/**
    * 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.replication;
  
  import java.io.IOException;
  import java.util.ArrayList;
  
  import org.apache.commons.logging.Log;
  import org.apache.commons.logging.LogFactory;
  import org.apache.hadoop.hbase.classification.InterfaceAudience;
  import org.apache.hadoop.hbase.HBaseInterfaceAudience;
  import com.google.common.collect.Lists;
  import com.google.common.util.concurrent.AbstractService;
  
  import static org.apache.hadoop.hbase.client.replication.ReplicationAdmin.REPLICATION_WALENTRYFILTER_CONFIG_KEY;
  
  /**
   * A Base implementation for {@link ReplicationEndpoint}s. Users should consider extending this
   * class rather than implementing {@link ReplicationEndpoint} directly for better backwards
   * compatibility.
   */
  @InterfaceAudience.LimitedPrivate(HBaseInterfaceAudience.REPLICATION)
  public abstract class BaseReplicationEndpoint extends AbstractService
    implements ReplicationEndpoint {
  
    private static final Log LOG = LogFactory.getLog(BaseReplicationEndpoint.class);
    protected Context ctx;
  
    @Override
    public void init(Context context) throws IOException {
      this.ctx = context;
  
      if (this.ctx != null){
        ReplicationPeer peer = this.ctx.getReplicationPeer();
        if (peer != null){
          peer.trackPeerConfigChanges(this);
        } else {
          LOG.warn("Not tracking replication peer config changes for Peer Id " + this.ctx.getPeerId() +
              " because there's no such peer");
        }
      }
    }
  
    @Override
    /**
     * No-op implementation for subclasses to override if they wish to execute logic if their config changes
     */
    public void peerConfigUpdated(ReplicationPeerConfig rpc){
  
    }
  
    /** Returns a default set of filters */
    @Override
    public WALEntryFilter getWALEntryfilter() {
      ArrayList<WALEntryFilter> filters = Lists.newArrayList();
      WALEntryFilter scopeFilter = getScopeWALEntryFilter();
      if (scopeFilter != null) {
        filters.add(scopeFilter);
      }
      WALEntryFilter tableCfFilter = getTableCfWALEntryFilter();
      if (tableCfFilter != null) {
        filters.add(tableCfFilter);
      }
      if (ctx != null && ctx.getPeerConfig() != null) {
        String filterNameCSV = ctx.getPeerConfig().getConfiguration().get(REPLICATION_WALENTRYFILTER_CONFIG_KEY);
        if (filterNameCSV != null && !filterNameCSV.isEmpty()) {
            String[] filterNames = filterNameCSV.split(",");
            for (String filterName : filterNames) {
                try {
                    Class<?> clazz = Class.forName(filterName);
                    filters.add((WALEntryFilter) clazz.newInstance());
                  } catch (Exception e) {
                    LOG.error("Unable to create WALEntryFilter " + filterName, e);
                  }
              }
          }
      }
      return filters.isEmpty() ? null : new ChainWALEntryFilter(filters);
    }
  
    /** Returns a WALEntryFilter for checking the scope. Subclasses can
     * return null if they don't want this filter */
    protected WALEntryFilter getScopeWALEntryFilter() {
     return new ScopeWALEntryFilter();
   }
 
   /** Returns a WALEntryFilter for checking replication per table and CF. Subclasses can
    * return null if they don't want this filter */
   protected WALEntryFilter getTableCfWALEntryFilter() {
     return new TableCfWALEntryFilter(ctx.getReplicationPeer());
   }
 
   @Override
   public boolean canReplicateToSameCluster() {
     return false;
   }
 
   public void close(){
     if(this.ctx != null) {
       ReplicationPeer peer = this.ctx.getReplicationPeer();
       peer.removeListenerOfPeerConfig(this);
     }
   }
 }