/*
    * ====================================================================
    * 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.List;
  
  import org.apache.http.HeaderElement;
  import org.apache.http.NameValuePair;
  import org.apache.http.ParseException;
  import org.apache.http.annotation.Immutable;
  import org.apache.http.message.BasicHeaderElement;
  import org.apache.http.message.BasicNameValuePair;
  import org.apache.http.message.ParserCursor;
  import org.apache.http.protocol.HTTP;
  import org.apache.http.util.Args;
  import org.apache.http.util.CharArrayBuffer;
  
  /**
   *
   * @since 4.0
   */
  @Immutable
  public class NetscapeDraftHeaderParser {
  
      public final static NetscapeDraftHeaderParser DEFAULT = new NetscapeDraftHeaderParser();
  
      public NetscapeDraftHeaderParser() {
          super();
      }
  
      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) {
          boolean terminated = false;
  
          int pos = cursor.getPos();
          final int indexFrom = cursor.getPos();
          final int indexTo = cursor.getUpperBound();
  
          // Find name
          String name = null;
          while (pos < indexTo) {
              final char ch = buffer.charAt(pos);
              if (ch == '=') {
                  break;
              }
              if (ch == ';') {
                  terminated = true;
                  break;
              }
              pos++;
          }
  
          if (pos == indexTo) {
              terminated = true;
              name = buffer.substringTrimmed(indexFrom, indexTo);
          } else {
              name = buffer.substringTrimmed(indexFrom, pos);
             pos++;
         }
 
         if (terminated) {
             cursor.updatePos(pos);
             return new BasicNameValuePair(name, null);
         }
 
         // Find value
         String value = null;
         int i1 = pos;
 
         while (pos < indexTo) {
             final char ch = buffer.charAt(pos);
             if (ch == ';') {
                 terminated = true;
                 break;
             }
             pos++;
         }
 
         int i2 = pos;
         // Trim leading white spaces
         while (i1 < i2 && (HTTP.isWhitespace(buffer.charAt(i1)))) {
             i1++;
         }
         // Trim trailing white spaces
         while ((i2 > i1) && (HTTP.isWhitespace(buffer.charAt(i2 - 1)))) {
             i2--;
         }
         value = buffer.substring(i1, i2);
         if (terminated) {
             pos++;
         }
         cursor.updatePos(pos);
         return new BasicNameValuePair(name, value);
     }
 
 }