/**
 * Copyright (C) 2007 - 2016 52°North Initiative for Geospatial Open Source
 * Software GmbH
 *
 * This program is free software; you can redistribute it and/or modify it
 * under the terms of the GNU General Public License version 2 as published
 * by the Free Software Foundation.
 *
 * If the program is linked with libraries which are licensed under one of
 * the following licenses, the combination of the program with the linked
 * library is not considered a "derivative work" of the program:
 *
 *       • Apache License, version 2.0
 *       • Apache Software License, version 1.0
 *       • GNU Lesser General Public License, version 3
 *       • Mozilla Public License, versions 1.0, 1.1 and 2.0
 *       • Common Development and Distribution License (CDDL), version 1.0
 *
 * Therefore the distribution of the program linked with libraries licensed
 * under the aforementioned licenses, is permitted by the copyright holders
 * if the distribution is compliant with both the GNU General Public
 * License version 2 and the aforementioned licenses.
 *
 * This program 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 General
 * Public License for more details.
 */
package org.n52.wps.server;

// import java.io.BufferedInputStream;
import java.io.BufferedReader;
import java.io.IOException;
import java.io.InputStream;
import java.io.InputStreamReader;
import java.io.OutputStream;
import java.io.PrintWriter;
import java.math.BigDecimal;

import javax.servlet.Filter;
import javax.servlet.FilterChain;
import javax.servlet.FilterConfig;
import javax.servlet.ServletException;
import javax.servlet.ServletInputStream;
import javax.servlet.ServletOutputStream;
import javax.servlet.ServletRequest;
import javax.servlet.ServletResponse;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletRequestWrapper;
import javax.servlet.http.HttpServletResponse;
import javax.servlet.http.HttpServletResponseWrapper;

import org.slf4j.Logger;
import org.slf4j.LoggerFactory;
import org.n52.wps.io.LargeBufferStream;


class ResponseSizeInfoStream extends ServletOutputStream {
	private OutputStream intStream;
	private LargeBufferStream baStream;
	private boolean closed = false;
	private long streamSize = 0;
	
	public ResponseSizeInfoStream(OutputStream outStream) {
		this.intStream = outStream;
		// baStream = new ByteArrayOutputStream();
	}
     
    public void write(int i) throws java.io.IOException {
    	this.streamSize++;
    	this.intStream.write(i);
    }
     
    public void close() throws java.io.IOException {
    	if (!this.closed) {
    		this.intStream.close();
    		this.closed = true;
    	}
    }
    
/*    public void flush() throws java.io.IOException {
        if (baStream.size() != 0) {
             if (! closed) {
//              processStream();              // need to synchronize the flush!
//              baStream = new ByteArrayOutputStream();
              }
           }
        }
*/
    public void processStream() throws java.io.IOException {
    	baStream.close();
    	baStream.writeTo(intStream);
    	this.intStream.flush();
    }
     
    public byte []  countBytes(byte [] inBytes) {
    	//streamSize = streamSize + inBytes.length;
    	return inBytes;
    }
    
    public long getSize() {
    	if(this.closed) {
    		return streamSize;
    	} else 
    		return -1;
    }

}

class ResponseSizeInfoWrapper extends HttpServletResponseWrapper {
    private PrintWriter tpWriter; 
    private ResponseSizeInfoStream tpStream;

    public ResponseSizeInfoWrapper(ServletResponse inResp) throws java.io.IOException { 
            super((HttpServletResponse) inResp);
            tpStream = new ResponseSizeInfoStream(inResp.getOutputStream());
            tpWriter = new PrintWriter(tpStream);
    }

    public ServletOutputStream getOutputStream() throws java.io.IOException {

            return tpStream;
     }
    public PrintWriter getWriter() throws java.io.IOException {

            return tpWriter;
     }
}

class RequestSizeInfoStream extends ServletInputStream {
    // private BufferedInputStream buStream;
    private boolean closed = false;
    private long streamSize = 0;
    private InputStream inputStream;
    
	public RequestSizeInfoStream(InputStream inStream) {
		this.inputStream = inStream;
		// buStream = new BufferedInputStream(inStream);
	}

    @Override
	public int read() throws IOException {
    	this.streamSize++;
		return this.inputStream.read();
	}
    
    public void close() throws java.io.IOException {
    	if (!this.closed) {
    		// processStream();
        	this.inputStream.close();
        	this.closed = true;
        }
    }

 /*  public void processStream() throws IOException {
	   byte[] bytes = new byte[8096];
	   int length = buStream.read(bytes, 0 , 8096);
	   while(length != -1) {
		   length = buStream.read(bytes, 0 , 8096);
		   streamSize = streamSize + length;
	   }
       
   }*/
   
   public long getSize() {
	   if(this.closed) {
		   return this.streamSize;
	   }
	   else
		   return -1;
   }
}
class RequestSizeInfoWrapper extends HttpServletRequestWrapper {
    private BufferedReader tpReader; 
    private RequestSizeInfoStream tpStream;

    public RequestSizeInfoWrapper(ServletRequest req) throws java.io.IOException {
    	super((HttpServletRequest) req);
    	this.tpStream = new RequestSizeInfoStream(req.getInputStream());
    	this.tpReader = new BufferedReader(new InputStreamReader(this.tpStream));
    }

    public ServletInputStream getInputStream() throws java.io.IOException {
    	return this.tpStream;
    }

	public BufferedReader getReader() throws IOException {
		return this.tpReader;
	}   
}

/** This class measures the payload of the post data
 * 
 * @author foerster
 *
 */
public final class CommunicationSizeLogFilter implements Filter {
	private static Logger LOGGER = LoggerFactory.getLogger(CommunicationSizeLogFilter.class);
    public void doFilter(ServletRequest request, ServletResponse response,
                         FilterChain chain)
	throws IOException, ServletException {
    	RequestSizeInfoWrapper myWrappedReq = new RequestSizeInfoWrapper(request);
    	ResponseSizeInfoWrapper myWrappedResp = new ResponseSizeInfoWrapper(response);
    	chain.doFilter(myWrappedReq,  myWrappedResp);
    	myWrappedReq.getInputStream().close();
    	myWrappedResp.getOutputStream().close();
    	long requestSize = ((RequestSizeInfoStream)myWrappedReq.getInputStream()).getSize();
    	long responseSize = ((ResponseSizeInfoStream)myWrappedResp.getOutputStream()).getSize();
    	if(requestSize == 0) {
    		return;
    	}
    	BigDecimal result = new BigDecimal((double)responseSize/(double)requestSize).setScale(4, BigDecimal.ROUND_HALF_UP);
    	result = result.movePointRight(2);
    	LOGGER.info("Simplification ratio " + result);
    }

    public void destroy() {
    }

    public void init(FilterConfig filterConfig) {
    }
}