package org.apache.rat.analysis;
   /*
    * 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.                                           *
   */
  
  import org.apache.commons.io.IOUtils;
  import org.apache.rat.api.Document;
  import org.apache.rat.api.MetaData;
  
  import java.io.BufferedReader;
  import java.io.IOException;
  import java.io.Reader;
  
  /**
   * <p>Reads from a stream to check license.</p>
   * <p><strong>Note</strong> that this class is not thread safe.</p> 
   */
  class HeaderCheckWorker {
  
      public static final int DEFAULT_NUMBER_OF_RETAINED_HEADER_LINES = 50;
  
      private final int numberOfRetainedHeaderLines;
      private final BufferedReader reader;
      private final IHeaderMatcher matcher;
      private final Document subject;
      
      private boolean match = false;
  
      private int headerLinesToRead;
      private boolean finished = false;
  
      public HeaderCheckWorker(Reader reader, int numberOfRetainedHeaderLine,
              final IHeaderMatcher matcher, final Document name) {
          this(new BufferedReader(reader), numberOfRetainedHeaderLine, matcher, name);
      }
  
  
      /**
       * Convenience constructor wraps given <code>Reader</code>
       * in a <code>BufferedReader</code>.
       * @param reader a <code>Reader</code> for the content, not null
       * @param name the name of the checked content, possibly null
       */
      public HeaderCheckWorker(Reader reader, final IHeaderMatcher matcher, final Document name) {
          this(new BufferedReader(reader), matcher, name);
      }
  
      public HeaderCheckWorker(BufferedReader reader, final IHeaderMatcher matcher,
              final Document name) {
          this(reader, DEFAULT_NUMBER_OF_RETAINED_HEADER_LINES, matcher, name);
      }
  
      public HeaderCheckWorker(BufferedReader reader, int numberOfRetainedHeaderLine, final IHeaderMatcher matcher,
              final Document name) {
          this.reader = reader;
          this.numberOfRetainedHeaderLines = numberOfRetainedHeaderLine;
          this.matcher = matcher;
          this.subject = name;
      }
  
      public boolean isFinished() {
          return finished;
      }
  
      public void read() throws RatHeaderAnalysisException {
          if (!finished) {
              final StringBuilder headers = new StringBuilder();
              headerLinesToRead = numberOfRetainedHeaderLines;
              try {
                  while(readLine(headers)) {
                      // do nothing
                  }
                  if (!match) {
                      final String notes = headers.toString();
                      final MetaData metaData = subject.getMetaData();
                      metaData.set(new MetaData.Datum(MetaData.RAT_URL_HEADER_SAMPLE, notes));
                      metaData.set(new MetaData.Datum(MetaData.RAT_URL_HEADER_CATEGORY, MetaData.RAT_LICENSE_FAMILY_CATEGORY_VALUE_UNKNOWN));
                      metaData.set(MetaData.RAT_LICENSE_FAMILY_NAME_DATUM_UNKNOWN);
                  }
              } catch (IOException e) {
                  throw new RatHeaderAnalysisException("Cannot read header for " + subject, e);
              }
              IOUtils.closeQuietly(reader);
              matcher.reset();
         }
         finished = true;
     }
 
     boolean readLine(StringBuilder headers) throws IOException, RatHeaderAnalysisException {
         String line = reader.readLine();
         boolean result = line != null;
         if (result) {
             if (headerLinesToRead-- > 0) {
                 headers.append(line);
                 headers.append('\n');
             }
             match = matcher.match(subject, line);
             result = !match;
         }
         return result;
     }
 }