/*
    * ====================================================================
    * 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.
   * ====================================================================
   *
   * This software consists of voluntary contributions made by many
   * individuals on behalf of the Apache Software Foundation.  For more
   * information on the Apache Software Foundation, please see
   * <http://www.apache.org/>.
   *
   */
  
  package org.apache.http.impl.cookie;
  
  import java.util.ArrayList;
  import java.util.BitSet;
  import java.util.List;
  
  import org.apache.http.HeaderElement;
  import org.apache.http.NameValuePair;
  import org.apache.http.ParseException;
  import org.apache.http.annotation.Contract;
  import org.apache.http.annotation.ThreadingBehavior;
  import org.apache.http.message.BasicHeaderElement;
  import org.apache.http.message.BasicNameValuePair;
  import org.apache.http.message.ParserCursor;
  import org.apache.http.message.TokenParser;
  import org.apache.http.util.Args;
  import org.apache.http.util.CharArrayBuffer;
  
  /**
   *
   * @since 4.0
   */
  @Contract(threading = ThreadingBehavior.IMMUTABLE)
  public class NetscapeDraftHeaderParser {
  
      public final static NetscapeDraftHeaderParsererParser.html#NetscapeDraftHeaderParser">NetscapeDraftHeaderParser DEFAULT = new NetscapeDraftHeaderParser();
  
      private final static char PARAM_DELIMITER                = ';';
  
      // IMPORTANT!
      // These private static variables must be treated as immutable and never exposed outside this class
      private static final BitSet TOKEN_DELIMS = TokenParser.INIT_BITSET('=', PARAM_DELIMITER);
      private static final BitSet VALUE_DELIMS = TokenParser.INIT_BITSET(PARAM_DELIMITER);
  
      private final TokenParser tokenParser;
  
      public NetscapeDraftHeaderParser() {
          super();
          this.tokenParser = TokenParser.INSTANCE;
      }
  
      public HeaderElement parseHeader(
              final CharArrayBuffer buffer,
              final ParserCursor cursor) throws ParseException {
          Args.notNull(buffer, "Char array buffer");
          Args.notNull(cursor, "Parser cursor");
          final NameValuePair nvp = parseNameValuePair(buffer, cursor);
          final List<NameValuePair> params = new ArrayList<NameValuePair>();
          while (!cursor.atEnd()) {
              final NameValuePair param = parseNameValuePair(buffer, cursor);
              params.add(param);
          }
          return new BasicHeaderElement(
                  nvp.getName(),
                  nvp.getValue(), params.toArray(new NameValuePair[params.size()]));
      }
  
      private NameValuePair parseNameValuePair(
              final CharArrayBuffer buffer, final ParserCursor cursor) {
          final String name = tokenParser.parseToken(buffer, cursor, TOKEN_DELIMS);
          if (cursor.atEnd()) {
              return new BasicNameValuePair(name, null);
          }
          final int delim = buffer.charAt(cursor.getPos());
          cursor.updatePos(cursor.getPos() + 1);
          if (delim != '=') {
              return new BasicNameValuePair(name, null);
          }
          final String value = tokenParser.parseToken(buffer, cursor, VALUE_DELIMS);
          if (!cursor.atEnd()) {
              cursor.updatePos(cursor.getPos() + 1);
          }
         return new BasicNameValuePair(name, value);
     }
 
 }