/*
    * 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.oodt.cas.crawl;
  
  //OODT imports
  import org.apache.oodt.cas.crawl.typedetection.MetExtractorSpec;
  import org.apache.oodt.cas.crawl.typedetection.MimeExtractorConfigReader;
  import org.apache.oodt.cas.crawl.typedetection.MimeExtractorRepo;
  import org.apache.oodt.cas.filemgr.metadata.CoreMetKeys;
  import org.apache.oodt.cas.metadata.MetExtractor;
  import org.apache.oodt.cas.metadata.Metadata;
  import org.apache.oodt.cas.metadata.filenaming.NamingConvention;
  import org.apache.oodt.cas.metadata.preconditions.PreCondEvalUtils;
  
  //JDK imports
  import java.io.File;
  import java.util.List;
  import java.util.logging.Level;
  
  //APACHE imports
  import org.apache.tika.mime.MimeType; //for javadoc
  
  //Spring imports
  import org.springframework.beans.factory.annotation.Required;
  
  /**
   * <p>
   * A {@link ProductCrawler} that uses a suite of files to define its crawling
   * and ingestion policy:
   * 
   * <ul>
   * <li><code>actions-map.xml</code> - This file is an XML specification for
   * actions that the crawler should take in response to its 3 lifecycle phases:
   * preIngest, postIngestSuccess, and postIngestFail. </li>
   * <li><code>met-extr-preconditions.xml</code> - This file defines
   * preconditions that {@link MetExtractor}s must pass before being called by
   * the AutoDetectCrawler. </li>
   * <li><code>mime-extractor-map.xml</code> - This file maps {@link MimeType}
   * names to names of {@link MetExtractor}s to call for a particular
   * {@link Product} {@link File} as it is encountered during a crawl (e.g.,
   * assuming that {@link Metadata} needs to be generated, as oppossed to being
   * available apriori). See
   * <code>./src/resources/examples/mime-extractor-map.xml</code> for an example
   * of the structure of this file. </li>
   * <li><code>mimetypes.xml</code> - An <a
   * href="http://tika.apache.org/">Apache Tika</a> style mimetypes
   * file, augmented with the ability to have arbitrary regular expressions that
   * define a particular {@link Product} {@link MimeType}. This {@link MimeType}
   * is then mapped to an extractor vai the <code>mime-extractor-map.xml</code>
   * file, described above. </li>
   * </p>.
   *
   * @author mattmann (Chris Mattmann)
   * @author bfoster (Brian Foster)
   */
  public class AutoDetectProductCrawler extends ProductCrawler implements
        CoreMetKeys {
  
     public static final String MIME_TYPES_HIERARCHY = "MimeTypesHierarchy"; 
  
     private MimeExtractorRepo mimeExtractorRepo;
  
     @Override
     protected Metadata getMetadataForProduct(File product) throws Exception {
        List<MetExtractorSpec> specs = this.mimeExtractorRepo
              .getExtractorSpecsForFile(product);
        Metadata metadata = new Metadata();
        metadata.addMetadata(MIME_TYPES_HIERARCHY,
              mimeExtractorRepo.getMimeTypes(product));
        for (int i = 0; i < specs.size(); i++) {
           Metadata m = ((MetExtractorSpec) specs.get(i)).getMetExtractor()
                 .extractMetadata(product);
           if (m != null) {
              metadata.addMetadata(m.getHashtable(), true);
           }
        }
        return metadata;
     }
  
     @Override
     protected boolean passesPreconditions(File product) {
        try {
           List<MetExtractorSpec> specs = this.mimeExtractorRepo
                 .getExtractorSpecsForFile(product);
           if (specs.size() > 0) {
             if (this.getApplicationContext() != null) {
                PreCondEvalUtils evalUtils = new PreCondEvalUtils(
                      this.getApplicationContext());
                for (int i = 0; i < specs.size(); i++) {
                   List<String> preCondComparatorIds = ((MetExtractorSpec) specs
                         .get(i)).getPreCondComparatorIds();
                   if (!evalUtils.eval(preCondComparatorIds, product))
                      return false;
                }
             }
             return true;
          } else {
             LOG.log(Level.WARNING, "No extractor specs specified for "
                   + product);
             return false;
          }
       } catch (Exception e) {
          LOG.log(Level.WARNING,
                "Failed to evaluate preconditions : " + e.getMessage());
          return false;
       }
    }
 
    @Override
    protected File renameProduct(File product, Metadata productMetadata)
          throws Exception {
       String namingConventionId = mimeExtractorRepo
             .getNamingConventionId(mimeExtractorRepo.getMimeType(product));
       if (namingConventionId != null) {
          NamingConvention namingConvention = (NamingConvention) getApplicationContext()
                .getBean(namingConventionId);
          return namingConvention.rename(product, productMetadata);
       } else {
          return product;
       }
    }
 
    @Required
    public void setMimeExtractorRepo(String mimeExtractorRepo) throws Exception {
       this.mimeExtractorRepo = MimeExtractorConfigReader
             .read(mimeExtractorRepo);
    }
 }