//
//  ========================================================================
//  Copyright (c) 1995-2014 Mort Bay Consulting Pty. Ltd.
//  ------------------------------------------------------------------------
//  All rights reserved. This program and the accompanying materials
//  are made available under the terms of the Eclipse Public License v1.0
//  and Apache License v2.0 which accompanies this distribution.
//
//      The Eclipse Public License is available at
//      http://www.eclipse.org/legal/epl-v10.html
//
//      The Apache License v2.0 is available at
//      http://www.opensource.org/licenses/apache2.0.php
//
//  You may elect to redistribute this code under either of these licenses.
//  ========================================================================
//

package org.eclipse.jetty.server;

import java.io.IOException;
import java.net.InetSocketAddress;
import java.util.Collections;
import java.util.Enumeration;
import java.util.concurrent.LinkedBlockingQueue;
import java.util.concurrent.ThreadPoolExecutor;
import java.util.concurrent.TimeUnit;

import javax.servlet.ServletException;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;

import org.eclipse.jetty.http.HttpGenerator;
import org.eclipse.jetty.http.HttpURI;
import org.eclipse.jetty.server.handler.HandlerWrapper;
import org.eclipse.jetty.server.nio.SelectChannelConnector;
import org.eclipse.jetty.util.Attributes;
import org.eclipse.jetty.util.AttributesMap;
import org.eclipse.jetty.util.LazyList;
import org.eclipse.jetty.util.MultiException;
import org.eclipse.jetty.util.TypeUtil;
import org.eclipse.jetty.util.URIUtil;
import org.eclipse.jetty.util.component.Destroyable;
import org.eclipse.jetty.util.component.LifeCycle;
import org.slf4j.Logger;
import org.slf4j.LoggerFactory;
import org.eclipse.jetty.util.thread.ShutdownThread;

/* ------------------------------------------------------------ */
/** Jetty HTTP Servlet Server.
 * This class is the main class for the Jetty HTTP Servlet server.
 * It aggregates Connectors (HTTP request receivers) and request Handlers.
 * The server is itself a handler and a ThreadPool.  Connectors use the ThreadPool methods
 * to run jobs that will eventually call the handle method.
 *
 *  @org.apache.xbean.XBean  description="Creates an embedded Jetty web server"
 */
public class Server extends HandlerWrapper implements Attributes
{
	private static final Logger LOG = LoggerFactory.getLogger(Server.class);

	private static final String __version = "8";

	private final AttributesMap _attributes = new AttributesMap();
	public final ThreadPoolExecutor threadPool;
	public final Connector connector;
	private boolean _sendServerVersion = true; //send Server: header
	private boolean _sendDateHeader = false; //send Date: header
	private int _graceful=0;
	private boolean _stopAtShutdown;
	private boolean _dumpAfterStart=false;
	private boolean _dumpBeforeStop=false;
	private boolean _uncheckedPrintWriter=false;


	/* ------------------------------------------------------------ */
	/** Convenience constructor
	 * Creates server and a {@link SelectChannelConnector} at the passed port.
	 */
	public Server(int port)
	{
		setServer(this);

		connector = new SelectChannelConnector();
		connector.setPort(port);
		connector.setServer(this);

		threadPool = new ThreadPoolExecutor(256, 256, 60, TimeUnit.SECONDS, new LinkedBlockingQueue<Runnable>());
	}


	/* ------------------------------------------------------------ */
	public static String getVersion()
	{
		return __version;
	}

	/* ------------------------------------------------------------ */
	public boolean getStopAtShutdown()
	{
		return _stopAtShutdown;
	}

	/* ------------------------------------------------------------ */
	public void setStopAtShutdown(boolean stop)
	{
		//if we now want to stop
		if (stop)
		{
			//and we weren't stopping before
			if (!_stopAtShutdown)
			{  
				//only register to stop if we're already started (otherwise we'll do it in doStart())
				if (isStarted()) 
					ShutdownThread.register(this);
			}
		}
		else
			ShutdownThread.deregister(this);
		
		_stopAtShutdown=stop;
	}

	/**
	 * @return true if {@link #dumpStdErr()} is called after starting
	 */
	public boolean isDumpAfterStart()
	{
		return _dumpAfterStart;
	}

	/**
	 * @param dumpAfterStart true if {@link #dumpStdErr()} is called after starting
	 */
	public void setDumpAfterStart(boolean dumpAfterStart)
	{
		_dumpAfterStart = dumpAfterStart;
	}

	/**
	 * @return true if {@link #dumpStdErr()} is called before stopping
	 */
	public boolean isDumpBeforeStop()
	{
		return _dumpBeforeStop;
	}

	/**
	 * @param dumpBeforeStop true if {@link #dumpStdErr()} is called before stopping
	 */
	public void setDumpBeforeStop(boolean dumpBeforeStop)
	{
		_dumpBeforeStop = dumpBeforeStop;
	}



	/* ------------------------------------------------------------ */
	@Override
	protected void doStart() throws Exception
	{
		if (getStopAtShutdown())
		{
			ShutdownThread.register(this);    
		}
		
		ShutdownMonitor.getInstance().start(); // initialize

		LOG.info("jetty-"+__version);
		HttpGenerator.setServerVersion(__version);
		
		MultiException mex=new MultiException();

		try
		{
			super.doStart();
		}
		catch(Throwable e)
		{
			mex.add(e);
		}

		if (mex.size()==0)
		{
			try{connector.start();}
			catch(Throwable e)
			{
				mex.add(e);
			}
		}

		if (isDumpAfterStart())
			dumpStdErr();

		mex.ifExceptionThrow();
	}

	/* ------------------------------------------------------------ */
	@Override
	protected void doStop() throws Exception
	{
		if (isDumpBeforeStop())
			dumpStdErr();

		MultiException mex=new MultiException();

		if (_graceful>0)
		{
			LOG.info("Graceful shutdown {}",connector);
			try{connector.close();}catch(Throwable e){mex.add(e);}

			Handler[] contexts = getChildHandlersByClass(Graceful.class);
			for (int c=0;c<contexts.length;c++)
			{
				Graceful context=(Graceful)contexts[c];
				LOG.info("Graceful shutdown {}",context);
				context.setShutdown(true);
			}
			Thread.sleep(_graceful);
		}

		try{connector.stop();}catch(Throwable e){mex.add(e);}

		threadPool.shutdownNow();

		try {super.doStop(); } catch(Throwable e) { mex.add(e);}

		mex.ifExceptionThrow();

		if (getStopAtShutdown())
			ShutdownThread.deregister(this);
	}

	/* ------------------------------------------------------------ */
	/* Handle a request from a connection.
	 * Called to handle a request on the connection when either the header has been received,
	 * or after the entire request has been received (for short requests of known length), or
	 * on the dispatch of an async request.
	 */
	public void handle(AbstractHttpConnection connection) throws IOException, ServletException
	{
		final String target=connection.getRequest().getPathInfo();
		final Request request=connection.getRequest();
		final Response response=connection.getResponse();

		if (LOG.isDebugEnabled())
		{
			LOG.debug("REQUEST "+target+" on "+connection);
			handle(target, request, request, response);
			LOG.debug("RESPONSE "+target+"  "+connection.getResponse().getStatus()+" handled="+request.isHandled());
		}
		else
			handle(target, request, request, response);
	}

	/* ------------------------------------------------------------ */
	/* Handle a request from a connection.
	 * Called to handle a request on the connection when either the header has been received,
	 * or after the entire request has been received (for short requests of known length), or
	 * on the dispatch of an async request.
	 */
	public void handleAsync(AbstractHttpConnection connection) throws IOException, ServletException
	{
		final AsyncContinuation async = connection.getRequest().getAsyncContinuation();
		final AsyncContinuation.AsyncEventState state = async.getAsyncEventState();

		final Request baseRequest=connection.getRequest();
		final String path=state.getPath();

		if (path!=null)
		{
			// this is a dispatch with a path
			final String contextPath=state.getServletContext().getContextPath();
			HttpURI uri = new HttpURI(URIUtil.addPaths(contextPath,path));
			baseRequest.setUri(uri);
			baseRequest.setRequestURI(null);
			baseRequest.setPathInfo(baseRequest.getRequestURI());
			if (uri.getQuery()!=null)
				baseRequest.mergeQueryString(uri.getQuery()); //we have to assume dispatch path and query are UTF8
		}

		final String target=baseRequest.getPathInfo();
		final HttpServletRequest request=(HttpServletRequest)async.getRequest();
		final HttpServletResponse response=(HttpServletResponse)async.getResponse();

		if (LOG.isDebugEnabled())
		{
			LOG.debug("REQUEST "+target+" on "+connection);
			handle(target, baseRequest, request, response);
			LOG.debug("RESPONSE "+target+"  "+connection.getResponse().getStatus());
		}
		else
			handle(target, baseRequest, request, response);

	}


	/* ------------------------------------------------------------ */
	public void join() throws InterruptedException
	{
		threadPool.awaitTermination(Long.MAX_VALUE, TimeUnit.MILLISECONDS);
	}

	/* ------------------------------------------------------------ */

	/* ------------------------------------------------------------ */
	public void setSendServerVersion (boolean sendServerVersion)
	{
		_sendServerVersion = sendServerVersion;
	}

	/* ------------------------------------------------------------ */
	public boolean getSendServerVersion()
	{
		return _sendServerVersion;
	}

	/* ------------------------------------------------------------ */
	/**
	 * @param sendDateHeader
	 */
	public void setSendDateHeader(boolean sendDateHeader)
	{
		_sendDateHeader = sendDateHeader;
	}

	/* ------------------------------------------------------------ */
	public boolean getSendDateHeader()
	{
		return _sendDateHeader;
	}

	/* ------------------------------------------------------------ */
	/** 
	 */
	@Deprecated
	public int getMaxCookieVersion()
	{
		return 1;
	}

	/* ------------------------------------------------------------ */
	/** 
	 */
	@Deprecated
	public void setMaxCookieVersion(int maxCookieVersion)
	{
	}

	/* ------------------------------------------------------------ */
	/*
	 * @see org.eclipse.util.AttributesMap#clearAttributes()
	 */
	public void clearAttributes()
	{
		_attributes.clearAttributes();
	}

	/* ------------------------------------------------------------ */
	/*
	 * @see org.eclipse.util.AttributesMap#getAttribute(java.lang.String)
	 */
	public Object getAttribute(String name)
	{
		return _attributes.getAttribute(name);
	}

	/* ------------------------------------------------------------ */
	/*
	 * @see org.eclipse.util.AttributesMap#getAttributeNames()
	 */
	public Enumeration getAttributeNames()
	{
		return AttributesMap.getAttributeNamesCopy(_attributes);
	}

	/* ------------------------------------------------------------ */
	/*
	 * @see org.eclipse.util.AttributesMap#removeAttribute(java.lang.String)
	 */
	public void removeAttribute(String name)
	{
		_attributes.removeAttribute(name);
	}

	/* ------------------------------------------------------------ */
	/*
	 * @see org.eclipse.util.AttributesMap#setAttribute(java.lang.String, java.lang.Object)
	 */
	public void setAttribute(String name, Object attribute)
	{
		_attributes.setAttribute(name, attribute);
	}

	/* ------------------------------------------------------------ */
	/**
	 * @return the graceful
	 */
	public int getGracefulShutdown()
	{
		return _graceful;
	}

	/* ------------------------------------------------------------ */
	/**
	 * Set graceful shutdown timeout.  If set, the internal <code>doStop()</code> method will not immediately stop the
	 * server. Instead, all {@link Connector}s will be closed so that new connections will not be accepted
	 * and all handlers that implement {@link Graceful} will be put into the shutdown mode so that no new requests
	 * will be accepted, but existing requests can complete.  The server will then wait the configured timeout
	 * before stopping.
	 * @param timeoutMS the milliseconds to wait for existing request to complete before stopping the server.
	 *
	 */
	public void setGracefulShutdown(int timeoutMS)
	{
		_graceful=timeoutMS;
	}

	/* ------------------------------------------------------------ */
	@Override
	public String toString()
	{
		return this.getClass().getName()+"@"+Integer.toHexString(hashCode());
	}

	/* ------------------------------------------------------------ */
	@Override
	public void dump(Appendable out,String indent) throws IOException
	{
		dumpThis(out);
		dump(out,indent,TypeUtil.asList(getHandlers()),getBeans(),Collections.singletonList(connector));
	}


	/* ------------------------------------------------------------ */
	public boolean isUncheckedPrintWriter()
	{
		return _uncheckedPrintWriter;
	}

	/* ------------------------------------------------------------ */
	public void setUncheckedPrintWriter(boolean unchecked)
	{
		_uncheckedPrintWriter=unchecked;
	}


	/* ------------------------------------------------------------ */
	/* A handler that can be gracefully shutdown.
	 * Called by doStop if a {@link #setGracefulShutdown} period is set.
	 * TODO move this somewhere better
	 */
	public interface Graceful extends Handler
	{
		public void setShutdown(boolean shutdown);
	}


	public final boolean isLowOnThreads()
	{
		// getActiveCount() locks the thread pool, so execute it last
		return threadPool.getPoolSize() == threadPool.getMaximumPoolSize() &&
				threadPool.getQueue().size() >= threadPool.getPoolSize() - threadPool.getActiveCount();
	}


	/* ------------------------------------------------------------ */
	public static void main(String...args) throws Exception
	{
		System.err.println(getVersion());
	}
}