/*
    * 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.any23.extractor;
  
  import org.openrdf.model.URI;
  
  /**
   * This class provides the context for the processing of
   * a single {@link Extractor}.
   */
  public class ExtractionContext {
  
      public static final String ROOT_EXTRACTION_RESULT_ID = "root-extraction-result-id";
  
      /**
       * Name of the extractor.
       */
      private final String extractorName;
  
      /**
       * URI of the document.
       */
      private final URI documentURI;
  
      /**
       * The document default language.
       */
      private String defaultLanguage;
  
      /**
       * ID identifying the document.
       */
      private final String uniqueID;
  
      public ExtractionContext(String extractorName, URI documentURI, String defaultLanguage, String localID) {
          checkNotNull(extractorName  , "extractor name");
          checkNotNull(documentURI    , "document URI");
          this.extractorName   = extractorName;
          this.documentURI     = documentURI;
          this.defaultLanguage = defaultLanguage;
          this.uniqueID      =
                  "urn:x-any23:" + extractorName + ":" +
                  (localID == null ? "" : localID) + ":" + documentURI;
      }
  
      public ExtractionContext(String extractorName, URI documentURI, String defaultLanguage) {
          this(extractorName, documentURI, defaultLanguage, ROOT_EXTRACTION_RESULT_ID);
      }
  
      public ExtractionContext(String extractorName, URI documentURI) {
          this(extractorName, documentURI, null);
      }
  
      public ExtractionContext copy(String localID) {
          return new ExtractionContext(
                  getExtractorName(),
                  getDocumentURI(),
                  getDefaultLanguage(),
                  localID
          );
      }
  
      public String getExtractorName() {
          return extractorName;
      }
  
      public URI getDocumentURI() {
          return documentURI;
      }
  
      public String getDefaultLanguage() {
          return defaultLanguage;
      }
  
      public String getUniqueID() {
          return uniqueID;
      }
  
      public int hashCode() {
          return uniqueID.hashCode();
      }
  
      public boolean equals(Object other) {
          if (!(other instanceof ExtractionContext)) return false;
         return ((ExtractionContext) other).uniqueID.equals(uniqueID);
     }
 
     public String toString() {
         return "ExtractionContext(" + uniqueID + ")";
     }
 
     private void checkNotNull(Object data, String desc) {
         if(data == null) throw new NullPointerException(desc + " cannot be null.");
     }
     
 }