/**
    *
    * Copyright 2003-2006 The Apache Software Foundation
    *
    *  Licensed 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 javax.mail.internet;
  
  import java.io.ByteArrayOutputStream;
  import java.io.UnsupportedEncodingException;
  import java.util.ArrayList;// Represents lists in things like
  import java.util.Collections;
  import java.util.Enumeration;
  import java.util.HashMap;
  import java.util.Iterator;
  import java.util.List;
  import java.util.Map;
  import java.util.StringTokenizer;
  
  import org.apache.geronimo.mail.util.ASCIIUtil;
  import org.apache.geronimo.mail.util.RFC2231Encoder;
  import org.apache.geronimo.mail.util.SessionUtil;
  
  // Content-Type: text/plain;charset=klingon
  //
  // The ;charset=klingon is the parameter list, may have more of them with ';'
  
  /**
   * @version $Rev: 421852 $ $Date: 2006-07-14 03:02:19 -0700 (Fri, 14 Jul 2006) $
   */
  public class ParameterList {
      private static final String MIME_ENCODEPARAMETERS = "mail.mime.encodeparameters";
      private static final String MIME_DECODEPARAMETERS = "mail.mime.decodeparameters";
      private static final String MIME_DECODEPARAMETERS_STRICT = "mail.mime.decodeparameters.strict";
  
      private static final int HEADER_SIZE_LIMIT = 76;
  
      private Map _parameters = new HashMap();
  
      private boolean encodeParameters = false;
      private boolean decodeParameters = false;
      private boolean decodeParametersStrict = false;
  
      public ParameterList() {
          // figure out how parameter handling is to be performed.
          getInitialProperties();
      }
  
      public ParameterList(String list) throws ParseException {
          // figure out how parameter handling is to be performed.
          getInitialProperties();
          // get a token parser for the type information
          HeaderTokenizer tokenizer = new HeaderTokenizer(list, HeaderTokenizer.MIME);
          while (true) {
              HeaderTokenizer.Token token = tokenizer.next();
  
              switch (token.getType()) {
                  // the EOF token terminates parsing.
                  case HeaderTokenizer.Token.EOF:
                      return;
  
                  // each new parameter is separated by a semicolon, including the first, which separates
                  // the parameters from the main part of the header.
                  case ';':
                      // the next token needs to be a parameter name
                      token = tokenizer.next();
                      // allow a trailing semicolon on the parameters.
                      if (token.getType() == HeaderTokenizer.Token.EOF) {
                          return;
                      }
  
                      if (token.getType() != HeaderTokenizer.Token.ATOM) {
                          throw new ParseException("Invalid parameter name: " + token.getValue());
                      }
  
                      // get the parameter name as a lower case version for better mapping.
                      String name = token.getValue().toLowerCase();
  
                      token = tokenizer.next();
  
                      // parameters are name=value, so we must have the "=" here.
                      if (token.getType() != '=') {
                          throw new ParseException("Missing '='");
                      }
  
                      // now the value, which may be an atom or a literal
                      token = tokenizer.next();
  
                     if (token.getType() != HeaderTokenizer.Token.ATOM && token.getType() != HeaderTokenizer.Token.QUOTEDSTRING) {
                         throw new ParseException("Invalid parameter value: " + token.getValue());
                     }
 
                     String value = token.getValue();
                     String decodedValue = null;
 
                     // we might have to do some additional decoding.  A name that ends with "*"
                     // is marked as being encoded, so if requested, we decode the value.
                     if (decodeParameters && name.endsWith("*")) {
                         // the name needs to be pruned of the marker, and we need to decode the value.
                         name = name.substring(0, name.length() - 1);
                         // get a new decoder
                         RFC2231Encoder decoder = new RFC2231Encoder(HeaderTokenizer.MIME);
 
                         try {
                             // decode the value
                             decodedValue = decoder.decode(value);
                         } catch (Exception e) {
                             // if we're doing things strictly, then raise a parsing exception for errors.
                             // otherwise, leave the value in its current state.
                             if (decodeParametersStrict) {
                                 throw new ParseException("Invalid RFC2231 encoded parameter");
                             }
                         }
                         _parameters.put(name, new ParameterValue(name, decodedValue, value));
                     }
                     else {
                         _parameters.put(name, new ParameterValue(name, value));
                     }
 
                     break;
 
                 default:
                     throw new ParseException("Missing ';'");
 
             }
         }
     }
 
     /**
      * Get the initial parameters that control parsing and values.
      * These parameters are controlled by System properties.
      */
     private void getInitialProperties() {
         decodeParameters = SessionUtil.getBooleanProperty(MIME_DECODEPARAMETERS, false);
         decodeParametersStrict = SessionUtil.getBooleanProperty(MIME_DECODEPARAMETERS_STRICT, false);
         encodeParameters = SessionUtil.getBooleanProperty(MIME_ENCODEPARAMETERS, true);
     }
 
     public int size() {
         return _parameters.size();
     }
 
     public String get(String name) {
         ParameterValue value = (ParameterValue)_parameters.get(name.toLowerCase());
         if (value != null) {
             return value.value;
         }
         return null;
     }
 
     public void set(String name, String value) {
         name = name.toLowerCase();
         _parameters.put(name, new ParameterValue(name, value));
     }
 
     public void set(String name, String value, String charset) {
         name = name.toLowerCase();
         // only encode if told to and this contains non-ASCII charactes.
         if (encodeParameters && !ASCIIUtil.isAscii(value)) {
             ByteArrayOutputStream out = new ByteArrayOutputStream();
 
             try {
                 RFC2231Encoder encoder = new RFC2231Encoder(HeaderTokenizer.MIME);
 
                 // extract the bytes using the given character set and encode
                 byte[] valueBytes = value.getBytes(MimeUtility.javaCharset(charset));
 
                 // the string format is charset''data
                 out.write(charset.getBytes());
                 out.write('\'');
                 out.write('\'');
                 encoder.encode(valueBytes, 0, valueBytes.length, out);
 
                 // default in case there is an exception
                 _parameters.put(name, new ParameterValue(name, value, new String(out.toByteArray())));
                 return;
 
             } catch (Exception e) {
                 // just fall through and set the value directly if there is an error
             }
         }
         // default in case there is an exception
         _parameters.put(name, new ParameterValue(name, value));
     }
 
     public void remove(String name) {
         _parameters.remove(name);
     }
 
     public Enumeration getNames() {
         return Collections.enumeration(_parameters.keySet());
     }
 
     public String toString() {
         // we need to perform folding, but out starting point is 0.
         return toString(0);
     }
 
     public String toString(int used) {
         StringBuffer stringValue = new StringBuffer();
 
         Iterator values = _parameters.values().iterator();
 
         while (values.hasNext()) {
             ParameterValue parm = (ParameterValue)values.next();
             // get the values we're going to encode in here.
             String name = parm.getEncodedName();
             String value = parm.toString();
 
             // add the semicolon separator.  We also add a blank so that folding/unfolding rules can be used.
             stringValue.append("; ");
             used += 2;
 
             // too big for the current header line?
             if ((used + name.length() + value.length() + 1) > HEADER_SIZE_LIMIT) {
                 // and a CRLF-whitespace combo.
                 stringValue.append("\r\n ");
                 // reset the counter for a fresh line
                 used = 3;
             }
             // now add the keyword/value pair.
             stringValue.append(name);
             stringValue.append("=");
 
             used += name.length() + 1;
 
             // we're not out of the woods yet.  It is possible that the keyword/value pair by itself might
             // be too long for a single line.  If that's the case, the we need to fold the value, if possible
             if (used + value.length() > HEADER_SIZE_LIMIT) {
                 String foldedValue = MimeUtility.fold(used, value);
 
                 stringValue.append(foldedValue);
 
                 // now we need to sort out how much of the current line is in use.
                 int lastLineBreak = foldedValue.lastIndexOf('\n');
 
                 if (lastLineBreak != -1) {
                     used = foldedValue.length() - lastLineBreak + 1;
                 }
                 else {
                     used += foldedValue.length();
                 }
             }
             else {
                 // no folding required, just append.
                 stringValue.append(value);
                 used += value.length();
             }
         }
 
         return stringValue.toString();
     }
 
 
     /**
      * Utility class for representing parameter values in the list.
      */
     class ParameterValue {
         public String name;              // the name of the parameter
         public String value;             // the original set value
         public String encodedValue;      // an encoded value, if encoding is requested.
 
         public ParameterValue(String name, String value) {
             this.name = name;
             this.value = value;
             this.encodedValue = null;
         }
 
         public ParameterValue(String name, String value, String encodedValue) {
             this.name = name;
             this.value = value;
             this.encodedValue = encodedValue;
         }
 
         public String toString() {
             if (encodedValue != null) {
                 return MimeUtility.quote(encodedValue, HeaderTokenizer.MIME);
             }
             return MimeUtility.quote(value, HeaderTokenizer.MIME);
         }
 
         public String getEncodedName() {
             if (encodedValue != null) {
                 return name + "*";
             }
             return name;
         }
     }
 }