/*
    *
    * 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.hadoop.hbase.namequeues;
  
  import java.util.ArrayList;
  import java.util.List;
  import org.apache.commons.lang.StringUtils;
  import org.apache.hadoop.hbase.classification.InterfaceAudience;
  import org.apache.hadoop.hbase.protobuf.generated.AdminProtos;
  import org.apache.hadoop.hbase.protobuf.generated.TooSlowLog;
  
  /**
   * Event Handler utility class
   */
  @InterfaceAudience.Private
  public final class LogHandlerUtils {
  
    private LogHandlerUtils() {
    }
  
    private static int getTotalFiltersCount(AdminProtos.SlowLogResponseRequest request) {
      int totalFilters = 0;
      if (StringUtils.isNotEmpty(request.getRegionName())) {
        totalFilters++;
      }
      if (StringUtils.isNotEmpty(request.getTableName())) {
        totalFilters++;
      }
      if (StringUtils.isNotEmpty(request.getClientAddress())) {
        totalFilters++;
      }
      if (StringUtils.isNotEmpty(request.getUserName())) {
        totalFilters++;
      }
      return totalFilters;
    }
  
    private static List<TooSlowLog.SlowLogPayload> filterLogs(
        AdminProtos.SlowLogResponseRequest request,
        List<TooSlowLog.SlowLogPayload> slowLogPayloadList, int totalFilters) {
      List<TooSlowLog.SlowLogPayload> filteredSlowLogPayloads = new ArrayList<>();
      final String regionName =
        StringUtils.isNotEmpty(request.getRegionName()) ? request.getRegionName() : null;
      final String tableName =
        StringUtils.isNotEmpty(request.getTableName()) ? request.getTableName() : null;
      final String clientAddress =
        StringUtils.isNotEmpty(request.getClientAddress()) ? request.getClientAddress() : null;
      final String userName =
        StringUtils.isNotEmpty(request.getUserName()) ? request.getUserName() : null;
      for (TooSlowLog.SlowLogPayload slowLogPayload : slowLogPayloadList) {
        int totalFilterMatches = 0;
        if (slowLogPayload.getRegionName().equals(regionName)) {
          totalFilterMatches++;
        }
        if (tableName != null && slowLogPayload.getRegionName().startsWith(tableName)) {
          totalFilterMatches++;
        }
        if (slowLogPayload.getClientAddress().equals(clientAddress)) {
          totalFilterMatches++;
        }
        if (slowLogPayload.getUserName().equals(userName)) {
          totalFilterMatches++;
        }
        if (request.hasFilterByOperator() && request.getFilterByOperator()
          .equals(AdminProtos.SlowLogResponseRequest.FilterByOperator.AND)) {
          // Filter by AND operator
          if (totalFilterMatches == totalFilters) {
            filteredSlowLogPayloads.add(slowLogPayload);
          }
        } else {
          // Filter by OR operator
          if (totalFilterMatches > 0) {
            filteredSlowLogPayloads.add(slowLogPayload);
          }
        }
      }
      return filteredSlowLogPayloads;
    }
  
    public static List<TooSlowLog.SlowLogPayload> getFilteredLogs(
        AdminProtos.SlowLogResponseRequest request, List<TooSlowLog.SlowLogPayload> logPayloadList) {
      int totalFilters = getTotalFiltersCount(request);
     if (totalFilters > 0) {
       logPayloadList = filterLogs(request, logPayloadList, totalFilters);
     }
     int limit = Math.min(request.getLimit(), logPayloadList.size());
     return logPayloadList.subList(0, limit);
   }
 
 }