/*
Wotonomy: OpenStep design patterns for pure Java applications.
Copyright (C) 2000 Blacksmith, Inc.

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, see http://www.gnu.org
*/

package net.wotonomy.web;

import java.text.SimpleDateFormat;
import java.util.Date;
import java.util.TimeZone;

import net.wotonomy.foundation.NSArray;

/**
* A pure java implementation of WOResponse.
*
* @author michael@mpowers.net
* @author $Author: cgruber $
* @version $Revision: 905 $
*/
public class WOResponse extends WOMessage
    implements WOActionResults
{
	protected static String defaultEncoding;
    private static SimpleDateFormat htmlDateFormat;
    static
    {
        defaultEncoding = "ISO8859_1";
        htmlDateFormat = new SimpleDateFormat(
            "EEE, dd MMM yyyy HH:mm:ss z" );
        htmlDateFormat.setTimeZone(
            TimeZone.getTimeZone( "GMT" ) );
    }

	private int status;

	/**
	* Parameterless constructor which should not be called.
	*/
    public WOResponse ()
    {
		status = -1; // -1 indicates not yet set
    }

	/**
	* Sets the status code of the response.
	* You should use the constants defined in HttpServletResponse.
	*/
    public void setStatus (int code)
    {
    	status = code;
    }

	/**
	* Gets the current status code for the response.
	*/
    public int status ()
    {
    	return status;
    }

	/**
	* Sets a header in the response to disable client caching.
	* (Whether this works depends on the client implementation.)
	*/
    public void disableClientCaching ()
    {
        String dateString = htmlDateFormat.format( new Date() );
        setHeader( dateString, "Date" );
        setHeader( dateString, "Expires" );
        setHeader( "no-cache", "Pragma" );
        setHeaders( new NSArray( new Object[] { 
            "private", "no-cache", "max-age = 0" } ), "Cache-Control" );
        //System.out.println( "disableClientCaching: " + dateString );        
    }

    /**
    * Returns this object.  (Implements the WOActionResults interface.)
    */
    public WOResponse generateResponse()
    {
    	return this;
    }

	/**
	* Generates the response using the specified servlet response,
	* but does not flush the buffer. The caller is responsible
	* for sending the response to the client.  <br><br>
	* Note that this method is currently responsible for setting 
	* the content type to "text/html".  As far as I can tell, WORequests
	* have no way to set the content type and therefore must always
	* be of type "text/html".
	*/
    void generateServletResponse 
    	(javax.servlet.http.HttpServletResponse response)
    {
        if ( WOApplication.application().isPageRefreshOnBacktrackEnabled() )
        {
            disableClientCaching();
        }

	    String key;
    	java.util.Enumeration e, f;
	    
	    // set content type: might be overwritten by headers below
        response.setContentType( "text/html" );
	    
	    // set status
	    if ( status != -1 )
	    {
	    	response.setStatus( status );	    
		}

	    // set headers
	    f = _headers.allKeys().objectEnumerator();
		while ( f.hasMoreElements() )
		{
            key = f.nextElement().toString();
	    	e = ((NSArray)_headers.objectForKey( key )).objectEnumerator();
	    	if ( e.hasMoreElements() )
            {
                // overwrite existing header
                response.setHeader( key, e.nextElement().toString() );
            }
            while ( e.hasMoreElements() )
            {
                response.addHeader( key, e.nextElement().toString() );
            }
		}

	    // set cookies
	    e = _cookies.allValues().objectEnumerator();
	    while ( e.hasMoreElements() )
	    {
	    	response.addCookie( (WOCookie) e.nextElement() );
	    }

		try
		{
            // write content
            response.getOutputStream().write(_contentData.bytes() );
            if ( status > 299 )
            {
                response.sendError( status );
            }
	    }
	    catch ( Exception exc )
		{
			throw new RuntimeException( 
				"Error writing response: " + exc );    	   
		}
    }


	/**
	* Returns the current default encoding seting.
	*/
    public static String defaultEncoding ()
    {
    	return defaultEncoding;
    }

	/**
	* Sets the default encoding setting.
	*/
    public static void setDefaultEncoding (String encoding)
    {
    	defaultEncoding = encoding;
    }

}