int i = 0; i < sortedKeys.size(); i++) {
                  final Bucket bucket = new Bucket();
                  final String minValue = sortedKeys.get(i);
  
                  if (Bucket.INFINITE_NEGATIVE.equals(minValue)) {
                      bucket.infiniteMin();
                  } else {
                      bucket.setMin(Integer.parseInt(minValue));
                  }
  
                  if (i == sortedKeys.size() - 1) {
                      // last element
                      bucket.infiniteMax();
                  } else {
                      final String max = sortedKeys.get(i + 1);
                      if (Bucket.INFINITE_POSITIVE.equals(max)) {
                          // If reach the infinite positive before the last element, ignore all other.
                          // Only for fail safe.
                          bucket.infiniteMax();
                          break;
                      } else {
                          bucket.setMax(Integer.parseInt(max));
                      }
                  }
                  this.addBucket(bucket);
              }
          }
  
          HeatMap.HeatMapColumn column = new HeatMap.HeatMapColumn();
          column.setId(id);
          sortedKeys.forEach(key -> {
              if (dataset.hasKey(key)) {
                  column.addValue(dataset.get(key));
              } else {
                  column.addValue((long) defaultValue);
              }
          });
          values.add(column);
      }
  
      public void fixMissingColumns(List<String> ids, int defaultValue) {
          for (int i = 0; i < ids.size(); i++) {
              final String expectedId = ids.get(i);
              boolean found = false;
              for (final HeatMapColumn value : values) {
                  if (expectedId.equals(value.id)) {
                      found = true;
                  }
              }
              if (!found) {
                  final HeatMapColumn emptyColumn = buildMissingColumn(expectedId, defaultValue);
                  values.add(i, emptyColumn);
              }
          }
      }
  
      private HeatMapColumn buildMissingColumn(String id, int defaultValue) {
          HeatMapColumn column = new HeatMapColumn();
          column.setId(id);
          buckets.forEach(bucket -> {
              column.addValue((long) defaultValue);
          });
          return column;
      }
  
      @Getter
      public static class HeatMapColumn {
          @Setter
          private String id;
          private List<Long> values = new ArrayList<>();
  
          public void addValue(Long value) {
              values.add(value);
          }
      }
  
      @RequiredArgsConstructor
      public static class KeyComparator implements Comparator<String> {
          private final boolean asc;
  
          @Override
          public int compare(final String k1, final String k2) {
              int result;
              String[] kk1 = parseKey(k1);
              String[] kk2 = parseKey(k2);
              result = kk1[0].compareTo(kk2[0]);
              if (result != 0) {
                  return result;
              }
              final String key1 = kk1[1];
              final String key2 = kk2[1];
              if (key1.equals(key2)) {
                  result = 0;
              } else if (Bucket.INFINITE_NEGATIVE.equals(key1) || Bucket.INFINITE_POSITIVE.equals(key2)) {
                  result = -1;
              } else if (Bucket.INFINITE_NEGATIVE.equals(key2) || Bucket.INFINITE_POSITIVE.equals(key1)) {
                  result = 1;
              } else {
                  result = new BigInteger(key1).subtract(new BigInteger(key2)).signum();
              }
  
              return asc ? result : -result;
          }
  
          private String[] parseKey(String key) {
              if (key.contains(":")) {
                  // split the group and bucket
                  return new String[] {
                      StringUtils.substringBeforeLast(key, ":"),
                      StringUtils.substringAfterLast(key, ":"),
                  };
              }
              return new String[] {"default", key};
          }
      }
  }
  