/*

  * 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.apache.any23.source.MemCopyFactory;

 import org.apache.any23.source.StringDocumentSource;

 import org.apache.any23.writer.TripleHandler;

 import org.apache.any23.writer.TripleHandlerException;

 import org.apache.any23.writer.TurtleWriter;

 import java.io.ByteArrayOutputStream;

 import java.io.IOException;

 import java.io.InputStream;

 /**

  * A reporter for example input and output of an extractor. Example

  * input is part of every extractor's metadata; example output is

  * obtained by running the extractor on its own example input. This

  * is useful as a documentation device.

  *

  * @author Richard Cyganiak (richard@cyganiak.de)

  */

 public class ExampleInputOutput {

     private final ExtractorFactory<?> factory;

     public ExampleInputOutput(String extractorName) {

         this(ExtractorRegistry.getInstance().getFactory(extractorName));

     }

     public ExampleInputOutput(ExtractorFactory<?> factory) {

         this.factory = factory;

     }

     public String getExampleInput() throws IOException {

         if (factory.getExampleInput() == null) {

             return null;

         }

         if (isBlindExtractor()) {

             return null;

         }

         InputStream in = factory.createExtractor().getClass().getResourceAsStream(

                 factory.getExampleInput());

         if (in == null) {

             throw new IllegalArgumentException(

                     "Example input resource not found for extractor " +

                             factory.getExtractorName() + ": " +

                             factory.getExampleInput());

         }

         return new String(MemCopyFactory.toByteArray(in), "utf-8");

     }

     public String getExampleURI() {

         if (factory.getExampleInput() == null) {

             return null;

         }

         if (isBlindExtractor()) {

             return factory.getExampleInput();    // Should be a URI.

         }

         return "http://example.com/";

     }

     public String getExampleOutput() throws IOException, ExtractionException {

         if (factory.getExampleInput() == null) {

             return null;

         }

         ByteArrayOutputStream out = new ByteArrayOutputStream();

         TripleHandler writer = new TurtleWriter(out);

         new SingleDocumentExtraction(

                 new StringDocumentSource(getExampleInput(), getExampleURI()),

                 factory,

                 writer).run();

         try {

             writer.close();

         } catch (TripleHandlerException e) {

             throw new ExtractionException("Error while closing the triple handler", e);

         }

         return out.toString("utf-8");

     }

     private boolean isBlindExtractor() {

         return factory.createExtractor() instanceof Extractor.BlindExtractor;

     }

 }