/*
    *
    * 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.rest;
  
  import java.io.IOException;
  import java.util.Map;
  
  import javax.ws.rs.GET;
  import javax.ws.rs.Produces;
  import javax.ws.rs.core.CacheControl;
  import javax.ws.rs.core.Context;
  import javax.ws.rs.core.Response;
  import javax.ws.rs.core.UriInfo;
  import javax.ws.rs.core.Response.ResponseBuilder;
  
  import org.apache.commons.logging.Log;
  import org.apache.commons.logging.LogFactory;
  
  import org.apache.hadoop.hbase.classification.InterfaceAudience;
  import org.apache.hadoop.hbase.TableName;
  import org.apache.hadoop.hbase.HRegionInfo;
  import org.apache.hadoop.hbase.ServerName;
  import org.apache.hadoop.hbase.TableNotFoundException;
  import org.apache.hadoop.hbase.client.Connection;
  import org.apache.hadoop.hbase.client.ConnectionFactory;
  import org.apache.hadoop.hbase.client.MetaScanner;
  import org.apache.hadoop.hbase.rest.model.TableInfoModel;
  import org.apache.hadoop.hbase.rest.model.TableRegionModel;
  
  @InterfaceAudience.Private
  public class RegionsResource extends ResourceBase {
    private static final Log LOG = LogFactory.getLog(RegionsResource.class);
  
    static CacheControl cacheControl;
    static {
      cacheControl = new CacheControl();
      cacheControl.setNoCache(true);
      cacheControl.setNoTransform(false);
    }
  
    TableResource tableResource;
  
    /**
     * Constructor
     * @param tableResource
     * @throws IOException
     */
    public RegionsResource(TableResource tableResource) throws IOException {
      super();
      this.tableResource = tableResource;
    }
  
    @GET
    @Produces({MIMETYPE_TEXT, MIMETYPE_XML, MIMETYPE_JSON, MIMETYPE_PROTOBUF,
      MIMETYPE_PROTOBUF_IETF})
    public Response get(final @Context UriInfo uriInfo) {
      if (LOG.isTraceEnabled()) {
        LOG.trace("GET " + uriInfo.getAbsolutePath());
      }
      servlet.getMetrics().incrementRequests(1);
      try {
        TableName tableName = TableName.valueOf(tableResource.getName());
        TableInfoModel model = new TableInfoModel(tableName.getNameAsString());
  
        Connection connection = ConnectionFactory.createConnection(servlet.getConfiguration());
        Map<HRegionInfo, ServerName> regions = MetaScanner.allTableRegions(connection, tableName);
        connection.close();
        for (Map.Entry<HRegionInfo,ServerName> e: regions.entrySet()) {
          HRegionInfo hri = e.getKey();
          ServerName addr = e.getValue();
          model.add(
            new TableRegionModel(tableName.getNameAsString(), hri.getRegionId(),
              hri.getStartKey(), hri.getEndKey(), addr.getHostAndPort()));
        }
        ResponseBuilder response = Response.ok(model);
        response.cacheControl(cacheControl);
        servlet.getMetrics().incrementSucessfulGetRequests(1);
        return response.build();
      } catch (TableNotFoundException e) {
        servlet.getMetrics().incrementFailedGetRequests(1);
        return Response.status(Response.Status.NOT_FOUND)
          .type(MIMETYPE_TEXT).entity("Not found" + CRLF)
         .build();
     } catch (IOException e) {
       servlet.getMetrics().incrementFailedGetRequests(1);
       return Response.status(Response.Status.SERVICE_UNAVAILABLE)
         .type(MIMETYPE_TEXT).entity("Unavailable" + CRLF)
         .build();
     }
   }
 }