/*
 * See the NOTICE file distributed with
 * this work for additional information regarding copyright ownership.
 * Esri Inc. 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 com.esri.gpt.catalog.harvest.clients;

import com.esri.gpt.catalog.harvest.clients.exceptions.HRConnectionException;
import com.esri.gpt.catalog.harvest.clients.exceptions.HRInvalidProtocolException;
import com.esri.gpt.catalog.harvest.clients.exceptions.HRInvalidResponseException;
import com.esri.gpt.framework.util.Val;
import java.io.BufferedReader;
import java.io.IOException;
import java.io.InputStream;
import java.io.InputStreamReader;

/**
 * ArcGIS Portal client.
 * NOTE! This is EXPERIMENTAL feature. It might be removed at any time in the future.
 */
public class HRAgpClient extends HRProtectedHttpClient {

  /** hostUrl */
  private String hostUrl;

  /**
   * Creates instance of the client.
   * @param hostUrl host URL
   */
  public HRAgpClient(String hostUrl) {
    this.hostUrl = Val.chkStr(hostUrl);
  }

  @Override
  protected String getHostUrl() {
    return hostUrl;
  }

  @Override
  public void ping() throws HRInvalidProtocolException, HRConnectionException, UnsupportedOperationException {
    validateProtocol();
    ping(createPingString());
  }

  @Override
  public boolean isPingSupported() {
    return true;
  }

  /**
   * Checks and verifies connection to the remote repository.
   * @param pingString ping string
   * @throws HRInvalidProtocolException if provided connection
   * definition is incomplete
   * @throws HRConnectionException if connection to the remote repository can not
   * be established at this moment
   */
  private void ping(String pingString)
      throws HRInvalidProtocolException, HRConnectionException {

    InputStream input = null;

    try {

      input = openConnection(pingString);
      analyzePingResponse(input);

    } finally {
      if (input != null) {
        try {
          input.close();
        } catch (IOException ignore) {
        }
      }
    }
  }

  /**
   * Analyzes response from the ping request.
   * @param response response from the server
   * @throws HRInvalidResponseException if response is invalid
   */
  private void analyzePingResponse(InputStream response)
      throws HRInvalidResponseException {
    try {
      BufferedReader reader = new BufferedReader(new InputStreamReader(response));
      reader.readLine();
      reader.close();
    } catch (IOException ex) {
      throw new HRInvalidResponseException("Invalid response.", ex);
    }
  }

  /**
   * Gets connection string
   * @return connection string
   */
  private String createPingString() {

    // remove trailing / or \
    String url = getHostUrl().replaceAll("[/\\\\]\\p{Blank}*$", "");

    return url;
  }
}