/* 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.lucene;

import com.esri.gpt.framework.util.Val;
import java.io.BufferedReader;
import java.io.IOException;
import java.io.InputStream;
import java.io.InputStreamReader;
import java.io.UnsupportedEncodingException;
import java.net.URL;
import java.net.URLEncoder;
import java.util.Properties;
import org.apache.lucene.queryParser.ParseException;

/**
 * Standard network parser adaptor.
 * <p/>
 * Provides mechanizm to delegate query parsing to the servlet on the network.
 */
public class StandardNetworkParserAdaptor implements IParserProxy {

  /** base url */
  private String baseUrl = "";

  /**
   * Gets base URL.
   * @return base URL
   */
  public String getBaseUrl() {
    return baseUrl;
  }

  /**
   * Sets base URL.
   * @param baseUrl base URL
   */
  public void setBaseUrl(String baseUrl) {
    this.baseUrl = Val.chkStr(baseUrl);
  }

  /**
   * Initializes adaptor.
   * <p/>
   * Reads <i>baseUrl</i> property from the properties.
   * @param properties properties
   */
  public void init(Properties properties) {
    setBaseUrl(properties.getProperty("baseUrl", ""));
  }

  public String parse(String queryText) throws ParseException {
    try {
      StringBuilder sb = new StringBuilder();

      queryText = Val.chkStr(queryText);
      if (queryText.length()>0) {
        URL url = new URL(getUrl(queryText));
        InputStream in = url.openStream();
        BufferedReader reader = new BufferedReader(new InputStreamReader(in));

        String line = null;
        while ((line = reader.readLine()) != null) {
          if (sb.length() > 0) {
            sb.append("\r\n");
          }
          sb.append(line);
        }
      }

      return sb.toString();

    } catch (IOException ex) {
      throw new ParseException("Ontology parser is unable to parse term: \""+
        queryText+"\" due to internal error: "+ex.getMessage());
    }
  }

  /**
   * Gets connection URL.
   * @param term term to search
   * @return connection URL
   */
  private String getUrl(String term) {
    try {
      term = Val.chkStr(term);
      term = URLEncoder.encode(term, "UTF-8");
    } catch (UnsupportedEncodingException ex) {
    }
    return baseUrl + term;
  }

}