/**
 * The contents of this file are subject to the OpenMRS Public License
 * Version 1.0 (the "License"); you may not use this file except in
 * compliance with the License. You may obtain a copy of the License at
 * http://license.openmrs.org
 *
 * Software distributed under the License is distributed on an "AS IS"
 * basis, WITHOUT WARRANTY OF ANY KIND, either express or implied. See the
 * License for the specific language governing rights and limitations
 * under the License.
 *
 * Copyright (C) OpenMRS, LLC.  All Rights Reserved.
 */
package org.openmrs.web.filter;

import java.io.IOException;
import java.io.OutputStreamWriter;
import java.io.PrintWriter;

import javax.servlet.ServletOutputStream;
import javax.servlet.http.HttpServletResponse;
import javax.servlet.http.HttpServletResponseWrapper;

import org.apache.commons.logging.Log;
import org.apache.commons.logging.LogFactory;

/**
 * Wraps Response for GZipFilter
 * 
 * @author Matt Raible, cmurphy@intechtual.com
 */
public class GZIPResponseWrapper extends HttpServletResponseWrapper {
	
	private static final Log log = LogFactory.getLog(GZIPResponseWrapper.class);
	
	protected HttpServletResponse origResponse = null;
	
	protected ServletOutputStream stream = null;
	
	protected PrintWriter writer = null;
	
	protected int error = 0;
	
	public GZIPResponseWrapper(HttpServletResponse response) {
		super(response);
		origResponse = response;
	}
	
	public ServletOutputStream createOutputStream() throws IOException {
		return (new GZIPResponseStream(origResponse));
	}
	
	public void finishResponse() {
		try {
			if (writer != null) {
				writer.close();
			} else {
				if (stream != null) {
					stream.close();
				}
			}
		}
		catch (IOException e) {}
	}
	
	public void flushBuffer() throws IOException {
		if (stream != null) {
			stream.flush();
		}
	}
	
	public ServletOutputStream getOutputStream() throws IOException {
		if (writer != null) {
			throw new IllegalStateException("getWriter() has already been called!");
		}
		
		if (stream == null) {
			stream = createOutputStream();
		}
		
		return (stream);
	}
	
	public PrintWriter getWriter() throws IOException {
		// From cmurphy@intechtual.com to fix:
		// https://appfuse.dev.java.net/issues/show_bug.cgi?id=59
		if (this.origResponse != null && this.origResponse.isCommitted()) {
			return super.getWriter();
		}
		
		if (writer != null) {
			return (writer);
		}
		
		if (stream != null) {
			throw new IllegalStateException("getOutputStream() has already been called!");
		}
		
		stream = createOutputStream();
		writer = new PrintWriter(new OutputStreamWriter(stream, origResponse.getCharacterEncoding()));
		
		return (writer);
	}
	
	public void setContentLength(int length) {
	}
	
	/**
	 * @see javax.servlet.http.HttpServletResponse#sendError(int, java.lang.String)
	 */
	public void sendError(int error, String message) throws IOException {
		super.sendError(error, message);
		this.error = error;
		
		if (log.isDebugEnabled()) {
			log.debug("sending error: " + error + " [" + message + "]");
		}
	}
}