package com.hfg.webapp;

import java.text.ParseException;
import java.text.SimpleDateFormat;
import java.util.ArrayList;
import java.util.Date;
import java.util.List;
import java.util.regex.Matcher;
import java.util.regex.Pattern;
import javax.servlet.http.Cookie;

import com.hfg.util.StringUtil;

//------------------------------------------------------------------------------
/**
 Cookie extension that handles encoding/decoding of cookie values.
 <div>
  @author J. Alex Taylor, hairyfatguy.com
 </div>
*/
//------------------------------------------------------------------------------
// com.hfg XML/HTML Coding Library
//
// This library is free software; you can redistribute it and/or
// modify it under the terms of the GNU Lesser General Public
// License as published by the Free Software Foundation; either
// version 2.1 of the License, or (at your option) any later version.
//
// This library is distributed in the hope that it will be useful,
// but WITHOUT ANY WARRANTY; without even the implied warranty of
// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
// Lesser General Public License for more details.
//
// You should have received a copy of the GNU Lesser General Public
// License along with this library; if not, write to the Free Software
// Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA
//
// J. Alex Taylor, President, Founder, CEO, COO, CFO, OOPS hairyfatguy.com
// jataylor@hairyfatguy.com
//------------------------------------------------------------------------------
// TODO: Add a toString().

public class HfgCookie extends Cookie
{
   private Date   mExpires;
   private String mDecodedValue;


   private static final Pattern COOKIE_NAME_VALUE_PATTERN = Pattern.compile("([^=]+)=(.+)");

   //  Mon, 09-Dec-2002 13:46:00 GMT
   private static final SimpleDateFormat EXPIRES_FORMAT = new SimpleDateFormat("EEE, dd-MMM-yyyy HH:mm:ss z");

   //###########################################################################
   // CONSTRUCTORS
   //###########################################################################

   //---------------------------------------------------------------------------
   public HfgCookie(String inName, String inValue)
   {
      super(inName, inValue);

      setValue(inValue);
   }

   //---------------------------------------------------------------------------
   public HfgCookie(Cookie inCookie)
   {
      this(inCookie.getName(), inCookie.getValue());

      if (inCookie.getPath() != null)
      {
         setPath(inCookie.getPath());
      }

      if (inCookie.getComment() != null)
      {
         setComment(inCookie.getComment());
      }

      if (inCookie.getDomain() != null)
      {
         setDomain(inCookie.getDomain());
      }

      setMaxAge(inCookie.getMaxAge());
      setHttpOnly(inCookie.isHttpOnly());
      setSecure(inCookie.getSecure());
      setVersion(inCookie.getVersion());
   }

   //###########################################################################
   // PUBLIC METHODS
   //###########################################################################

   //---------------------------------------------------------------------------
   /**
    * Returns one or more cookies from an http response's "Set-Cookie" or
    * "Set-Cookie2" header field.
    * <div>
    * "Set-Cookie" is covered by RFC2109.
    * RFC 2965 section 3.2.2 says that one "Set-Cookie2" header line
    * can contain more than one cookie definition.
    * </div>
    * @param inSetCookieValue the value of the "Set-Cookie" or "Set-Cookie2" header
    * @return one or more parsed cookies
    */
   public static List<HfgCookie> parse(String inSetCookieValue)
   {
      List<HfgCookie> cookies = null;

      // Ex:   JSESSIONID=3AF5DD38614E80FCCC0632902E3C8E18; Path=/; Secure; HttpOnly
      if (StringUtil.isSet(inSetCookieValue))
      {
         List<String> cookieStrings = splitIntoCookieStrings(inSetCookieValue);

         cookies = new ArrayList<>(cookieStrings.size());
         for (String cookieString : cookieStrings)
         {
            HfgCookie currentCookie = null;

            String[] pieces = cookieString.split(";");
            for (String piece : pieces)
            {
               piece = piece.trim();

               Matcher m = COOKIE_NAME_VALUE_PATTERN.matcher(piece);
               if (m.matches())
               {
                  String name = m.group(1).trim();
                  String value = m.group(2).trim();

                  if (name.equalsIgnoreCase("Path"))
                  {
                     if (currentCookie != null)
                     {
                        currentCookie.setPath(value);
                     }
                  }
                  else if (name.equalsIgnoreCase("Domain"))
                  {
                     if (currentCookie != null)
                     {
                        currentCookie.setDomain(value);
                     }
                  }
                  else if (name.equalsIgnoreCase("Version"))
                  {
                     if (currentCookie != null)
                     {
                        currentCookie.setVersion(Integer.parseInt(value));
                     }
                  }
                  else if (name.equalsIgnoreCase("Max-Age")) // Seconds to keep the cookie
                  {
                     if (currentCookie != null)
                     {
                        currentCookie.setMaxAge(Integer.parseInt(value));
                     }
                  }
                  else if (name.equalsIgnoreCase("Expires"))
                  {
                     if (currentCookie != null)
                     {
                        try
                        {
                           //  Mon, 09-Dec-2002 13:46:00 GMT
                           currentCookie.setExpires(EXPIRES_FORMAT.parse(value));
                        }
                        catch (ParseException e)
                        {
                           throw new RuntimeException(e);
                        }
                     }
                  }
                  else
                  {
                     currentCookie = new HfgCookie(name, value);
                     cookies.add(currentCookie);
                  }
               }
               else if (piece.equalsIgnoreCase("Secure"))
               {
                  if (currentCookie != null)
                  {
                     currentCookie.setSecure(true);
                  }
               }
               else if (piece.equalsIgnoreCase("HttpOnly"))
               {
                  if (currentCookie != null)
                  {
                     currentCookie.setHttpOnly(true);
                  }
               }

            }
         }

      }

      return cookies;
   }

   //---------------------------------------------------------------------------
   @Override
   public String toString()
   {
      return getName() + "=" + getValue();
   }

   //---------------------------------------------------------------------------
   @Override
   public void setValue(String inValue)
   {
      super.setValue(inValue);
      // The incoming value could be encoded or decoded.
      if (inValue != null)
      {
         if (WebappUtil.isCookieEncoded(this))
         {
            mDecodedValue = WebappUtil.decodeCookieValue(getValue());
            // Sometimes we have double-encoded values. Try unwinding further...
            while (WebappUtil.isCookieEncoded(mDecodedValue))
            {
               mDecodedValue = WebappUtil.decodeCookieValue(mDecodedValue);
            }
         }
         else if (WebappUtil.cookieNeedsEncoding(this))
         {
            mDecodedValue = getValue();
            setValue(WebappUtil.encodeCookieValue(getValue()));
         }
         else
         {
            mDecodedValue = getValue();
         }
      }
   }

   //---------------------------------------------------------------------------
   public HfgCookie setExpires(Date inValue)
   {
      mExpires = inValue;
      return this;
   }

   //---------------------------------------------------------------------------
   public Date getExpires()
   {
      return mExpires;
   }

   //---------------------------------------------------------------------------
   public String getDecodedValue()
   {
      return mDecodedValue;
   }


   //###########################################################################
   // PRIVATE METHODS
   //###########################################################################

   //---------------------------------------------------------------------------
   private static List<String> splitIntoCookieStrings(String inValue)
   {
      List<String> cookies;

      // Only bother looking closely if the is a comma somewhere in the string
      if (inValue.indexOf(",") > 0)
      {
         cookies = new ArrayList<>(2);

         // Make sure the comma isn't inside of quotes
         boolean inQuotes = false;
         int startIndex = 0;
         for (int i = 0; i < inValue.length(); i++)
         {
            char currentChar = inValue.charAt(i);
            if (currentChar == '"')
            {
               inQuotes = ! inQuotes;
            }
            else if (currentChar == ','
                  && ! inQuotes)
            {
               cookies.add(inValue.substring(startIndex, i));
               startIndex = i + 1;
            }
         }

         // Add whatever is remaining
         cookies.add(inValue.substring(startIndex));
      }
      else
      {
         cookies = new ArrayList<>(1);
         cookies.add(inValue);
      }

      return cookies;
   }
}