/*
    * ====================================================================
    * 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.Collections;
  import java.util.List;
  
  import org.apache.http.annotation.NotThreadSafe;
  
  import org.apache.http.Header;
  import org.apache.http.HeaderElement;
  import org.apache.http.cookie.ClientCookie;
  import org.apache.http.cookie.Cookie;
  import org.apache.http.cookie.CookieOrigin;
  import org.apache.http.cookie.CookiePathComparator;
  import org.apache.http.cookie.CookieRestrictionViolationException;
  import org.apache.http.cookie.CookieSpec;
  import org.apache.http.cookie.MalformedCookieException;
  import org.apache.http.cookie.SM;
  import org.apache.http.message.BufferedHeader;
  import org.apache.http.util.CharArrayBuffer;
  
  /**
   * RFC 2109 compliant {@link CookieSpec} implementation. This is an older
   * version of the official HTTP state management specification superseded
   * by RFC 2965.
   *
   * @see RFC2965Spec
   *
   * @since 4.0
   */
  @NotThreadSafe // superclass is @NotThreadSafe
  public class RFC2109Spec extends CookieSpecBase {
  
      private final static CookiePathComparator PATH_COMPARATOR = new CookiePathComparator();
  
      private final static String[] DATE_PATTERNS = {
          DateUtils.PATTERN_RFC1123,
          DateUtils.PATTERN_RFC1036,
          DateUtils.PATTERN_ASCTIME
      };
  
      private final String[] datepatterns;
      private final boolean oneHeader;
  
      /** Default constructor */
      public RFC2109Spec(final String[] datepatterns, boolean oneHeader) {
          super();
          if (datepatterns != null) {
              this.datepatterns = datepatterns.clone();
          } else {
              this.datepatterns = DATE_PATTERNS;
          }
          this.oneHeader = oneHeader;
          registerAttribHandler(ClientCookie.VERSION_ATTR, new RFC2109VersionHandler());
          registerAttribHandler(ClientCookie.PATH_ATTR, new BasicPathHandler());
          registerAttribHandler(ClientCookie.DOMAIN_ATTR, new RFC2109DomainHandler());
          registerAttribHandler(ClientCookie.MAX_AGE_ATTR, new BasicMaxAgeHandler());
          registerAttribHandler(ClientCookie.SECURE_ATTR, new BasicSecureHandler());
          registerAttribHandler(ClientCookie.COMMENT_ATTR, new BasicCommentHandler());
          registerAttribHandler(ClientCookie.EXPIRES_ATTR, new BasicExpiresHandler(
                  this.datepatterns));
      }
  
      /** Default constructor */
      public RFC2109Spec() {
          this(null, false);
      }
  
      public List<Cookie> parse(final Header header, final CookieOrigin origin)
              throws MalformedCookieException {
          if (header == null) {
              throw new IllegalArgumentException("Header may not be null");
         }
         if (origin == null) {
             throw new IllegalArgumentException("Cookie origin may not be null");
         }
         if (!header.getName().equalsIgnoreCase(SM.SET_COOKIE)) {
             throw new MalformedCookieException("Unrecognized cookie header '"
                     + header.toString() + "'");
         }
         HeaderElement[] elems = header.getElements();
         return parse(elems, origin);
     }
 
     @Override
     public void validate(final Cookie cookie, final CookieOrigin origin)
             throws MalformedCookieException {
         if (cookie == null) {
             throw new IllegalArgumentException("Cookie may not be null");
         }
         String name = cookie.getName();
         if (name.indexOf(' ') != -1) {
             throw new CookieRestrictionViolationException("Cookie name may not contain blanks");
         }
         if (name.startsWith("$")) {
             throw new CookieRestrictionViolationException("Cookie name may not start with $");
         }
         super.validate(cookie, origin);
     }
 
     public List<Header> formatCookies(List<Cookie> cookies) {
         if (cookies == null) {
             throw new IllegalArgumentException("List of cookies may not be null");
         }
         if (cookies.isEmpty()) {
             throw new IllegalArgumentException("List of cookies may not be empty");
         }
         if (cookies.size() > 1) {
             // Create a mutable copy and sort the copy.
             cookies = new ArrayList<Cookie>(cookies);
             Collections.sort(cookies, PATH_COMPARATOR);
         }
         if (this.oneHeader) {
             return doFormatOneHeader(cookies);
         } else {
             return doFormatManyHeaders(cookies);
         }
     }
 
     private List<Header> doFormatOneHeader(final List<Cookie> cookies) {
         int version = Integer.MAX_VALUE;
         // Pick the lowest common denominator
         for (Cookie cookie : cookies) {
             if (cookie.getVersion() < version) {
                 version = cookie.getVersion();
             }
         }
         CharArrayBuffer buffer = new CharArrayBuffer(40 * cookies.size());
         buffer.append(SM.COOKIE);
         buffer.append(": ");
         buffer.append("$Version=");
         buffer.append(Integer.toString(version));
         for (Cookie cooky : cookies) {
             buffer.append("; ");
             Cookie cookie = cooky;
             formatCookieAsVer(buffer, cookie, version);
         }
         List<Header> headers = new ArrayList<Header>(1);
         headers.add(new BufferedHeader(buffer));
         return headers;
     }
 
     private List<Header> doFormatManyHeaders(final List<Cookie> cookies) {
         List<Header> headers = new ArrayList<Header>(cookies.size());
         for (Cookie cookie : cookies) {
             int version = cookie.getVersion();
             CharArrayBuffer buffer = new CharArrayBuffer(40);
             buffer.append("Cookie: ");
             buffer.append("$Version=");
             buffer.append(Integer.toString(version));
             buffer.append("; ");
             formatCookieAsVer(buffer, cookie, version);
             headers.add(new BufferedHeader(buffer));
         }
         return headers;
     }
 
     /**
      * Return a name/value string suitable for sending in a <tt>"Cookie"</tt>
      * header as defined in RFC 2109 for backward compatibility with cookie
      * version 0
      * @param buffer The char array buffer to use for output
      * @param name The cookie name
      * @param value The cookie value
      * @param version The cookie version
      */
     protected void formatParamAsVer(final CharArrayBuffer buffer,
             final String name, final String value, int version) {
         buffer.append(name);
         buffer.append("=");
         if (value != null) {
             if (version > 0) {
                 buffer.append('\"');
                 buffer.append(value);
                 buffer.append('\"');
             } else {
                 buffer.append(value);
             }
         }
     }
 
     /**
      * Return a string suitable for sending in a <tt>"Cookie"</tt> header
      * as defined in RFC 2109 for backward compatibility with cookie version 0
      * @param buffer The char array buffer to use for output
      * @param cookie The {@link Cookie} to be formatted as string
      * @param version The version to use.
      */
     protected void formatCookieAsVer(final CharArrayBuffer buffer,
             final Cookie cookie, int version) {
         formatParamAsVer(buffer, cookie.getName(), cookie.getValue(), version);
         if (cookie.getPath() != null) {
             if (cookie instanceof ClientCookie
                     && ((ClientCookie) cookie).containsAttribute(ClientCookie.PATH_ATTR)) {
                 buffer.append("; ");
                 formatParamAsVer(buffer, "$Path", cookie.getPath(), version);
             }
         }
         if (cookie.getDomain() != null) {
             if (cookie instanceof ClientCookie
                     && ((ClientCookie) cookie).containsAttribute(ClientCookie.DOMAIN_ATTR)) {
                 buffer.append("; ");
                 formatParamAsVer(buffer, "$Domain", cookie.getDomain(), version);
             }
         }
     }
 
     public int getVersion() {
         return 1;
     }
 
     public Header getVersionHeader() {
         return null;
     }
 
     @Override
     public String toString() {
         return "rfc2109";
     }
 
 }