/* 
    * 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.url;
  
  import org.esigate.api.BaseUrlRetrieveStrategy;
  import org.esigate.http.IncomingRequest;
  
  public class IpHashBaseUrlRetrieveStrategy implements BaseUrlRetrieveStrategy {
      private final String[] urls;
  
      public IpHashBaseUrlRetrieveStrategy(String[] urls) {
          this.urls = urls;
      }
  
      @Override
      public String getBaseURL(IncomingRequest originalRequest) {
          int index = getHashCode(originalRequest.getRemoteAddr()) % this.urls.length;
          return this.urls[Math.abs(index)];
      }
  
      private int getHashCode(String ip) {
          final int prime = 31;
          int result = 1;
          int ipHashcode = 0;
          if (ip != null) {
              ipHashcode = ip.hashCode();
          }
          result = prime * result + ipHashcode;
          return result;
      }
  
  }