/*
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;
	}

}