/* 
    * Licensed 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.esigate;
  
  import java.util.ArrayList;
  import java.util.Collection;
  import java.util.List;
  import java.util.Properties;
  
  import org.esigate.api.BaseUrlRetrieveStrategy;
  import org.esigate.impl.UriMapping;
  import org.esigate.url.IpHashBaseUrlRetrieveStrategy;
  import org.esigate.url.RoundRobinBaseUrlRetrieveStrategy;
  import org.esigate.url.SingleBaseUrlRetrieveStrategy;
  import org.esigate.url.StickySessionBaseUrlRetrieveStrategy;
  
  /**
   * Driver configuration parameters.
   * 
   * @author Francois-Xavier Bonnet
   * @author Nicolas Richeton
   */
  public class DriverConfiguration {
  
      private final String instanceName;
      private final String uriEncoding;
      private final String visibleBaseURL;
      private final Properties properties;
      private final boolean preserveHost;
      private final BaseUrlRetrieveStrategy baseUrlRetrieveStrategy;
      private final List<UriMapping> uriMappings;
      private boolean stripMappingPath;
  
      public DriverConfiguration(String instanceName, Properties props) {
          this.instanceName = instanceName;
          this.baseUrlRetrieveStrategy = getBaseUrlRetrieveSession(props);
          this.uriEncoding = Parameters.URI_ENCODING.getValue(props);
          this.preserveHost = Parameters.PRESERVE_HOST.getValue(props);
          this.visibleBaseURL = Parameters.VISIBLE_URL_BASE.getValue(props);
          this.stripMappingPath = Parameters.STRIP_MAPPING_PATH.getValue(props);
          this.uriMappings = parseMappings(props);
          properties = props;
      }
  
      /**
       * Read the "Mappings" parameter and create the corresponding UriMapping rules.
       * 
       * @param props
       * @return The mapping rules for this driver instance.
       */
      private static List<UriMapping> parseMappings(Properties props) {
          List<UriMapping> mappings = new ArrayList<>();
  
          Collection<String> mappingsParam = Parameters.MAPPINGS.getValue(props);
          for (String mappingParam : mappingsParam) {
              mappings.add(UriMapping.create(mappingParam));
          }
  
          return mappings;
      }
  
      private BaseUrlRetrieveStrategy getBaseUrlRetrieveSession(Properties props) {
          BaseUrlRetrieveStrategy urlStrategy;
          String[] baseURLs = Parameters.REMOTE_URL_BASE.getValue(props);
          if (baseURLs.length == 0) {
              throw new ConfigurationException(Parameters.REMOTE_URL_BASE.getName()
                      + " property cannot be empty for instance '" + instanceName + "'");
          } else if (baseURLs.length == 1) {
              urlStrategy = new SingleBaseUrlRetrieveStrategy(baseURLs[0]);
          } else {
              String strategy = Parameters.REMOTE_URL_BASE_STRATEGY.getValue(props);
              if (Parameters.ROUNDROBIN.equalsIgnoreCase(strategy)) {
                  urlStrategy = new RoundRobinBaseUrlRetrieveStrategy(baseURLs);
              } else if (Parameters.IPHASH.equalsIgnoreCase(strategy)) {
                  urlStrategy = new IpHashBaseUrlRetrieveStrategy(baseURLs);
              } else if (Parameters.STICKYSESSION.equalsIgnoreCase(strategy)) {
                  urlStrategy = new StickySessionBaseUrlRetrieveStrategy(baseURLs);
              } else {
                  throw new ConfigurationException("No such BaseUrlRetrieveStrategy '" + strategy + "'");
              }
          }
          return urlStrategy;
      }
  
      public String getVisibleBaseURL() {
          return visibleBaseURL;
     }
 
     public boolean isPreserveHost() {
         return preserveHost;
     }
 
     public String getInstanceName() {
         return instanceName;
     }
 
     public String getUriEncoding() {
         return uriEncoding;
     }
 
     public Properties getProperties() {
         return properties;
     }
 
     public BaseUrlRetrieveStrategy getBaseUrlRetrieveStrategy() {
         return baseUrlRetrieveStrategy;
     }
 
     /**
      * Get the URI mappings for this driver instance.
      * 
      * @return The URI mappings for this driver instance.
      */
     public List<UriMapping> getUriMappings() {
         return this.uriMappings;
     }
 
     /**
      * 
      * @return stripMappingPath
      */
     public boolean isStripMappingPath() {
         return stripMappingPath;
     }
 }